diff options
| author | Roger Frank <rfrank@pglaf.org> | 2025-10-14 20:02:35 -0700 |
|---|---|---|
| committer | Roger Frank <rfrank@pglaf.org> | 2025-10-14 20:02:35 -0700 |
| commit | a9cbc523c96a0f30e2b278447c473a370e7351f3 (patch) | |
| tree | 84607a25c7dcfbb837fdce40065d90cf633d3a79 /34878-h | |
Diffstat (limited to '34878-h')
| -rw-r--r-- | 34878-h/34878-h.htm | 20663 | ||||
| -rw-r--r-- | 34878-h/images/img764.jpg | bin | 0 -> 5551 bytes | |||
| -rw-r--r-- | 34878-h/images/img765.jpg | bin | 0 -> 19344 bytes | |||
| -rw-r--r-- | 34878-h/images/img766a.jpg | bin | 0 -> 12791 bytes | |||
| -rw-r--r-- | 34878-h/images/img766b.jpg | bin | 0 -> 13926 bytes | |||
| -rw-r--r-- | 34878-h/images/img766c.jpg | bin | 0 -> 11022 bytes | |||
| -rw-r--r-- | 34878-h/images/img766d.jpg | bin | 0 -> 11299 bytes | |||
| -rw-r--r-- | 34878-h/images/img766e.jpg | bin | 0 -> 9603 bytes | |||
| -rw-r--r-- | 34878-h/images/img767.jpg | bin | 0 -> 23112 bytes | |||
| -rw-r--r-- | 34878-h/images/img768a.jpg | bin | 0 -> 58445 bytes | |||
| -rw-r--r-- | 34878-h/images/img768b.jpg | bin | 0 -> 13740 bytes | |||
| -rw-r--r-- | 34878-h/images/img769a.jpg | bin | 0 -> 32768 bytes | |||
| -rw-r--r-- | 34878-h/images/img769b.jpg | bin | 0 -> 23503 bytes | |||
| -rw-r--r-- | 34878-h/images/img769c.jpg | bin | 0 -> 9832 bytes | |||
| -rw-r--r-- | 34878-h/images/img769d.jpg | bin | 0 -> 38316 bytes | |||
| -rw-r--r-- | 34878-h/images/img770a.jpg | bin | 0 -> 27965 bytes | |||
| -rw-r--r-- | 34878-h/images/img770b.jpg | bin | 0 -> 4241 bytes | |||
| -rw-r--r-- | 34878-h/images/img771a.jpg | bin | 0 -> 18409 bytes | |||
| -rw-r--r-- | 34878-h/images/img771b.jpg | bin | 0 -> 31048 bytes | |||
| -rw-r--r-- | 34878-h/images/img771c.jpg | bin | 0 -> 49109 bytes | |||
| -rw-r--r-- | 34878-h/images/img772a.jpg | bin | 0 -> 10090 bytes | |||
| -rw-r--r-- | 34878-h/images/img772b.jpg | bin | 0 -> 41496 bytes | |||
| -rw-r--r-- | 34878-h/images/img772c.jpg | bin | 0 -> 10765 bytes | |||
| -rw-r--r-- | 34878-h/images/img772d.jpg | bin | 0 -> 32348 bytes | |||
| -rw-r--r-- | 34878-h/images/img773a.jpg | bin | 0 -> 42432 bytes | |||
| -rw-r--r-- | 34878-h/images/img773b.jpg | bin | 0 -> 7756 bytes | |||
| -rw-r--r-- | 34878-h/images/img773c.jpg | bin | 0 -> 10934 bytes | |||
| -rw-r--r-- | 34878-h/images/img774a.jpg | bin | 0 -> 25211 bytes | |||
| -rw-r--r-- | 34878-h/images/img774b.jpg | bin | 0 -> 15249 bytes | |||
| -rw-r--r-- | 34878-h/images/img774c.jpg | bin | 0 -> 50684 bytes | |||
| -rw-r--r-- | 34878-h/images/img775a.jpg | bin | 0 -> 19405 bytes | |||
| -rw-r--r-- | 34878-h/images/img775b.jpg | bin | 0 -> 18429 bytes | |||
| -rw-r--r-- | 34878-h/images/img776a.jpg | bin | 0 -> 12352 bytes | |||
| -rw-r--r-- | 34878-h/images/img776b.jpg | bin | 0 -> 22916 bytes | |||
| -rw-r--r-- | 34878-h/images/img776c.jpg | bin | 0 -> 15383 bytes | |||
| -rw-r--r-- | 34878-h/images/img778.jpg | bin | 0 -> 27278 bytes | |||
| -rw-r--r-- | 34878-h/images/img779.jpg | bin | 0 -> 98203 bytes | |||
| -rw-r--r-- | 34878-h/images/img779a.jpg | bin | 0 -> 46473 bytes | |||
| -rw-r--r-- | 34878-h/images/img780a.jpg | bin | 0 -> 12247 bytes | |||
| -rw-r--r-- | 34878-h/images/img780b.jpg | bin | 0 -> 6130 bytes | |||
| -rw-r--r-- | 34878-h/images/img780c.jpg | bin | 0 -> 10302 bytes | |||
| -rw-r--r-- | 34878-h/images/img781.jpg | bin | 0 -> 3779 bytes | |||
| -rw-r--r-- | 34878-h/images/img782a.jpg | bin | 0 -> 20775 bytes | |||
| -rw-r--r-- | 34878-h/images/img782b.jpg | bin | 0 -> 42549 bytes | |||
| -rw-r--r-- | 34878-h/images/img783a.jpg | bin | 0 -> 17589 bytes | |||
| -rw-r--r-- | 34878-h/images/img783b.jpg | bin | 0 -> 70289 bytes | |||
| -rw-r--r-- | 34878-h/images/img783c.jpg | bin | 0 -> 37496 bytes | |||
| -rw-r--r-- | 34878-h/images/img783d.jpg | bin | 0 -> 19253 bytes | |||
| -rw-r--r-- | 34878-h/images/img784a.jpg | bin | 0 -> 20982 bytes | |||
| -rw-r--r-- | 34878-h/images/img784b.jpg | bin | 0 -> 18900 bytes | |||
| -rw-r--r-- | 34878-h/images/img784c.jpg | bin | 0 -> 64365 bytes | |||
| -rw-r--r-- | 34878-h/images/img788a.jpg | bin | 0 -> 456 bytes | |||
| -rw-r--r-- | 34878-h/images/img788b.jpg | bin | 0 -> 352 bytes | |||
| -rw-r--r-- | 34878-h/images/img788c.jpg | bin | 0 -> 466 bytes | |||
| -rw-r--r-- | 34878-h/images/img788d.jpg | bin | 0 -> 399 bytes | |||
| -rw-r--r-- | 34878-h/images/img788e.jpg | bin | 0 -> 362 bytes | |||
| -rw-r--r-- | 34878-h/images/img788f.jpg | bin | 0 -> 374 bytes | |||
| -rw-r--r-- | 34878-h/images/img788g.jpg | bin | 0 -> 318 bytes | |||
| -rw-r--r-- | 34878-h/images/img788h.jpg | bin | 0 -> 328 bytes | |||
| -rw-r--r-- | 34878-h/images/img788i.jpg | bin | 0 -> 420 bytes | |||
| -rw-r--r-- | 34878-h/images/img790a.jpg | bin | 0 -> 72418 bytes | |||
| -rw-r--r-- | 34878-h/images/img790b.jpg | bin | 0 -> 90368 bytes | |||
| -rw-r--r-- | 34878-h/images/img791.jpg | bin | 0 -> 55502 bytes | |||
| -rw-r--r-- | 34878-h/images/img792a.jpg | bin | 0 -> 13247 bytes | |||
| -rw-r--r-- | 34878-h/images/img792b.jpg | bin | 0 -> 15886 bytes | |||
| -rw-r--r-- | 34878-h/images/img793a.jpg | bin | 0 -> 64155 bytes | |||
| -rw-r--r-- | 34878-h/images/img793b.jpg | bin | 0 -> 81004 bytes | |||
| -rw-r--r-- | 34878-h/images/img799a.jpg | bin | 0 -> 10498 bytes | |||
| -rw-r--r-- | 34878-h/images/img799b.jpg | bin | 0 -> 25578 bytes | |||
| -rw-r--r-- | 34878-h/images/img811.jpg | bin | 0 -> 86444 bytes | |||
| -rw-r--r-- | 34878-h/images/img825.jpg | bin | 0 -> 7541 bytes | |||
| -rw-r--r-- | 34878-h/images/img870.jpg | bin | 0 -> 15212 bytes |
72 files changed, 20663 insertions, 0 deletions
diff --git a/34878-h/34878-h.htm b/34878-h/34878-h.htm new file mode 100644 index 0000000..61f7940 --- /dev/null +++ b/34878-h/34878-h.htm @@ -0,0 +1,20663 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> + + <head> + <meta http-equiv="Content-Type" content= + "text/html; charset=iso-8859-1" /> + + <title> + The Project Gutenberg eBook of Encyclopædia Britannica, Volume VIII Slice IX - Dyer to Echidna. + </title> + + <style type="text/css"> + + body { margin-left: 12%; margin-right: 12%; text-align: justify; } + p { margin-top: .75em; margin-bottom: .75em; text-indent: 1em; line-height: 1.4em;} + p.c { margin-top: .25em; margin-bottom: .25em; text-indent: 1em; padding-left: 1em; line-height: 1.4em;} + p.noind { margin-top: .75em; margin-bottom: .75em; text-indent: 0; } + + h2,h3 { text-align: center; } + hr { margin-left: auto; margin-right: auto; text-align: center; width: 70%; height: 5px; background-color: #dcdcdc; border:none; } + hr.art { margin-left: auto; margin-right: auto; width: 40%; height: 5px; background-color: #778899; + margin-top: 2em; margin-bottom: 6em } + hr.foot {margin-left: 2em; width: 16%; background-color: black; margin-top: 1em; margin-bottom: 0; height: 1px; } + hr.full {width: 100%} + + table.ws {white-space: nowrap; border-collapse: collapse; margin-left: auto; margin-right: auto; + margin-top: 2em; margin-bottom: 2em;} + table.reg { margin-left: auto; margin-right: auto; clear: both;} + table.reg td { white-space: normal;} + table.nobctr { margin-left: auto; margin-right: auto; border-collapse: collapse; } + table.flt { border-collapse: collapse; } + table.pic { margin-left: auto; margin-right: auto; } + table.math0 { vertical-align: middle; margin-left: auto; margin-right: auto; border-collapse: collapse;} + table.math0a { vertical-align: middle; margin-left: auto; margin-right: auto; border-collapse: separate;} + table.math0 td, table.math0a td {text-align: center;} + table.math0 td.np {text-align: center; padding-left: 0; padding-right: 0;} + + table.reg p {text-indent: 1em; margin-left: 1.5em; text-align: justify;} + table.reg td.tc5p { padding-left: 2em; text-indent: 0em; white-space: normal;} + table.nobctr td, table.flt td { white-space: normal; } + table.pic td { white-space: normal; text-indent: 1em; padding-left: 2em; padding-right: 1em;} + table.nobctr p, table.flt p {text-indent: -1.5em; margin-left: 1.5em;} + table.pic td p {text-indent: -1.5em; margin-left: 1.5em;} + + td { white-space: nowrap; padding-right: 0.3em; padding-left: 0.3em;} + td.norm { white-space: normal; } + td.denom { border-top: 1px solid black; text-align: center; padding-right: 0.3em; padding-left: 0.3em;} + + td.tcc { padding-right: 0.5em; padding-left: 0.5em; text-align: center; vertical-align: top;} + td.tccm { padding-right: 0.5em; padding-left: 0.5em; text-align: center; vertical-align: middle;} + td.tccb { padding-right: 0.5em; padding-left: 0.5em; text-align: center; vertical-align: bottom;} + td.tcr { padding-right: 0.5em; padding-left: 0.5em; text-align: right; vertical-align: top;} + td.tcrb { padding-right: 0.5em; padding-left: 0.5em; text-align: right; vertical-align: bottom;} + td.tcrm { padding-right: 0.5em; padding-left: 0.5em; text-align: right; vertical-align: middle;} + td.tcl { padding-right: 0.5em; padding-left: 0.5em; text-align: left; vertical-align: top;} + td.tclb { padding-right: 0.5em; padding-left: 0.5em; text-align: left; vertical-align: bottom;} + td.tclm { padding-right: 0.5em; padding-left: 0.5em; text-align: left; vertical-align: middle;} + td.vb { vertical-align: bottom; } + + .caption { font-size: 0.9em; text-align: center; padding-bottom: 1em; padding-left: 1em; padding-right: 1em;} + .caption1 { font-size: 0.9em; text-align: left; padding-bottom: 1em; padding-left: 3em; padding-right: 2em;} + .caption80 { font-size: 0.8em; text-align: left; padding-bottom: 1em; padding-left: 3em; padding-right: 2em;} + + td.lb {border-left: black 1px solid;} + td.ltb {border-left: black 1px solid; border-top: black 1px solid;} + td.rb {border-right: black 1px solid;} + td.rb2 {border-right: black 2px solid;} + td.tb, span.tb {border-top: black 1px solid;} + td.bb {border-bottom: black 1px solid;} + td.bb1 {border-bottom: #808080 3px solid; padding-top: 1em; padding-bottom: 1em;} + td.rlb {border-right: black 1px solid; border-left : black 1px solid;} + td.allb {border: black 1px solid;} + td.cl {background-color: #e8e8e8} + + table p { margin: 0;} + + a:link, a:visited, link {text-decoration:none} + + .author {text-align: right; margin-top: -1em; margin-right: 1em; font-variant: small-caps;} + .author1 {text-align: right; margin-top: -1em; margin-right: 1em;} + .center {text-align: center; text-indent: 0;} + .center1 {text-align: center; text-indent: 0; margin-top: 1em; margin-bottom: 1em;} + .grk {font-style: normal; font-family:"Palatino Linotype","New Athena Unicode",Gentium,"Lucida Grande", Galilee, "Arial Unicode MS", sans-serif;} + + .f80 {font-size: 80%} + .f90 {font-size: 90%} + .f150 {font-size: 150%} + .f200 {font-size: 200%} + + .sp {position: relative; bottom: 0.5em; font-size: 0.65em;} + .sp1 {position: relative; bottom: 1.5em; font-size: 0.75em;} + .su {position: relative; top: 0.3em; font-size: 0.75em;} + .su1 {position: relative; top: 0.5em; font-size: 0.75em; margin-left: -1.8ex;} + .su2 {position: relative; top: 0.5em; font-size: 0.75em; margin-left: -1ex;} + .spp {position: relative; bottom: 0.5em; font-size: 0.6em;} + .suu {position: relative; top: 0.2em; font-size: 0.6em;} + .sc {font-variant: small-caps;} + .scs {text-transform: lowercase; font-variant: small-caps;} + .ov {text-decoration: overline} + .cl {background-color: #f5f5f5;} + .bk {padding-left: 0; font-size: 80%;} + .bk1 {margin-left: -1em;} + + .pagenum {position: absolute; right: 5%; text-align: right; font-size: 10pt; + background-color: #f5f5f5; color: #778899; text-indent: 0; + padding-left: 0.5em; padding-right: 0.5em; font-style: normal; } + span.sidenote {width: 8em; margin-bottom: 1em; margin-top: 1.7em; margin-right: 2em; + font-size: 85%; float: left; clear: left; font-weight: bold; + font-style: italic; text-align: left; text-indent: 0; + background-color: #f5f5f5; color: black; } + .note {margin-left: 2em; margin-right: 2em; font-size: 0.9em; } + .fn { position: absolute; left: 12%; text-align: left; background-color: #f5f5f5; + text-indent: 0; padding-left: 0.2em; padding-right: 0.2em; } + span.correction {border-bottom: 1px dashed red;} + + div.poemr { margin-top: .75em; margin-bottom: .75em;} + div.poemr p { margin-left: 0; padding-left: 3em; text-indent: -3em; margin-top: 0em; margin-bottom: 0em; } + div.poemr p.s { margin-top: 1.5em; } + div.poemr p.i05 { margin-left: 0.4em; } + div.poemr p.i1 { margin-left: 1em; } + div.poemr p.i2 { margin-left: 2em; } + + .figright1 { padding-right: 1em; padding-left: 2em; padding-top: 1.5em; text-align: center; } + .figleft1 { padding-right: 2em; padding-left: 1em; padding-top: 1.5em; text-align: center; } + .figcenter {text-align: center; margin: auto; margin-left: auto; margin-right: auto; padding-top: 1.5em;} + .figcenter1 {text-align: center; margin-left: auto; margin-right: auto; padding-top: 2em; padding-bottom: 2em;} + .figure {text-align: center; padding-left: 1.5em; padding-right: 1.5em; padding-top: 1.5em; padding-bottom: 0;} + .bold {font-weight: bold; } + + div.minind {text-align: justify;} + div.condensed, div.condensed1 { line-height: 1.3em; margin-left: 3%; margin-right: 3%; font-size: 95%; } + div.condensed1 p {margin-left: 0; padding-left: 2em; text-indent: -2em;} + div.condensed span.sidenote {font-size: 90%} + + div.list {margin-left: 0;} + div.list p {padding-left: 4em; text-indent: -2em;} + div.list1 {margin-left: 0;} + div.list1 p {padding-left: 5em; text-indent: -3em;} + + .pt05 {padding-top: 0.5em;} + .pt1 {padding-top: 1em;} + .pt2 {padding-top: 2em;} + .ptb1 {padding-top: 1em; padding-bottom: 1em;} + td.prl {padding-left: 10%; padding-right: 7em; text-align: left; vertical-align: top;} + + </style> + </head> +<body> + + +<pre> + +The Project Gutenberg EBook of Encyclopaedia Britannica, 11th Edition, +Volume 8, Slice 9, by Various + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 9 + "Dyer" to "Echidna" + +Author: Various + +Release Date: January 8, 2011 [EBook #34878] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK ENCYCLOPAEDIA BRITANNICA *** + + + + +Produced by Marius Masi, Don Kretz and the Online +Distributed Proofreading Team at http://www.pgdp.net + + + + + + +</pre> + + + +<table border="0" cellpadding="10" style="background-color: #dcdcdc; color: #696969; " summary="Transcriber's note"> +<tr> +<td style="width:25%; vertical-align:top"> +Transcriber’s note: +</td> +<td class="norm"> +A few typographical errors have been corrected. They +appear in the text <span class="correction" title="explanation will pop up">like this</span>, and the +explanation will appear when the mouse pointer is moved over the marked +passage. Sections in Greek will yield a transliteration +when the pointer is moved over them, and words using diacritic characters in the +Latin Extended Additional block, which may not display in some fonts or browsers, will +display an unaccented version. <br /><br /> +<a name="artlinks">Links to other EB articles:</a> Links to articles residing in other EB volumes will +be made available when the respective volumes are introduced online. +</td> +</tr> +</table> +<div style="padding-top: 3em; "> </div> + +<h2>THE ENCYCLOPÆDIA BRITANNICA</h2> + +<h2>A DICTIONARY OF ARTS, SCIENCES, LITERATURE AND GENERAL INFORMATION</h2> + +<h3>ELEVENTH EDITION</h3> +<div style="padding-top: 3em; "> </div> + +<hr class="full" /> +<h3>VOLUME VIII SLICE IX<br /><br /> +Dyer to Echidna</h3> +<hr class="full" /> +<div style="padding-top: 3em; "> </div> + +<p class="center1" style="font-size: 150%; font-family: 'verdana';">Articles in This Slice</p> +<table class="reg" style="width: 90%; font-size: 90%; border: gray 2px solid;" cellspacing="8" summary="Contents"> + +<tr><td class="tcl"><a href="#ar1">DYER, SIR EDWARD</a></td> <td class="tcl"><a href="#ar65">EAST LIVERPOOL</a></td></tr> +<tr><td class="tcl"><a href="#ar2">DYER, JOHN</a></td> <td class="tcl"><a href="#ar66">EAST LONDON</a></td></tr> +<tr><td class="tcl"><a href="#ar3">DYER, THOMAS HENRY</a></td> <td class="tcl"><a href="#ar67">EASTON</a></td></tr> +<tr><td class="tcl"><a href="#ar4">DYMOKE</a></td> <td class="tcl"><a href="#ar68">EAST ORANGE</a></td></tr> +<tr><td class="tcl"><a href="#ar5">DYNAMICS</a></td> <td class="tcl"><a href="#ar69">EASTPORT</a></td></tr> +<tr><td class="tcl"><a href="#ar6">DYNAMITE</a></td> <td class="tcl"><a href="#ar70">EAST PROVIDENCE</a></td></tr> +<tr><td class="tcl"><a href="#ar7">DYNAMO</a></td> <td class="tcl"><a href="#ar71">EAST PRUSSIA</a></td></tr> +<tr><td class="tcl"><a href="#ar8">DYNAMOMETER</a></td> <td class="tcl"><a href="#ar72">EASTWICK, EDWARD BACKHOUSE</a></td></tr> +<tr><td class="tcl"><a href="#ar9">DYNASTY</a></td> <td class="tcl"><a href="#ar73">EATON, DORMAN BRIDGMAN</a></td></tr> +<tr><td class="tcl"><a href="#ar10">DYSART</a></td> <td class="tcl"><a href="#ar74">EATON, MARGARET O’NEILL</a></td></tr> +<tr><td class="tcl"><a href="#ar11">DYSENTERY</a></td> <td class="tcl"><a href="#ar75">EATON, THEOPHILUS</a></td></tr> +<tr><td class="tcl"><a href="#ar12">DYSPEPSIA</a></td> <td class="tcl"><a href="#ar76">EATON, WILLIAM</a></td></tr> +<tr><td class="tcl"><a href="#ar13">DYSTELEOLOGY</a></td> <td class="tcl"><a href="#ar77">EATON, WYATT</a></td></tr> +<tr><td class="tcl"><a href="#ar14">DZUNGARIA</a></td> <td class="tcl"><a href="#ar78">EAU CLAIRE</a></td></tr> +<tr><td class="tcl"><a href="#ar15">E</a></td> <td class="tcl"><a href="#ar79">EAU DE COLOGNE</a></td></tr> +<tr><td class="tcl"><a href="#ar16">EA</a></td> <td class="tcl"><a href="#ar80">EAUX-BONNES</a></td></tr> +<tr><td class="tcl"><a href="#ar17">EABANI</a></td> <td class="tcl"><a href="#ar81">EAVES</a></td></tr> +<tr><td class="tcl"><a href="#ar18">EACHARD, JOHN</a></td> <td class="tcl"><a href="#ar82">EAVESDRIP</a></td></tr> +<tr><td class="tcl"><a href="#ar19">EADBALD</a></td> <td class="tcl"><a href="#ar83">EBBW VALE</a></td></tr> +<tr><td class="tcl"><a href="#ar20">EADIE, JOHN</a></td> <td class="tcl"><a href="#ar84">EBEL, HERMANN WILHELM</a></td></tr> +<tr><td class="tcl"><a href="#ar21">EADMER</a></td> <td class="tcl"><a href="#ar85">EBEL, JOHANN GOTTFRIED</a></td></tr> +<tr><td class="tcl"><a href="#ar22">EADS, JAMES BUCHANAN</a></td> <td class="tcl"><a href="#ar86">EBER, PAUL</a></td></tr> +<tr><td class="tcl"><a href="#ar23">EAGLE</a></td> <td class="tcl"><a href="#ar87">EBERBACH</a> (town of Germany)</td></tr> +<tr><td class="tcl"><a href="#ar24">EAGLEHAWK</a></td> <td class="tcl"><a href="#ar88">EBERBACH</a> (monastery of Germany)</td></tr> +<tr><td class="tcl"><a href="#ar25">EAGRE</a></td> <td class="tcl"><a href="#ar89">EBERHARD</a></td></tr> +<tr><td class="tcl"><a href="#ar26">EAKINS, THOMAS</a></td> <td class="tcl"><a href="#ar90">EBERHARD, CHRISTIAN AUGUST GOTTLOB</a></td></tr> +<tr><td class="tcl"><a href="#ar27">EALING</a></td> <td class="tcl"><a href="#ar91">EBERHARD, JOHANN AUGUSTUS</a></td></tr> +<tr><td class="tcl"><a href="#ar28">EAR</a></td> <td class="tcl"><a href="#ar92">EBERLIN, JOHANN ERNST</a></td></tr> +<tr><td class="tcl"><a href="#ar29">EARL</a></td> <td class="tcl"><a href="#ar93">EBERS, GEORG MORITZ</a></td></tr> +<tr><td class="tcl"><a href="#ar30">EARLE, JOHN</a></td> <td class="tcl"><a href="#ar94">EBERSWALDE</a></td></tr> +<tr><td class="tcl"><a href="#ar31">EARLE, RALPH</a></td> <td class="tcl"><a href="#ar95">EBERT, FRIEDRICH ADOLF</a></td></tr> +<tr><td class="tcl"><a href="#ar32">EARL MARSHAL</a></td> <td class="tcl"><a href="#ar96">EBINGEN</a></td></tr> +<tr><td class="tcl"><a href="#ar33">EARLOM, RICHARD</a></td> <td class="tcl"><a href="#ar97">EBIONITES</a></td></tr> +<tr><td class="tcl"><a href="#ar34">EARLSTON</a></td> <td class="tcl"><a href="#ar98">EBNER-ESCHENBACH, MARIE</a></td></tr> +<tr><td class="tcl"><a href="#ar35">EARLY, JUBAL ANDERSON</a></td> <td class="tcl"><a href="#ar99">EBOLI</a></td></tr> +<tr><td class="tcl"><a href="#ar36">EARLY ENGLISH PERIOD</a></td> <td class="tcl"><a href="#ar100">EBONY</a></td></tr> +<tr><td class="tcl"><a href="#ar37">EARN</a></td> <td class="tcl"><a href="#ar101">EBRARD, JOHANNES HEINRICH AUGUST</a></td></tr> +<tr><td class="tcl"><a href="#ar38">EARNEST</a></td> <td class="tcl"><a href="#ar102">EBRO</a></td></tr> +<tr><td class="tcl"><a href="#ar39">EAR-RING</a></td> <td class="tcl"><a href="#ar103">EBROÏN</a></td></tr> +<tr><td class="tcl"><a href="#ar40">EARTH</a></td> <td class="tcl"><a href="#ar104">EBURĀCUM</a></td></tr> +<tr><td class="tcl"><a href="#ar41">EARTH, FIGURE OF THE</a></td> <td class="tcl"><a href="#ar105">EÇA DE QUEIROZ, JOSÉ MARIA</a></td></tr> +<tr><td class="tcl"><a href="#ar42">EARTH CURRENTS</a></td> <td class="tcl"><a href="#ar106">ÉCARTÉ</a></td></tr> +<tr><td class="tcl"><a href="#ar43">EARTH-NUT</a></td> <td class="tcl"><a href="#ar107">ECBATANA</a></td></tr> +<tr><td class="tcl"><a href="#ar44">EARTH PILLAR</a></td> <td class="tcl"><a href="#ar108">ECCARD, JOHANN</a></td></tr> +<tr><td class="tcl"><a href="#ar45">EARTHQUAKE</a></td> <td class="tcl"><a href="#ar109">ECCELINO DA ROMANO</a></td></tr> +<tr><td class="tcl"><a href="#ar46">EARTH-STAR</a></td> <td class="tcl"><a href="#ar110">ECCENTRIC</a></td></tr> +<tr><td class="tcl"><a href="#ar47">EARTHWORM</a></td> <td class="tcl"><a href="#ar111">ECCHELLENSIS, ABRAHAM</a></td></tr> +<tr><td class="tcl"><a href="#ar48">EARWIG</a></td> <td class="tcl"><a href="#ar112">ECCLES</a></td></tr> +<tr><td class="tcl"><a href="#ar49">EASEMENT</a></td> <td class="tcl"><a href="#ar113">ECCLESFIELD</a></td></tr> +<tr><td class="tcl"><a href="#ar50">EAST, ALFRED</a></td> <td class="tcl"><a href="#ar114">ECCLESHALL</a></td></tr> +<tr><td class="tcl"><a href="#ar51">EAST ANGLIA </a></td> <td class="tcl"><a href="#ar115">ECCLESIA</a></td></tr> +<tr><td class="tcl"><a href="#ar52">EASTBOURNE</a></td> <td class="tcl"><a href="#ar116">ECCLESIASTES</a></td></tr> +<tr><td class="tcl"><a href="#ar53">EAST CHICAGO</a></td> <td class="tcl"><a href="#ar117">ECCLESIASTICAL COMMISSIONERS</a></td></tr> +<tr><td class="tcl"><a href="#ar54">EASTER</a></td> <td class="tcl"><a href="#ar118">ECCLESIASTICAL JURISDICTION</a></td></tr> +<tr><td class="tcl"><a href="#ar55">EASTER ISLAND</a></td> <td class="tcl"><a href="#ar119">ECCLESIASTICAL LAW</a></td></tr> +<tr><td class="tcl"><a href="#ar56">EASTERN BENGAL AND ASSAM</a></td> <td class="tcl"><a href="#ar120">ECCLESIASTICUS</a></td></tr> +<tr><td class="tcl"><a href="#ar57">EASTERN QUESTION, THE</a></td> <td class="tcl"><a href="#ar121">ECGBERT</a> (king of the West Saxons)</td></tr> +<tr><td class="tcl"><a href="#ar58">EAST GRINSTEAD</a></td> <td class="tcl"><a href="#ar122">ECGBERT</a> (archbishop of York)</td></tr> +<tr><td class="tcl"><a href="#ar59">EAST HAM</a></td> <td class="tcl"><a href="#ar123">ECGFRITH</a></td></tr> +<tr><td class="tcl"><a href="#ar60">EASTHAMPTON</a></td> <td class="tcl"><a href="#ar124">ECGONINE</a></td></tr> +<tr><td class="tcl"><a href="#ar61">EAST HAMPTON</a></td> <td class="tcl"><a href="#ar125">ECHEGARAY Y EIZAGUIRRE, JOSÉ</a></td></tr> +<tr><td class="tcl"><a href="#ar62">EAST INDIA COMPANY</a></td> <td class="tcl"><a href="#ar126">ÉCHELON</a></td></tr> +<tr><td class="tcl"><a href="#ar63">EAST INDIES</a></td> <td class="tcl"><a href="#ar127">ECHIDNA</a></td></tr> +<tr><td class="tcl"><a href="#ar64">EASTLAKE, SIR CHARLES LOCK</a></td> <td> </td></tr> +</table> + +<hr class="art" /> +<p><span class="pagenum"><a name="page755" id="page755"></a>755</span></p> +<p><span class="bold">DYER, SIR EDWARD<a name="ar1" id="ar1"></a></span> (d. 1607), English courtier and poet, +son of Sir Thomas Dyer, Kt., was born at Sharpham Park, +Somersetshire. He was educated, according to Anthony à Wood, +either at Balliol College or at Broadgates Hall, Oxford. He +left the university without taking a degree, and after some time +spent abroad appeared at Queen Elizabeth’s court. His first +patron was the earl of Leicester, who seems to have thought +of putting him forward as a rival to Sir Christopher Hatton +in the queen’s favour. He is mentioned by Gabriel Harvey +with Sidney as one of the ornaments of the court. Sidney in his +will desired that his books should be divided between Fulke +Greville (Lord Brooke) and Dyer. He was employed by +Elizabeth on a mission (1584) to the Low Countries, and in 1589 +was sent to Denmark. In a commission to inquire into manors +unjustly alienated from the crown in the west country he did +not altogether please the queen, but he received a grant of some +forfeited lands in Somerset in 1588. He was knighted and made +chancellor of the order of the Garter in 1596. William Oldys +says of him that he “would not stoop to fawn,” and some of +his verses seem to show that the exigencies of life at court +oppressed him. He was buried at St Saviour’s, Southwark, on +the 11th of May 1607. Wood says that many esteemed him +to be a Rosicrucian, and that he was a firm believer in alchemy. +He had a great reputation as a poet among his contemporaries, +but very little of his work has survived. Puttenham in the +<i>Arte of English Poesie</i> speaks of “Maister Edward Dyar, for +Elegie most sweete, solempne, and of high conceit.” One of +the poems universally accepted as his is “My Mynde to me a +kingdome is.” Among the poems in <i>England’s Helicon</i> (1600), +signed S.E.D., and included in Dr A.B. Grosart’s collection +of Dyer’s works (<i>Miscellanies of the Fuller Worthies Library</i>, +vol. iv., 1876) is the charming pastoral “My Phillis hath the +morninge sunne,” but this comes from the <i>Phillis</i> of Thomas +Lodge. Grosart also prints a prose tract entitled <i>The Prayse +of Nothing</i> (1585). The <i>Sixe Idillia</i> from Theocritus, reckoned +by J.P. Collier among Dyer’s works, were dedicated to, not +written by, him.</p> + + +<hr class="art" /> +<p><span class="bold">DYER, JOHN<a name="ar2" id="ar2"></a></span> (<i>c.</i> 1700-1758), British poet, the son of a solicitor, +was born in 1699 or 1700 at Aberglasney, in Carmarthenshire. +He was sent to Westminster school and was destined for +the law, but on his father’s death he began to study painting. +He wandered about South Wales, sketching and occasionally +painting portraits. In 1726 his first poem, <i>Grongar Hill</i>, appeared +in a miscellany published by Richard Savage, the poet. It was +an irregular ode in the so-called Pindaric style, but Dyer entirely +rewrote it into a loose measure of four cadences, and printed it +separately in 1727. It had an immediate and brilliant success. +<i>Grongar Hill</i>, as it now stands, is a short poem of only 150 lines, +describing in language of much freshness and picturesque charm +the view from a hill overlooking the poet’s native vale of Towy. +A visit to Italy bore fruit in <i>The Ruins of Rome</i> (1740), a descriptive +piece in about 600 lines of Miltonic blank verse. He was +ordained priest in 1741, and held successively the livings of +Calthorp in Leicestershire, Belchford (1751), Coningsby (1752), +and Kirby-on-Bane (1756), the last three being Lincolnshire +parishes. He married, in 1741, a Miss Ensor, said to be descended +from the brother of Shakespeare. In 1757 he published his +longest work, the didactic blank-verse epic of <i>The Fleece</i>, in four +books, discoursing of the tending of sheep, of the shearing and +preparation of the wool, of weaving, and of trade in woollen +manufactures. The town took no interest in it, and Dodsley +facetiously prophesied that “Mr Dyer would be buried in +woollen.” He died at Coningsby of consumption, on the 15th +of December 1758.</p> + +<div class="condensed"> +<p>His <span class="correction" title="amended from peoms">poems</span> were collected by Dodsley in 1770, and by Mr Edward +Thomas in 1903 for the <i>Welsh Library</i>, vol. iv.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">DYER, THOMAS HENRY<a name="ar3" id="ar3"></a></span> (1804-1888), English historical and +antiquarian writer, was born in London on the 4th of May +1804. He was originally intended for a business career, and for +some time acted as clerk in a West India house; but finding his +services no longer required after the passing of the Negro Emancipation +Act, he decided to devote himself to literature. In 1850 +he published the <i>Life of Calvin</i>, a conscientious and on the whole +impartial work, though the character of Calvin is somewhat +harshly drawn, and his influence in the religious world generally +is insufficiently appreciated. Dyer’s first historical work was +the <i>History of Modern Europe</i> (1861-1864; 3rd ed. revised and +continued to the end of the 19th century, by A. Hassall, 1901), +a meritorious compilation and storehouse of facts, but not very +readable. The <i>History of the City of Rome</i> (1865) down to +the end of the middle ages was followed by the <i>History of the +Kings of Rome</i> (1868), which, upholding against the German +school the general credibility of the account of early Roman +history, given in Livy and other classical authors, was violently +attacked by J.R. Seeley and the <i>Saturday Review</i>, as showing +ignorance of the comparative method. More favourable opinions +of the work were expressed by others, but it is generally agreed +that the author’s scholarship is defective and that his views are +far too conservative. <i>Roma Regalis</i> (1872) and <i>A Plea for Livy</i> +(1873) were written in reply to his critics. Dyer frequently +visited Greece and Italy, and his topographical works are +probably his best; amongst these mention may be made of +<i>Pompeii, its History, Buildings and Antiquities</i> (1867, new ed. +in Bohn’s <i>Illustrated Library</i>), and <i>Ancient Athens, its History, +Topography and Remains</i> (1873). His last publication was <i>On +Imitative Art</i> (1882). He died at Bath on the 30th of January +1888.</p> + + +<hr class="art" /> +<p><span class="bold">DYMOKE,<a name="ar4" id="ar4"></a></span> the name of an English family holding the office +of king’s champion. The functions of the champion were to ride +into Westminster Hall at the coronation banquet, and challenge +all comers to impugn the king’s title (see <span class="sc"><a href="#artlinks">Champion</a></span>). The +earliest record of the ceremony at the coronation of an English +king dates from the accession of Richard II. On this occasion +the champion was Sir John Dymoke (d. 1381), who held the +manor of Scrivelsby, Lincolnshire, in right of his wife Margaret, +granddaughter of Joan Ludlow, who was the daughter and +co-heiress of Philip Marmion, last Baron Marmion. The Marmions +claimed descent from the lords of Fontenay, hereditary +champions of the dukes of Normandy, and held the castle of +Tamworth, Leicestershire, and the manor of Scrivelsby, Lincolnshire. +The right to the championship was disputed with the +Dymoke family by Sir Baldwin de Freville, lord of Tamworth, +who was descended from an elder daughter of Philip Marmion. +The court of claims eventually decided in favour of the owners +of Scrivelsby on the ground that Scrivelsby was held in grand +serjeanty, that is, that its tenure was dependent on rendering +a special service, in this case the championship.</p> + +<p>Sir Thomas Dymoke (1428?-1471) joined a Lancastrian +rising in 1469, and, with his brother-in-law Richard, Lord Willoughby +and Welles, was beheaded in 1471 by order of Edward IV. +after he had been induced to leave sanctuary on a promise of +personal safety. The estates were restored to his son Sir Robert +Dymoke (d. 1546), champion at the coronations of Richard III., +Henry VII. and Henry VIII., who distinguished himself at the +siege of Tournai and became treasurer of the kingdom. His +descendants acted as champions at successive coronations. +Lewis Dymoke (d. 1820) put in an unsuccessful claim before the +House of Lords for the barony of Marmion. His nephew Henry +(1801-1865) was champion at the coronation of George IV. +He was accompanied on that occasion by the duke of Wellington +and Lord Howard of Effingham. Henry Dymoke was created +a baronet; he was succeeded by his brother John, rector of +Scrivelsby (1804-1873), whose son Henry Lionel died without +<span class="pagenum"><a name="page756" id="page756"></a>756</span> +issue in 1875, when the baronetcy became extinct, the estate +passing to a collateral branch of the family. After the coronation +of George IV. the ceremony was allowed to lapse, but at the +coronation of King Edward VII. H.S. Dymoke bore the standard +of England in Westminster Abbey.</p> + + +<hr class="art" /> +<p><span class="bold">DYNAMICS<a name="ar5" id="ar5"></a></span> (from Gr. <span class="grk" title="dynamis">δύναμις</span>, strength), the name of a branch +of the science of Mechanics (<i>q.v.</i>). The term was at one time +restricted to the treatment of motion as affected by force, being +thus opposed to Statics, which investigated equilibrium or +conditions of rest. In more recent times the word has been +applied comprehensively to the action of force on bodies either +at rest or in motion, thus including “dynamics” (now termed +kinetics) in the restricted sense and “statics.”</p> + +<p><span class="sc">Analytical Dynamics.</span>—The fundamental principles of +dynamics, and their application to special problems, are explained +in the articles <span class="sc"><a href="#artlinks">Mechanics</a></span> and <span class="sc"><a href="#artlinks">Motion, Laws of</a></span>, where +brief indications are also given of the more general methods of +investigating the properties of a dynamical system, independently +of the accidents of its particular constitution, which were inaugurated +by J.L. Lagrange. These methods, in addition to the unity +and breadth which they have introduced into the treatment +of pure dynamics, have a peculiar interest in relation to modern +physical speculation, which finds itself confronted in various +directions with the problem of explaining on dynamical principles +the properties of systems whose ultimate mechanism can +at present only be vaguely conjectured. In determining the +properties of such systems the methods of analytical geometry +and of the infinitesimal calculus (or, more generally, of mathematical +analysis) are necessarily employed; for this reason the +subject has been named Analytical Dynamics. The following +article is devoted to an outline of such portions of general dynamical +theory as seem to be most important from the physical point +of view.</p> + +<div class="condensed"> +<p class="pt2 center">1. <i>General Equations of Impulsive Motion.</i></p> + +<p>The systems contemplated by Lagrange are composed of discrete +particles, or of rigid bodies, in finite number, connected (it may be) +in various ways by invariable geometrical relations, the fundamental +postulate being that the position of every particle of the +system at any time can be completely specified by means of the +instantaneous values of a finite number of independent variables +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>, each of which admits of continuous variation over a +certain range, so that if x, y, z be the Cartesian co-ordinates of any +one particle, we have for example</p> + +<p class="center">x = ƒ(q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>), y = &c., z = &c.,</p> +<div class="author">(1)</div> + +<p class="noind">where the functions ƒ differ (of course) from particle to particle. +In modern language, the variables q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span> are <i>generalized co-ordinates</i> +serving to specify the <i>configuration</i> of the system; their +derivatives with respect to the time are denoted by q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">n</span>, and +are called the <i>generalized components of velocity</i>. The continuous +sequence of configurations assumed by the system in any actual or +imagined motion (subject to the given connexions) is called the +<i>path</i>.</p> + +<p>For the purposes of a connected outline of the whole subject it +is convenient to deviate somewhat from the historical order of +development, and to begin with the consideration of +<span class="sidenote">Impulsive motion.</span> +<i>impulsive</i> motion. Whatever the actual motion of the +system at any instant, we may conceive it to be generated +instantaneously from rest by the application of proper impulses. +On this view we have, if x, y, z be the rectangular co-ordinates of any +particle m,</p> + +<p class="center">mẋ = X′, mẏ = Y′, mz˙ = Z′,</p> +<div class="author">(2)</div> + +<p class="noind">where X′, Y′, Z′ are the components of the impulse on m. Now +let δx, δy, δz be any infinitesimal variations of x, y, z which are consistent +with the connexions of the system, and let us form the +equation</p> + +<p class="center">Σm(ẋδx + ẏδy + z˙δz) = Σ(X′δx + Y′δy + Z′δz),</p> +<div class="author">(3)</div> + +<p class="noind">where the sign Σ indicates (as throughout this article) a summation +extending over all the particles of the system. To transform (3) +into an equation involving the variations δq<span class="su">1</span>, δq<span class="su">2</span>, ... of the generalized +co-ordinates, we have</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ẋ =</td> <td>∂x</td> +<td rowspan="2">q˙<span class="su">1</span> +</td> <td>∂x</td> +<td rowspan="2">q˙<span class="su">2</span> + ..., &c., &c.</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(4)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">δx =</td> <td>∂x</td> +<td rowspan="2">δq<span class="su">1</span> +</td> <td>∂x</td> +<td rowspan="2">δq<span class="su">2</span> + ..., &c., &c.</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(5)</div> + +<p class="noind">and therefore</p> + +<p class="center">Σm(ẋδx + ẏδy + z˙δz) = A<span class="su">11</span>q˙<span class="su">1</span> + A<span class="su">12</span>q˙<span class="su">2</span> + ...)δq<span class="su">1</span> + + (A<span class="su">21</span>q˙<span class="su">1</span> + A<span class="su">22</span>q˙<span class="su">2</span> + ...)δq<span class="su">2</span> + ...,</p> +<div class="author">(6)</div> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">A<span class="su">rr</span> = Σm <span class="f150">{ (</span></td> <td>∂x</td> +<td rowspan="2"><span class="f150">)</span></td> <td>²</td> +<td rowspan="2">+ <span class="f150">(</span></td> <td>∂y</td> +<td rowspan="2"><span class="f150">)</span></td> <td>²</td> +<td rowspan="2">+ <span class="f150">(</span></td> <td>∂z</td> +<td rowspan="2"><span class="f150">)</span></td> <td>²</td> +<td rowspan="2"><span class="f150">}</span>,</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td> <td> </td> +<td class="denom">∂q<span class="su">r</span></td> <td> </td> +<td class="denom">∂q<span class="su">r</span></td> <td> </td></tr></table> +<div class="author">(7)</div> + +<table class="math0a" summary="math"> +<tr><td rowspan="2">A<span class="su">rs</span> = Σm <span class="f150">{</span></td> +<td>∂x</td> <td>∂x</td> <td rowspan="2">+</td> +<td>∂y</td> <td>∂y</td> <td rowspan="2">+</td> +<td>∂z</td> <td>∂z</td> <td rowspan="2"><span class="f150">}</span> = A<span class="su">sr</span>.</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">s</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">s</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">s</span></td></tr></table> + +<p class="noind">If we form the expression for the kinetic energy Τ of the system, +we find</p> + +<p class="center">2Τ = Σm(ẋ² + ẏ² + z˙²) = A<span class="su">11</span>q˙<span class="su">1</span>² + A<span class="su">22</span>q˙<span class="su">2</span>² ... 2A<span class="su">12</span>q˙<span class="su">1</span>q˙<span class="su">2</span> + ...</p> +<div class="author">(8)</div> + +<p class="noind">The coefficients A<span class="su">11</span>, A<span class="su">22</span>, ... A<span class="su">12</span>, ... are by an obvious analogy called +the <i>coefficients of inertia</i> of the system; they are in general functions +of the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>,.... The equation (6) may now be written</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Σm(ẋδx + ẏδy + z˙δz) =</td> <td>∂Τ</td> +<td rowspan="2">δq<span class="su">1</span> +</td> <td>∂Τ</td> +<td rowspan="2">δq<span class="su">2</span> + ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">2</span></td></tr></table> +<div class="author">(9)</div> + +<p class="noind">This maybe regarded as the cardinal formula in Lagrange’s method. +For the right-hand side of (3) we may write</p> + +<p class="center">Σ(X′δx + Y′δy + Z′δz) = Q′<span class="su">1</span>δq<span class="su">1</span> + Q′<span class="su">2</span>δq<span class="su">2</span> + ... ,</p> +<div class="author">(10)</div> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Q′<span class="su">r</span> = Σ<span class="f150">(</span>X′</td> <td>∂x</td> +<td rowspan="2">+ Y′</td> <td>∂y</td> +<td rowspan="2">+ Z′</td> <td>∂z</td> +<td rowspan="2"><span class="f150">)</span>.</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(11)</div> + +<p class="noind">The quantities Q<span class="su">1</span>, Q<span class="su">2</span>, ... are called the <i>generalized components of +impulse</i>. Comparing (9) and (10), we have, since the variations +δq<span class="su">1</span>, δq<span class="su">2</span>,... are independent,</p> + +<table class="math0" summary="math"> +<tr><td>∂Τ</td> <td rowspan="2"> = Q′<span class="su">1</span>,</td> +<td>∂Τ</td> <td rowspan="2">= Q′<span class="su">2</span>, ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">2</span></td></tr></table> +<div class="author">(12)</div> + +<p class="noind">These are the general equations of impulsive motion.</p> + +<p>It is now usual to write</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">p<span class="su">r</span> =</td> <td>∂Τ</td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">∂q˙<span class="su">r</span></td></tr></table> +<div class="author">(13)</div> + +<p class="noind">The quantities p<span class="su">1</span>, p<span class="su">2</span>, ... represent the effects of the several component +impulses on the system, and are therefore called the <i>generalized +components of momentum</i>. In terms of them we have</p> + +<p class="center">Σm(ẋδx + ẏδy + z˙δz) = p<span class="su">1</span>δq<span class="su">1</span> + p<span class="su">2</span>δq<span class="su">2</span> + ...</p> +<div class="author">(14)</div> + +<p class="noind">Also, since Τ is a homogeneous quadratic function of the velocities +q˙<span class="su">1</span>, q˙<span class="su">2</span> ...,</p> + +<p class="center">2Τ = p<span class="su">1</span>q˙<span class="su">1</span> + p<span class="su">2</span>q˙<span class="su">2</span> + ...</p> +<div class="author">(15)</div> + +<p class="noind">This follows independently from (14), assuming the special variations +δx = ẋdt, &c., and therefore δq<span class="su">1</span> = q˙<span class="su">1</span>dt, δq<span class="su">2</span> = q˙<span class="su">2</span>dt, ...</p> + +<p>Again, if the values of the velocities and the momenta +<span class="sidenote">Reciprocal theorems.</span> +in any other motion of the system through the same configuration +be distinguished by accents, we have the identity</p> + +<p class="center">p<span class="su">1</span>q˙′<span class="su">1</span> + p<span class="su">2</span>q˙′<span class="su">2</span> + ... = p′<span class="su">1</span>q˙<span class="su">1</span> + p′<span class="su">2</span>q˙<span class="su">2</span> + ...,</p> +<div class="author">(16)</div> + +<p class="noind">each side being equal to the symmetrical expression</p> + +<p class="center">A<span class="su">11</span>q˙<span class="su">1</span>q˙′<span class="su">1</span> + A<span class="su">22</span>q˙<span class="su">2</span>q˙′<span class="su">2</span> + ... + A<span class="su">12</span>(q˙<span class="su">1</span>q˙′<span class="su">2</span> + q˙′<span class="su">1</span>q˙<span class="su">2</span>) + ...</p> +<div class="author">(17)</div> + +<p>The theorem (16) leads to some important reciprocal relations. +Thus, let us suppose that the momenta p<span class="su">1</span>, p<span class="su">2</span>, ... all vanish with +the exception of p<span class="su">1</span>, and similarly that the momenta p′<span class="su">1</span>, p′<span class="su">2</span>, ... all +vanish except p′<span class="su">2</span>. We have then p<span class="su">1</span>q˙′<span class="su">1</span> = p′<span class="su">2</span>q˙<span class="su">2</span>, or</p> + +<p class="center">q˙<span class="su">2</span> : p<span class="su">1</span> = q˙′<span class="su">1</span> : p′<span class="su">2</span></p> +<div class="author">(18)</div> + +<p class="noind">The interpretation is simplest when the co-ordinates q<span class="su">1</span>, q<span class="su">2</span> are +both of the same kind, <i>e.g.</i> both lines or both angles. We may +then conveniently put p<span class="su">1</span> = p′<span class="su">2</span>, and assert that the velocity of the +first type due to an impulse of the second type is equal to the velocity +of the second type due to an equal impulse of the first type. As an +example, suppose we have a chain of straight links hinged each to +the next, extended in a straight line, and free to move. A blow +at right angles to the chain, at any point P, will produce a certain +velocity at any other point Q; the theorem asserts that an equal +velocity will be produced at P by an equal blow at Q. Again, an +impulsive couple acting on any link A will produce a certain angular +velocity in any other link B; an equal couple applied to B will +produce an equal angular velocity in A. Also if an impulse F applied +at P produce an angular velocity ω in a link A, a couple Fa applied +to A will produce a linear velocity ωa at P. Historically, we may +note that reciprocal relations in dynamics were first recognized by +H.L.F. Helmholtz in the domain of acoustics; their use has been +greatly extended by Lord Rayleigh.</p> + +<p>The equations (13) determine the momenta p<span class="su">1</span>, p<span class="su">2</span>,... as linear +functions of the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>,... Solving these, we can express +q˙<span class="su">1</span>, q˙<span class="su">2</span> ... as linear functions of p<span class="su">1</span>, p<span class="su">2</span>,... The resulting +equations give us the velocities produced by any given +<span class="sidenote">Velocities in terms of momenta.</span> +system of impulses. Further, by substitution in (8), +we can express the kinetic energy as a homogeneous +quadratic function of the momenta p<span class="su">1</span>, p<span class="su">2</span>,... The kinetic energy, +<i>as so expressed</i>, will be denoted by Τ`; thus</p> + +<p class="center">2Τ` = A`<span class="su">11</span>p<span class="su">1</span>² + A`<span class="su">22</span>p<span class="su">2</span>² + ... + 2A`<span class="su">12</span>p-p<span class="su">2</span> + ...</p> +<div class="author">(19)</div> + +<p class="noind">where A`<span class="su">11</span>, A`<span class="su">22</span>,... A`<span class="su">12</span>,... are certain coefficients depending on the +configuration. They have been called by Maxwell the <i>coefficients +of mobility</i> of the system. When the form (19) is given, the values +<span class="pagenum"><a name="page757" id="page757"></a>757</span> +of the velocities in terms of the momenta can be expressed in a remarkable +form due to Sir W.R. Hamilton. The formula (15) may +be written</p> + +<p class="center">p<span class="su">1</span>q˙<span class="su">1</span> + p<span class="su">2</span>q˙<span class="su">2</span> + ... = Τ + Τ`,</p> +<div class="author">(20)</div> + +<p class="noind">where Τ is supposed expressed as in (8), and Τ` as in (19). Hence +if, for the moment, we denote by δ a variation affecting the velocities, +and therefore the momenta, but not the configuration, we have</p> + +<p class="center">p<span class="su">1</span>δq˙<span class="su">1</span> + q˙<span class="su">1</span>δp + p<span class="su">2</span>δq˙<span class="su">2</span> + q˙<span class="su">2</span>δp<span class="su">2</span> + ... = δΤ + δΤ`</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">    =</td> <td>∂Τ</td> +<td rowspan="2">δq˙<span class="su">1</span> +</td> <td>∂Τ</td> +<td rowspan="2">δq˙<span class="su">2</span> + ... +</td> <td>∂Τ`</td> +<td rowspan="2">δp<span class="su">1</span> +</td> <td>∂Τ`</td> +<td rowspan="2">δp<span class="su">2</span> + ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">2</span></td> +<td class="denom">∂p<span class="su">1</span></td> <td class="denom">∂p<span class="su">2</span></td></tr></table> +<div class="author">(21)</div> + +<p class="noind">In virtue of (13) this reduces to</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">q˙<span class="su">1</span>δp<span class="su">1</span> + q˙<span class="su">2</span>δp<span class="su">2</span> + ... =</td> <td>∂Τ`</td> +<td rowspan="2">δp<span class="su">1</span> +</td> <td>∂Τ`</td> +<td rowspan="2">δp<span class="su">2</span> + ...</td></tr> +<tr><td class="denom">∂p<span class="su">1</span></td> <td class="denom">∂p<span class="su">2</span></td></tr></table> +<div class="author">(22)</div> + +<p class="noind">Since δp<span class="su">1</span>, δp<span class="su">2</span>, ... may be taken to be independent, we infer that</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">q˙<span class="su">1</span> =</td> <td>∂Τ`</td> +<td rowspan="2">,    q˙<span class="su">2</span> =</td> <td>∂Τ`</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂p<span class="su">1</span></td> <td class="denom">∂p<span class="su">2</span></td></tr></table> +<div class="author">(23)</div> + +<p class="noind">In the very remarkable exposition of the matter given by James +Clerk Maxwell in his <i>Electricity and Magnetism</i>, the Hamiltonian +expressions (23) for the velocities in terms of the impulses are +obtained directly from first principles, and the formulae (13) are +then deduced by an inversion of the above argument.</p> + +<p>An important modification of the above process was introduced +by E.J. Routh and Lord Kelvin and P.G. Tait. Instead of expressing +the kinetic energy in terms of the velocities alone, +or in terms of the momenta alone, we may express it in +<span class="sidenote">Routh’s modification.</span> +terms of the velocities corresponding to some of the co-ordinates, +say q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>, and of the momenta corresponding +to the remaining co-ordinates, which (for the sake of distinction) +we may denote by χ, χ′, χ″, .... Thus, Τ being expressed +as a homogeneous quadratic function of q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, χ˙, χ˙′, χ˙″, ..., +the momenta corresponding to the co-ordinates χ, χ′, χ″, ... may be +written</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">κ =</td> <td>∂Τ</td> +<td rowspan="2">,   κ′ =</td> <td>∂Τ</td> +<td rowspan="2">,   κ″ =</td> <td>∂Τ</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂χ˙</td> <td class="denom">∂χ˙′</td> +<td class="denom">∂χ˙″</td></tr></table> +<div class="author">(24)</div> + +<p class="noind">These equations, when written out in full, determine χ˙, χ˙′, χ˙″, ... +as linear functions of q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, κ, κ′, κ″,... We now consider +the function</p> + +<p class="center">R = Τ − κχ˙ − κ′χ˙′ − κ″χ˙″ − ... ,</p> +<div class="author">(25)</div> + +<p class="noind">supposed expressed, by means of the above relations in terms of +q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, κ, κ′, κ″, ... Performing the operation δ on both sides +of (25), we have</p> + +<table class="math0" summary="math"> +<tr><td>∂R</td> +<td rowspan="2">δq˙<span class="su">1</span> + ... +</td> <td>∂R</td> +<td rowspan="2">δκ + ... =</td> <td>∂Τ</td> +<td rowspan="2">δq˙<span class="su">1</span> + ... +</td> <td>∂Τ</td> +<td rowspan="2">δχ˙ + ... − κ∂χ˙ − χ˙δκ − ... ,</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂κ</td> +<td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂χ˙</td></tr></table> +<div class="author">(26)</div> + +<p class="noind">where, for brevity, only one term of each type has been exhibited. +Omitting the terms which cancel in virtue of (24), we have</p> + +<table class="math0" summary="math"> +<tr><td>∂R</td> +<td rowspan="2">δq˙<span class="su">1</span> + ... +</td> <td>∂R</td> +<td rowspan="2">δκ + ... =</td> <td>∂Τ</td> +<td rowspan="2">δq˙<span class="su">1</span> + ... − χ˙δκ − ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂κ</td> +<td class="denom">∂q˙<span class="su">1</span></td></tr></table> +<div class="author">(27)</div> + +<p class="noind">Since the variations δq<span class="su">1</span>, δq<span class="su">2</span>, ... δq<span class="su">m</span>, δκ, δκ′, δκ″, ... may be taken to be +independent, we have</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">p<span class="su">1</span> =</td> <td>∂Τ</td> +<td rowspan="2">=</td> <td>∂R</td> +<td rowspan="2">,   p<span class="su">2</span> =</td> <td>∂Τ</td> +<td rowspan="2">=</td> <td>∂R</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">1</span></td> +<td class="denom">∂q˙<span class="su">2</span></td> <td class="denom">∂q˙<span class="su">2</span></td></tr></table> +<div class="author">(28)</div> + +<p class="noind">and</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">χ˙ = −</td> <td>∂R</td> +<td rowspan="2">,   χ˙′ = −</td> <td>∂R</td> +<td rowspan="2">,   χ˙″ = −</td> <td>∂R</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂κ</td> <td class="denom">∂κ′</td> +<td class="denom">∂κ″</td></tr></table> +<div class="author">(29)</div> + +<p>An important property of the present transformation is that, +when expressed in terms of the new variables, the kinetic energy is +the sum of two homogeneous quadratic functions, thus</p> + +<p class="center">Τ = ⅋ + K,</p> +<div class="author">(30)</div> + +<p class="noind">where ⅋ involves the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span> alone, and K the +momenta κ, κ′, κ″, ... alone. For in virtue of (29) we have, from +(25),</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Τ = R − <span class="f150">(</span>κ</td> <td>∂R</td> +<td rowspan="2">+ κ′</td> <td>∂R</td> +<td rowspan="2">+ κ″</td> <td>∂R</td> +<td rowspan="2">+ ... <span class="f150">)</span>,</td></tr> +<tr><td class="denom">∂κ</td> <td class="denom">∂κ′</td> +<td class="denom">∂κ″</td></tr></table> +<div class="author">(31)</div> + +<p class="noind">and it is evident that the terms in R which are bilinear in respect +of the two sets of variables q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span> and κ, κ′, κ″, ... will disappear +from the right-hand side.</p> + +<p>It may be noted that the formula (30) gives immediate proof +of two important theorems due to Bertrand and to Lord Kelvin +respectively. Let us suppose, in the first place, that +the system is started by given impulses of certain types, +<span class="sidenote">Maximum and minimum energy.</span> +but is otherwise free. J.L.F. Bertrand’s theorem is to +the effect that the kinetic energy is <i>greater</i> than if by +impulses of the remaining types the system were constrained +to take any other course. We may suppose the co-ordinates +to be so chosen that the constraint is expressed by the vanishing +of the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, whilst the given impulses are κ, κ′, κ″,... +Hence the energy in the actual motion is greater than in the +constrained motion by the amount ⅋.</p> + +<p>Again, suppose that the system is started with prescribed velocity +components q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, by means of proper impulses of the corresponding +types, but is otherwise free, so that in the motion actually +generated we have κ = 0, κ′ = 0, κ″ = 0, ... and therefore K = 0. The +kinetic energy is therefore <i>less</i> than in any other motion consistent +with the prescribed velocity-conditions by the value which K +assumes when κ, κ′, κ″, ... represent the impulses due to the +constraints.</p> + +<p>Simple illustrations of these theorems are afforded by the chain +of straight links already employed. Thus if a point of the chain +be held fixed, or if one or more of the joints be made rigid, the +energy generated by any given impulses is less than if the chain +had possessed its former freedom.</p> + +<p class="pt2 center">2. <i>Continuous Motion of a System.</i></p> + +<p>We may proceed to the continuous motion of a system. The +<span class="sidenote">Lagrange’s equations.</span> +equations of motion of any particle of the system are of the form</p> + +<p class="center">mẍ = X,   mÿ = Y,   mz¨ = Z</p> +<div class="author">(1)</div> + +<p class="noind">Now let x + δx, y + δy, z + δz be the co-ordinates of m in any +arbitrary motion of the system differing infinitely little +from the actual motion, and let us form the equation</p> + +<p class="center">Σm (ẍδx + ÿδy + z¨δz) += Σ (Xδx + Yδy + Zδz)</p> +<div class="author">(2)</div> + +<p class="noind">Lagrange’s investigation consists in the transformation of (2) into +an equation involving the independent variations δq<span class="su">1</span>, δq<span class="su">2</span>, ... δq<span class="su">n</span>.</p> + +<p>It is important to notice that the symbols δ and d/dt are commutative, +since</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">δẋ =</td> <td>d</td> +<td rowspan="2">(x + δx) −</td> <td>dx</td> +<td rowspan="2">=</td> <td>d</td> +<td rowspan="2">δx, &c.</td></tr> +<tr><td class="denom">dt</td> <td class="denom">dt</td> <td class="denom">dt</td></tr></table> +<div class="author">(3)</div> + +<p class="noind">Hence</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Σm(ẍδx + ÿδy + z¨δz) =</td> <td>d</td> +<td rowspan="2">Σm (ẋδx + ẏδy + z˙δz) + − Σm (ẋδẋ + ẏδẏ + z˙δz˙)</td></tr> +<tr><td class="denom">dt</td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">=</td> <td>d</td> +<td rowspan="2">(p<span class="su">1</span>δq<span class="su">1</span> + p<span class="su">2</span>δq<span class="su">2</span> + ...) − δΤ,</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(4)</div> + +<p class="noind">by § 1 (14). The last member may be written</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ṗ<span class="su">1</span>δq<span class="su">1</span> + p<span class="su">1</span>δq˙<span class="su">1</span> + ṗ<span class="su">2</span>δq<span class="su">2</span> + p<span class="su">2</span>δq˙<span class="su">2</span> + ... + −</td> <td>∂Τ</td> +<td rowspan="2">δq˙<span class="su">1</span> −</td> <td>∂Τ</td> +<td rowspan="2">δq<span class="su">1</span> −</td> <td>∂Τ</td> +<td rowspan="2">δq˙<span class="su">2</span> −</td> <td>∂Τ</td> +<td rowspan="2">δq<span class="su">2</span> − ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q˙<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(5)</div> + +<p class="noind">Hence, omitting the terms which cancel in virtue of § 1 (13), we +find</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Σm(ẍδx + ÿδy + z¨δz) = <span class="f150">(</span>ṗ<span class="su">1</span> −</td> <td>∂Τ</td> +<td rowspan="2"><span class="f150">)</span> δq<span class="su">1</span> + <span class="f150">(</span>ṗ<span class="su">2</span> −</td> <td>∂Τ</td> +<td rowspan="2"><span class="f150">)</span> δq<span class="su">2</span> + ...</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(6)</div> + +<p>For the right-hand side of (2) we have</p> + +<p class="center">Σ(Xδx + Yδy + Zδz) = Q<span class="su">1</span>δq<span class="su">1</span> + Q<span class="su">2</span>δq<span class="su">2</span> + ... ,</p> +<div class="author">(7)</div> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Q<span class="su">r</span> = Σ <span class="f150">(</span>X</td> <td>∂x</td> +<td rowspan="2">+ Y</td> <td>∂y</td> +<td rowspan="2">+ Z</td> <td>∂z</td> +<td rowspan="2"><span class="f150">)</span>.</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(8)</div> + +<p class="noind">The quantities Q<span class="su">1</span>, Q<span class="su">2</span>, ... are called the <i>generalized components of +force</i> acting on the system.</p> + +<p>Comparing (6) and (7) we find</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ṗ<span class="su">1</span> −</td> <td>∂Τ</td> +<td rowspan="2">= Q<span class="su">1</span>,   ṗ<span class="su">2</span> −</td> <td>∂Τ</td> +<td rowspan="2">= Q<span class="su">2</span>, ... ,</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">2</span></td></tr></table> +<div class="author">(9)</div> + +<p class="noind">or, restoring the values of p<span class="su">1</span>, p<span class="su">2</span>, ...,</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"><span class="f150">(</span></td> +<td>∂Τ</td> <td rowspan="2"><span class="f150">)</span> −</td> +<td>∂Τ</td> <td rowspan="2">= Q<span class="su">1</span>,  </td> +<td>d</td> <td rowspan="2"><span class="f150">(</span></td> +<td>∂Τ</td> <td rowspan="2"><span class="f150">)</span> −</td> +<td>∂Τ</td> <td rowspan="2">= Q<span class="su">2</span>, ...</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">1</span></td> +<td class="denom">∂q<span class="su">1</span></td> <td class="denom">dt</td> +<td class="denom">∂q˙<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(10)</div> + +<p class="noind">These are Lagrange’s general equations of motion. Their number +is of course equal to that of the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... to be determined.</p> + +<p>Analytically, the above proof is that given by Lagrange, but +the terminology employed is of much more recent date, having +been first introduced by Lord Kelvin and P.G. Tait; it has greatly +promoted the physical application of the subject. Another proof of +the equations (10), by direct transformation of co-ordinates, has +been given by Hamilton and independently by other writers (see +<span class="sc"><a href="#artlinks">Mechanics</a></span>), but the variational method of Lagrange is that which +stands in closest relation to the subsequent developments of the +subject. The chapter of Maxwell, already referred to, is a most +instructive commentary on the subject from the physical point of +view, although the proof there attempted of the equations (10) is +fallacious.</p> + +<p>In a “conservative system” the work which would have to be +done by extraneous forces to bring the system from rest in some +standard configuration to rest in the configuration (q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>) +is independent of the path, and may therefore be regarded as a +definite function of q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>. Denoting this function (the <i>potential +energy</i>) by V, we have, if there be no extraneous force on the system,</p> + +<p class="center">Σ (Xδx + Yδy + Zδz) = − δV,</p> +<div class="author">(11)</div> + +<p class="noind">and therefore</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Q<span class="su">1</span> = −</td> <td>∂V</td> +<td rowspan="2">,   Q<span class="su">2</span> = −</td> <td>∂V</td> +<td rowspan="2">, ....</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(12)</div> + +<p><span class="pagenum"><a name="page758" id="page758"></a>758</span></p> + +<p>Hence the typical Lagrange’s equation may be now written in +the form</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"><span class="f150">(</span></td> +<td>∂Τ</td> <td rowspan="2"><span class="f150">)</span> −</td> +<td>∂Τ</td> <td rowspan="2">= −</td> +<td>∂V</td> <td rowspan="2">,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(13)</div> + +<p class="noind">or, again,</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ṗ<span class="su">r</span> = −</td> <td>∂</td> +<td rowspan="2">(V − Τ).</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(14)</div> + +<p class="noind">It has been proposed by Helmholtz to give the name <i>kinetic potential</i> +to the combination V − Τ.</p> + +<p>As shown under <span class="sc"><a href="#artlinks">Mechanics</a></span>, § 22, we derive from (10)</p> + +<table class="math0" summary="math"> +<tr><td>dΤ</td> <td rowspan="2">= Q<span class="su">1</span>q˙<span class="su">1</span> + Q<span class="su">2</span>q˙<span class="su">2</span> + ... ,</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(15)</div> + +<p class="noind">and therefore in the case of a conservative system free from extraneous +force,</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2">(Τ + V) = 0 or Τ + V = const.,</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(16)</div> + +<p class="noind">which is the equation of energy. For examples of the application +of the formula (13) see <span class="sc"><a href="#artlinks">Mechanics</a></span>, § 22.</p> + +<p class="pt2 center">3. <i>Constrained Systems.</i></p> + +<p>It has so far been assumed that the geometrical relations, if +any, which exist between the various parts of the system +<span class="sidenote">Case of varying relations.</span> +are of the type § 1 (1), and so do not contain t explicitly. +The extension of Lagrange’s equations to the case of +“varying relations” of the type</p> + +<p class="center">x = ƒ(t, q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>), y = &c., z = &c.,</p> +<div class="author">(1)</div> + +<p class="noind">was made by J.M.L. Vieille. We now have</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ẋ =</td> <td>∂x</td> +<td rowspan="2">+</td> <td>∂x</td> +<td rowspan="2">q˙<span class="su">1</span> +</td> <td>∂x</td> +<td rowspan="2">q˙<span class="su">2</span> + ..., &c., &c.,</td></tr> +<tr><td class="denom">∂t</td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(2)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">∂x =</td> <td>∂x</td> +<td rowspan="2">δq<span class="su">1</span> +</td> <td>∂x</td> +<td rowspan="2">δq<span class="su">2</span> + ..., &c., &c.,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(3)</div> + +<p class="noind">so that the expression § 1 (8) for the kinetic energy is to be replaced +by</p> + +<p class="center">2Τ = α<span class="su">0</span> + 2α<span class="su">1</span>q˙<span class="su">1</span> + 2α<span class="su">2</span>q˙<span class="su">2</span> + ... + A<span class="su">11</span>q˙<span class="su">1</span>² + A<span class="su">22</span>q˙<span class="su">2</span>² + ... + A<span class="su">12</span>q˙<span class="su">1</span>q˙<span class="su">2</span> + ...,</p> +<div class="author">(4)</div> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">α<span class="su">0</span> = Σm <span class="f150">{ (</span></td> <td>∂x</td> +<td rowspan="2"><span class="f150">)</span></td> <td>²</td> +<td rowspan="2">+ <span class="f150">(</span></td> <td>∂y</td> +<td rowspan="2"><span class="f150">)</span></td> <td>²</td> +<td rowspan="2">+ <span class="f150">(</span></td> <td>∂z</td> +<td rowspan="2"><span class="f150">)</span></td> <td>²</td> +<td rowspan="2"><span class="f150">}</span>,</td></tr> +<tr><td class="denom">∂t</td> <td> </td> +<td class="denom">∂t</td> <td> </td> +<td class="denom">∂t</td> <td> </td></tr></table> +<div class="author">(5)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">α<span class="su">r</span> = Σm <span class="f150">{</span></td> <td>∂x</td> +<td rowspan="2"> </td> <td>∂x</td> +<td rowspan="2">+</td> <td>∂y</td> +<td rowspan="2"> </td> <td>∂y</td> +<td rowspan="2">+</td> <td>∂z</td> +<td rowspan="2"> </td> <td>∂z</td> +<td rowspan="2"><span class="f150">}</span>,</td></tr> +<tr><td class="denom">∂t</td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂t</td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂t</td> <td class="denom">∂q<span class="su">r</span></td></tr></table> + +<p class="noind">and the forms of A<span class="su">rr</span>, A<span class="su">rs</span> are as given by § 1 (7). It is to be remembered +that the coefficients α<span class="su">0</span>, α<span class="su">1</span>, α<span class="su">2</span>, ... A<span class="su">11</span>, A<span class="su">22</span>, ... A<span class="su">12</span> ... will in +general involve t explicitly as well as implicitly through the co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>,.... Again, we find</p> + +<p class="center">Σm (ẋδx + ẏδy + z˙δz) = (α<span class="su">1</span> + A<span class="su">11</span>q˙<span class="su">1</span> + A<span class="su">12</span>q˙<span class="su">2</span> + ...) δq<span class="su">1</span> + + (α<span class="su">2</span> + A<span class="su">21</span>q˙<span class="su">1</span> + A<span class="su">22</span>q˙<span class="su">2</span> + ...) ∂q<span class="su">2</span> + ...</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">=</td> <td>∂Τ</td> +<td rowspan="2">δq<span class="su">1</span> +</td> <td>∂Τ</td> +<td rowspan="2">δq<span class="su">2</span> + ... + = p<span class="su">1</span>δq<span class="su">1</span> + p<span class="su">2</span>δq<span class="su">2</span> + ...,</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">2</span></td></tr></table> +<div class="author">(6)</div> + +<p class="noind">where p<span class="su">r</span> is defined as in § 1 (13). The derivation of Lagrange’s +equations then follows exactly as before. It is to be noted that +the equation § 2 (15) does not as a rule now hold. The proof involved +the assumption that Τ is a homogeneous quadratic function +of the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>....</p> + +<p>It has been pointed out by R.B. Hayward that Vieille’s case can +be brought under Lagrange’s by introducing a new co-ordinate (χ) +in place of t, so far as it appears explicitly in the relations (1). We +have then</p> + +<p class="center">2Τ = α<span class="su">0</span>χ˙² + 2(α<span class="su">1</span>q˙<span class="su">1</span> + α<span class="su">2</span>q˙<span class="su">2</span> + ...) χ˙ + A<span class="su">11</span>q˙<span class="su">1</span>² + A<span class="su">22</span>q˙<span class="su">2</span>² + ... + 2A<span class="su">12</span>q˙<span class="su">1</span>q˙<span class="su">2</span> + ....</p> +<div class="author">(7)</div> + +<p class="noind">The equations of motion will be as in § 2 (10), with the additional +equation</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">−</td> +<td>∂Τ</td> <td rowspan="2">= X,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂χ˙</td> +<td class="denom">∂χ</td></tr></table> +<div class="author">(8)</div> + +<p class="noind">where X is the force corresponding to the co-ordinate χ. We may +suppose X to be adjusted so as to make χ¨ = 0, and in the remaining +equations nothing is altered if we write t for χ before, instead of +after, the differentiations. The reason why the equation § 2 (15) +no longer holds is that we should require to add a term Xχ˙ on the +right-hand side; this represents the rate at which work is being +done by the constraining forces required to keep χ˙ constant.</p> + +<p>As an example, let x, y, z be the co-ordinates of a particle relative +to axes fixed in a solid which is free to rotate about the axis of z. +If φ be the angular co-ordinate of the solid, we find without difficulty</p> + +<p class="center">2Τ = m (ẋ² + ẏ² +z˙²) + 2φ˙m (xẏ − yẋ) + {I + m (x² + y²)} φ˙²,</p> +<div class="author">(9)</div> + +<p class="noind">where I is the moment of inertia of the solid. The equations of +motion, viz.</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">−</td> +<td>∂Τ</td> <td rowspan="2">= X,  </td> +<td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">−</td> +<td>∂Τ</td> <td rowspan="2">= Y,  </td> +<td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">−</td> +<td>∂Τ</td> <td rowspan="2">= Z,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂ẋ</td> +<td class="denom">∂x</td> <td class="denom">dt</td> +<td class="denom">∂ẏ</td> <td class="denom">∂y</td> +<td class="denom">dt</td> <td class="denom">∂z˙</td> +<td class="denom">∂z</td></tr></table> +<div class="author">(10)</div> + +<p class="noind">and</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">−</td> +<td>∂Τ</td> <td rowspan="2">= Φ,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂φ˙</td> +<td class="denom">∂φ</td></tr></table> +<div class="author">(11)</div> + +<p class="noind">become</p> + +<p class="center">m (ẍ − 2φ˙ẏ − xφ˙² − yφ¨) = X, m (ÿ + 2φ˙ẋ − yφ˙² + xφ¨) = Y, mz¨ = Z,</p> +<div class="author">(12)</div> + +<p class="noind">and</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2">[{I + m (x² + y²)} φ˙ + m (xẏ − yẋ)] = Φ.</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(13)</div> + +<p class="noind">If we suppose Φ adjusted so as to maintain φ¨ = 0, or (again) if we +suppose the moment of inertia I to be infinitely great, we obtain +the familiar equations of motion relative to moving axes, viz.</p> + +<p class="center">m (ẍ − 2ωẏ − ω²x) = X, m (ÿ + 2ωẋ − ω²y) = Y, mz¨ = Z,</p> +<div class="author">(14)</div> + +<p class="noind">where ω has been written for φ. These are the equations which +we should have obtained by applying Lagrange’s rule at once to +the formula</p> + +<p class="center">2Τ = m (ẋ² + ẏ² + z˙²) + 2mω (xẏ − yẋ) + mω² (x² + y²),</p> +<div class="author">(15)</div> + +<p class="noind">which gives the kinetic energy of the particle referred to axes rotating +with the constant angular velocity ω. (See <span class="sc"><a href="#artlinks">Mechanics</a></span>, § 13.)</p> + +<p>More generally, let us suppose that we have a certain group of +co-ordinates χ, χ′, χ″, ... whose absolute values do not affect the +expression for the kinetic energy, and that by suitable forces of the +corresponding types the velocity-components χ˙, χ˙′, χ˙″, ... are maintained +constant. The remaining co-ordinates being denoted by +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>, we may write</p> + +<p class="center">2T = ⅋ + T<span class="su">0</span> + 2(α<span class="su">1</span>q˙<span class="su">1</span> + α<span class="su">2</span>q˙<span class="su">2</span> + ...) χ˙ + 2(α′<span class="su">1</span>q˙<span class="su">1</span> + α′<span class="su">2</span>q˙<span class="su">2</span> + ...) χ˙′ + ...,</p> +<div class="author">(16)</div> + +<p class="noind">where ⅋ is a homogeneous quadratic function of the velocities +q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">n</span> of the type § 1 (8), whilst Τ<span class="su">0</span> is a homogeneous quadratic +function of the velocities χ˙, χ˙′, χ˙″, ... alone. The remaining terms, +which are bilinear in respect of the two sets of velocities, are indicated +more fully. The formulae (10) of § 2 give n equations of +the type</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"><span class="f150">(</span></td> +<td>∂⅋</td> <td rowspan="2"><span class="f150">)</span> −</td> +<td>∂⅋</td> <td rowspan="2">+ (r, 1) q˙<span class="su">1</span> + (r, 2) q˙<span class="su">2</span> + ... −</td> +<td>∂T<span class="su">0</span></td> <td rowspan="2">= Q<span class="su">r</span></td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(17)</div> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">(r, s) = <span class="f150">(</span></td> <td>∂α<span class="su">r</span></td> +<td rowspan="2">−</td> <td>∂α<span class="su">s</span></td> +<td rowspan="2"><span class="f150">)</span>χ˙ + <span class="f150">(</span></td> <td>∂α′<span class="su">r</span></td> +<td rowspan="2">−</td> <td>∂α′<span class="su">s</span></td> +<td rowspan="2"><span class="f150">)</span>χ˙′ + ....</td></tr> +<tr><td class="denom">∂q<span class="su">s</span></td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂q<span class="su">s</span></td> <td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(18)</div> + +<p class="noind">These quantities (r, s) are subject to the relations</p> + +<p class="center">(r, s) = −(s, r), (r, r) = 0</p> +<div class="author">(19)</div> + +<p class="noind">The remaining dynamical equations, equal in number to the co-ordinates +χ, χ′, χ″, ..., yield expressions for the forces which +must be applied in order to maintain the velocities χ˙, χ˙′, χ˙″, ... +constant; they need not be written down. If we follow the method +by which the equation of energy was established in § 2, the equations +(17) lead, on taking account of the relations (19), to</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2">(⅋ − T<span class="su">0</span>) = Q<span class="su">1</span>q˙<span class="su">1</span> + Q<span class="su">2</span>q˙<span class="su">2</span> + ... + Q<span class="su">n</span>q˙<span class="su">n</span>,</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(20)</div> + +<p class="noind">or, in case the forces Q<span class="su">r</span> depend only on the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span> +and are conservative,</p> + +<p class="center">⅋ + V − T<span class="su">0</span> = const.</p> +<div class="author">(21)</div> + +<p>The conditions that the equations (17) should be satisfied by zero +values of the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">n</span> +are</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Q<span class="su">r</span> = −</td> <td>∂T<span class="su">0</span></td> +<td rowspan="2">,</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(22)</div> + +<p class="noind">or in the case of conservative forces</p> + +<table class="math0" summary="math"> +<tr><td>∂</td> <td rowspan="2">(V − T<span class="su">0</span>) = 0,</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(23)</div> + +<p class="noind"><i>i.e.</i> the value of V − Τ<span class="su">0</span> must be <i>stationary</i>.</p> + +<p>We may apply this to the case of a system whose configuration +relative to axes rotating with constant angular velocity (ω) +is defined by means of the n co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>. +<span class="sidenote">Rotating axes.</span> +This is important on account of its bearing on the kinetic +theory of the tides. Since the Cartesian co-ordinates +x, y, z of any particle m of the system relative to the moving axes +are functions of q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>, of the form § 1 (1), we have, by (15)</p> + +<p class="center">2⅋ = Σm (ẋ² + ẏ² + z˙²),   2Τ<span class="su">0</span> = ω²Σm (x² + y²),</p> +<div class="author">(24)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">α<span class="su">r</span> = Σm <span class="f150">(</span>x</td> <td>∂y</td> +<td rowspan="2">− y</td> <td>∂x</td> +<td rowspan="2"><span class="f150">)</span>,</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(25)</div> + +<p class="noind">whence</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">(r, s) = 2ω·Σm</td> <td>∂(x, y)</td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">∂(q<span class="su">s</span>, q<span class="su">r</span>)</td></tr></table> +<div class="author">(26)</div> + +<p class="noind">The conditions of relative equilibrium are given by (23).</p> + +<p>It will be noticed that this expression V − T<span class="su">0</span>, which is to be +stationary, differs from the true potential energy by a term which +represents the potential energy of the system in relation to fictitious +“centrifugal forces.” The question of stability of relative equilibrium +will be noticed later (§ 6).</p> + +<p>It should be observed that the remarkable formula (20) may in +the present case be obtained directly as follows. From (15) and +(14) we find</p> + +<table class="math0" summary="math"> +<tr><td>dT</td> <td rowspan="2">=</td> +<td>d</td> <td rowspan="2">(⅋ + T<span class="su">0</span>) + ω·Σm (xÿ − yẍ) =</td> +<td>d</td> <td rowspan="2">(⅋ − T<span class="su">0</span>) + ω·Σ (xY − yX).</td></tr> +<tr><td class="denom">dt</td> <td class="denom">dt</td> +<td class="denom">dt</td></tr></table> +<div class="author">(27)</div> + +<p><span class="pagenum"><a name="page759" id="page759"></a>759</span></p> + +<p class="noind">This must be equal to the rate at which the forces acting on the +system do work, viz. to</p> + +<p class="center">ωΣ (xY − yX) + Q<span class="su">1</span>q˙<span class="su">1</span> + Q<span class="su">2</span>q˙<span class="su">2</span> + ... + Q<span class="su">n</span>q˙<span class="su">n</span>,</p> + +<p class="noind">where the first term represents the work done in virtue of the +rotation.</p> + +<p>We have still to notice the modifications which Lagrange’s +equations undergo when the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span> +<span class="sidenote">Constrained systems.</span> +are not all independently variable. In the first place, +we may suppose them connected by a number m (< n) +of relations of the type</p> + +<p class="center">A (t, q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>) = 0,   B (t, q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>) = 0, &c.</p> +<div class="author">(28)</div> + +<p class="noind">These may be interpreted as introducing partial constraints into +a previously free system. The variations δq<span class="su">1</span>, δq<span class="su">2</span>, ... δq<span class="su">n</span> in the expressions +(6) and (7) of § 2 which are to be equated are no longer +independent, but are subject to the relations</p> + +<table class="math0" summary="math"> +<tr><td>∂A</td> <td rowspan="2">δq<span class="su">1</span> +</td> +<td>∂A</td> <td rowspan="2">δq<span class="su">2</span> + ... = 0,  </td> +<td>∂B</td> <td rowspan="2">δq<span class="su">1</span> +</td> +<td>∂B</td> <td rowspan="2">δq<span class="su">2</span> + ... = 0, &c.</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td> +<td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(29)</div> + +<p class="noind">Introducing indeterminate multipliers λ, μ, ..., one for each of these +equations, we obtain in the usual manner n equations of the type</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂T</td> <td rowspan="2">−</td> +<td>∂T</td> <td rowspan="2">= Q<span class="su">r</span> + λ</td> +<td>∂A</td> <td rowspan="2">+ μ</td> +<td>∂B</td> <td rowspan="2">+ ...,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom"> ∂q<span class="su">r</span></td></tr></table> +<div class="author">(30)</div> + +<p class="noind">in place of § 2 (10). These equations, together with (28), serve +to determine the n co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span> and the m multipliers +λ, μ, ....</p> + +<p>When t does not occur explicitly in the relations (28) the system +is said to be <i>holonomic</i>. The term connotes the existence of integral +(as opposed to differential) relations between the co-ordinates, +independent of the time.</p> + +<p>Again, it may happen that although there are no prescribed +relations between the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>, yet from the circumstances +of the problem certain geometrical conditions are imposed +on their <i>variations</i>, thus</p> + +<p class="center">A<span class="su">1</span>δq<span class="su">1</span> + A<span class="su">2</span>δq<span class="su">2</span> + ... = 0,   B<span class="su">1</span>δq<span class="su">1</span> + B<span class="su">2</span>δq<span class="su">2</span> + ... = 0, &c.,</p> +<div class="author">(31)</div> + +<p class="noind">where the coefficients are functions of q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span> and (possibly) of t. +It is assumed that these equations are not integrable as regards the +variables q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>; otherwise, we fall back on the previous conditions. +Cases of the present type arise, for instance, in ordinary +dynamics when we have a solid rolling on a (fixed or moving) surface. +The six co-ordinates which serve to specify the position of the solid +at any instant are not subject to any necessary relation, but the +conditions to be satisfied at the point of contact impose three conditions +of the form (31). The general equations of motion are +obtained, as before, by the method of indeterminate multipliers, +thus</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂T</td> <td rowspan="2">−</td> +<td>∂T</td> <td rowspan="2">= Q<span class="su">r</span> + λA<span class="su">r</span> + μB<span class="su">r</span> + ...</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(32)</div> + +<p class="noind">The co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">n</span>, and the indeterminate multipliers +λ, μ, ..., are determined by these equations and by the velocity-conditions +corresponding to (31). When t does not appear explicitly +in the coefficients, these velocity-conditions take the forms</p> + +<p class="center">A<span class="su">1</span>q˙<span class="su">1</span> + A<span class="su">2</span>q˙<span class="su">2</span> + ... = 0,   B<span class="su">1</span>q˙<span class="su">1</span> + B<span class="su">2</span>q˙<span class="su">2</span> + ... = 0, &c.</p> +<div class="author">(33)</div> + +<p class="noind">Systems of this kind, where the relations (31) are not integrable, are +called <i>non-holonomic</i>.</p> + +<p class="pt2 center">4. <i>Hamiltonian Equations of Motion.</i></p> + +<p>In the Hamiltonian form of the equations of motion of a conservative +system with unvarying relations, the kinetic energy is +supposed expressed in terms of the momenta p<span class="su">1</span>, p<span class="su">2</span>, ... and the co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>, ..., as in § 1 (19). Since the symbol δ now denotes +a variation extending to the co-ordinates as well as to the momenta, +we must add to the last member of § 1 (21) terms of the types</p> + +<table class="math0" summary="math"> +<tr><td>∂T</td> <td rowspan="2">δq<span class="su">1</span> +</td> +<td>∂T`</td> <td rowspan="2">δq<span class="su">2</span> + ....</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(1)</div> + +<p class="noind">Since the variations δp<span class="su">1</span>, δp<span class="su">2</span>, ... δq<span class="su">1</span>, δq<span class="su">2</span>, ... may be taken to be independent, +we infer the equations § 1 (23) as before, together with</p> + +<table class="math0" summary="math"> +<tr><td>∂T</td> <td rowspan="2">= −</td> +<td>∂T`</td> <td rowspan="2">,   </td> +<td>∂T</td> <td rowspan="2">= −</td> +<td>∂T`</td> <td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(2)</div> + +<p class="noind">Hence the Lagrangian equations § 2 (14) transform into</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ṗ<span class="su">1</span> = −</td> <td>∂</td> +<td rowspan="2">(T` + V),   ṗ<span class="su">2</span> = −</td> <td>∂</td> +<td rowspan="2">(T` + V), ...</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(3)</div> + +<p class="noind">If we write</p> + +<p class="center">H = T` + V,</p> +<div class="author">(4)</div> + +<p class="noind">so that H denotes the <i>total energy</i> of the system, supposed expressed +in terms of the new variables, we get</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ṗ<span class="su">1</span> = −</td> <td>∂H</td> +<td rowspan="2">,   ṗ<span class="su">2</span> = −</td> <td>∂H</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(5)</div> + +<p class="noind">If to these we join the equations</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">q˙<span class="su">1</span> =</td> <td>∂H</td> +<td rowspan="2">,   q˙<span class="su">2</span> =</td> <td>∂H</td> +<td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂p<span class="su">1</span></td> <td class="denom">∂p<span class="su">2</span></td></tr></table> +<div class="author">(6)</div> + +<p class="noind">which follow at once from § 1 (23), since V does not involve p<span class="su">1</span>, p<span class="su">2</span>, ..., +we obtain a complete system of differential equations <i>of the first +order</i> for the determination of the motion.</p> + +<p>The equation of energy is verified immediately by (5) and (6), +since these make</p> + +<table class="math0" summary="math"> +<tr><td>dH</td> <td rowspan="2">=</td> +<td>∂H</td> <td rowspan="2">ṗ<span class="su">1</span> +</td> +<td>∂H</td> <td rowspan="2">ṗ<span class="su">2</span> + ... +</td> +<td>∂H</td> <td rowspan="2">q˙<span class="su">1</span> +</td> +<td>∂H</td> <td rowspan="2">q˙<span class="su">2</span> + ... = 0.</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂p<span class="su">1</span></td> +<td class="denom">∂p<span class="su">2</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(7)</div> + +<p>The Hamiltonian transformation is extended to the case of +varying relations as follows. Instead of (4) we write</p> + +<p class="center">H = p<span class="su">1</span>q˙<span class="su">1</span> + p<span class="su">2</span>q˙<span class="su">2</span> + ... − T + V,</p> +<div class="author">(8)</div> + +<p class="noind">and imagine H to be expressed in terms of the momenta p<span class="su">1</span>, p<span class="su">2</span>, ..., +the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ..., and the time. The internal forces of +the system are assumed to be conservative, with the potential +energy V. Performing the variation δ on both sides, we find</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">δH = q˙<span class="su">1</span>δp<span class="su">1</span> + ... −</td> <td>∂T</td> +<td rowspan="2">δq<span class="su">1</span> +</td> <td>∂V</td> +<td rowspan="2">δq + ...,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td></tr></table> +<div class="author">(9)</div> + +<p class="noind">terms which cancel in virtue of the definition of p<span class="su">1</span>, p<span class="su">2</span>, ... being +omitted. Since δp<span class="su">1</span>, δp<span class="su">2</span>, ..., δq<span class="su">1</span>, δq<span class="su">2</span>, ... may be taken to be independent, +we infer</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">q˙<span class="su">1</span> =</td> <td>∂H</td> +<td rowspan="2">,   q˙<span class="su">2</span> =</td> <td>∂H</td> +<td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂p<span class="su">1</span></td> <td class="denom">∂p<span class="su">2</span></td></tr></table> +<div class="author">(10)</div> + +<p class="noind">and</p> + +<table class="math0" summary="math"> +<tr><td>∂</td> <td rowspan="2">(T − V) = −</td> +<td>∂H</td> <td rowspan="2">,  </td> +<td>∂</td> <td rowspan="2">(T − V) = −</td> +<td>∂H</td> <td rowspan="2">, ....</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(11)</div> + +<p class="noind">It follows from (11) that</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">ṗ<span class="su">1</span> = −</td> <td>∂H</td> +<td rowspan="2">,   ṗ<span class="su">2</span> = −</td> <td>∂H</td> +<td rowspan="2">, ....</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(12)</div> + +<p class="noind">The equations (10) and (12) have the same form as above, but H +is no longer equal to the energy of the system.</p> + +<p class="pt2 center">5. <i>Cyclic Systems.</i></p> + +<p>A <i>cyclic</i> or <i>gyrostatic</i> system is characterized by the following +properties. In the first place, the kinetic energy is not affected if +we alter the absolute values of certain of the co-ordinates, which +we will denote by χ, χ′, χ″, ..., provided the remaining co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span> and the velocities, including of course the velocities +χ˙, χ˙′, χ˙″, ..., are unaltered. Secondly, there are no forces acting +on the system of the types χ, χ′, χ″, .... This case arises, for example, +when the system includes gyrostats which are free to rotate about +their axes, the co-ordinates χ, χ′, χ″, ... then being the angular co-ordinates +of the gyrostats relatively to their frames. Again, in +theoretical hydrodynamics we have the problem of moving solids +in a frictionless liquid; the ignored co-ordinates χ, χ′, χ″, ... then refer +to the fluid, and are infinite in number. The same question presents +itself in various physical speculations where certain phenomena are +ascribed to the existence of <i>latent motions</i> in the ultimate constituents +of matter. The general theory of such systems has been treated by +E.J. Routh, Lord Kelvin, and H.L.F. Helmholtz.</p> + +<p>If we suppose the kinetic energy Τ to be expressed, as in +Lagrange’s method, in terms of the co-ordinates and +<span class="sidenote">Routh’s equations.</span> +the velocities, the equations of motion corresponding +to χ, χ′, χ″, ... reduce, in virtue of the above hypotheses, +to the forms</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">= 0,   </td> +<td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">= 0,   </td> +<td>d</td> <td rowspan="2"> </td> +<td>∂Τ</td> <td rowspan="2">= 0, ...,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂χ˙</td> +<td class="denom">dt</td> <td class="denom">∂χ˙′</td> +<td class="denom">dt</td> <td class="denom">∂χ˙″</td></tr></table> +<div class="author">(1)</div> + +<p class="noind">whence</p> + +<table class="math0" summary="math"> +<tr><td>∂Τ</td> <td rowspan="2">= κ,  </td> +<td>∂Τ</td> <td rowspan="2">= κ′,  </td> +<td>∂Τ</td> <td rowspan="2">= κ″, ...,</td></tr> +<tr><td class="denom">∂χ˙</td> <td class="denom">∂χ˙′</td> +<td class="denom">∂χ˙″</td></tr></table> +<div class="author">(2)</div> + +<p class="noind">where κ, κ′, κ″, ... are the constant momenta corresponding to the +cyclic co-ordinates χ, χ′, χ″, .... These equations are linear in +χ˙, χ˙′, χ˙″, ...; solving them with respect to these quantities and +substituting in the remaining Lagrangian equations, we obtain +m differential equations to determine the remaining co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>. The object of the present investigation is to ascertain +the general form of the resulting equations. The retained co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span> may be called (for distinction) the <i>palpable</i> +co-ordinates of the system; in many practical questions they are +the only co-ordinates directly in evidence.</p> + +<p>If, as in § 1 (25), we write</p> + +<p class="center">R = T − κχ˙ − κ′χ˙′ − κ″χ˙″ − ...,</p> +<div class="author">(3)</div> + +<p class="noind">and imagine R to be expressed by means of (2) as a quadratic function +of q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, κ, κ′, κ″, ... with coefficients which are in general +functions of the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>, then, performing the +operation δ on both sides, we find</p> + +<table class="math0" summary="math"> +<tr><td>∂R</td> <td rowspan="2">δq˙<span class="su">1</span> + ... +</td> +<td>∂R</td> <td rowspan="2">δκ + ... +</td> +<td>∂R</td> <td rowspan="2">δq<span class="su">1</span> + ... =</td> +<td>∂T</td> <td rowspan="2">δq˙<span class="su">1</span> + ... +</td> +<td>∂T</td> <td rowspan="2">δq<span class="su">1</span> + ...</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂κ</td> +<td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">1</span></td> +<td class="denom">∂q<span class="su">1</span></td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">+</td> <td>∂T</td> +<td rowspan="2">δχ˙ + ... +</td> <td>∂T</td> +<td rowspan="2">δq<span class="su">1</span> + ... − κδχ˙ − χ˙δκ − ....</td></tr> +<tr><td class="denom">∂χ˙</td> <td class="denom">∂χ<span class="su">1</span></td></tr></table> +<div class="author">(4)</div> + +<p><span class="pagenum"><a name="page760" id="page760"></a>760</span></p> + +<p class="noind">Omitting the terms which cancel by (2), we find</p> + +<table class="math0" summary="math"> +<tr><td>∂T</td> <td rowspan="2">=</td> +<td>∂R</td> <td rowspan="2">,   </td> +<td>∂T</td> <td rowspan="2">=</td> +<td>∂R</td> <td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q˙<span class="su">1</span></td> +<td class="denom">∂q˙<span class="su">2</span></td> <td class="denom">∂q˙<span class="su">2</span></td></tr></table> +<div class="author">(5)</div> + +<table class="math0" summary="math"> +<tr><td>∂T</td> <td rowspan="2">=</td> +<td>∂R</td> <td rowspan="2">,   </td> +<td>∂T</td> <td rowspan="2">=</td> +<td>∂R</td> <td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(6)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">χ˙ = −</td> <td>∂R</td> +<td rowspan="2">,   χ˙′ = −</td> <td>∂R</td> +<td rowspan="2">,   χ˙″ = −</td> <td>∂R</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂κ</td> <td class="denom">∂κ′</td> +<td class="denom">∂κ″</td></tr></table> +<div class="author">(7)</div> + +<p>Substituting in § 2 (10), we have</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂R</td> <td rowspan="2">−</td> +<td>∂R</td> <td rowspan="2">= Q<span class="su">1</span>,   </td> +<td>d</td> <td rowspan="2"> </td> +<td>∂R</td> <td rowspan="2">−</td> +<td>∂R</td> <td rowspan="2">= Q<span class="su">2</span>, ...</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">1</span></td> +<td class="denom">∂q<span class="su">1</span></td> <td class="denom">dt</td> +<td class="denom">∂q˙<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(8)</div> + +<p class="noind">These are Routh’s forms of the modified Lagrangian equations. +Equivalent forms were obtained independently by Helmholtz at a +later date.</p> + +<p>The function R is made up of three parts, thus</p> + +<p class="center">R = R<span class="su">2, 0</span> + R<span class="su">1, 1</span> + R<span class="su">0, 2</span>, ...</p> +<div class="author">(9)</div> + +<p>where R<span class="su">2, 0</span> is a homogeneous quadratic function of q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span>, R<span class="su">0, 2</span> is +<span class="sidenote">Kelvin’s equations.</span> +a homogeneous quadratic function of κ, κ′, κ″, ..., whilst +R<span class="su">1, 1</span> consists of products of the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span> into +the momenta κ, κ′, κ″.... Hence from (3) and (7) we +have</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">T = R − <span class="f150">(</span>κ</td> <td>∂R</td> +<td rowspan="2">+ κ′</td> <td>∂R</td> +<td rowspan="2">+ κ″</td> <td>∂R</td> +<td rowspan="2">+ ...<span class="f150">)</span> = R<span class="su">2, 0</span> − R<span class="su">0, 2</span>.</td></tr> +<tr><td class="denom">∂κ</td> <td class="denom">∂κ′</td> +<td class="denom">∂κ″</td></tr></table> +<div class="author">(10)</div> + +<p>If, as in § 1 (30), we write this in the form</p> + +<p class="center">Τ = ⅋ + K,</p> +<div class="author">(11)</div> + +<p class="noind">then (3) may be written</p> + +<p class="center">R = ⅋ − K + β<span class="su">1</span>q˙<span class="su">1</span> + β<span class="su">2</span>q˙<span class="su">2</span> + ...,</p> +<div class="author">(12)</div> + +<p class="noind">where β<span class="su">1</span>, β<span class="su">2</span>, ... are linear functions of κ, κ′, κ″, ..., say</p> + +<p class="center">β<span class="su">r</span> = α<span class="su">r</span>κ + α′<span class="su">r</span>κ′ + α″<span class="su">r</span>κ″ + ...,</p> +<div class="author">(13)</div> + +<p class="noind">the coefficients α<span class="su">r</span>, α′<span class="su">r</span>, α″<span class="su">r</span>, ... being in general functions of the co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>. Evidently β<span class="su">r</span> denotes that part of the momentum-component +∂R / ∂q˙<span class="su">r</span> which is due to the cyclic motions. Now</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂R</td> <td rowspan="2">=</td> +<td>d</td> <td rowspan="2"><span class="f150">(</span></td> +<td>∂⅋</td> <td rowspan="2">+ β<span class="su">r</span><span class="f150">)</span> =</td> +<td>d</td> <td rowspan="2"> </td> +<td>∂⅋</td> <td rowspan="2">+</td> +<td>∂β<span class="su">r</span></td> <td rowspan="2">q˙<span class="su">1</span> +</td> +<td>∂β<span class="su">r</span></td> <td rowspan="2">q˙<span class="su">2</span>+ ...,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(14)</div> + +<table class="math0" summary="math"> +<tr><td>∂R</td> <td rowspan="2">=</td> +<td>∂⅋</td> <td rowspan="2">−</td> +<td>∂K</td> <td rowspan="2">+</td> +<td>∂β<span class="su">1</span></td> <td rowspan="2">q˙<span class="su">1</span> +</td> +<td>∂β<span class="su">2</span></td> <td rowspan="2">q˙<span class="su">2</span> + ....</td></tr> +<tr><td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(15)</div> + +<p class="noind">Hence, substituting in (8), we obtain the typical equation of motion +of a gyrostatic system in the form</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂⅋</td> <td rowspan="2">−</td> +<td>∂⅋</td> <td rowspan="2">+ (r, 1) q˙<span class="su">1</span> + (r, 2) q˙<span class="su">2</span> + ... + (r, s) q˙<span class="su">s</span> + ... +</td> +<td>∂K</td> <td rowspan="2">= Q<span class="su">r</span>,</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td> <td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(16)</div> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">(r, s) =</td> <td>∂β<span class="su">r</span></td> +<td rowspan="2">−</td> <td>∂β<span class="su">s</span></td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">∂q<span class="su">s</span></td> <td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(17)</div> + +<p>This form is due to Lord Kelvin. When q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span> have been +determined, as functions of the time, the velocities corresponding +to the cyclic co-ordinates can be found, if required, from the relations +(7), which may be written</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">χ˙ =</td> <td>∂K</td> +<td rowspan="2">− α<span class="su">1</span>q˙<span class="su">1</span> − α<span class="su">2</span>q˙<span class="su">2</span> − ...,</td></tr> +<tr><td class="denom">∂κ</td></tr></table> +<div class="author">(18)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">χ˙′ =</td> <td>∂K</td> +<td rowspan="2">− α′<span class="su">1</span>q˙<span class="su">1</span> − α′<span class="su">2</span>q˙<span class="su">2</span> − ...,</td></tr> +<tr><td class="denom">∂κ′</td></tr></table> + +<p class="center">&c., &c.</p> + +<p>It is to be particularly noticed that</p> + +<p class="center">(r, r) = 0, (r, s) = −(s, r).</p> +<div class="author">(19)</div> + +<p class="noind">Hence, if in (16) we put r = 1, 2, 3, ... m, and multiply by q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">m</span> +respectively, and add, we find</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2">(⅋ + K) = Q<span class="su">1</span>q˙<span class="su">1</span> + Q<span class="su">2</span>q˙<span class="su">2</span> + ...,</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(20)</div> + +<p class="noind">or, in the case of a conservative system</p> + +<p class="center">⅋ + V + K = const.,</p> +<div class="author">(21)</div> + +<p class="noind">which is the equation of energy.</p> + +<p>The equation (16) includes § 3 (17) as a particular case, the +eliminated co-ordinate being the angular co-ordinate of a rotating +solid having an infinite moment of inertia.</p> + +<p>In the particular case where the cyclic momenta κ, κ′, κ″, ... are +all zero, (16) reduces to</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2"> </td> +<td>∂⅋</td> <td rowspan="2">−</td> +<td>∂⅋</td> <td rowspan="2">= Q<span class="su">r</span>.</td></tr> +<tr><td class="denom">dt</td> <td class="denom">∂q˙<span class="su">r</span></td> +<td class="denom">∂q<span class="su">r</span></td></tr></table> +<div class="author">(22)</div> + +<p class="noind">The form is the same as in § 2, and the system now behaves, as +regards the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>, exactly like the acyclic type +there contemplated. These co-ordinates do not, however, now +fix the position of every particle of the system. For example, if +by suitable forces the system be brought back to its initial configuration +(so far as this is defined by q<span class="su">1</span>, q<span class="su">2</span>, ..., q<span class="su">m</span>), after performing +any evolutions, the ignored co-ordinates χ, χ′, χ″, ... will not in +general return to their original values.</p> + +<p>If in Lagrange’s equations § 2 (10) we reverse the sign of the time-element +dt, the equations are unaltered. The motion is therefore +reversible; that is to say, if as the system is passing through any +configuration its velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>, ..., q˙<span class="su">m</span> be all reversed, it will (if the +forces be the same in the same configuration) retrace its former +path. But it is important to observe that the statement does not +in general hold of a gyrostatic system; the terms of (16), which are +linear in q˙<span class="su">1</span>, q˙<span class="su">2</span>, ..., q˙<span class="su">m</span>, change sign with dt, whilst the others do not. +Hence the motion of a gyrostatic system is not reversible, unless +indeed we reverse the cyclic motions as well as the velocities +q˙<span class="su">1</span>, q˙<span class="su">2</span>, ..., q˙<span class="su">m</span>. For instance, the precessional motion of a top cannot +be reversed unless we reverse the spin.</p> + +<p>The <i>conditions of equilibrium</i> of a system with latent cyclic motions +<span class="sidenote">Kineto-statics.</span> +are obtained by putting q˙<span class="su">1</span> = 0, q˙<span class="su">2</span> = 0, ... q˙<span class="su">m</span> = 0 in (16); +viz. they are</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Q<span class="su">1</span> =</td> <td>∂K</td> +<td rowspan="2">,   Q<span class="su">2</span> =</td> <td>∂K</td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(23)</div> + +<p class="noind">These may of course be obtained independently. Thus if the system +be guided from (apparent) rest in the configuration (q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>) +to rest in the configuration q<span class="su">1</span> + δq<span class="su">1</span>, q<span class="su">2</span> + δq<span class="su">2</span>, ..., q<span class="su">m</span> + δq<span class="su">m</span>, the work +done by the forces must be equal to the increment of the kinetic +energy. Hence</p> + +<p class="center">Q<span class="su">1</span>δq<span class="su">1</span> + Q<span class="su">2</span>δq<span class="su">2</span> + ... = δK,</p> +<div class="author">(24)</div> + +<p class="noind">which is equivalent to (23). The conditions are the same as for +the equilibrium of a system without latent motion, but endowed +with potential energy K. This is important from a physical point +of view, as showing how energy which is apparently potential may +in its ultimate essence be kinetic.</p> + +<p>By means of the formulae (18), which now reduce to</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">χ˙ =</td> <td>∂K</td> +<td rowspan="2">,   χ˙′ =</td> <td>∂K</td> +<td rowspan="2">,   χ˙″ =</td> <td>∂K</td> +<td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂κ</td> <td class="denom">∂κ′</td> +<td class="denom">∂κ″</td></tr></table> +<div class="author">(25)</div> + +<p class="noind">K may also be expressed as a homogeneous quadratic function of +the cyclic velocities χ˙, χ˙′, χ˙″,... Denoting it in this form by Τ<span class="su">0</span>, +we have</p> + +<p class="center">δ (T<span class="su">0</span> + K) = 2δK = δ (κχ˙ + κ′χ˙′ + κ″χ˙″ + ...)</p> +<div class="author">(26)</div> + +<p class="noind">Performing the variations, and omitting the terms which cancel by +(2) and (25), we find</p> + +<table class="math0" summary="math"> +<tr><td>∂Τ<span class="su">0</span></td> <td rowspan="2">= −</td> +<td>∂K</td> <td rowspan="2">,   </td> +<td>∂Τ<span class="su">0</span></td> <td rowspan="2">= −</td> +<td>∂K</td> <td rowspan="2">, ...,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(27)</div> + +<p class="noind">so that the formulae (23) become</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Q<span class="su">1</span> = −</td> <td>∂Τ<span class="su">0</span></td> +<td rowspan="2">,   Q<span class="su">2</span> = −</td> <td>∂Τ<span class="su">0</span></td> +<td rowspan="2">, ...</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(28)</div> + +<p>A simple example is furnished by the top (<span class="sc"><a href="#artlinks">Mechanics</a></span>, § 22). The +cyclic co-ordinates being ψ, φ, we find</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">2⅋ = Aθ˙²,   2K =</td> <td>(μ − ν cos θ)²</td> +<td rowspan="2">+</td> <td>ν²</td> +<td rowspan="2">,</td></tr> +<tr><td class="denom">A sin² θ</td> <td class="denom">C</td></tr></table> + +<p class="center">2Τ<span class="su">0</span> = A sin² θψ˙² + C (φ˙ + ψ cos θ)²,</p> +<div class="author">(29)</div> + +<p class="noind">whence we may verify that ∂Τ<span class="su">0</span> / ∂θ = −∂K / ∂θ in accordance with +(27). And the condition of equilibrium</p> + +<table class="math0" summary="math"> +<tr><td>∂K</td> <td rowspan="2">= −</td> +<td>∂V</td></tr> +<tr><td class="denom">∂θ</td> <td class="denom">∂θ</td></tr></table> +<div class="author">(30)</div> + +<p class="noind">gives the condition of steady precession.</p> + +<p class="pt2 center">6. <i>Stability of Steady Motion.</i></p> + +<p>The small oscillations of a conservative system about a configuration +of equilibrium, and the criterion of stability, are discussed +in <span class="sc"><a href="#artlinks">Mechanics</a></span>, § 23. The question of the stability of given types of +motion is more difficult, owing to the want of a sufficiently general, +and at the same time precise, definition of what we mean by +“stability.” A number of definitions which have been propounded by +different writers are examined by F. Klein and A. Sommerfeld in their +work <i>Über die Theorie des Kreisels</i> (1897-1903). Rejecting previous +definitions, they base their criterion of stability on the character +of the changes produced in the <i>path</i> of the system by small arbitrary +disturbing impulses. If the undisturbed path be the <i>limiting form</i> +of the disturbed path when the impulses are indefinitely diminished, +it is said to be stable, but not otherwise. For instance, the vertical +fall of a particle under gravity is reckoned as stable, although for a +<i>given</i> impulsive disturbance, however small, the deviation of the +particle’s position at any time t from the position which it would have +occupied in the original motion increases indefinitely with t. Even +this criterion, as the writers quoted themselves recognize, is not free +from ambiguity unless the phrase “limiting form,” as applied to a +path, be strictly defined. It appears, moreover, that a definition +which is analytically precise may not in all cases be easy to reconcile +with geometrical prepossessions. Thus a particle moving in a circle +about a centre of force varying inversely as the cube of the distance +will if slightly disturbed either fall into the centre, or recede to infinity, +after describing in either case a spiral with an infinite number of +<span class="pagenum"><a name="page761" id="page761"></a>761</span> +convolutions. Each of these spirals has, analytically, the circle as +its limiting form, although the motion in the circle is most naturally +described as unstable.</p> + +<p>A special form of the problem, of great interest, presents itself in +the steady motion of a gyrostatic system, when the non-eliminated +co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span> all vanish (see § 5). This has been discussed +by Routh, Lord Kelvin and Tait, and Poincaré. These +writers treat the question, by an extension of Lagrange’s method, +as a problem of small oscillations. Whether we adopt the notion +of stability which this implies, or take up the position of Klein and +Sommerfeld, there is no difficulty in showing that stability is ensured +if V + K be a minimum as regards variations of q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>. The +proof is the same as that of Dirichlet for the case of statical stability.</p> + +<p>We can illustrate this condition from the case of the top, where, +in our previous notation,</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">V + K = Mgh cos θ +</td> <td>(μ − νcos θ)²</td> +<td rowspan="2">+</td> <td>ν²</td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">2A sin² θ</td> <td class="denom">2C</td></tr></table> +<div class="author">(1)</div> + +<p class="noind">To examine whether the steady motion with the centre of gravity +vertically above the pivot is stable, we must put μ = ν. We then +find without difficulty that V + K is a minimum provided ν² ≥ 4AMgh. +The method of small oscillations gave us the condition ν² > 4AMgh, +and indicated instability in the cases ν² ≤ 4AMgh. The present +criterion can also be applied to show that the steady precessional +motions in which the axis has a constant inclination to the vertical +are stable.</p> + +<p>The question remains, as before, whether it is <i>essential</i> for stability +that V + K should be a minimum. It appears that from the point +of view of the theory of small oscillations it is not essential, and +that there may even be stability when V + K is a maximum. The +precise conditions, which are of a somewhat elaborate character, +have been formulated by Routh. An important distinction has, +however, been established by Thomson and Tait, and by Poincaré, +between what we may call <i>ordinary</i> or <i>temporary</i> stability (which +is stability in the above sense) and <i>permanent</i> or <i>secular</i> stability, +which means stability when regard is had to possible dissipative +forces called into play whenever the co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span> vary. +Since the total energy of the system at any instant is given (in +the notation of § 5) by an expression of the form ⅋ + V + K, where +⅋ cannot be negative, the argument of Thomson and Tait, given +under <span class="sc"><a href="#artlinks">Mechanics</a></span>, § 23, for the statical question, shows that it is a +necessary as well as a sufficient condition for secular stability that +V + K should be a minimum. When a system is “ordinarily” +stable, but “secularly” unstable, the operation of the frictional +forces is to induce a gradual increase in the amplitude of the free +vibrations which are called into play by accidental disturbances.</p> + +<p>There is a similar theory in relation to the constrained systems +considered in § 3 above. The equation (21) there given leads to +the conclusion that for secular stability of any type of motion in +which the velocities q˙<span class="su">1</span>, q˙<span class="su">2</span>, ... q˙<span class="su">n</span> are zero it is necessary and sufficient +that the function V − Τ<span class="su">0</span> should be a minimum.</p> + +<p>The simplest possible example of this is the case of a particle at +the lowest point of a smooth spherical bowl which rotates with +constant angular velocity (ω) about the vertical diameter. This +position obviously possesses “ordinary” stability. If a be the +radius of the bowl, and θ denote angular distance from the lowest +point, we have</p> + +<p class="center">V − Τ<span class="su">0</span> = mga(1 − cos θ) − ½mω²a² sin² θ;</p> +<div class="author">(2)</div> + +<p class="noind">this is a minimum for θ = 0 only so long as ω² < g/a. For greater +values of ω the only position of “permanent” stability is that in +which the particle rotates with the bowl at an angular distance +cos<span class="sp">−1</span> (g/ω²a) from the lowest point. To examine the motion in the +neighbourhood of the lowest point, when frictional forces are taken +into account, we may take fixed ones, in a horizontal plane, through +the lowest point. Assuming that the friction varies as the relative +velocity, we have</p> + +<p class="center"> +ẍ = −p²x − k (ẋ + ωy),<br /> +ÿ = −p²y − k (ẏ − ωx),</p> +<div class="author">(3)</div> + +<p class="noind">where p² = g/a. These combine into</p> + +<p class="center">z¨ + kz˙ + (p² − ikω) z = 0,</p> +<div class="author">(4)</div> + +<p class="noind">where z = x + iy, i = √−1. Assuming z = Ce<span class="sp">λt</span>, we find</p> + +<p class="center">λ = −½k(1 ∓ ω/p) ± ip,</p> +<div class="author">(5)</div> + +<p class="noind">if the square of k be neglected. The complete solution is then</p> + +<p class="center">x + iy = C<span class="su">1</span>e<span class="sp">−β1t</span> e<span class="sp">ipt</span> + + + C<span class="su">2</span>e<span class="sp">−β2t</span> e<span class="sp">−ipt</span>,</p> +<div class="author">(6)</div> + +<p class="noind">where</p> + +<p class="center">β<span class="su">1</span> = ½k (1 − ω/p),   β<span class="su">2</span> = ½k (1 + ω/p).</p> +<div class="author">(7)</div> + +<p class="noind">This represents two superposed circular vibrations, in opposite +directions, of period 2π/p. If ω < p, the amplitude of each of these +diminishes asymptotically to zero, and the position x = 0, y = 0 is +permanently stable. But if ω > p the amplitude of that circular +vibration which agrees in sense with the rotation ω will continually +increase, and the particle will work its way in an ever-widening +spiral path towards the eccentric position of secular stability. If +the bowl be not spherical but ellipsoidal, the vertical diameter being +a principal axis, it may easily be shown that the lowest position is +permanently stable only so long as the period of the rotation is +longer than that of the slower of the two normal modes in the +absence of rotation (see <span class="sc"><a href="#artlinks">Mechanics</a></span>, § 13).</p> + +<p class="pt2 center">7. <i>Principle of Least Action.</i></p> + +<p>The preceding theories give us statements applicable to the system +at any one instant of its motion. We now come to a series of +theorems relating to the whole motion of the system +between any two configurations through which it passes, +<span class="sidenote">Stationary Action.</span> +viz. we consider the actual motion and compare it with +other imaginable motions, differing infinitely little from it, between +the same two configurations. We use the symbol δ to denote the +transition from the actual to any one of the hypothetical motions.</p> + +<p>The best-known theorem of this class is that of <i>Least Action</i>, +originated by P.L.M. de Maupertuis, but first put in a definite form +by Lagrange. The “action” of a single particle in passing from +one position to another is the space-integral of the momentum, or +the time-integral of the <i>vis viva</i>. The action of a dynamical system +is the sum of the actions of its constituent particles, and is accordingly +given by the formula</p> + +<p class="center">A = Σ <span class="f150">∫</span> mvds = Σ <span class="f150">∫</span> mv²dt = 2 <span class="f150">∫</span> Τdt.</p> +<div class="author">(1)</div> + +<p class="noind">The theorem referred to asserts that the free motion of a conservative +system between any two given configurations is characterized +by the property</p> + +<p class="center">δA = 0,</p> +<div class="author">(2)</div> + +<p class="noind">provided the total energy have the same constant value in the +varied motion as in the actual motion.</p> + +<p>If t, t′ be the times of passing through the initial and final configurations +respectively, we have</p> + +<p class="center">δA = δ <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> + Σm (ẋ² + ẏ² + z˙²) dt</p> + +<p class="center">= <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> δΤdt + 2Τ′δt′ + 2Τδt,</p> +<div class="author">(3)</div> + +<p class="noind">since the upper and lower limits of the integral must both be regarded +as variable. This may be written</p> + +<p class="center">δA = <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> δΤdt + + <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> Σm (ẋδẋ + ẏδẏ + z˙δz˙) dt + 2Τ′δt′ − 2Τδt</p> + +<p class="center">= <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> δΤdt + <span class="f150">[</span> Σm (ẋδx + ẏδy + z˙δz)<span class="f150">]</span><span class="sp1">t′</span><span class="su2">t</span></p> + +<p class="center">− <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> Σm (ẍδx + ÿδy + z¨δz) dt + 2Τ′δt′ − 2Τδt.</p> +<div class="author">(4)</div> + +<p class="noind">Now, by d’Alembert’s principle,</p> + +<p class="center">Σm (ẍδx + ÿδy + z¨δz) = −δV,</p> +<div class="author">(5)</div> + +<p class="noind">and by hypothesis we have</p> + +<p class="center">δ(Τ + V) = 0.</p> +<div class="author">(6)</div> + +<p class="noind">The formula therefore reduces to</p> + +<p class="center">δA = <span class="f150">[</span>Σm (ẋδx + ẏδy + z˙δz)<span class="f150">]</span><span class="sp1">t′</span><span class="su2">t</span> + + 2Τ′δt′ − 2Τδt.</p> +<div class="author">(7)</div> + +<p class="noind">Since the terminal configurations are unaltered, we must have at +the lower limit</p> + +<p class="center">δx + ẋδt = 0,   δy + ẏδt = 0,   δz + z˙δt = 0,</p> +<div class="author">(8)</div> + +<p class="noind">with similar relations at the upper limit. These reduce (7) to the +form (2).</p> + +<p>The equation (2), it is to be noticed, merely expresses that the +variation of A vanishes <i>to the first order</i>; the phrase <i>stationary +action</i> has therefore been suggested as indicating more accurately +what has been proved. The action in the free path between two +given configurations is in fact not invariably a minimum, and even +when a minimum it need not be the <i>least possible</i> subject to the +given conditions. Simple illustrations are furnished by the case +of a single particle. A particle moving on a smooth surface, and +free from extraneous force, will have its velocity constant; hence +the theorem in this case resolves itself into</p> + +<p class="center">δ <span class="f150">∫</span> ds = 0,</p> +<div class="author">(9)</div> + +<p class="noind"><i>i.e.</i> the path must be a geodesic line. Now a geodesic is not necessarily +the <i>shortest</i> path between two given points on it; for example, +on the sphere a great-circle arc ceases to be the shortest +path between its extremities when it exceeds 180°. More generally, +taking any surface, let a point P, starting from O, move along +a geodesic; this geodesic will be a minimum path from O to P until +P passes through a point O′ (if such exist), which is the intersection +with a consecutive geodesic through O. After this point the minimum +property ceases. On an anticlastic surface two geodesics +cannot intersect more than once, and each geodesic is therefore a +minimum path between any two of its points. These illustrations +are due to K.G.J. Jacobi, who has also formulated the general +criterion, applicable to all dynamical systems, as follows:—Let +O and P denote any two configurations on a natural path of the +system. If this be the sole free path from O to P with the prescribed +amount of energy, the action from O to P is a minimum. But if +<span class="pagenum"><a name="page762" id="page762"></a>762</span> +there be several distinct paths, let P vary from coincidence with O +along the first-named path; the action will then cease to be a +minimum when a configuration O′ is reached such that two of the +possible paths from O to O′ coincide. For instance, if O and P be +positions on the parabolic path of a projectile under gravity, there +will be a second path (with the same energy and therefore the same +velocity of projection from O), these two paths coinciding when +P is at the other extremity (O′, say) of the focal chord through O. +The action from O to P will therefore be a minimum for all positions +of P short of O′. Two configurations such as O and O′ in the +general statement are called conjugate <i>kinetic foci</i>. Cf. <span class="sc"><a href="#artlinks">Variations, +Calculus of</a></span>.</p> + +<p>Before leaving this topic the connexion of the principle of +stationary action with a well-known theorem of optics may be +noticed. For the motion of a particle in a conservative field of +force the principle takes the form</p> + +<p class="center">δ <span class="f150">∫</span> vds = 0.</p> +<div class="author">(10)</div> + +<p class="noind">On the corpuscular theory of light v is proportional to the refractive +index μ of the medium, whence</p> + +<p class="center">δ <span class="f150">∫</span> μds = 0.</p> +<div class="author">(11)</div> + +<p>In the formula (2) the energy in the hypothetical motion is prescribed, +whilst the time of transit from the initial to the final configuration +<span class="sidenote">Hamiltonian principle.</span> +is variable. In another and generally more +convenient theorem, due to Hamilton, the time of transit +is prescribed to be the same as in the actual motion, whilst +the energy may be different and need not (indeed) be +constant. Under these conditions we have</p> + +<p class="center">δ <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (T − V)dt = 0,</p> +<div class="author">(12)</div> + +<p class="noind">where t, t′ are the prescribed times of passing through the given +initial and final configurations. The proof of (12) is simple; we +have</p> + +<p class="center">δ <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> + (T − V)dt = <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (δΤ − δV)dt = + <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> {Σm (ẋδẋ + ẏδẏ + z˙δz˙) − δV} dt</p> + +<p class="center">= <span class="f150">[</span> Σm (ẋδx + ẏδy + z˙δz)<span class="f150">]</span><span class="sp1">t′</span><span class="su2">t</span> + − <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> + {Σm (ẍδx + ÿδy + z¨δz) + δV} dt.</p> +<div class="author">(13)</div> + +<p class="noind">The integrated terms vanish at both limits, since by hypothesis +the configurations at these instants are fixed; and the terms under +the integral sign vanish by d’Alembert’s principle.</p> + +<p>The fact that in (12) the variation does not affect the time of +transit renders the formula easy of application in any system of +co-ordinates. Thus, to deduce Lagrange’s equations, we have</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2"><span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> + (δΤ − δV) dt = <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> <span class="f150">{</span></td> <td>∂T </td> +<td rowspan="2">δq˙<span class="su">1</span> +</td> <td>∂T</td> +<td rowspan="2">δq<span class="su">1</span> + ... −</td> <td>∂V</td> +<td rowspan="2">δq<span class="su">1</span> − ... <span class="f150">}</span> dt</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">1</span></td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">= <span class="f150">[</span>p<span class="su">1</span>δq<span class="su">1</span> + p<span class="su">2</span>δq<span class="su">2</span> + ...<span class="f150">]</span><span class="sp1">t′</span><span class="su2">t</span> + − <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> <span class="f150">{ [</span>ṗ<span class="su">1</span> −</td> <td>∂T </td> +<td rowspan="2">+</td> <td>∂V</td> +<td rowspan="2"><span class="f150">)</span> δq<span class="su">1</span> + <span class="f150">(</span>ṗ<span class="su">2</span> −</td> <td>∂T</td> +<td rowspan="2">+</td> <td>∂V</td> +<td rowspan="2"><span class="f150">)</span> δq<span class="su">2</span> + ...<span class="f150">}</span> dt.</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td> +<td class="denom">∂q<span class="su">2</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> +<div class="author">(14)</div> + +<p class="noind">The integrated terms vanish at both limits; and in order that the +remainder of the right-hand member may vanish it is necessary +that the coefficients of δq<span class="su">1</span>, δq<span class="su">2</span>, ... under the integral sign should +vanish for all values of t, since the variations in question are independent, +and subject only to the condition of vanishing at the +limits of integration. We are thus led to Lagrange’s equation of +motion for a conservative system. It appears that the formula +(12) is a convenient as well as a compact embodiment of the whole +of ordinary dynamics.</p> + +<p>The modification of the Hamiltonian principle appropriate to +<span class="sidenote">Extension to cyclic systems.</span> +the case of cyclic systems has been given by J. Larmor. +If we write, as in § 1 (25),</p> + +<p class="center">R = Τ − κχ˙ − κ′χ˙′ − κ″χ˙″ − ...,</p> +<div class="author">(15)</div> + +<p class="noind">we shall have</p> + +<p class="center">δ <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (R − V) dt = 0,</p> +<div class="author">(16)</div> + +<p class="noind">provided that the variation does not affect the cyclic momenta +κ, κ′, κ″, ..., and that the configurations at times t and t′ are unaltered, +so far as they depend on the palpable co-ordinates +q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>. The initial and final values of the ignored co-ordinates +will in general be affected.</p> + +<p>To prove (16) we have, on the above understandings,</p> + +<p class="center">δ <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (R − V) dt = + <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (δT − κδχ˙ − ... − δV) dt</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">= <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> <span class="f150">(</span></td> <td>∂T</td> +<td rowspan="2">δq˙<span class="su">1</span> + ... +</td> <td>∂T</td> +<td rowspan="2">δq<span class="su">1</span> + ... − δV<span class="f150">)</span> dt,</td></tr> +<tr><td class="denom">∂q˙<span class="su">1</span></td> <td class="denom">∂q<span class="su">1</span></td></tr></table> +<div class="author">(17)</div> + +<p class="noind">where terms have been cancelled in virtue of § 5 (2). The last +member of (17) represents a variation of the integral</p> + +<p class="center"><span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (T − V) dt</p> + +<p class="noind">on the supposition that δX = 0, δX′ = 0, δX″ = 0, ... throughout, whilst +δq<span class="su">1</span>, δq<span class="su">2</span>, δq<span class="su">m</span> vanish at times t and t′; <i>i.e.</i> it is a variation in which +the initial and final configurations are absolutely unaltered. It +therefore vanishes as a consequence of the Hamiltonian principle +in its original form.</p> + +<p>Larmor has also given the corresponding form of the principle +of least action. He shows that if we write</p> + +<p class="center">A = <span class="f150">∫</span> (2T − κχ˙ − κ′χ˙′ − κ″χ˙″ − ...) dt,</p> +<div class="author">(18)</div> + +<p class="noind">then</p> + +<p class="center">δA = 0,</p> +<div class="author">(19)</div> + +<p class="noind">provided the varied motion takes place with the same constant +value of the energy, and with the same constant cyclic momenta, +between the same two configurations, these being regarded as +defined by the palpable co-ordinates alone.</p> + +<p class="pt2 center">§ 8. <i>Hamilton’s Principal and Characteristic Functions.</i></p> + +<p>In the investigations next to be described a more extended +meaning is given to the symbol δ. We will, in the first +instance, denote by it an infinitesimal variation of the most +<span class="sidenote">Principal function.</span> +general kind, affecting not merely the values of the co-ordinates +at any instant, but also the initial and final configurations +and the times of passing through them. If we put</p> + +<p class="center">S = <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (Τ − V) dt,</p> +<div class="author">(1)</div> + +<p class="noind">we have, then,</p> + +<p class="center">δS = (T′ − V′) δt′ − (T − V) δt + + <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> (δΤ − δV) dt</p> + +<p class="center">= (T′ − V′) δt′ − (T − V) δt + <span class="f150">[</span>Σm + (ẋδx + ẏδy + z˙δz)<span class="f150">]</span><span class="sp1">t′</span><span class="su2">t</span>.</p> +<div class="author">(2)</div> + +<p>Let us now denote by x′ + δx′, y′ + δy′, z′ + δz′, the final co-ordinates +(<i>i.e.</i> at time t′ + δt′) of a particle m. In the terms in (2) which relate +to the upper limit we must therefore write δx′ − ẋ′δt′, δy′ − ẏ′δt′, +δz′ − z˙′δt′ for δx, δy, δz. With a similar modification at the lower +limit, we obtain</p> + +<p class="center">δS = −Hδτ + Σm (ẋ′δx′ + ẏ′δy′ + z˙′δz′) +− Σm (ẋδx + ẏδy + z˙δz),</p> +<div class="author">(3)</div> + +<p class="noind">where H (= T + V) is the constant value of the energy in the free +motion of the system, and τ (= t′ − t) is the time of transit. In +generalized co-ordinates this takes the form</p> + +<p class="center">δS = −Hδτ + p′<span class="su">1</span>δq′<span class="su">1</span> + p′<span class="su">2</span>δq′<span class="su">2</span> + ... + − p<span class="su">1</span>δq<span class="su">1</span> − p<span class="su">2</span>δq<span class="su">2</span> − ....</p> +<div class="author">(4)</div> + +<p class="noind">Now if we select any two arbitrary configurations as initial and +final, it is evident that we can in general (by suitable initial velocities +or impulses) start the system so that it will of itself pass from the +first to the second in any prescribed time τ. On this view of the +matter, S will be a function of the initial and final co-ordinates +(q<span class="su">1</span>, q<span class="su">2</span>, ... and q′<span class="su">1</span>, q′<span class="su">2</span>, ...) and the time τ, as independent variables. +And we obtain at once from (4)</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">p′<span class="su">1</span> =</td> <td>∂S</td> +<td rowspan="2">,   p′<span class="su">2</span> =</td> <td>∂S</td> +<td rowspan="2">, ... ,</td></tr> +<tr><td class="denom">∂q′<span class="su">1</span></td> <td class="denom">∂q′<span class="su">2</span></td></tr></table> +<div class="author">(5)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">p<span class="su">1</span> = −</td> <td>∂S</td> +<td rowspan="2">,   p<span class="su">2</span> = −</td> <td>∂S</td> +<td rowspan="2">, ... ,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> + +<p class="noind">and</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">H = −</td> <td>∂S</td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">∂τ</td></tr></table> +<div class="author">(6)</div> + +<p class="noind">S is called by Hamilton the <i>principal function</i>; if its general form +for any system can be found, the preceding equations suffice to +determine the motion resulting from any given conditions. If we +substitute the values of p<span class="su">1</span>, p<span class="su">2</span>, ... and H from (5) and (6) in the expression +for the kinetic energy in the form T′ (see § 1), the equation</p> + +<p class="center">T¹ + V = H</p> +<div class="author">(7)</div> + +<p class="noind">becomes a partial differential equation to be satisfied by S. It has +been shown by Jacobi that the dynamical problem resolves itself +into obtaining a “complete” solution of this equation, involving +n + 1 arbitrary constants. This aspect of the subject, as a problem +in partial differential equations, has received great attention at the +hands of mathematicians, but must be passed over here.</p> + +<p>There is a similar theory +<span class="sidenote">Characteristic function.</span> +for the function</p> + +<p class="center">A = 2 <span class="f150">∫</span> Tdt = S + Hτ</p> +<div class="author">(8)</div> + +<p class="noind">It follows from (4) that</p> + +<p class="center">δA = τδH + p′<span class="su">1</span>δq′<span class="su">1</span> + p′<span class="su">2</span>δq′<span class="su">2</span> + ... + − p<span class="su">1</span>δq<span class="su">1</span> − p<span class="su">2</span>δq<span class="su">2</span> − ....</p> +<div class="author">(9)</div> + +<p class="noind">This formula (it may be remarked) contains the principle of “least +<span class="pagenum"><a name="page763" id="page763"></a>763</span> +action” as a particular case. Selecting, as before, any two arbitrary +configurations, it is in general possible to start the system from one +of these, with a prescribed value of the total energy H, so that it +shall pass through the other. Hence, regarding A as a function of +the initial and final co-ordinates and the energy, we find</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">p′<span class="su">1</span> =</td> <td>∂A</td> +<td rowspan="2">,   p′<span class="su">2</span> =</td> <td>∂A</td> +<td rowspan="2">, ... ,</td></tr> +<tr><td class="denom">∂q′<span class="su">1</span></td> <td class="denom">∂q′<span class="su">2</span></td></tr></table> +<div class="author">(10)</div> + +<table class="math0" summary="math"> +<tr><td rowspan="2">p<span class="su">1</span> = −</td> <td>∂A</td> +<td rowspan="2">,   p<span class="su">2</span> = −</td> <td>∂A</td> +<td rowspan="2">, ... ,</td></tr> +<tr><td class="denom">∂q<span class="su">1</span></td> <td class="denom">∂q<span class="su">2</span></td></tr></table> + +<p class="noind">and</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">τ =</td> <td>∂A</td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">∂H</td></tr></table> +<div class="author">(11)</div> + +<p class="noind">A is called by Hamilton the <i>characteristic function</i>; it represents, +of course, the “action” of the system in the free motion (with +prescribed energy) between the two configurations. Like S, it +satisfies a partial differential equation, obtained by substitution +from (10) in (7).</p> + +<p>The preceding theorems are easily adapted to the case of cyclic +systems. We have only to write</p> + +<p class="center">S = <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> + (R − V) dt = <span class="f150">∫</span><span class="sp1">t′</span><span class="su2">t</span> + (T − κχ˙ − κ′χ˙′ − ... − V) dt</p> +<div class="author">(12)</div> + +<p class="noind">in place of (1), and</p> + +<p class="center">A = <span class="f150">∫</span> (2T − κχ˙ − κ′χ˙′ − ...) dt,</p> +<div class="author">(13)</div> + +<p class="noind">in place of (8); cf. § 7 <i>ad fin</i>. It is understood, of course, that in +(12) S is regarded as a function of the initial and final values of the +palpable co-ordinates q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>, and of the time of transit τ, the +cyclic momenta being invariable. Similarly in (13), A is regarded +as a function of the initial and final values of q<span class="su">1</span>, q<span class="su">2</span>, ... q<span class="su">m</span>, and of the +total energy H, with the cyclic momenta invariable. It will be +found that the forms of (4) and (9) will be conserved, provided the +variations δq<span class="su">1</span>, δq<span class="su">2</span>, ... be understood to refer to the palpable co-ordinates +alone. It follows that the equations (5), (6) and (10), +(11) will still hold under the new meanings of the symbols.</p> + +<p class="pt2 center">9. <i>Reciprocal Properties of Direct and Reversed Motions.</i></p> + +<p>We may employ Hamilton’s principal function to prove a very +remarkable formula connecting any <i>two</i> slightly disturbed +<span class="sidenote">Lagrange’s formula.</span> +natural motions of the system. If we use the symbols +δ and Δ to denote the corresponding variations, the +theorem is</p> + +<table class="math0" summary="math"> +<tr><td>d</td> <td rowspan="2">Σ (δp<span class="su">r</span>·Δq<span class="su">r</span> − Δp<span class="su">r</span>·δq<span class="su">r</span>) = 0;</td></tr> +<tr><td class="denom">dt</td></tr></table> +<div class="author">(1)</div> + +<p class="noind">or integrating from t to t′,</p> + +<p class="center">Σ (δp′<span class="su">r</span>·Δq′<span class="su">r</span> − Δq′<span class="su">r</span>·δq′<span class="su">r</span>) = Σ (δp<span class="su">r</span>·Δq<span class="su">r</span> − Δp<span class="su">r</span>·δq<span class="su">r</span>).</p> +<div class="author">(2)</div> + +<p class="noind">If for shortness we write</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">(r, s) =</td> <td>∂²S</td> +<td rowspan="2">,   (r, s′) =</td> <td>∂²S</td> +<td rowspan="2">,</td></tr> +<tr><td class="denom">∂q<span class="su">r</span>∂q<span class="su">s</span></td> <td class="denom">∂q<span class="su">r</span>∂q′<span class="su">s</span></td></tr></table> +<div class="author">(3)</div> + +<p class="noind">we have</p> + +<p class="center">∂p<span class="su">r</span> = −Σ<span class="su">s</span> (r, s) δq<span class="su">s</span> − Σ<span class="su">s</span> (r, s′) δq′<span class="su">s</span></p> +<div class="author">(4)</div> + +<p class="noind">with a similar expression for Δp<span class="su">r</span>. Hence the right-hand side of +(2) becomes</p> + +<p class="center">− Σ<span class="su">r</span> {Σ<span class="su">s</span>(r, s) δq<span class="su">s</span> + Σ<span class="su">s</span>(r, s′) δq′<span class="su">s</span>} Δq<span class="su">r</span> + Σ<span class="su">r</span> {Σ<span class="su">s</span>(r, s)Δq<span class="su">s</span> + Σ<span class="su">s</span>(r, s′) Δq′<span class="su">s</span>} δq<span class="su">r</span></p> + +<p class="center">= Σ<span class="su">r</span>Σ<span class="su">s</span>(r, s′) {δq<span class="su">r</span>·Δq′<span class="su">s</span> − Δq<span class="su">r</span>·δq′<span class="su">s</span>}.</p> +<div class="author">(5)</div> + +<p class="noind">The same value is obtained in like manner for the expression on +the left hand of (2); hence the theorem, which, in the form (1), +is due to Lagrange, and was employed by him as the basis of his +method of treating the dynamical theory of <i>Variation of Arbitrary +Constants</i>.</p> + +<p>The formula (2) leads at once to some remarkable reciprocal relations +which were first expressed, in their complete form, by +Helmholtz. Consider any natural motion of a conservative +system between two configurations O and O′ +<span class="sidenote">Helmholtz’s reciprocal theorems.</span> +through which it passes at times t and t′ respectively, +and let t′ − t = τ. As the system is passing through O +let a small impulse δp<span class="su">r</span> be given to it, and let the consequent +alteration in the co-ordinate q<span class="su">s</span> after the time τ be δq′<span class="su">s</span>. Next +consider the <i>reversed</i> motion of the system, in which it would, if +undisturbed, pass from O′ to O in the same time τ. Let a small +impulse δp′<span class="su">s</span> be applied as the system is passing through O′, and +let the consequent change in the co-ordinate q<span class="su">r</span> after a time τ be δq<span class="su">r</span>. +Helmholtz’s first theorem is to the effect that</p> + +<p class="center">δq<span class="su">r</span> : δp′<span class="su">s</span> = δq′<span class="su">s</span> : δp<span class="su">r</span>.</p> +<div class="author">(6)</div> + +<p class="noind">To prove this, suppose, in (2), that all the δq vanish, and likewise +all the δp with the exception of δp<span class="su">r</span>. Further, suppose all the Δq′ +to vanish, and likewise all the Δp′ except Δp′<span class="su">s</span>, the formula then +gives</p> + +<p class="center">δp<span class="su">r</span>·Δq<span class="su">r</span> = −Δp′<span class="su">s</span>·δq′<span class="su">s</span>,</p> +<div class="author">(7)</div> + +<p class="noind">which is equivalent to Helmholtz’s result, since we may suppose +the symbol Δ to refer to the reversed motion, provided we +change the signs of the Δp. In the most general motion of a top +(<span class="sc"><a href="#artlinks">Mechanics</a></span>, § 22), suppose that a small impulsive couple about the +vertical produces after a time τ a change δθ in the inclination of the +axis, the theorem asserts that in the reversed motion an equal impulsive +couple in the plane of θ will produce after a time τ a change +δψ, in the azimuth of the axis, which is equal to δθ. It is understood, +of course, that the couples have no components (in the +generalized sense) except of the types indicated; for instance, they +may consist in each case of a force applied to the top at a point of +the axis, and of the accompanying reaction at the pivot. Again, in +the corpuscular theory of light let O, O′ be any two points on the axis +of a symmetrical optical combination, and let V, V′ be the corresponding +velocities of light. At O let a small impulse be applied perpendicular +to the axis so as to produce an angular deflection δθ, and +let β′ be the corresponding lateral deviation at O′. In like manner +in the reversed motion, let a small deflection δθ′ at O′ produce a +lateral deviation β at O. The theorem (6) asserts that</p> + +<table class="math0" summary="math"> +<tr><td>β</td> <td rowspan="2">=</td> +<td>β′β′</td> <td rowspan="2">,</td></tr> +<tr><td class="denom">V′δθ′</td> <td class="denom">Vδθ</td></tr></table> +<div class="author">(8)</div> + +<p class="noind">or, in optical language, the “apparent distance” of O from O′ is to +that of O′ from O in the ratio of the refractive indices at O′ and O +respectively.</p> + +<p>In the second reciprocal theorem of Helmholtz the configuration +O is slightly varied by a change δq<span class="su">r</span> in one of the co-ordinates, +the momenta being all unaltered, and δq′<span class="su">s</span> is +<span class="sidenote">Helmholtz’s second reciprocal theorem.</span> +the consequent variation in one of the momenta after +time τ. Similarly in the reversed motion a change δp′<span class="su">s</span> +produces after time τ a change of momentum δp<span class="su">r</span>. The +theorem asserts that</p> + +<p class="center">δp′<span class="su">s</span> : δq<span class="su">r</span> = δp<span class="su">r</span> : δq′<span class="su">s</span></p> +<div class="author">(9)</div> + +<p class="noind">This follows at once from (2) if we imagine all the δp to vanish, and +likewise all the δq save δq<span class="su">r</span>, and if (further) we imagine all the Δp′ +to vanish, and all the Δq′ save Δq′<span class="su">s</span>. Reverting to the optical +illustration, if F, F′, be principal foci, we can infer that the convergence +at F′ of a parallel beam from F is to the convergence at F of +a parallel beam from F′ in the inverse ratio of the refractive indices +at F′ and F. This is equivalent to Gauss’s relation between the +two principal focal lengths of an optical instrument. It may be +obtained otherwise as a particular case of (8).</p> + +<p>We have by no means exhausted the inferences to be drawn from +Lagrange’s formula. It may be noted that (6) includes as particular +cases various important reciprocal relations in optics and acoustics +formulated by R.J.E. Clausius, Helmholtz, Thomson (Lord Kelvin) +and Tait, and Lord Rayleigh. In applying the theorem care must +be taken that in the reversed motion the reversal is complete, and +extends to every velocity in the system; in particular, in a cyclic +system the cyclic motions must be imagined to be reversed with +the rest. Conspicuous instances of the failure of the theorem +through incomplete reversal are afforded by the propagation of +sound in a wind and the propagation of light in a magnetic +medium.</p> + +<p>It may be worth while to point out, however, that there is no +such limitation to the use of Lagrange’s formula (1). In applying +it to cyclic systems, it is convenient to introduce conditions already +laid down, viz. that the co-ordinates q<span class="su">r</span> are the palpable co-ordinates +and that the cyclic momenta are invariable. Special inference can +then be drawn as before, but the interpretation cannot be expressed +so neatly owing to the non-reversibility of the motion.</p> + +<p><span class="sc">Authorities.</span>—The most important and most accessible early +authorities are J.L. Lagrange, <i>Mécanique analytique</i> (1st ed. Paris, +1788, 2nd ed. Paris, 1811; reprinted in <i>Œuvres</i>, vols. xi., xii., Paris, +1888-89); Hamilton, “On a General Method in Dynamics,” <i>Phil. Trans.</i> +1834 and 1835; C.G.J. Jacobi, <i>Vorlesungen über Dynamik</i> (Berlin, +1866, reprinted in <i>Werke</i>, Supp.-Bd., Berlin, 1884). An account of +the extensive literature on the differential equations of dynamics and +on the theory of variation of parameters is given by A. Cayley, +“Report on Theoretical Dynamics,” <i>Brit. Assn. Rep.</i> (1857), <i>Mathematical +Papers</i>, vol. iii. (Cambridge, 1890). For the modern developments +reference may be made to Thomson and Tait, <i>Natural Philosophy</i> +(1st ed. Oxford, 1867, 2nd ed. Cambridge, 1879); Lord +Rayleigh, <i>Theory of Sound</i>, vol. i. (1st ed. London, 1877; 2nd ed. +London, 1894); E.J. Routh, <i>Stability of Motion</i> (London, 1877), +and <i>Rigid Dynamics</i> (4th ed. London, 1884); H. Helmholtz, +“Über die physikalische Bedeutung des Prinzips der kleinsten +Action,” <i>Crelle</i>, vol. c., 1886, reprinted (with other cognate papers) +in <i>Wiss. Abh.</i> vol. iii. (Leipzig, 1895); J. Larmor, “On Least +Action,” <i>Proc. Lond. Math. Soc.</i> vol. xv. (1884); E.T. Whittaker, +<i>Analytical Dynamics</i> (Cambridge, 1904). As to the question of +stability, reference may be made to H. Poincaré, “Sur l’équilibre +d’une masse fluide animée d’un mouvement de rotation” <i>Acta math.</i> +vol. vii. (1885); F. Klein and A. Sommerfeld, <i>Theorie des Kreisels</i>, +pts. 1, 2 (Leipzig, 1897-1898); A. Lioupanoff and J. Hadamard, +<i>Liouville</i>, 5me série, vol. iii. (1897); T.J.I. Bromwich, Proc. Lond. +Math. Soc. vol. xxxiii. (1901). A remarkable interpretation of +various dynamical principles is given by H. Hertz in his posthumous +work <i>Die Prinzipien der Mechanik</i> (Leipzig, 1894), of which an +English translation appeared in 1900.</p> +</div> +<div class="author">(H. Lb.)</div> + +<p><span class="pagenum"><a name="page764" id="page764"></a>764</span></p> + + +<hr class="art" /> +<p><span class="bold">DYNAMITE<a name="ar6" id="ar6"></a></span> (Gr. <span class="grk" title="dynamis">δύναμις</span>, power), the name given to several +explosive preparations containing nitroglycerin (<i>q.v.</i>) which are +almost exclusively used for blasting purposes. The first practical +application of nitroglycerin in this way was made by A. Nobel in +1863. He soaked gunpowder with the liquid and fired the gunpowder +by an ordinary fuse. Later he found that nitroglycerin +could be detonated by the explosion of several materials such as +fulminate of mercury, the use of which as a detonator he patented +in 1867. In 1866-1867 he experimented with charcoal and other +substances, and found the infusorial earth known as kieselguhr, +which consists mainly of silica (nearly 95%), eminently adapted +to the purpose, as it was inert, non-combustible, and after a little +heating and preparation very porous, retaining a large amount +of nitroglycerin as water is held in a sponge, without very serious +exudation on standing. This kieselguhr dynamite is generally +made by incorporating three parts of nitroglycerin with one part +of the dry earth, the paste being then formed into cylindrical +cartridges. This work is done by hand. Generally a small +percentage of the kieselguhr is replaced by a mixture containing +sodium and ammonium carbonates, talc and ochre. This product +is known as dynamite No. 1. Disabilities attaching to kieselguhr +dynamite are that when placed in water the nitroglycerin is +liable to be exuded or displaced, also that, like nitroglycerin +itself, it freezes fairly easily and thawing the frozen cartridges +is a dangerous operation. Other substances, <i>e.g.</i> kaolin, tripoli, +magnesia alba (magnesium carbonate), alumina, sugar, charcoal, +some powdered salts and mixtures of sawdust and salts, have been +shown to be absorbents more or less adapted to the purpose of +making a dynamite. Charcoal from cork is said to absorb about +90% of its weight of nitroglycerin. With the idea of obtaining +greater safety, mixtures have been made of nitroglycerin with +wood fibre, charcoal and metallic nitrates. Lithofracteur, for +instance, consists of 50% nitroglycerin and a mixture of +prepared sawdust, kieselguhr and barium nitrate. Carbonite +contains 25% of nitroglycerin, the remainder being +a mixture of wood-meal and alkali nitrates, with about 1% +of sulphur. Dualin, atlas dynamite and potentite are other +modifications.</p> + +<p>A convenient form in which nitroglycerin can be made up for +blasting purposes, especially in wet ground, is the gelatinous +material obtained by the action of nitroglycerin, either alone +or with the help of solvents, on low-grade or soluble gun-cottons. +It is known as blasting gelatin, and was first made by Nobel +by incorporating 6 or 7% of low nitrated cellulose (collodion +cotton or soluble gun-cotton) with slightly warmed nitroglycerin. +The result is a transparent plastic material, of specific gravity +1.5 to 1.6, which may be kept under water for a long time without +appreciable change. It is less sensitive to detonation than +ordinary dynamite, and although its explosion is slightly slower +it is more powerful than dynamite and much superior to the +liquid nitroglycerin. Blasting gelatin also freezes and is +sensitive to percussion in this state. Camphor and other substances +have been added to blasting gelatin to render it more +solid and less sensitive. Some modifications of blasting gelatin, +<i>e.g.</i> gelignite, contain wood-meal and such oxygen-containing +salts as potassium nitrate. Experience has conclusively shown +that dynamites are more satisfactory, quicker, and more intense +in action than liquid nitroglycerin.</p> + +<p>To prevent nitroglycerin and some of the forms of dynamite +from freezing it has been proposed to add to them small quantities +of either monochlor-dinitroglycerin or of a nitrated poly-glycerin. +The former is obtained by first acting upon glycerin with hydrogen +chloride to produce <i>u-</i>chlorhydrin or chlor-propylene glycol, +C<span class="su">3</span>H<span class="su">7</span>O<span class="su">2</span>Cl, which is then nitrated as in the case of glycerin. The +latter is obtained by heating glycerin for six or seven hours to +about 300° C., whereby water is split off in such manner that a +diglycerin C<span class="su">6</span>H<span class="su">14</span>O<span class="su">5</span>, for the most part, results. This on nitration +in the usual manner gives a product C<span class="su">6</span>H<span class="su">10</span>N<span class="su">4</span>O<span class="su">13</span>, which burns and +explodes in a similar manner to ordinary nitroglycerin, but is +less sensitive and does not so easily freeze. The mono- and +di-nitrates of glycerin have also been proposed as additions to +ordinary nitroglycerin (<i>q.v.</i>) for the same purpose.</p> +<div class="author">(W. R. E. H.)</div> + + +<hr class="art" /> +<p><span class="bold">DYNAMO<a name="ar7" id="ar7"></a></span> (a shortened form of “dynamo-electric machine,” +from Gr. <span class="grk" title="dynamis">δύναμις</span>, power), a machine for converting mechanical +into electrical energy.</p> + +<table class="flt" style="float: right; width: 230px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:182px; height:121px" src="images/img764.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 1.</span></td></tr></table> + +<p>The dynamo ranks with the telegraph and telephone as one +of the three striking applications of electrical and magnetic +science to which the material progress that marked the second +half of the 19th century was in no small measure due. Since +the discovery of the principle of the dynamo by Faraday in 1831 +the simple model which he first constructed has been gradually +developed into the machines of 5000 horse-power or more which +are now built to meet the needs of large cities for electric lighting +and power, while at the same time the numbers of dynamos +in use have increased almost beyond estimate. Yet such was the +insight of Faraday into the fundamental nature of the dynamo that +the theory of its action which he laid down has remained essentially +unchanged. His experiments on the current which was set +up in a coil of wire during its movement across the poles of a +magnet led naturally to the explanation of induced electromotive +force as caused by the linking or unlinking of magnetic +lines of flux with an electric circuit. For the more definite case +of the dynamo, however, we may, with Faraday, make the +transition from line-linkage to the equivalent conception of +“line-cutting” as the source of E.M.F.—in other words, to +the idea of electric conductors “cutting” or intersecting<a name="fa1p" id="fa1p" href="#ft1p"><span class="sp">1</span></a> the +lines of flux in virtue of relative motion of the magnetic field +and electric circuit. On the 28th of October 1831 Faraday +mounted a copper disk so that it could be rotated edgewise +between the poles of a permanent horse-shoe magnet. When +so rotated, it cut the lines of flux which passed transversely +through its lower half, and by means of two rubbing contacts, +one on its periphery and the other on its spindle, the circuit +was closed through a galvanometer, which indicated the passage +of a continuous current so long as the disk was rotated (fig. 1). +Thus by the invention of the first +dynamo Faraday proved his idea that +the E.M.F. induced through the interaction +of a magnetic field and an electric +circuit was due to the passage of a +portion of the electric circuit <i>across</i> the +lines of flux, or vice versa, and so could +be maintained if the cutting of the +lines were made continuous.<a name="fa2p" id="fa2p" href="#ft2p"><span class="sp">2</span></a> In comparison +with Faraday’s results, the subsequent advance is to be +regarded as a progressive perfecting of the mechanical and +electro-magnetic design, partly from the theoretical and partly +from the practical side, rather than as modifying or adding to +the idea which was originally present in his mind, and of which +he already saw the possibilities.</p> + +<p>A dynamo, then, is a machine in which, by means of continuous +relative motion, an electrical conductor or system of conductors +forming part of a circuit is caused to cut the lines of a magnetic +field or fields; the cutting of the magnetic flux induces an electromotive +force in the conductors, and when the circuit is closed +a current flows, whereby mechanical energy is converted into +electrical energy.</p> + +<div class="condensed"> +<p>Little practical use could be made of electrical energy so long as its +only known sources were frictional machines and voltaic batteries. +The cost of the materials for producing electrical currents on a large +scale by chemical action was prohibitive, while the frictional machine +only yielded very small currents at extremely high potentials. In +the dynamo, on the other hand, electrical energy in a convenient form +could be cheaply and easily obtained by mechanical means, and +with its invention the application of electricity to a wide range of +commercial purposes became economically possible. As a converter +of energy from one form to another it is only surpassed in efficiency +by another electrical appliance, namely, the transformer (see +<span class="sc"><a href="#artlinks">Transformers</a></span>). In this there is merely conversion of electrical +energy at a high potential into electrical energy at a low potential, +or vice versa, but in the dynamo the mechanical energy which must +be applied to maintain the relative movement of magnetic field and +conductor is absorbed, and reappears in an electrical form. A true +transformation takes place, and the proportion which the rate of +<span class="pagenum"><a name="page765" id="page765"></a>765</span> +delivery of electrical energy bears to the power absorbed, or in other +words the <i>efficiency</i>, is the more remarkable. The useful return or +“output” at the terminals of a large machine may amount to as +much as 95% of the mechanical energy which forms the “input.” +Since it needs some prime mover to drive it, the dynamo has not +made any direct addition to our sources of energy, and does not +therefore rank with the primary battery or oil-engine, or even the +steam-engine, all of which draw their energy more immediately from +nature. Yet by the aid of the dynamo the power to be derived +from waterfalls can be economically and conveniently converted +into an electrical form and brought to the neighbouring factory or +distant town, to be there reconverted by motors into mechanical +power. Over any but very short distances energy is most easily +transmitted when it is in an electrical form, and turbine-driven +dynamos are very largely and successfully employed for such +transmission. Thus by conducing to the utilization of water-power +which may previously have had but little value owing to its disadvantageous +situation, the dynamo may almost be said to have +added another to our available natural resources.</p> +</div> + +<p>The two essential parts of the dynamo, as required by its +definition, may be illustrated by the original disk machine of +Faraday. They are (1) the <i>iron magnet</i>, between the poles of +which a magnetic field exists, and (2) the <i>electrical conductors</i>, +represented by the rotating copper disk. The sector of the disk +cutting the lines of the field forms part of a closed electric circuit, +and has an E.M.F. induced in it, by reason of which it is no longer +simply a conductor, but has become “active.” In its more +highly developed form the simple copper disk is elaborated into +a system of many active wires or bars which form the “winding,” +and which are so interconnected as to add up their several +E.M.F.’s. Since these active wires are usually mounted on an +iron structure, which may be likened to the keeper or “armature” +of a magnet rotating between its poles, the term “armature” +has been extended to cover not only the iron core, but also +the wires on it, and when there is no iron core it is even applied +to the copper conductors themselves. In the dynamo of Faraday +the “armature” was the rotating portion, and such is the case +with modern continuous-current dynamos; in alternators, +however, the magnet, or a portion of it, is more commonly rotated +while the armature is stationary. It is in fact immaterial to the +action whether the one or the other is moved, or both, so long as +their relative motion causes the armature conductors to cut the +magnetic flux. As to the ultimate reason why an E.M.F. should +be thereby induced, physical science cannot as yet yield any +surer knowledge than in the days of Faraday.<a name="fa3p" id="fa3p" href="#ft3p"><span class="sp">3</span></a> For the engineer, +it suffices to know that the E.M.F. of the dynamo is due to the +cutting of the magnetic flux by the active wires, and, further, +is proportional to the rate at which the lines are cut.<a name="fa4p" id="fa4p" href="#ft4p"><span class="sp">4</span></a></p> + +<table class="flt" style="float: right; width: 310px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:261px; height:156px" src="images/img765.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 2.</span></td></tr></table> + +<p>The equation of the <i>electromotive force</i> which is required in +order to render this statement quantitative must contain three +factors, namely, the density of the flux in the air-gap through +which the armature conductors move, the active length of these +wires, and the speed of their movement. For given values of +the first and third factors and a single straight wire moved +parallel to itself through a uniform field, the maximum rate of +cutting is evidently obtained when the three directions of the lines +of the conductor’s length and +of the relative motion are respectively +at right angles to +each other, as shown by the +three co-ordinate axes of fig. 2. +The E.M.F. of the single wire is then</p> + +<p class="center">E = B<span class="su">g</span>LV × 10<span class="sp">−8</span> volts</p> +<div class="author">(1)</div> + +<p class="noind">where B<span class="su">g</span> is the density of the +flux within the air-gap expressed +in C.G.S. lines per +square centimetre, L is the active length of the conductor +within the field in centimetres, and V is the velocity of movement +in centimetres per second. Further, the direction +in which the E.M.F. has the above maximum value is along +the length of the conductor, its “sense” being determined by +the direction of the movement<a name="fa5p" id="fa5p" href="#ft5p"><span class="sp">5</span></a> in relation to the direction of the +field.</p> + +<p>The second fundamental equation of the dynamo brings to +light its mechanical side, and rests on H.C. Oersted’s discovery +of the interaction of a magnetic field and an electric current. If +a straight electric conductor through which a current is passing +be so placed in a magnetic field that its length is not parallel +to the direction of the lines of flux, it is acted on by a force which +will move it, if free, in a definite direction relatively to the +magnet; or if the conductor is fixed and the magnet is free, the +latter will itself move in the opposite direction. Now in the +dynamo the active wires are placed so that their length is at right +angles to the field; hence when they are rotated and an electric +current begins to flow under the E.M.F. which they induce, a +mutual force at once arises between the copper conductors and +the magnet, and the direction of this force must by Lenz’s law +be opposed to the direction of the movement. Thus as soon +as the disk of fig. 1 is rotated and its circuit is closed, it experiences +a mechanical pull or drag which must be overcome by the +force applied to turn the disk. While the magnet must be firmly +held so as to remain stationary, the armature must be of such +mechanical construction that its wires can be forcibly driven +through the magnetic field against the mutual pull. This law +of electrodynamic action may be quantitatively stated in an +<i>equation of mechanical force</i>, analogous to the equation (I.) of +electromotive force, which states the law of electromagnetic +induction. If a conductor of length L cm., carrying a current +C amperes, is immersed in a field of uniform density B<span class="su">g</span>, and the +length of the conductor is at right angles to the direction of the +lines, it is acted on by a force</p> + +<p class="center">F = B<span class="su">g</span>LC × 10<span class="sp">−1</span> dynes,</p> +<div class="author">(2)</div> + +<p class="noind">and the direction of this force is at right angles to the conductor +and to the field. The rate at which electrical energy is developed, +when this force is overcome by moving the conductor as a +dynamo through the field, is EC = B<span class="su">g</span>LVC × 10<span class="sp">−8</span> watts, whence +the equality of the mechanical power absorbed and the electrical +power developed (as required by the law of the conservation +of energy) is easily established. The whole of this power is not, +however, available at the terminals of the machine; if R<span class="su">a</span> be the +resistance of the armature in ohms, the passage of the current C<span class="su">a</span> +through the armature conductors causes a drop of pressure of +C<span class="su">a</span>R<span class="su">a</span> volts, and a corresponding loss of energy in the armature +at the rate of C<span class="su">a</span>²R<span class="su">a</span> watts. As the resistance of the external +circuit R<span class="su">e</span> is lowered, the current C = E<span class="su">a</span> / (R<span class="su">e</span> + R<span class="su">a</span>) is increased. +The increase of the current is, however, accompanied by a progressive +increase in the loss of energy over the armature, and as +this is expended in heating the armature conductors, their temperature +may rise so much as to destroy the insulating materials +with which they are covered. Hence the temperature which +the machine may be permitted to attain in its working is of great +importance in determining its output, the current which forms +one factor therein being primarily limited by the heating which +it produces in the armature winding. The lower the resistance +of the armature, the less the rise of its temperature for a given +current flowing through it; and the reason for the almost +universal adoption of copper as the material for the armature +conductors is now seen to lie in its high conductivity.<a name="fa6p" id="fa6p" href="#ft6p"><span class="sp">6</span></a></p> + +<p>Since the voltage of the dynamo is the second factor to which +its output is proportional, the conditions which render the induced +E.M.F. a maximum must evidently be reproduced as far +as possible in practice, if the best use is to be made of a given +mass of iron and copper. The first problem, therefore, in the +construction of the dynamo is the disposition of the wires and +field in such a manner that the three directions of field, length of +active conductors, and movement are at right angles to one +another, and so that the relative motion is continuous. Reciprocating +motion, such as would be obtained by direct attachment +of the conductors to the piston of a steam-engine, has +<span class="pagenum"><a name="page766" id="page766"></a>766</span> +been successfully employed only in the special case of an +“oscillator,”<a name="fa7p" id="fa7p" href="#ft7p"><span class="sp">7</span></a> producing a small current very rapidly changing +in direction. Rotary motion is therefore universally adopted, +and with this two distinct cases arise. Either (A) the active +length of the wire is parallel to the axis of rotation, or (B) it is at +right angles to it.</p> + +<table class="flt" style="float: right; width: 320px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:178px; height:272px" src="images/img766a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 3.</span></td></tr> +<tr><td class="figright1"><img style="width:192px; height:201px" src="images/img766b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 4.</span></td></tr></table> + +<p>(A) If a conductor is rotated in the gap between the poles of +a horse-shoe magnet, and these poles have plane parallel faces +opposing one another as in fig. 3, not only is the density of the +flux in the interpolar gap small, but the direction of movement +is not always at right angles to the +direction of the lines, which for the +most part pass straight across from one +opposing face to the other. When the +conductor is midway between the poles +(<i>i.e.</i> either at its highest or lowest point), +it is at this instant sliding along the lines +and does not cut them, so that its +E.M.F. is zero. Taking this position as +the starting-point, as the conductor +moves round, its rate of line-cutting +increases to a maximum when it has +moved through a right angle and is opposite +to the centre of a pole-face (as in +fig. 3), from which point onward the +rate decreases to zero when it has moved +through 180°. Each time the conductor crosses a line drawn symmetrically +through the gap between the poles and at right angles +to the axis of rotation, the E.M.F. along its length is reversed in +direction, since the motion relatively to the direction of the field +is reversed. If the ends of the active conductor are electrically +connected to two collecting rings fixed upon, but insulated from, +the shaft, two stationary brushes <i>bb</i> can be pressed on the rings +so as to make a sliding contact. An external circuit can then +be connected to the brushes, which will form the “terminals” +of the machine, the periodically reversed or alternating E.M.F. +induced in the active conductor will cause an alternating current +to flow through conductor and external circuit, and the simplest +form of “alternator” is obtained. If the field cut by the +straight conductor is of uniform density, and all the lines pass +straight across from one pole-face to the other (both of which +assumptions are approximately correct), a curve connecting the +instantaneous values of the E.M.F. as ordinates with time +or degrees of angular movement as abscissae (as shown at the +foot of fig. 3), will, if the speed of rotation be uniform, be a sine +curve. If, however, the conductor is mounted on an iron +cylinder (fig. 4),<a name="fa8p" id="fa8p" href="#ft8p"><span class="sp">8</span></a> a sufficient margin +being allowed for mechanical clearance +between it and the poles, not only will +the reluctance of the magnetic circuit +be reduced and the total flux and its +density in the air-gap B<span class="su">g</span> be thereby +increased, but the path of the lines +will become nearly radial, except at +the “fringe” near the edges of the +pole-tips; hence the relative directions +of the movement and of the lines will +be continuously at right angles. The +shape of the E.M.F. curve will then be +as shown in fig. 4—flat-topped, with rounded corners rapidly +sloping down to the zero line.</p> + +<table class="flt" style="float: right; width: 230px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:182px; height:124px" src="images/img766c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 5.</span></td></tr></table> + +<p>But a single wire cannot thus be made to give more than a few +volts, and while dynamos for voltages from 5 to 10 are required +for certain purposes, the voltages in common use range from +100 to 10,000. It is therefore necessary to connect a number +of such wires in series, so as to form an “armature winding.” +If several similar conductors are arranged along the length of +the iron core parallel to the first (fig. 5), the E.M.F.’s generated +in the conductors which at any +moment are under the same pole are +similarly directed, and are opposite to +the directions of the E.M.F.’s in the +conductors under the other pole (cf +fig. 5 where the dotted and crossed +ends of the wires indicate E.M.F.’s +directed respectively towards and away +from the observer). Two distinct +methods of winding thence arise, the similarity of the E.M.F.’s +under the same pole being taken advantage of in the first, and +the opposite E.M.F.’s under N and S poles in the second.</p> + +<table class="flt" style="float: left; width: 240px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:190px; height:243px" src="images/img766d.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 6.</span></td></tr></table> + +<p>1. The first, or <i>ring</i>-winding, was invented by Dr Antonio +Pacinotti of Florence<a name="fa9p" id="fa9p" href="#ft9p"><span class="sp">9</span></a> in 1860, and was subsequently and independently +reintroduced in 1870<a name="fa10p" id="fa10p" href="#ft10p"><span class="sp">10</span></a> by the Belgian electrician, +Zénobe Théophile Gramme, whence it is also frequently called +the “Gramme” winding. By this method the farther end of +conductor 1 (fig. 5) is joined in series to the near end of conductor +2; this latter lies next to it on the surface of the core or +immediately above it, so that both are simultaneously under +the same pole-piece. For this series connexion to be possible, the +armature core must be a hollow cylinder, +supported from the shaft on an +open non-magnetic spider or hub, between +the arms of which there is room +for the internal wire completing the +loop (fig. 6). The end of one complete +loop or turn embracing one side of the +armature core thus forms the starting-point +for another loop, and the process +can be continued if required to form +a coil of two or more turns. In the +ring armature the iron core serves +the double purpose of conducting the +lines across from one pole to the +other, and also of shielding from the magnetic flux the +hollow interior through which the connecting wires pass. Any +lines which leak across the central space are cut by the internal +wires, and the direction of cutting is such that the E.M.F. +caused thereby opposes the E.M.F. due to the active conductors +proper on the external surface. If, however, the section of iron +in the core be correctly proportioned, the number of lines which +cross the interior will bear but a small ratio to those which pass +entirely through the iron, and the counter E.M.F. of the internal +wires will become very small; they may then be regarded simply +as connectors for joining the external active wires in series.</p> + +<table class="flt" style="float: right; width: 220px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:168px; height:213px" src="images/img766e.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 7.</span></td></tr></table> + +<p>2. The second or <i>drum</i> method was used in the original +“shuttle-wound” armatures invented +by Dr Werner von Siemens in 1856, and +is sometimes called the “Siemens” +winding. The farther end of conductor 1 +(fig. 5) is joined by a connecting wire to +the farther end of another conductor +2’ situated nearly diametrically opposite +on the other side of the core and under +the opposite pole-piece. The near end of +the complete loop or turn is then brought +across the end of the core, and can be +used as the starting-point for another +loop beginning with conductor 2, which +is situated by the side of the first conductor. The iron +core may now be solid from the surface to the shaft, since +no connecting wires are brought through the centre, and +each loop embraces the entire armature core (fig. 7). By the +formation of two loops in the ring armature and of the single loop +in the drum armature, two active wires are placed in series; +<span class="pagenum"><a name="page767" id="page767"></a>767</span> +the curves of instantaneous E.M.F. are therefore similar in shape +to that of the single wire (fig. 4), but with their ordinates raised +throughout to double their former height, as shown at the foot +of fig. 6.</p> + +<p>Next, if the free ends of either the ring or drum loops, instead +of being connected to two collecting rings, are attached to the +two halves of a split-ring insulated from the shaft (as shown in +fig. 7 in connexion with a drum armature), and the stationary +brushes are so set relatively to the loops that they pass over from +the one half of the split-ring to the other half at the moment +when the loops are passing the centre of the interpolar gap, and +so are giving little or no E.M.F., each brush will always remain +either positive or negative. The current in the external circuit +attached to the brushes will then have a constant direction, +although the E.M.F. in the active wires still remains alternating; +the curve of E.M.F. obtained at the brushes is thus (as in fig. 7) +entirely above the zero line. The first dynamo of H. Pixii,<a name="fa11p" id="fa11p" href="#ft11p"><span class="sp">11</span></a> +which immediately followed Faraday’s discovery, gave an +alternating current, but in 1832<a name="fa12p" id="fa12p" href="#ft12p"><span class="sp">12</span></a> the alternator was converted +into a machine giving a <i>unidirected current</i> by the substitution +of a rudimentary “commutator” in place of mercury collecting +cups.</p> + +<p>(B) So far the length of the active wires has been parallel to the +axis of rotation, but they may equally well be arranged perpendicularly +thereto. The poles will then have plane faces and the +active wires will be disposed with their length approximately +radial to the axis of the shaft. In order to add their E.M.F.’s in +series, two types of winding may be employed, which are precisely +analogous in principle to the ring and drum windings under +arrangement (A).</p> + +<p>3. The <i>discoidal</i> or flat-ring armature is equivalent to a ring +of which the radial depth greatly exceeds the length, with the +poles presented to one side of the ring instead of embracing its +cylindrical surface. A similar set of poles is also presented to +the opposite side of the ring, like poles being opposite to one +another, so that in effect each polar surface is divided into two +halves, and the groups of lines from each side bifurcate and pass +circumferentially through the armature core to issue into the +adjacent poles of opposite sign.</p> + +<p>4. In the <i>disk</i> machine, no iron core is necessary for the armature, +the two opposite poles of unlike sign being brought close +together, leaving but a short path for the lines in the air-gap +through which the active wires are rotated.</p> + +<table class="flt" style="float: right; width: 360px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:313px; height:167px" src="images/img767.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 8.</span></td></tr></table> + +<p>If the above elementary dynamos are compared with fig. 1, +it will be found that they all possess a distinctive feature which +is not present in the original disk machine of Faraday. In the +four types of machine above described each active wire in each +revolution first cuts the group of lines forming a field in one +direction, and then cuts the same lines again in the opposite +direction relatively to the sense of the lines, so that along the +length of the wire the E.M.F. alternates in direction. But in +the dynamo of fig. 1 the sector of the copper disk which is at any +moment moving through the magnetic field and which forms +the single active element is always cutting the lines in the same +manner, so that the E.M.F. generated along its radial length is +continuous and unchanged in direction. This radical distinction +differentiates the two classes of <i>heteropolar</i> and <i>homopolar</i> +dynamos, Faraday’s disk machine of fig. 1 being the type of the +latter class. In it the active element may be arranged either +parallel or at right angles to the axis of rotation; but in both +cases, in order to increase the E.M.F. by placing two or more +elements in series, it becomes necessary either (1) to employ +some form of sliding contact by which the current may be +collected from the end of one active element and passed round +a connecting wire into the next element without again cutting +the field in the reverse direction, or (2) to form on the armature +a loop of which each side is alternately active and inactive. The +first method limits the possibilities of the homopolar machine +so greatly when large currents and high voltages are required +that it is now only used in rare instances, as <i>e.g.</i> occasionally in +dynamos driven by steam-turbines which have a very high +speed of rotation. The second alternative may be carried into +effect with any of the four methods of armature winding, but +is practically confined to the drum and disk types. In its drum +form the field is divided into two or more projecting poles, all +of the same sign, with intervening neutral spaces of equal width, +and the span of the loop in the direction of rotation is at least +equal to the width of a polar projection, as in fig. 8, where two +polar projections are shown. Each side of the loop then plays +a dual part; it first cuts the lines of one polar projection and +generates an E.M.F., and next becomes an inactive connecting +wire, while the action is taken up by the opposite side of the +loop which has previously served as a connector but now cuts +the lines of the next polar projection. The E.M.F. is thus always +in the same direction along the side which is at any moment +active, but alternates round the loop as a whole, and the distinctive +peculiarity of the homopolar machine, so soon as +any form of “winding” +is introduced into its +armature, is lost. It +results that the homopolar +principle, which +would prima facie appear +specially suitable for the +generation of a unidirectional +E.M.F. and +continuous current, can +seldom be used for this +purpose and is practically confined to alternators. It may +therefore be said that in almost all dynamos, whether they +supply an alternating or a continuous current in the external +circuit, the E.M.F. and current in the armature are alternating.</p> + +<p>Ring winding was largely employed in early continuous-current +dynamos and also in the alternators of Gramme and +H. Wilde, and later of Auguste de Méritens. Disk winding was +also successfully introduced for alternators, as in the magneto-machines +of Nollet (1849) and the alternators of Wilde (1866) +and Siemens (1878), and its use was continued in the machines +of W.M. Mordey and S.Z. Ferranti. But although the ring, +discoidal-ring and disk methods of winding deserve mention +from their historical importance, experience has shown that +drum winding possesses a marked superiority for both electrical +and manufacturing reasons; the three former methods have +in fact been practically discarded in its favour, so that the drum +method will hereafter alone be considered.</p> + +<p>The drum coil, composed of several loops wound side by side, +may therefore be regarded as the constituent active element out +of which the armature winding of the modern dynamo is developed. +Its application to the multipolar machine is easily +followed from fig. 9, which illustrates the heteropolar type of +dynamo. The span of the loops, which is nearly 180° or across +the diameter of the two-pole machine, is reduced approximately +to 90° in the four-pole or to 60° in the six-pole machine and so on, +the curvature of the coil becoming gradually less as the number +of poles is increased. The passage of a coil through two magnetic +fields of opposite direction yields a complete wave of E.M.F., +such as is shown in fig. 6, and the time in seconds taken to pass +through such a complete cycle is the “period” of the alternating +E.M.F. The number of complete periods through which the +E.M.F. of the coil passes per second is called the “periodicity” +or “frequency” of the machine. In the bipolar machine this +<span class="pagenum"><a name="page768" id="page768"></a>768</span> +is equal to the number of revolutions per second, and in the +multipolar machine it is equal to the number of pairs of fields +through which the coil passes in one second; hence in general +the periodicity is pN / 60, where N = the number of revolutions +per minute and p = the number of pairs of poles, and this holds +true of the E.M.F. and current round the coil, even though the +E.M.F. and current furnished to the external circuit may be +rendered unidirectional or continuous. The only difference on +this point is that in the continuous-current machine the poles +are usually fewer than in the alternator, and the periodicity is +correspondingly lower. Thus in the former case the number +of poles ranges from 2 to 12 and the usual frequencies from 5 to +20; but with alternators the frequencies in commercial use +range from 25 to 120, and in large machines driven by slow-speed +engines the number of poles may even be as high as 96.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter" colspan="2"><img style="width:752px; height:335px" src="images/img768a.jpg" alt="" /></td></tr> +<tr><td class="caption">I. Smooth.</td> +<td class="caption">II. Toothed.</td></tr> +<tr><td class="caption" colspan="2"><span class="sc">Fig. 9.</span></td></tr></table> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:383px; height:220px" src="images/img768b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 10.</span></td></tr></table> + +<p>The drum coil may be applied either to the external surface +of a rotating armature, the field-magnet being external and +stationary (fig. 9), or to the internal surface of a stationary +armature (fig. 10), the field-magnet being internal and rotating. +While the former combination is universally adopted +in the continuous-current dynamo, the latter is more usual in +the modern alternator. In either case the iron armature core +must be “laminated”; the passage of the lines of the field +across its surface sets up E.M.F.’s which are in opposite directions +under poles of opposite sign, so that if the core were a +solid mass a current-sheet would flow along its surface opposite +to a pole, and complete its circuit by passing through the deeper +layers of metal or by returning in a sheet under a pole of opposite +sign. Such “eddy-currents” can be practically avoided by +dividing the metal core into laminations at right angles to the +length of the active wires which are themselves arranged to +secure the greatest rate of line-cutting and maximum E.M.F. +The production of the eddy-current E.M.F. is not thereby +prevented, but the paths of the eddy-currents are so broken up +that the comparatively high resistance with which they meet +reduces their amount very greatly. The laminae must be lightly +insulated from one another, right up to their edges, so that the +E.M.F.’s which still act across their thickness will not be added +up along the length of the core, but will only produce extremely +small currents circulating through the interior of the separate +laminations. Each thin iron plate is either coated with an +insulating varnish or has one of its sides covered with a sheet of +very thin paper; the thickness of the laminae is usually about +one-fortieth of an inch, and if this is not exceeded the rate at +which energy is dissipated by eddy-currents in the core is +so far reduced that it does not +seriously impair the efficiency of the +machine.</p> + +<p>Lastly, the drum coils may be +either attached to the surface of a +smooth armature core (fig. 9, I.), or +may be wound through holes formed +close to the periphery of the core, +or may be embedded in the slots +between projecting iron teeth (figs. +9 [II.] and 10). Originally employed +by Antonio Pacinotti in connexion +with ring winding, the toothed +armature was after some considerable +use largely discarded in favour +of the smooth core; it has, however, +been reintroduced with a +fuller understanding of the special +precautions necessitated in its design, +and it is now so commonly used +that it may be said to have superseded the smooth-surface +armature.</p> + +<div class="condensed"> +<p>Not only does the toothed armature reduce the length of the +air-gap to the minimum permitted by mechanical and magnetic +considerations, and furnish better mechanical protection to the +armature coils, but it also ensures the positive holding of the active +wires against the mechanical drag which they experience as they +pass through the magnetic field. Further, the active wires in the +toothed armature are relieved of a large proportion of this mechanical +drag, which is transferred to the iron teeth. The lines of the field, +after passing through the air-gap proper, divide between the teeth +and the slots in proportion to their relative permeances. Hence +at any moment the active wires are situated in a weak field, and +for a given armature current the force on them is only proportional +to this weak field. This important result is connected with the +fact that when the armature is giving current the distribution of +the lines over the face of each tooth is distorted, so that they become +denser on the “trailing” side than on the “leading” side;<a name="fa13p" id="fa13p" href="#ft13p"><span class="sp">13</span></a> the +effect of the non-uniform distribution acting on all the teeth is to +produce a magnetic drag on the armature core proportional to the +current passing through the wires, so that the total resisting force +remains the same as if the armature had a smooth core. The amount +by which the stress on the active wires is reduced entirely depends +upon the degree to which the teeth are saturated, but, since the +relative permeability of iron even at a flux density of 20,000 lines +per sq. cm. is to that of air approximately as 33 : 1, the embedded wires +are very largely relieved of the driving stress. An additional gain +is that solid bars of much greater width can be used in the toothed +armature than on a smooth core without appreciable loss from +eddy-currents within their mass.</p> + +<p>A disadvantage of the slotted core is, however, that it usually +necessitates the lamination of the pole-pieces. If the top of the slot +is open, and its width of opening is considerably greater than the +length of the air-gap from the iron of the pole-face to the surface +of the teeth, the lines become unequally distributed not only at the +surface of the teeth, but also at the face of the pole-pieces; and +this massing of the lines into bands causes the density at the pole-face +to be rhythmically varied as the teeth pass under it. No such +variation can take place in a solid mass of metal without the production +of eddy-currents within it; hence if the width of the slot-opening +is equal to or exceeds twice the length of the single air-gap, +lamination of the pole-pieces in the same plane as that of the +armature core becomes advisable.</p> + +<p>If the wires are threaded through holes or tunnels pierced close +to the periphery of the core, the same advantages are gained as +with open slots, and lamination of the pole-pieces is rendered unnecessary. +But on the other hand, the process of winding becomes +laborious and expensive, while the increase in the inductance of +<span class="pagenum"><a name="page769" id="page769"></a>769</span> +the coils owing to their being surrounded by a closed iron circuit +is prejudicial to sparkless commutation in the continuous-current +dynamo and to the regulation of the voltage of the alternator. A +compromise is found in the half-closed slot, which is not uncommon +in alternators, although the open slot is more usual in continuous-current +dynamos.</p> +</div> + +<table class="flt" style="float: right; width: 370px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:323px; height:323px" src="images/img769a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 11.</span></td></tr></table> + +<p>With the addition of more turns to the elementary drum loop +or of several complete coils, new questions arise, and in connexion +therewith the two great classes of machines, viz. alternators +and continuous-current dynamos, which have above been +treated side by side, diverge considerably, so that they are best +considered separately. The electromotive-force equation of +the alternator will be +first deduced, and subsequently +that of the +continuous-current +machine.</p> + +<p>Corresponding to the +number of pairs of +poles in the multipolar +alternator, it is evident +that there may also be +an equal number of +coils as shown diagrammatically +in fig. +11. The additional +coils, being similarly +situated in respect to +other pairs of poles, +will exactly reproduce +the E.M.F. of the original coil in phase and magnitude, so +that when they are connected in series the total E.M.F. will +be proportional to the number of coils in series; or if they +are connected in parallel, while not adding to the E.M.F., they +will proportionately increase the current-carrying capacity of +the combination. But within each coil the addition of more +loops will not cause an equal increase in the total E.M.F., unless +the phases of the component E.M.F.’s due to the several turns +are identical, and on this account it becomes necessary to +consider the effect of the width of the coil-side.</p> + +<table class="flt" style="float: left; width: 280px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:234px; height:283px" src="images/img769b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 12.</span></td></tr></table> + +<p>If the additional loops are wound within the same slots as the +original loop, the winding is “concentrated,” and each turn will +then add the same E.M.F. But if the coil-side is divided between +two or more slots, the phase of the E.M.F. yielded by the wires +in one slot being different from that of the wires in another +neighbouring slot, the sum of all the E.M.F.’s will be less than +the E.M.F. of one component loop +multiplied by the number of loops +or turns in the coil. The percentage +reduction in the E.M.F. +will depend upon the number of +the slots in a coil-side and their +distance apart, <i>i.e.</i> on the virtual +width of the coil-side expressed as +a fraction of the “pole-pitch” or +the distance measured along the +pitch-line from the centre of one +pole to the centre of a neighbouring +pole of opposite sign (fig. 12). +The winding is now to be regarded +as “grouped,” since a small +number of distinct phases corresponding +to the groups within the two, three or four slots have +to be compounded together. As the number of slots per coil-side +is increased, an approach is gradually made to the case +of “uniform distribution,” such as would obtain in a smooth-core +armature in which the turns of the coil are wound closely +side by side. Thus in the six-turn coil of fig. 12 A, which +represents the development of a two-pole armature when the +core is cut down to the shaft and opened out flat, there are +in effect six phases compounded together, each of which differs +but little from that of its next neighbour. With numerous +wires lying still closer together a large number of phases are +compounded until the distribution becomes practically uniform; +the decrease in the E.M.F., as compared with that of a single +turn multiplied by the number in series, is then immediately +dependent upon the width of the coil-side relatively to the pole-pitch.</p> + +<table class="flt" style="float: right; width: 250px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:199px; height:141px" src="images/img769c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 13.</span></td></tr></table> + +<p>If the width of the inner loop of fig. 12 A is less than that of +the pole-face, its two sides will for some portion of each period +be moving under the same pole, and “differential action” +results, the net E.M.F. being only that due to the difference +between the E.M.F.’s of the two sides. The loop of smallest +width must therefore exceed the width of pole-face, if direct +differential action is to be avoided. The same consideration also +determines the width of the outer loop; if this be deducted from +twice the pole-pitch, the difference should not be less than the +width of the pole-face, so that, <i>e.g.</i>, in a bipolar machine the outer +loop may stand to the S. pole exactly +as the inner loop stands to the N. +pole (fig. 13). In other words, the +width of the coil-side must not exceed +the width of the interpolar gap +between two fields. Evidently then +if the ratio of the pole-width to the +pole-pitch approaches unity, the +width of the coil-side must be very +small, and vice versa. A compromise between these conflicting +considerations is found if the pole is made not much +more than half the pole-pitch, and the width of the coil-side is +similarly about half the pole-pitch and therefore equal in width +to the pole (fig. 13). A single large coil, such as that of fig. 12 A, +can, however, equally well be divided into two halves by taking +the end-connexions of one half of the turns round the opposite +side of the shaft (fig. 12 B), as indeed has already been done +in fig. 13. Each sheaf or band of active wires corresponding +to a pole is thereby unaffected, but the advantages are gained +that the axial length of the end-connexions is halved, and that +they have less inductance. Thus if in fig. 11 there are four turns +per coil, fig. 14 is electrically equivalent to it (save that the coils +are here shown divided into two parallel paths, each carrying +half the total current). When the large coils are divided as +above described, it results that there are as many coils as there +are poles, the outer loop of the small coil having a width equal +to the pole-pitch, and the inner a width equal to the pole-face.</p> + +<table class="flt" style="float: left; width: 380px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:326px; height:324px" src="images/img769d.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 14.</span></td></tr></table> + +<p>Such is the form which the “single-phase alternator” takes, +but since only one-half of the armature core is now covered +with winding, an entirely +distinct but +similar set of coils +may be wound to form +a second armature +circuit between the +coils of the first circuit. +The phase of +this second circuit will +differ by 90° or a +quarter of a period +from that of the first, +and it may either be +used to feed an entirely +separate external +circuit possibly at a +different pressure or, if +it be composed of the +same number of turns and therefore gives the same voltage, it may +be interconnected with the first circuit to form a “quarter-phase +alternator,” as will be more fully described later. By an extension +of the same process, if the width of each side of a coil is +reduced to one-sixth of the pole-pitch, three armature circuits +can be wound on the same core, and a “three-phase alternator,” +giving waves of E.M.F. differing in phase by 120°, is obtained.</p> + +<div class="condensed"> +<p>The fundamental “electromotive-force equation” of the heteropolar +alternator can now be given a more definite form. Let Z<span class="su">a</span> be +the number of C. G. S. lines or the total flux, which issuing from any +<span class="pagenum"><a name="page770" id="page770"></a>770</span> +one pole flows through the armature core, to leave it by another pole +of opposite sign. Since each active wire cuts these lines, first as they +enter the armature core and then as they emerge from it to enter +another pole, the total number of lines cut in one revolution by any +one active wire is 2pZ<span class="su">a</span>. The time in seconds taken by one revolution +is 60/N. The average E.M.F. induced in each active wire in one +revolution being proportional to the number of lines cut divided +by the time taken to cut them is therefore 2Z<span class="su">a</span> (pN / 60) × 10<span class="sp">−8</span> volts. +The active wires which are in series and form one distinct phase +may be divided into as many bands as there are poles; let each +such band contain t active wires, which as before explained may +either form one side of a single large coil or the adjacent sides of +two coils when the large coil is divided into two halves. Since the +wires are joined up into loops, two bands are best considered together, +which with either arrangement yield in effect a single coil of t turns. +The average E.M.F.’s of all the wires in the two bands when added +together will therefore be 4Z<span class="su">a</span> (pN / 60)t × 10<span class="sp">−8</span>. But unless each band +is concentrated within a single slot, there must be some differential +action as they cross the neutral line between the poles, so that the +last expression is virtually the <i>gross</i> average E.M.F. of the loops +on the assumption that the component E.M.F.’s always act in agreement +round the coil and do not at times partially neutralize one +another. The <i>net</i> average E.M.F. of the coil as a whole, or the +arithmetical mean of all the instantaneous values of a half-wave +of the actual E.M.F. curve, is therefore reduced to an extent depending +upon the amount of differential action and so upon the width +of the coil-side when this is not concentrated. Let k′ = the coefficient +by which the gross average E.M.F. must be multiplied to +give the net average E.M.F.; then k′ may be called the “width-factor,” +and will have some value less than unity when the wires +of each band are spread over a number of slots. The net average +E.M.F. of the two bands corresponding to a pair of poles is thus +e<span class="su">av</span> = 4k′Z<span class="su">a</span> (pN / 60)t × 10<span class="sp">−8</span>.</p> + +<p>The shape of the curve of instantaneous E.M.F. of the coil must +further be taken into account. The “effective” value of an alternating +E.M.F. is equal to the square root of the mean square of its +instantaneous values, since this is the value of the equivalent unidirectional +and unvarying E.M.F., which when applied to a given +resistance develops energy at the same rate as the alternating +E.M.F., when the effect of the latter is averaged over one or any +whole number of periods. Let k″ = the ratio of the square root of the +mean square to the average E.M.F. of the coil, <i>i.e.</i> = effective E.M.F. / average E.M.F. +Since it depends upon the shape of the E.M.F. curve, k″ is also +known as the “form-factor”; thus if the length of gap between +pole-face and armature core and the spacing of the wires were so +graduated as to give a curve of E.M.F. varying after a sine law, +the form-factor would have the particular value of π/2 √2 = 1.11, +and to this condition practical alternators more or less conform. +The effective E.M.F. of the two bands corresponding to a pair of poles +is thus e<span class="su">eff</span> = 4k′k″Z<span class="su">a</span> (pN / 60)t × 10<span class="sp">−8</span>.</p> + +<p>In any one phase there are p pairs of bands, and these may be +divided into q parallel paths, where q is one or any whole number +of which p is a multiple. The effective E.M.F. of a complete phase +is therefore pe<span class="su">eff</span>/q. Lastly, if m = the number of phases into which +the armature winding is divided, and τ = the total number of active +wires on the armature counted all round its periphery, t = τ / 2pm, +and the effective E.M.F. per phase is E<span class="su">a</span> = 2k′k″Z<span class="su">a</span> (pNτ / 60mq) × 10<span class="sp">−8</span>.</p> + +<p>The two factors k′ and k″ may be united into one coefficient, and +the equation then takes its final form</p> + +<p class="center">E<span class="su">a</span> = 2KZ<span class="su">a</span> (pNτ / 60mq) × 10<span class="sp">−8</span> volts</p> +<div class="author1">(1<i>a</i>)</div> + +<p class="noind">In the alternator q is most commonly 1, and there is only one circuit +per phase; finally the value of K or the product of the width-factor +and the form-factor usually falls between the limits of 1 and 1.25.</p> +</div> + +<p>We have next to consider the effect of the addition of more +armature loops in the case of dynamos which give a unidirectional +E.M.F. in virtue of their split-ring collecting device, <i>i.e.</i> of the +type shown in fig. 7 with drum armature or its equivalent ring +form. As before, if the additional loops are wound in continuation +of the first as one coil connected to a single split-ring, this +coil must be more or less concentrated into a narrow band; +since if the width becomes nearly equal to or exceeds the width +of the interpolar gap, the two edges of the coil-side will just as in +the alternator act differentially against one another during part +of each revolution. The drum winding with a single coil thus +gives an armature of the H- or “shuttle” form invented by +Dr Werner von Siemens. Although the E.M.F. of such an +arrangement may have a much higher maximum value than that +of the curve of fig. 7 for a single loop, yet it still periodically +varies during each revolution and so gives a pulsating current, +which is for most practical uses unsuitable. But such pulsation +might be largely reduced if, for example, a second coil were +placed at right angles to the original coil and the two were connected +in series; the crests of the wave of E.M.F. of the second +coil will then coincide with the hollows of the first wave, and +although the maximum of the resultant curve of E.M.F. may +be no higher its fluctuations will be greatly decreased. A +spacial displacement of the new coils along the pole-pitch, +somewhat as in a polyphase machine, thus suggests itself, and +the process may be carried still further by increasing the number +of equally spaced coils, provided that they can be connected +in series and yet can have their connexion with the external +circuit reversed as they pass the neutral line between the poles.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:467px; height:260px" src="images/img770a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 15.</span></td></tr></table> + +<table class="flt" style="float: right; width: 150px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:98px; height:142px" src="images/img770b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 16.</span></td></tr></table> + +<p>Given two coils at right angles and with their split-rings +displaced through a corresponding angle of 90°, they may be +connected in series by joining one brush to the opposite brush +of the second coil, the external circuit being applied to the two +remaining brushes.<a name="fa14p" id="fa14p" href="#ft14p"><span class="sp">14</span></a> The same arrangement may again be repeated +with another pair of coils in parallel with the first, and +we thus obtain fig. 15 with four split-rings, their connexions to +the loops being marked by corresponding numerals; the four +coils will give the same E.M.F. as the two, but they will be jointly +capable of carrying twice the current, owing to their division +into two parallel circuits. Now in place of the four split-rings +may be employed the greatly simplified four-segment structure +shown in fig. 16, which serves precisely the same purpose as the +four split-rings but only requires two instead of eight brushes. +The effect of joining brush 2 in fig. 15 across to brush 3, brush 4 +to brush 5, 5 to 6, &c., has virtually been to connect the end +of coil A with the beginning of coil B, and the end of coil B with +the beginning of coil A′, and so on, until they form a continuous +closed helix. Each sector of fig. 16 will therefore replace two +halves of a pair of adjacent split-rings, if the end and beginning +of a pair of adjacent coils are connected to it in a regular order +of sequence. The four sectors are insulated from one another +and from the shaft, and the whole structure is +known as the “commutator,”<a name="fa15p" id="fa15p" href="#ft15p"><span class="sp">15</span></a> its function +being not simply to collect the current but also +to commute its direction in any coil as it passes +the interpolar gap. The principle of the “closed-coil +continuous-current armature” is thus reached, +in which there are at least two parallel circuits +from brush to brush, and from which a practically +steady current can be obtained. Each coil +is successively short-circuited, as a brush bridges +over the insulation between the two sectors which terminate +it; and the brushes must be so set that the period of +short-circuit takes place when the coil is generating little +or no E.M.F., <i>i.e.</i> when it is moving through the zone between +the pole-tips. The effect of the four coils in reducing the +percentage fluctuation of the E.M.F. is very marked, as +shown at the foot of fig. 15 (where the upper curve is the +resultant obtained by adding together the separate curves +of coils A and B), and the levelling process may evidently be +carried still further by the insertion of more coils and more +corresponding sectors in the commutator, until the whole +<span class="pagenum"><a name="page771" id="page771"></a>771</span> +armature is covered with winding. For example, figs. 17 and 18 +show a ring and a drum armature, each with eight coils and +eight commutator sectors; their resultant curve, on the assumption +that a single active wire gives the flat-topped curve of fig. 4, +will be the upper wavy line +of E.M.F. obtained by adding +together two of the resultant +curves of fig. 15, with a relative +displacement of 45°. The +amount of fluctuation for a +given number of commutator +sectors depends upon the shape +of the curve of E.M.F. yielded +by the separate small sections +of the armature winding; the +greater the polar arc, the less +the fluctuation. In practice, +with a polar arc equal to about +0.75 of the pitch, any number +of sectors over 32 per pair of +poles yields an E.M.F. which +is sensibly constant throughout +one or any number of +revolutions.</p> + +<table class="flt" style="float: right; width: 310px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:230px; height:174px" src="images/img771a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 17.</span></td></tr> +<tr><td class="figright1"><img style="width:260px; height:301px" src="images/img771b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 18.</span></td></tr></table> + +<div class="condensed"> +<p>The fundamental electro-motive-force +equation of the +continuous-current heteropolar +machine is easily obtained by +analogy from that of the alternator. +The gross average +E.W.F. from the two sides of +a drum loop without reference +to its direction is as before +4Z<span class="su">a</span> (pN / 60) × 10<span class="sp">−8</span> volts. But for +two reasons its net average E.M.F. +may be less; the span of the loop may be less than the pole-pitch, +so that even when the brushes are so set that the position of short-circuit +falls on the line where the field changes its direction, the two +sides of the loop for some little time act against each other; or, +secondly, even if the span of the loop be equal to the pole-pitch, the +brushes may be so set that the reversal of the direction of its induced +E.M.F. does not coincide with reversal of the current by the passage +of the coil under the brushes. The net average E.M.F. of the loop +is therefore proportional to the algebraic sum of the lines which it +cuts in passing from one brush to another, and this is equal to the +net amount of the flux which is included within the loop when +situated in the position of short-circuit under a brush. The amount +of this flux may be expressed as k′Z<span class="su">a</span> where k′ is some coefficient, +less than unity if the span of the coil be less than the pole-pitch, and +also varying with the position of +the brushes. The net average +E.M.F. of the loop is therefore</p> + +<p class="center">4k′Z<span class="su">a</span> (pN / 60) × 10<span class="sp">−8</span>.</p> + +<p>In practice the number of sections +of the armature winding is so +large and their distribution round +the armature periphery is so +uniform, that the sum total of +the instantaneous E.M.F.’s of +the several sections which are in +series becomes at any moment +equal to the net average E.M.F. +of one loop multiplied by the +number which are in series. If +the winding is divided into q +parallel circuits, the number of +loops in series is τ/2q, so that the +total E.M.F. is E<span class="su">a</span> = 2(k′ / q) Z<span class="su">a</span> (pN / 60)τ × 10<span class="sp">−8</span> volts. Thus as compared +with the alternator not only is there no division of the +winding into separate phases, but the form-factor k′ disappears, +since the effective and average E.M.F.’s are the same. Further +whereas in the alternator q may = 1, in the continuous-current +closed-coil armature there can never be less than two circuits in +parallel from brush to brush, and if more, their number must always +be a multiple of two, so that q can never be less than two and +must always be an even number. Lastly, the factor k′ is usually so +closely equal to 1, that the simplified equation may in practice be +adopted, viz.</p> + +<p class="center">E<span class="su">a</span> = (2/q) (ZpN / 60) τ × 10<span class="sp">−8</span> volts.</p> +<div class="author1">(1<i>b</i>)</div> + +<p>The fundamental equation of the electromotive force of the +dynamo in its fully developed forms (1 <i>a</i>) (and 1 <i>b</i>) may be compared +with its previous simple statement (I.). The three variable +terms still find their equivalents, but are differently expressed, the +density B<span class="su">g</span> being replaced by the total flux of one field Z<span class="su">a</span>, the length +L of the single active wire by the total number of such wires τ, and +the velocity of movement V by the number of revolutions per second. +Even when the speed is fixed, an endless number of changes may +be rung by altering the relative values of the remaining two factors; +and in successful practice these may be varied between fairly wide +limits without detriment to the working or economy of the machine. +While it may be said that the equation of the E.M.F. was implicitly +known from Faraday’s time onwards, the difficulty under which +designers laboured in early days was the problem of choosing the +correct relation of Z<span class="su">a</span> or τ for the required output; this, again, +was due chiefly to the difficulty of predetermining the total flux +before the machine was constructed. The general error lay in +employing too weak a field and too many turns on the armature, and +credit must here be given to the American inventors, E. Weston and +T.A. Edison, for their early appreciation of the superiority in +practical working of the drum armature, with comparatively few +active wires rotating in a strong field.</p> +</div> + +<p><i>Continuous-current Dynamos.</i>—On passing to the separate +consideration of alternators and continuous-current dynamos, +the chief constructive features of the latter will first +be taken in greater detail. As already stated in the +<span class="sidenote">The armature core.</span> +continuous-current dynamo the armature is usually +the rotating portion, and the necessity of laminating its core +has been generally described. The thin iron stampings employed +to build up the core take the form of circular washers or “disks,” +which in small machines are strung directly on the shaft; in +larger multipolar machines, in which the required radial depth +of iron is small relatively to the diameter, a central cast iron +hub supports the disks. Since the driving force is transmitted +through the shaft to the disks, they must in the former case be +securely fixed by keys sunk into the shaft; when a central hub +is employed (fig. 19) it is keyed to the shaft, and its projecting +arms engage in notches stamped on the inner circumference +of the disks, or the latter have dovetailed projections fitting +into the arms. The disks are then tightly compressed and +clamped between stout end-plates so as to form a nearly solid +iron cylinder of axial length slightly exceeding the corresponding +dimension of the poles. If the armature is more than 4 ft. +in diameter, the disks become too large to be conveniently +handled in one piece, and are therefore made in segments, which +are built up so as to break joint alternately. Prior to assemblage, +the external circumference of each disk is notched in a +stamping machine with the required number of slots to receive +the armature coils, and the longitudinal grooves thereby formed +in the finished core only require to have their sharp edges +smoothed off so that there may be no risk of injury to the +insulation of the coils.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:820px; height:260px" src="images/img771c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 19.</span></td></tr></table> + +<p>With open slots either the armature coils may be encased +with wrappings of oiled linen, varnished paper and thin flexible +micanite sheeting in order to insulate them electrically +from the iron slots in which they are afterwards embedded; +<span class="sidenote">Armature winding.</span> +or the slots may be themselves lined with +moulded troughs of micanite, &c., for the reception of the armature +coils, the latter method being necessary with half-closed +slots. According to the nature of the coils armatures may be +divided into the two classes of coil-wound and bar-wound. In +the former class, round copper wire, double-cotton covered, is +<span class="pagenum"><a name="page772" id="page772"></a>772</span> +employed, and the coils are either wound by hand directly on +to the armature core, or are shaped on formers prior to being +inserted in the armature slots. Hand-winding is now only +employed in very small bipolar machines, the process being +expensive and accompanied by the disadvantage that if one +section requires to be repaired, the whole armature usually has +to be dismantled and re-wound. Former-wound coils are, on +the other hand, economical in labour, perfectly symmetrical +and interchangeable, and can be thoroughly insulated before +they are placed in the slots. The shapers employed in the forming +process are very various, but are usually arranged to give +to the finished coil a lozenge shape, the two straight active +sides which fit into the straight slots being joined by V-shaped +ends; at each apex of the coil the wire is given a twist, so that +the two sides fall into different levels, an upper and a lower, +corresponding to the two layers which the coil-sides form on the +finished armature. Rectangular wire of comparatively small +section may be similarly treated, and if only one loop is required +per section, wide and thin strip can be bent into a complete +loop, so that the only soldered joints are those at the commutator +end where the loops are interconnected. But finally with +massive rectangular conductors, the transition must be made to +bar-winding, in which each bar is a half-loop, insulated by being +taped after it has been bent to the required shape; the separate +bars are arranged on the armature in two layers, and their ends +are soldered together subsequently to form loops. As a general +rule, whether bars or former-wound coils are employed, the +armature is barrel-wound, <i>i.e.</i> the end-connexions project outwards +from the slots with but little change of level, so that they +form a cylindrical mass supported on projections from the end-plates +of the core (fig. 19); but, in certain cases, the end-connexions +are bent downwards at right angles to the shaft, and +they may then consist of separate strips of copper bent to a +so-called butterfly or evolute shape.</p> + +<p>After the coils or loops have been assembled in the slots on the +armature core, and the commutator has been fixed in place on +the shaft, the soldering of the ends of the coils proceeds, by which +at once the union of the end of one coil with the beginning of the +next, and also their connexion to the commutator sectors, is +effected, and in this lies the essential part of armature winding.</p> + +<table class="flt" style="float: right; width: 290px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:240px; height:241px" src="images/img772a.jpg" alt="" /></td></tr> +<tr><td class="caption">Lap-loops<br /><span class="sc">Fig.</span> 20.</td></tr></table> + +<div class="condensed"> +<p>The development of the modern drum armature, with its numerous +coils connected in orderly sequence into a symmetrical winding, +as contrasted with the earlier Siemens armatures, was +initiated by F. von Hefner Alteneck (1871), and the laws +governing the interconnexion of the coils have now been +elaborated into a definite system of winding formulae. Whatever +the number of wires or bars in each side of a coil, <i>i.e.</i> whether it +consist of a single loop or of many turns, the final connexions of its +free ends are not thereby affected, and it may be mentally replaced +by a single loop with two active inducing sides. The coil-sides in +their final position are thus to be +regarded as separate primary elements, +even in number, and distributed +uniformly round the +armature periphery or divided into +small, equally spaced groups by +being located within the slots of a +toothed armature. Attention must +then be directed simply to the +span of the back connexion between +the elements at the end of the +armature further from the commutator, +and to the span of the +front connexion by which the last +turn of a coil is finally connected +to the first turn of the next in +sequence, precisely as if each coil +of many turns were reduced to a +single loop. In order to avoid +direct differential action, the span of the back connexion which +fixes the width of the coil must exceed the width of the pole-face, +and should not be far different from the pole-pitch; it +is usually a little less than the pole-pitch. Taking any one +element as No. 1 in fig. 20, where for simplicity a smooth-core +bipolar armature is shown, the number of winding-spaces, each +to be occupied by an element, which must be counted off in order +to find the position of the next element in series, is called the “pitch” +of the end-connexion, front or back, as the case may be. Thus the +back pitch of the winding as marked by the dotted line in fig. 20 is +7, the second side of the first loop being the element numbered +1 + 7 = 8. In forming the front end-connexion which completes +the loop and joins it to the next in succession, two possible cases +present themselves. By the first, or “lap-winding,” the front +end-connexion is brought backwards, and passing on its way to a +junction with a commutator sector is led to a third element lying +within the two sides of the first loop, <i>i.e.</i> the second loop starts with +the element, No. 3, lying next but one to the starting-point of the +first loop. The winding therefore returns backwards on itself to form +each front end, but as a whole it works continually forwards round +the armature, until it finally “re-enters,” after every element has +been traversed. The development of the completed winding on a +flat surface shows that it takes the form of a number of partially +overlapping loops, whence its name originates. The firm-line +portion of fig. 21 gives the development of an armature similar to +that of fig. 18 when cut through at the point marked X and opened +out; two of the overlapping loops +are marked thereon in heavy lines. +The multipolar lap-wound armature +is obtained by simply repeating the +bipolar winding p times, as indicated +by the dotted additions of fig. 21 +which convert it from a two-pole to +a four-pole machine. The characteristic +feature of the lap-wound armature +is that there are as many +parallel paths from brush to brush, +and as many points at which the +current must be collected, as there +are poles. As the bipolar closed-coil +continuous-current armature has +been shown to consist in reality of +two circuits in parallel, each giving +the same E.M.F. and carrying half +the total current, so the multipolar +lap-wound drum consists of p pairs of parallel paths, each giving +the same E.M.F. and carrying 1/2p of the total current. Thus in +equation 1.b we have q = 2p, and the special form which the <i>E.M.F. +equation of the lap-wound armature</i> takes is E<span class="su">a</span> = Z<span class="su">a</span> (N / 60)τ × 10<span class="sp">−8</span> +volts. All the brushes which are of the same sign must be connected +together in order to collect the total armature current. The several +brush-sets of the multipolar lap-wound machine may again be +reduced to two by “cross-connexion” of sectors situated 360°/p +apart, but this is seldom done, since the commutator must then be +lengthened p times in order to obtain the necessary brush contact-surface +for the collection of the entire current.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:476px; height:284px" src="images/img772b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 21.</span></td></tr> +<tr><td class="figcenter"><img style="width:449px; height:229px" src="images/img772d.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 23.</span></td></tr></table> + +<table class="flt" style="float: right; width: 290px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:237px; height:245px" src="images/img772c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Wave-loops<br />Fig. 22.</span></td></tr></table> + +<p>But for many purposes, especially where the voltage is high and +the current small, it is advantageous to add together the inductive +effect of the several poles of the multipolar machine by +throwing the E.M.F’s of half the total number of elements +<span class="sidenote">Wave-winding.</span> +into series, the number of parallel circuits being conversely +again reduced to two. This is effected by the second method of +winding the closed-coil continuous current drum, which is known +<span class="pagenum"><a name="page773" id="page773"></a>773</span> +as “wave-winding.” The front pitch is now in the same direction +round the armature as the back pitch (fig. 22), so that the beginning +of the second loop, <i>i.e.</i> element No. 15, lies outside the first loop. +After p loops have been formed and as many elements have been +traversed as there are poles, the distance covered either falls short of +or exceeds a complete tour of the armature by two winding-spaces, +or the width of two elements. A second and third tour are then +made, and so on, until finally the winding again closes upon itself. +When the completed winding is developed as in fig. 23, it is seen +to work continuously forwards round the armature in zigzag waves, +one of which is marked in heavy lines, and the number of complete +tours is equal to the average of the back and front pitches. Since +the number of parallel circuits from brush to brush is q = 2, the +<i>E.M.F. equation of the wave-wound drum</i> is E<span class="su">a</span> = pZ<span class="su">a</span> (N / 60)τ × 10<span class="sp">−8</span> +volts. Only two sets of brushes are necessary, but in order to +shorten the length of the commutator, other sets may also be added +at the point of highest and lowest potential up to as many in number +as there are poles. Thus the advantage of the wave-wound armature +is that for a given voltage and number of poles the number of active +wires is only 1/p of that in the lap-wound drum, each being of larger +cross-section in order to carry p times as much current; hence the +ratio of the room occupied by the insulation to the copper area is +less, and the available space is better utilized. A further advantage +is that the two circuits from brush to brush consist of elements +influenced by all the poles, so that if for any reason, such as eccentricity +of the armature within the bore of the pole-pieces, or want of +uniformity in the magnetic qualities of the poles, the flux of each +field is not equal to that of every other, the equality of the voltage +produced by the two halves of the winding is not affected thereby.</p> + +<p>In appearance the two classes of armatures, lap and wave, may +be distinguished in the barrel type of winding by the slope of the +upper layer of back end-connexions, and that of the front connexions +at the commutator end being parallel to one another in the latter, +and oppositely directed in the former.</p> +</div> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:520px; height:275px" src="images/img773a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 24.</span></td></tr></table> + +<p>After completion of the winding, the end-connexions are +firmly bound down by bands of steel or phosphor bronze binding +wire, so as to resist the stress of centrifugal force. In the case +of smooth-surface armatures, such bands are also placed at +intervals along the length of the armature core, but in toothed +armatures, although the coils are often in small machines secured +in the slots by similar bands of a non-magnetic high-resistance +wire, the use of hard-wood wedges driven into notches at the +sides of the slots becomes preferable, and in very large machines +indispensable. The external appearance of a typical armature +with lap-winding is shown in fig. 24.</p> + +<p>A sound mechanical construction of the commutator is of +vital importance to the good working of the continuous-current +dynamo. The narrow, wedge-shaped sectors of hard-drawn +copper, with their insulating strips of thin +<span class="sidenote">The commutator.</span> +mica, are built up into a cylinder, tightly clamped +together, and turned in the lathe; at each end a V-shaped +groove is turned, and into these are fitted rings of micanite +of corresponding section (fig. 19); the whole is then slipped +over a cast iron sleeve, and at either end strong rings are forced +into the V-shaped grooves under great pressure and fixed by a +number of closely-pitched tightening bolts. In dynamos driven +by steam-turbines in which the peripheral speed of the commutator +is very high, rings of steel are frequently shrunk on the +surface of the commutator at either end and at its centre. But +in every case the copper must be entirely insulated from the +supporting body of metal by the interposition of mica or micanite +and the prevention of any movement of the sectors under +frequent and long-continued heating and cooling calls for the +greatest care in both the design and the manufacture.</p> + +<p>On passing to the second fundamental part of the dynamo, +namely, the field-magnet, its functions may be briefly recalled as +follows:—It has to supply the magnetic flux; to provide +for it an iron path as nearly closed as possible +<span class="sidenote">Forms of field-magnet.</span> +upon the armature, save for the air-gaps which must +exist between the pole-system and the armature core, +the one stationary and the other rotating; and, lastly, it has +to give the lines such direction and intensity within the air-gaps +that they may be cut by the armature wires to the best advantage. +Roughly corresponding to the three functions above +summarized are the three portions which are more or less differentiated +in the complete structure. These are: (1) the magnet +“cores” or “<i>limbs</i>,” carrying the exciting coils whereby the +inert iron is converted into an electro-magnet; (2) the <i>yoke</i>, +which joins the limbs together and conducts the flux between +them; and (3) the <i>pole-pieces</i>, which face the armature and +transmit the lines from the limbs through the air-gap to the +armature core, or vice versa.</p> + +<table class="flt" style="float: right; width: 190px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:140px; height:165px" src="images/img773b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 25.</span></td></tr></table> + +<div class="condensed"> +<p>Of the countless shapes which the field-magnet may take, it +may be said, without much exaggeration, that almost all have been +tried; yet those which have proved economical +and successful, and hence have met with general +adoption, may be classed under a comparatively +small number of types. For bipolar +machines the <i>single horse-shoe</i> (fig. 25), which +is the lineal successor of the permanent magnet +employed in the first magneto-electric machines, +was formerly very largely used. It takes two +principal forms, according as the pole-pieces and +armature are above or beneath the magnet +limbs and yoke. The “over-type” form is +best suited to small belt-driven dynamos, while +the “under-type” is admirably adapted to be +directly driven by the steam-engine, the armature +shaft being immediately coupled to the crank-shaft of the engine. +In the latter case the magnet must be mounted on non-magnetic +supports of gun-metal or zinc, so as to hold it at some distance +away from the iron bedplate which carries both engine and dynamo; +otherwise a large proportion of the flux which passes through the +magnet limbs would leak through the bedplate across from pole +to pole without passing through the armature core, and so would not +be cut by the armature wires.</p> + +<table class="flt" style="float: left; width: 270px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:219px; height:155px" src="images/img773c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 26.</span></td></tr></table> + +<p>Next may be placed the “Manchester” field (fig. 26)—the type +of a divided magnetic circuit in which the flux forming one field or +pole is divided between two magnets. An exciting coil is placed +on each half of the double horse-shoe magnet, the pair being so +wound that consequent poles are formed above and below the +armature. Each magnet thus carries one-half of the total flux, the +lines of the two halves uniting to +form a common field where they issue +forth into or leave the air-gaps. The +pole-pieces may be lighter than in the +single horse-shoe type, and the field +is much more symmetrical, whence it +is well suited to ring armatures of +large diameter. Yet these advantages +are greatly discounted by the excessive +magnetic leakage, and by the increased +weight of copper in the exciting coils. +Even if the greater percentage which +the leakage lines bear to the useful flux is neglected, and the cross +sectional area of each magnet core is but half that of the equivalent +single horse-shoe, the weight of wire in the double magnet for the +same rise of temperature in the coils must be some 40% more than +in the single horse-shoe, and the rate at which energy is expended +in heating the coils will exceed that of the single horse-shoe in the +same proportion.</p> + +<p>Thirdly comes the two-pole <i>ironclad</i> type, so called from the +exciting coil being more or less encased by the iron yoke; this latter +is divided into two halves, which pass on either side of the armature. +Unless the yoke be kept well away from the polar edges and armature, +the leakage across the air into the yoke becomes considerable, +especially if only one exciting coil is used, as in fig. 27 <span class="scs">A</span>; it is better, +therefore, to divide the excitation between two coils, as in fig. 27 <span class="scs">B</span>, +when the field also becomes symmetrical.</p> + +<p>From this form is easily derived the <i>multipolar</i> type of fig. 28 or +fig. 29, which is by far the most usual for any number of poles from +four upwards; its leakage coefficient is but small, and it is economical +in weight both of iron and copper.</p> + +<table class="flt" style="float: right; width: 390px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:326px; height:199px" src="images/img774a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 27.</span></td></tr></table> + +<p>As regards the materials of which magnets are made, generally +speaking there is little difference in the permeability of “wrought +iron” or “mild steel forgings” and good “cast steel”; typical +<span class="pagenum"><a name="page774" id="page774"></a>774</span> +<span class="sidenote">Materials of magnets.</span> +(B, H) curves connecting the magnetizing force required with different +flux-densities for these materials are given under <span class="sc"><a href="#artlinks">Electromagnetism</a></span>. +On the other hand there is a marked inferiority in the +case of “cast iron,” which for a flux-density of B = +8000 C.G.S. lines per sq. cm. requires practically the +same number of ampere-turns per centimetre length as steel requires +for B = 16,000. Whatever the material, if the flux-density be pressed +to a high value the ampere-turns are very largely increased owing to +its approaching saturation, and this implies either a large amount +of copper in the field coils or an undue expenditure of electrical +energy in their excitation. Hence there is a limit imposed by +practical considerations to the density at which the magnet should +be worked, and this limit may be placed at about B = 16,000 for +wrought iron or steel, and at half this value for cast iron. For +a given flux, therefore, the cast iron magnet must have twice the +sectional area and be twice as heavy, although this disadvantage +is partly compensated +by its greater cheapness. +If, however, cast +iron be used for the +portion of the magnetic +circuit which is covered +with the exciting coils, +the further disadvantage +must be added +that the weight of copper +on the field-magnet +is much increased, so +that it is usual to employ +forgings or cast +steel for the magnet +cores on which the coils are wound. If weight is not a disadvantage, +a cast iron yoke may be combined with the wrought iron or cast +steel magnet cores. An absence of joints in the magnetic circuit +is only desirable from the point of view of economy of expense in +machining the component parts during manufacture; when the +surfaces which abut against each other are drawn firmly together +by screws, the want of homogeneity at the joint, which virtually +amounts to the presence of a very thin film of air, produces little +or no effect on the total reluctance by comparison with the very +much longer air-gaps surrounding the armature. In order to reduce +the eddy-currents in the pole-pieces, due to the use of toothed +armatures with relatively wide slots, the poles themselves must be +laminated, or must have fixed to them laminated pole-shoes, built +up of thin strips of mild steel riveted together (as shown in fig. 29).</p> + +<table class="flt" style="float: left; width: 256px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:206px; height:214px" src="images/img774b.jpg" alt="" /></td></tr> +<tr><td class="caption1"><span class="sc">Fig. 28.</span></td></tr></table> + +<p>However it be built up, the mechanical strength of the magnet +system must be carefully considered. Any two surfaces between +which there exists a field of density B<span class="su">g</span> experience a force tending +to draw them together proportional to the square of the density, +and having a value of B<span class="su">g</span>² / (1.735 × 10<span class="su">6</span>) ℔ per sq. in. of surface, +over which the density may be regarded as having the uniform +value B<span class="su">g</span>. Hence, quite apart from the torque with which the +stationary part of the dynamo tends to +turn with the rotating part as soon as +current is taken out of the armature, +there exists a force tending to make the +pole-pieces close on the armature as soon +as the field is excited. Since both armature +and magnet must be capable of +resisting this force, they require to be +rigidly held; although the one or the other +must be capable of rotation, there should +otherwise be no possibility of one part of +the magnetic circuit shifting relatively +to any other part. An important conclusion +may be drawn from this circumstance. +If the armature be placed +exactly concentric within the bore of the poles, and the two or +more magnetic fields be symmetrical about a line joining their +centres, there is no tendency for the armature core to be drawn in +one direction more than in another; but if there is any difference +between the densities of the several fields, it will cause an unbalanced +stress on the armature and its shaft, under which it will bend, and +as this bending is continually reversed relatively to the fibres of the +shaft, they will eventually become weakened and give way. Especially +is this likely to take place in dynamos with short air-gaps, +wherein any difference in the lengths of the air-gaps produces a +much greater percentage difference in the flux-density than in +dynamos with long air-gaps. In toothed armatures with short +air-gaps the shaft must on this account be sufficiently strong to +withstand the stress without appreciable bending.</p> +</div> + +<p>Reference has already been made to the importance in dynamo +design of the <i>predetermination of the flux</i> due to a given number +of ampere-turns wound on the field-magnet, or, conversely, +of the number of ampere-turns which must +<span class="sidenote">The magnetic circuit.</span> +be furnished by the exciting coils in order that a certain +flux corresponding to one field may flow through the +armature core from each pole. An equally important problem +is the correct proportioning of the field-magnet, so that the +useful flux Z<span class="su">a</span> may be obtained with the greatest economy in +materials and exciting energy. The key to the two problems is +to be found in the concept of a magnetic circuit as originated by +H.A. Rowland and R.H.M. Bosanquet;<a name="fa16p" id="fa16p" href="#ft16p"><span class="sp">16</span></a> and the full solution +of both may be especially connected with the name of Dr J. +Hopkinson, from his practical application of the concept in his +design of the Edison-Hopkinson machine, and in his paper on +“Dynamo-Electric Machinery.”<a name="fa17p" id="fa17p" href="#ft17p"><span class="sp">17</span></a> The publication of this paper +in 1886 begins the second era in the history of the dynamo; +it at once raised its design from the level of empirical rules-of-thumb +to a science, and is thus worthy to be ranked as the +necessary supplement of the original discoveries of Faraday. +The process of predetermining the necessary ampere-turns is +described in a simple case under <span class="sc"><a href="#artlinks">Electromagnetism</a></span>. In its +extension to the complete dynamo, it consists merely in the +division of the magnetic circuit into such portions as have the +same sectional area and permeability and carry approximately +the same total flux; the difference of magnetic potential that +must exist between the ends of each section of the magnet in +order that the flux may pass through it is then calculated +<i>seriatim</i> for the several portions into which the magnetic circuit +is divided, and the separate items are summed up into one +magnetomotive force that must be furnished by the exciting +coils.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:517px; height:316px" src="images/img774c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 29.</span></td></tr></table> + +<div class="condensed"> +<p>The chief sections of the magnetic circuit are (1) the air-gaps, +(2) the armature core, and (3) the iron magnet.</p> + +<p>The <i>air-gap</i> of a dynamo with smooth-core armature is partly +filled with copper and partly with the cotton, mica, or other materials +used to insulate the core and wires; all these substances are, however, +sensibly non-magnetic, so that the whole interferric gap +between the iron of the pole-pieces and the iron of the armature +may be treated as an air-space, of which the permeability is constant +for all values of the flux density, and in the C.G.S. system is unity. +Hence if l<span class="su">g</span> and A<span class="su">g</span> be the length and area of the single air-gap in cm. +and sq. cm., the reluctance of the double air-gap is 2l<span class="su">g</span> / A<span class="su">g</span>, and the +difference of magnetic potential required to pass Z<span class="su">a</span> lines over this +reluctance is Z<span class="su">a</span>·2l<span class="su">g</span> / A<span class="su">g</span> = B<span class="su">g</span>·2l<span class="su">g</span>; or, since one ampere-turn gives +1.257 C.G.S. units of magnetomotive force, the exciting power in +ampere-turns required over the two air-gaps is X<span class="su">g</span> = B<span class="su">g</span>·2l<span class="su">g</span> / 1.257 = +0.8B<span class="su">g</span>·2l<span class="su">g</span>. In the determination of the area A<span class="su">g</span> small allowance +must be made for the fringe of lines which extend beyond the actual +polar face. In the toothed armature with open slots, the lines are +no longer uniformly distributed over the air-gap area, but are +graduated into alternate bands of dense and weak induction corresponding +to the teeth and slots. Further, the lines curve round into +the sides of the teeth, so that their average length of path in the +air and the air-gap reluctance is not so easily calculated. Allowance +must be made for this by taking an increased length of air-gap += ml<span class="su">g</span>, where m is the ratio <i>maximum density/mean density</i>, of which +the value is chiefly determined by the ratios of the width of tooth +to width of slot and of the width of slot to the air-gap between +pole-face and surface of the armature core.</p> + +<p><span class="pagenum"><a name="page775" id="page775"></a>775</span></p> + +<p>The <i>armature core</i> must be divided into the teeth and the core +proper below the teeth. Owing to the tapering section of the teeth, +the density rises towards their root, and when this reaches a high +value, such as 18,000 or more lines per sq. cm., the saturation of +the iron again forces an increasing proportion of the lines outwards +into the slot. A distinction must then be drawn between the +“apparent” induction which would hold if all the lines were concentrated +in the teeth, and the “real” induction. The area of the +iron is obtained by multiplying the number of teeth under the pole-face +by their width and by the net length of the iron core parallel +to the axis of rotation. The latter is the gross length of the armature +less the space lost through the insulating varnish or paper between +the disks or through the presence of ventilating ducts, which are +introduced at intervals along the length of the core. The former +deduction averages about 7 to 10% of the gross length, while the +latter, especially in large multipolar machines, is an even more +important item. Alter calculating the density at different sections +of the teeth, reference has now to be made to a (B, H) or flux-density +curve, from which may be found the number of ampere-turns +required per cm. length of path. This number may be expressed +as a function of the density in the teeth, and ƒ(B<span class="su">t</span>) be its average +value over the length of a tooth, the ampere-turns of excitation +required over the teeth on either side of the core as the lines of one +field enter or leave the armature is X<span class="su">t</span> = ƒ(B<span class="su">t</span>)·2l<span class="su">t</span>, where l<span class="su">t</span> is the +length of a single tooth in cm.</p> + +<p>In the core proper below the teeth the length of path continually +shortens as we pass from the middle of the pole towards the centre +line of symmetry. On the other hand, as the lines gradually accumulate +in the core, their density increases from zero midway under the +poles until it reaches a maximum on the line of symmetry. The +two effects partially counteract one another, and tend to equalize +the difference of magnetic potential required over the paths of +varying lengths; but since the reluctivity of the iron increases +more rapidly than the density of the lines, we may approximately +take for the length of path (l<span class="su">a</span>) the minimum peripheral distance +between the edges of adjacent pole-faces, and then assume the +maximum value of the density of the lines as holding throughout +this entire path. In ring and drum machines the flux issuing from +one pole divides into two halves in the armature core, so that the +maximum density of lines in the armature is B<span class="su">a</span> = Z<span class="su">a</span> / 2ab, where a = +the radial depth of the disks in centimetres and b = the net length of +iron core. The total exciting power required between the pole-pieces +is therefore, at no load, X<span class="su">p</span> = X<span class="su">g</span> + X<span class="su">t</span> + X<span class="su">a</span>, where X<span class="su">a</span> = +ƒ(B<span class="su">a</span>)·l<span class="su">a</span>; in order, however, to allow for the effect of the armature +current, which increases with the load, a further term X<span class="su">b</span>, must be +added.</p> + +<table class="flt" style="float: right; width: 290px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:236px; height:171px" src="images/img775a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 30.</td></tr></table> + +<p>In the continuous-current dynamo it may be, and usually is, +necessary to move the brushes forward from the interpolar line of +symmetry through a small angle in the direction of rotation, in +order to avoid sparking between the brushes and the commutator +(<i>vide infra</i>). When the dynamo is giving current, the wires on +either side of the diameter of commutation form a current-sheet +flowing along the surface of the armature from end to end, and +whatever the actual end-connexions of the wires, the wires may be +imagined to be joined together into a system of loops such that the +two sides of each loop are carrying current in opposite directions. +Thus a number of armature ampere-turns are formed, and their +effect on the entire system of magnet and armature must be taken +into account. So long as the diameter of commutation coincides +with the line of symmetry, the armature may be regarded as a +cylindrical electromagnet producing a flux of lines, as shown in +fig. 30. The direction of the self-induced flux in the air-gaps is +the same as that of the lines of the external field in one quadrant +on one side of DC, but opposed to it in the other quadrant on the +same side of DC; hence in the +resultant field due to the combined +action of the field-magnet and +armature ampere-turns, the flux is +as much strengthened over the one +half of each polar face as it is +weakened over the other, and the +total number of lines is unaffected, +although their distribution is +altered. The armature ampere-turns +are then called <i>cross-turns</i>, +since they produce a cross-field, +which, when combined with the symmetrical +field, causes the leading +pole-corners <i>ll</i> to be weakened and the trailing pole-corners tt to be +strengthened, the neutral line of zero field being thus twisted forwards +in the direction of rotation. But when the brushes and diameter of +commutation are shifted forward, as shown in fig. 31, it will be seen +that a number of ampere-turns, forming a zone between the lines +D<i>n</i> and <i>m</i>C, are in effect wound immediately on the magnetic circuit +proper, and this belt of ampere-turns is in direct opposition to the +ampere-turns of the field, as shown by the dotted and crossed wires +on the pole-pieces. The armature ampere-turns are then divisible +into the two bands, the <i>back-turns</i>, included within twice the angle +of lead λ, weakening the field, and the cross-turns, bounded by the +lines Dm, nC, again producing distortion of the weakened symmetrical +field. If, therefore, a certain flux is to be passed through +the armature core in opposition to the demagnetizing turns, the +difference of magnetic potential between the pole-faces must include +not only X<span class="su">a</span>, X<span class="su">t</span>, and X<span class="su">g</span>, but also an item X<span class="su">b</span>, in order to balance the +“back” ampere-turns of the armature. The amount by which +the brushes must be shifted forward increases with the armature +current, and in corresponding proportion the back ampere-turns +are also increased, their value being cτ2λ / 360°, where c = the current +carried by each of the τ active wires. Thus the term X<span class="su">b</span>, takes into +account the effect of the armature reaction on the total flux; it +varies as the armature current and angle of lead required to avoid +sparking are increased; and the reason for its introduction in the +fourth place (X<span class="su">p</span> = X<span class="su">g</span> + X<span class="su">t</span> + X<span class="su">a</span> + X<span class="su">b</span>), is that it increases the magnetic +difference of potential which +must exist between the poles of the +dynamo, and to which the greater +part of the leakage is due. The +leakage paths which are in parallel +with the armature across the poles +must now be estimated, and so a new +value be derived for the flux at the +commencement of the <i>iron-magnet</i> +path. If P = their joint permeance, +the leakage flux due to the difference +of potential at the poles is +z<span class="su">l</span> = 1.257X<span class="su">p</span> × P, and this must be added to the useful flux +Z<span class="su">a</span>, or Z<span class="su">p</span> = Z<span class="su">a</span> + Z<span class="su">l</span>. There are also certain leakage paths in +parallel with the magnet cores, and upon the permeance of these +a varying number of ampere-turns is acting as we proceed along +the magnet coils; the magnet flux therefore increases by the addition +of leakage along the length of the limbs, and finally reaches +a maximum near the yoke. Either, then, the density in the magnet +B<span class="su">m</span> = Z<span class="su">m</span> / A<span class="su">m</span> will vary if the same sectional area be retained throughout, +or the sectional area of the magnet must itself be progressively +increased. In general, sufficient accuracy will be obtained by +assuming a certain number of additional leakage lines z<span class="su">n</span> as traversing +the entire length of magnet limbs and yoke (= l<span class="su">m</span>), so that the +density in the magnet has the uniform value B<span class="su">m</span> = (Z<span class="su">p</span> + z<span class="su">n</span>) / A<span class="su">m</span>. +The leakage flux added on actually within the length of the magnet +core or z<span class="su">n</span> will be approximately equal to half the total M.M.F. of +the coils multiplied by the permeance of the leakage paths around +one coil. The corresponding value of H can then be obtained from +the (B, H) curve of the material of which the magnet is composed, +and the ampere-turns thus determined must be added to X<span class="su">p</span>, or +X = X<span class="su">p</span> + X<span class="su">m</span>, where X<span class="su">m</span> = ƒ(B<span class="su">m</span>)l<span class="su">m</span>. The final equation for the exciting +power required on a magnetic circuit as a whole will therefore +take the form</p> + +<p class="center">X = AT = 0.8B<span class="su">g</span>·2l<span class="su">g</span> + ƒ(B<span class="su">t</span>) 2l<span class="su">t</span> + ƒ(B<span class="su">a</span>) l<span class="su">a</span> + X<span class="su">b</span> + ƒ(B<span class="su">m</span>) l<span class="su">m</span>.</p> +<div class="author">(3)</div> + +<table class="flt" style="float: right; width: 275px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:225px; height:151px" src="images/img775b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 31.</span></td></tr></table> + +<p>If the magnet cores are of wrought iron or cast steel, and the yoke +is of cast iron, the last term must be divided into two portions +corresponding to the different materials, <i>i.e.</i> into f(B<span class="su">m</span>)l<span class="su">m</span> + f(B<span class="su">y</span>)l<span class="su">y</span>. +In the ordinary multipolar machine with as many magnet-coils as +there are poles, each coil must furnish half the above number of +ampere-turns.</p> + +<p>Since no substance is impermeable to the passage of magnetic flux, +the only form of magnetic circuit free from leakage is one uniformly +wound with ampere-turns over its whole length. The +reduction of the <i>magnetic leakage</i> to a minimum in any +<span class="sidenote">Magnetic leakage.</span> +given type is therefore primarily a question of distributing +the winding as far as possible uniformly upon the circuit, and +as the winding must be more or less concentrated into coils, it resolves +itself into the necessity of introducing as long air-paths as possible +between any surfaces which are at different magnetic potentials. +No iron should be brought near the machine which does not form +part of the magnetic circuit proper, and especially no iron should be +brought near the poles, between which the difference of magnetic +potential practically reaches its maximum value. In default of a +machine of the same size or similar type on which to experiment, +the probable direction of the leakage flux must be assumed from +the drawing, and the air surrounding the machine must be mapped +out into areas, between which the permeances are calculated as +closely as possible by means of such approximate formulae as those +devised by Professor G. Forbes.</p> + +<p>In the earliest “magneto-electric” machines permanent steel +magnets, either simple or compound, were employed, and for many +years these were retained in certain alternators, some +of which are still in use for arc lighting in lighthouses. +<span class="sidenote">Excitation of field-magnet.</span> +But since the field they furnish is very weak, a great +advance was made when they were replaced by soft +iron electromagnets, which could be made to yield a much more +intense flux. As early as 1831 Faraday<a name="fa18p" id="fa18p" href="#ft18p"><span class="sp">18</span></a> experimented with electromagnets, +and after 1850 they gradually superseded the permanent +magnet. When the total ampere-turns required to excite the +electromagnet have been determined, it remains to decide how +the excitation shall be obtained; and, according to the method +<span class="pagenum"><a name="page776" id="page776"></a>776</span> +adopted, continuous-current machines may be divided into four +well-defined classes.</p> + +<table class="flt" style="float: right; width: 300px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:253px; height:245px" src="images/img776a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 32.</span></td></tr></table> + +<p>The simplest method, and that which was first used, is <i>separate +excitation</i> from some other source of direct current, which may +be either a primary or a secondary battery or another dynamo +(fig. 32). But since the armature yields a continuous current, it +was early suggested (by J. Brett in 1848 and F. Sinsteden in 1851) +that this current might be utilized to increase the flux; combinations +of permanent and electromagnets were therefore next employed, +acting either on the main armature or on separate armatures, until +in 1867 Dr Werner von Siemens +and Sir C. Wheatstone almost +simultaneously discovered that +the dynamo could be made <i>self-exciting</i> +through the residual +magnetism retained in the soft +iron cores of the electromagnet. +The former proposed to take the +whole of the current round the +magnet coils which were in series +with the armature and external +circuit, while the latter proposed +to utilize only a portion derived +by a shunt from the main circuit; +we thus arrive at the +second and third classes, namely, +<i>series</i> and <i>shunt</i> machines. The +starting of the process of excitation +in either case is the +same; when the brushes are touching the commutator and the +armature is rotated, the small amount of flux left in the magnet +is cut by the wires, and a very small current begins to flow round +the closed circuit; this increases the flux, which in turn further +increases the E.M.F. and current, until, finally, the cumulative effect +stops through the increasing saturation of the iron cores. Fig. 33, +illustrating the <i>series</i> machine, shows the winding of the exciting +coils to be composed of a few turns of thick wire. Since the current +is undivided throughout the whole circuit, the resistance of both the +armature and field-magnet winding must be low as compared with +that of the external circuit, if the useful power available at the +terminals of the machine is to form a large percentage of the total +electrical power—in other words, if the efficiency is to be high. +Fig. 34 shows the third method, in which the winding of the field-magnets +is a <i>shunt</i> or fine-wire circuit of many turns applied to the +terminals of the machine; in this ease the resistance of the shunt +must be high as compared with that of the external circuit, in order +that only a small proportion of the total energy may be absorbed +in the field.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter" colspan="2"><img style="width:491px; height:234px" src="images/img776b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 33.</span></td> +<td class="caption"><span class="sc">Fig. 34.</span></td></tr></table> + +<p>Since the whole of the armature current passes round the field-magnet +of the series machine, any alteration in the resistance of +the external circuit will affect the excitation and also the voltage. +A curve connecting together corresponding values of external +current and terminal voltage for a given speed of rotation is known +as the <i>external-characteristic</i> of the machine; in its main features +it has the same appearance as a curve of magnetic flux, but when +the current exceeds a certain amount it begins to bend downwards +and the voltage decreases. The reason for this will be found in +the armature reaction at large loads, which gradually produces a +more and more powerful demagnetizing effect, as the brushes are +shifted forwards to avoid sparking; eventually the back ampere-turns +overpower any addition to the field that would otherwise +be due to the increased current flowing round the magnet. The +“external characteristic” for a shunt machine has an entirely +different shape. The field-magnet circuit being connected in +parallel with the external circuit, the exciting current, if the applied +voltage remains the same, is in no way affected by alterations in the +resistance of the latter. As, however, an increase in the external +current causes a greater loss of volts in the armature and a greater +armature reaction, the terminal voltage, which is also the exciting +voltage, is highest at no load and then diminishes. The fall is at +first gradual, but after a certain critical value of the armature +current is reached, the machine is rapidly demagnetized and loses +its voltage entirely.</p> + +<table class="flt" style="float: right; width: 250px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:201px; height:230px" src="images/img776c.jpg" alt="" /></td></tr> +<tr><td class="caption1"><span class="sc">Fig.</span> 35.</td></tr></table> + +<p>The last method of excitation, namely, <i>compound-winding</i> (fig. 35), +is a combination of the two preceding, and was first used by S.A. +Varley and by C.F. Brush. If a machine is in the first instance shunt-wound, +and a certain number of series-turns are added, the latter, since +they carry the external current, can be made to counteract the effect +which the increased external current +would have in lowering the voltage +of the simple shunt machine. The +ampere-turns of the series winding +must be such that they not only +balance the increase of the demagnetizing +back ampere-turns on the +armature, but further increase the +useful flux, and compensate for the +loss of volts over their own resistance +and that of the armature. The machine +will then give for a constant speed +a nearly constant voltage at its terminals, +and the curve of the external +characteristic becomes a straight line +for all loads within its capacity. Since +with most prime movers an increase of +the load is accompanied by a drop in +speed, this effect may also be counteracted; while, lastly, if the +series-turns are still further increased, the voltage may be made to +rise with an increasing load, and the machine is “over-compounded.”</p> +</div> + +<p>At the initial moment when an armature coil is first short-circuited +by the passage of the two sectors forming its ends under +the contact surface of a brush, a certain amount of +electromagnetic energy is stored up in its magnetic +<span class="sidenote">Commutation and sparking at the brushes.</span> +field as linked with the ampere-turns of the coil when +carrying its full share of the total armature current. +During the period of short-circuit this quantity of +energy has to be dissipated as the current falls to zero, +and has again to be re-stored as the current is reversed and raised +to the same value, but in the opposite direction. The period +of short-circuit as fixed by the widths of the brush and of the +mica insulation between the sectors, and by the peripheral +speed of the commutator is extremely brief, and only lasts on +an average from <span class="spp">1</span>⁄<span class="suu">200</span>th to <span class="spp">1</span>⁄<span class="suu">1000</span>th of a second. The problem of +sparkless commutation is therefore primarily a question of our +ability to dissipate and to re-store the required amount of energy +with sufficient rapidity.</p> + +<p>An important aid towards the solution of this problem is +found in the effect of the varying contact-resistance between +the brush and the surfaces of the leading and trailing sectors +which it covers. As the commutator moves under the brush, +the area of contact which the brush makes with the leading +sector diminishes, and the resistance between the two rises; +conversely, the area of contact between the brush and the trailing +sector increases and the resistance falls. This action tends +automatically to bring the current through each sector into +strict proportionality to the amount of its surface which is +covered by the brush, and so to keep the current-density and +the loss of volts over the contacts uniform and constant. As +soon as the current-density in the two portions of the brush +becomes unequal, a greater amount of heat is developed at the +commutator surface, and this in the first place affords an additional +outlet for the dissipation of the stored energy of the coil, +while after reversal of the current it is the accompaniment of +a re-storage of the required energy. This energy, as well as +that which is spent in heating the coil, can in fact, in default of +other sources, be derived through the action of the unequal +current-density from the electrical output of the rest of the +armature winding, and so only indirectly from the prime mover.</p> + +<p>In practice, when the normal contact-resistance of the brushes +is low relatively to the resistance of the coil, as is the case with +metal brushes of copper or brass gauze, but little benefit can be +obtained from the action of the varying contact-resistance. It +exerts no appreciable effect until close towards the end of the +period of short-circuit, and then only with such a high-current-density +at the trailing edge of the leaving sector that at the +moment of parting the brush-tip is fused, or its metal volatilized, +and sparking has in fact set in. With such brushes, then, it +becomes necessary to call in the aid of a reversing E.M.F. +impressed upon the coil by the magnetic field through which +it is moving. If such a reversing field comes into action while +<span class="pagenum"><a name="page777" id="page777"></a>777</span> +the current is still unreversed, its E.M.F. is opposed to the +direction of the current, and the coil is therefore driving the +armature forward as in a motor; it thus affords a ready means +of rapidly dissipating part of the initial energy in the form of +mechanical work instead of as heat. After the current has +been reversed, the converse process sets in, and the prime +mover directly expends mechanical energy not only in heating +the coil, but also in storing up electromagnetic energy with a +rapidity dependent upon the strength of the reversing field. +The required direction of external field can be obtained in the +dynamo by shifting the brushes forward, so that the short-circuited +coil enters into the fringe of lines issuing from the +leading pole-tip, <i>i.e.</i> by giving the brushes an “angle of lead.” +An objection to this process is that the main flux is thereby +weakened owing to the belt of back ampere-turns which arises +(<i>v. supra</i>). A still greater objection is that the amount of the +angle of lead must be suited to the value of the load, the corrective +power of copper brushes being very small if the reversing +E.M.F. is not closely adjusted in proportion to the armature +current.</p> + +<p>On this account metal brushes have been almost entirely +superseded by carbon moulded into hard blocks. With these, +owing to their higher specific contact-resistance, a very considerable +reversing effect can be obtained through the action of +unequal current-density, and indeed in favourable cases complete +sparklessness can be obtained throughout the entire range of +load of the machine with a fixed position of the brushes. Yet +if the work which they are called upon to perform exceeds certain +limits, they tend to become overheated with consequent glowing +or sparking at their tips, so that, wherever possible, it is advisable +to reinforce their action by a certain amount of reversing field, +the brushes being set so that its strength is roughly correct for, +say, half load.</p> + +<p>In the case of dynamos driven by steam-turbines, sparkless +commutation is especially difficult to obtain owing to the high +speed of rotation and the very short space of time in which the +current has to be reversed. Special “reversing poles” then +become necessary; these are wound with magnetizing coils in +series with the main armature current, so that the strength of +field which they yield is roughly proportional to the current +which has to be reversed. These again may be combined with +a “compensating winding” embedded in the pole-faces and +carrying current in the opposite direction to the armature +ampere-turns, so as to neutralize the cross effect of the latter +and prevent distortion of the resultant field.</p> + +<div class="condensed"> +<p>From the moment that a dynamo begins to run with excited +field, heat is continuously generated by the passage of the current +through the windings of the field-magnet coils and the +armature, as well as by the action of hysteresis and +<span class="sidenote">Heating effects.</span> +eddy currents in the armature and pole-pieces. Whether +the source of the heat be in the field-magnet or in the armature, the +mass in which it originates will continue to rise in temperature +until such a difference of temperature is established between itself +and the surrounding air that the rate at which the heat is carried +off by radiation, convection and conduction is equal to the rate at +which it is being generated. Evidently, then, the temperature +which any part of the machine attains after a prolonged run must +depend on the extent and effectiveness of the cooling surface from +which radiation takes place, upon the presence or absence of any +currents of air set up by the rotation of itself or surrounding parts, +and upon the presence of neighbouring masses of metal to carry +away the heat by conduction. In the field-magnet coils the rate +at which heat is being generated is easily determined, since it is equal +to the square of the current passing through them multiplied by +their resistance. Further, the magnet is usually stationary, and +only indirectly affected by draughts of air due to the rotating armature. +Hence for machines of a given type and of similar proportions, +it is not difficult to decide upon some method of reckoning the cooling +surface of the magnet coils S<span class="su">c</span>, such that the rise of temperature +above that of the surrounding air may be predicted from an equation +of the form <i>t° = kW / S<span class="su">c</span></i>, where W = the rate in watts at which heat +is generated in the coils, and k is some constant depending upon the +exact method of reckoning their cooling surface. As a general rule +the cooling surface of a field-coil is reckoned as equal to the exposed +outer surface of its wire, the influence of the end flanges being +neglected, or only taken into account in the case of very short +bobbins wound with a considerable depth of wire. In the case of +the rotating armature a similar formula must be constructed, but +with the addition of a factor to allow for the increase in the effectiveness +of any given cooling surface due to the rotation causing convection +currents in the surrounding air. Only experiment can +determine the exact effect of this, and even with a given type of +armature it is dependent on the number of poles, each of which helps +to break up the air-currents, and so to dissipate the heat. For +example, in two-pole machines with drum bar-armatures, if the cooling +surface be reckoned as equal to the cylindrical exterior plus the +area of the two ends, the heating coefficient for a peripheral speed of +1500 ft. per minute is less than half of that for the same armature +when at rest. A further difficulty still meets the designer in the +correct predetermination of the total loss of watts in an armature +before the machine has been tested. It is made up of three separate +items, namely, the copper loss in the armature winding, the loss +by hysteresis in the iron, and the loss by eddy currents, which +again may be divided into those in the armature bars and end-connexions, +and those in the core and its end-plates. The two +latter items are both dependent upon the speed of the machine; +but whereas the hysteresis loss is proportional to the speed for a +given density of flux in the armature, the eddy current loss is +proportional to the square of the speed, and owing to this difference, +the one loss can be separated from the other by testing an +armature at varying speeds. Thus for a given rise of temperature, +the question of the amount of current which can be taken out of +an armature at different speeds depends upon the proportion which +the hysteresis and eddy watts bear to the copper loss, and the ratio +in which the effectiveness of the cooling surface is altered by the +alteration in speed. Experimental data, again, can alone decide +upon the amount of eddy currents that may be expected in given +armatures, and caution is required in applying the results of one +machine to another in which any of the conditions, such as the +number of poles, density in the teeth, proportions of slot depth to +width, &c., are radically altered.</p> + +<p>It remains to add, that the rise of temperature which may be +permitted in any part of a dynamo after a prolonged run is very +generally placed at about 70° Fahr. above the surrounding air. +Such a limit in ordinary conditions of working leads to a final +temperature of about 170° Fahr., beyond which the durability of +the insulation of the wires is liable to be injuriously affected. Upon +some such basis the output of a dynamo in continuous working is +rated, although for short periods of, say, two hours the normal full-load +current of a large machine may be exceeded by some 25% +without unduly heating the armature.</p> +</div> + +<p>For the electro-deposition of metals or the electrolytic treatment +of ores a continuous current is a necessity; but, apart from +such use, the purposes from which the continuous-current +dynamo is well adapted are so numerous that +<span class="sidenote">Uses of continuous current dynamos.</span> +they cover nearly the whole field of electrical engineering, +with one important exception. To meet these +various uses, the pressures for which the machine is +designed are of equally wide range; for the transmission of +power over long distances they may be as high as 3000 volts, +and for electrolytic work as low as five. Each electrolytic bath, +with its leads, requires on an average only some four or five volts, +so that even when several are worked in series the voltage of the +dynamo seldom exceeds 60. On the other hand, the current is +large and may amount to as much as from 1000 to 14,000 amperes, +necessitating the use of two commutators, one at either end of +the armature, in order to collect the current without excessive +heating of the sectors and brushes. The field-magnets are invariably +shunt-wound, in order to avoid reversal of the current +through polarization at the electrodes of the bath. For incandescent +lighting by glow lamps, the requirements of small +isolated installations and of central stations for the distribution +of electrical energy over large areas must be distinguished. For +the lighting of a private house or small factory, the dynamo +giving from 5 to 100 kilo-watts of output is commonly wound +for a voltage of 100, and is driven by pulley and belt from a gas, +oil or steam-engine; or, if approaching the higher limit above +mentioned, it is often directly coupled to the crank-shaft of the +steam-engine. If used in conjunction with an accumulator of +secondary cells, it is shunt-wound, and must give the higher +voltage necessary to charge the battery; otherwise it is compound-wound, +in order to maintain the pressure on the lamps +constant under all loads within its capacity. The compound-wound +dynamo is likewise the most usual for the lighting of +steamships, and is then directly coupled to its steam-engine; +its output seldom exceeds 100 kilo-watts, at a voltage of 100 or +110. For larger installations a voltage of 250 is commonly used, +while for central-station work, economy in the distributing +<span class="pagenum"><a name="page778" id="page778"></a>778</span> +mains dictates a higher voltage, especially in connexion with +a three-wire system; the larger dynamos may then give 500 +volts, and be connected directly across the two outer wires. A +pair of smaller machines coupled together, and each capable of +giving 250 volts, are often placed in series across the system, +with their common junction connected to the middle wire; the +one which at any time is on the side carrying the smaller current +will act as a motor and drive the other as a dynamo, so as to +balance the system. The directly-coupled steam dynamo may +be said to have practically displaced the belt- or rope-driven +sets which were formerly common in central stations. The +generating units of the central station are arranged in progressive +sizes, rising from, it may be, 250 or 500 horse-power up to 750 +or 1000, or in large towns to as much as 5000 horse-power. If +for lighting only, they are usually shunt-wound, the regulation +of the voltage, to keep the pressure constant on the distributing +system under the gradual changes of load, being effected by +variable resistances in the shunt circuit of the field-magnets.</p> + +<p>Generators used for supplying current to electric tramways +are commonly wound for 500 volts at no load and are over-compounded, +so that the voltage rises to 550 volts at the maximum +load, and thus compensates for the loss of volts over the +transmitting lines. For arc lighting it was formerly usual to +employ a class of dynamo which, from the nature of its construction, +was called an “open-coil” machine, and which gave +a unidirectional but pulsating current. Of such machines the +Brush and Thomson-Houston types were very widely used; +their E.M.F. ranged from 2000 to 3000 volts for working a large +number of arcs in series, and by means of special regulators their +current was maintained constant over a wide range of voltage. +But as their efficiency was low and they could not be applied to +any other purpose, they have been largely superseded in central +stations by closed-coil dynamos or alternators, which can also +be used for incandescent lighting. In cases where the central +station is situated at some distance from the district to which +the electric energy is to be supplied, voltages from 1000 to 2000 +are employed, and these are transformed down at certain +distributing centres by continuous-current transformers (see +<span class="sc"><a href="#artlinks">Transformers</a></span> and <span class="sc"><a href="#artlinks">Electricity Supply</a></span>). These latter +machines are in reality motor-driven dynamos, and hence are also +called <i>motor-generators</i>; the armatures of the motor and +dynamo are often wound on the same core, with a commutator +at either end, the one to receive the high-pressure motor current, +and the other to collect the low-pressure current furnished by +the dynamo.</p> + +<div class="condensed"> +<p>In all large central stations it is necessary that the dynamos +should be capable of being run <i>in parallel</i>, so that their outputs +may be combined on the same “omnibus bars” and thence distributed +to the network of feeders. With simple shunt-wound +machines this is easily effected by coupling together terminals of +like sign when the voltage of the two or more machines are closely +equal. With compound-wound dynamos not only must the external +terminals of like sign be coupled together, but the junctions of the +brush leads with the series winding must be connected by an +“equalizing” lead of low resistance; otherwise, should the E.M.F. +of one machine for any reason fall below the voltage of the omnibus +bars, there is a danger of its polarity being reversed by a back +current from the others with which it is in parallel.</p> + +<p>Owing to the necessary presence in the continuous-current dynamo +of the commutator, with its attendant liability to sparking at the +brushes, and further, owing to the difficulty of insulating the rotating +armature wires, a pressure of 3000 volts has seldom been exceeded +in any one continuous-current machine, and has been given above +as the limiting voltage of the class. If therefore it is required to +work with higher pressures in order to secure economy in the transmitting +lines, two or more machines must be coupled <i>in series</i> by +connecting together terminals which are of unlike sign.<a name="fa19p" id="fa19p" href="#ft19p"><span class="sp">19</span></a> The stress +of the total voltage may still fall on the insulation of the winding +from the body of the machine; hence for high-voltage transmission +of power over very long distances, the continuous-current dynamo +in certain points yields in convenience to the alternator. In this +there is no commutator, the armature coils may be stationary and +can be more thoroughly insulated, while further, if it be thought +undesirable to design the machine for the full transmitting voltage, +it is easy to wind the armature for a low pressure; this can be +subsequently transformed up to a high pressure by means of the +alternating-current transformer, which has stationary windings +and so high an efficiency that but little loss arises from its use. +With these remarks, the transition may be made to the fuller +discussion of the alternator.</p> +</div> + +<p class="pt2 center"><i>Alternators.</i></p> + +<p>The frequency employed in alternating-current systems for +distributing power and light varies between such wide limits +as 25 and 133; yet in recent times the tendency +has been towards standard frequencies of 25, 50 +<span class="sidenote">Frequency.</span> +and 100 as a maximum. High frequencies involve more +copper in the magnet coils, owing to the greater number of poles, +and a greater loss of power in their excitation, but the alternator +as a whole is somewhat lighter, and the transformers are cheaper. +On the other hand, high frequency may cause prejudicial effects, +due to the inductance and capacity of the distributing lines; +and in asynchronous motors used on polyphase systems the +increased number of poles necessary to obtain reasonable speeds +reduces their efficiency, and is otherwise disadvantageous, +especially for small horse-powers. A frequency lower than 40 is, +however, not permissible where arc lighting is to form any considerable +portion of the work and is to be effected by the alternating +current without rectification, since below this value the +eye can detect the periodic alteration in the light as the carbons +alternately cool and become heated. Thus for combined lighting +and power 50 or 60 are the most usual frequencies; but if the +system is designed solely or chiefly for the distribution of power, +a still lower frequency is preferable. On this account 25 was +selected by the engineers for the Niagara Falls power transmission, +after careful consideration of the problem, and this +frequency has since been widely adopted in similar cases.</p> + +<p>The most usual type of heteropolar alternator has an internal +rotating field-magnet system, and an external stationary armature, +as in fig. 10. The coils of the armature, which +must for high voltages be heavily insulated, are then +<span class="sidenote">Alternator construction.</span> +not subjected to the additional stresses due to centrifugal +force; and further, the collecting rings which +must be attached to the rotating portion need only transmit +the exciting current at a low voltage.</p> + +<table class="flt" style="float: right; width: 380px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:329px; height:238px" src="images/img778.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 36.</td></tr></table> + +<p>The homopolar machine possesses the advantages that only +a single exciting coil is required, whatever the number of polar +projections, and that both the armature and field-magnet coils +may be stationary. From fig. 8 it will be seen that it is not +essential that the exciting +coil should +revolve with the internal +magnet, but it +may be supported +from the external +stationary armature +while still embracing +the central part of the +rotor. The E.M.F. is +set up in the armature +coils through the +periodic variation of +the flux through them +as the iron projections sweep past, and these latter may +be likened to a number of “keepers,” which complete the +magnetic circuit. From the action of the rotating iron masses +they may also be considered as the inducing elements or +“inductors,” and the homopolar machine is thence also +known as the “inductor alternator.” If the end of the +rotor marked S in fig. 8 is split up into a number of S polar +projections similar to the N poles, a second set of armature coils +may be arranged opposite to them, and we obtain an inductor +<span class="pagenum"><a name="page779" id="page779"></a>779</span> +alternator with double armature. Or the polar projections at +the two ends may be staggered, and a single armature winding +be passed straight through the armature, as in fig. 36, which +shows at the side the appearance of the revolving inductor with +its crown of polar projections in one ring opposite to the gaps +between the polar projections of the other ring. But in spite +of its advantage of the single stationary exciting coil, the inductor +alternator has such a high degree of leakage, and the effect +of armature reaction is so detrimental in it, that the type has +been gradually abandoned, and a return has been almost universally +made to the heteropolar alternator with internal poles +radiating outwards from a circular yoke-ring. The construction +of a typical machine of this class is illustrated in fig. 37.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:920px; height:424px" src="images/img779.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 37.</td></tr></table> + +<p>Since the field-magnet coils rotate, they must be carefully +designed to withstand centrifugal force, and are best composed +of flat copper strip wound on edge with thin insulation between +adjacent layers. The coil is secured by the edges of the pole-shoes +which overhang the pole and tightly compress the coil +against the yoke-ring; the only effect from centrifugal force is +then to compress still further the flat turns of copper against +the pole-shoes without deformation. The poles are either of +cast steel of circular or oblong section, bolted to the rim of the +yoke-ring, or are built up of thin laminations of sheet steel. +When the peripheral speed is very high, the yoke-ring will be +of cast steel or may itself be built up of sheet steel laminations, +this material being reliable and easily tested to ensure its sound +mechanical strength. If the armature slots are open, the pole-pieces +will in any case be laminated to reduce the eddy currents +set up by the variation of the flux-density.</p> + +<p>Owing to the great number of poles<a name="fa20p" id="fa20p" href="#ft20p"><span class="sp">20</span></a> of the alternator when +driven by a reciprocating steam-engine, the diameter of its +rotor is usually larger and its length less than in the continuous-current +dynamo of corresponding output. The support of the +armature core when of large diameter is therefore a more difficult +problem, since, apart from any magnetic strains to which it +may be subjected, its own weight tends to deform it. The +segmental core-disks are usually secured to the internal circumference +of a circular cast iron frame; the latter has a box section +of considerable radial depth to give stiffness to it, and the disks +are tightly clamped between internal flanges, one being a fixed +part of the frame and the other loose, with transverse bolts +passing right through from side to side (fig. 37). In order to +lessen the weight of the structure and its expense in material, +the cast iron frame has in some cases been entirely dispensed +with, and braced tie-rods have been used to render the effective +iron of the armature core-disks self-supporting.</p> + +<table class="flt" style="float: right; width: 360px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:309px; height:457px" src="images/img779a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 38.</td></tr></table> + +<p>Owing to the high speed of the turbo-alternator, its rotor calls +for the utmost care in its design to withstand the effect of +centrifugal force without +any shifting of the +exciting coils, and to +secure a perfect balance.</p> + +<p>The appearance of +the armature of a +typical three-phase +alternator is illustrated +in fig. 38, which shows +a portion of the lower +half after removal of +the field-magnet.</p> + +<p>With open slots the +coils, after being wound +on formers to the required +shape, are +thoroughly impregnated +with insulating +compound, dried, and +after a further wrapping +with several layers of +insulating material, +finally pressed into the +slots together with a +sheet of leatheroid or +flexible micanite. The end-connexions of each group of coils +of one phase project straight out from the slots or are +bent upwards alternately with those of the other phases, so +that they may clear one another (fig. 37). A wooden wedge +driven into a groove at the top of each slot is often used +to lock the coil in place. With slots nearly closed at the +top, the coils are formed by hand by threading the wire +<span class="pagenum"><a name="page780" id="page780"></a>780</span> +through tubes of micanite or specially prepared paper lining +the slots; or with single-turn loops, stout bars of copper of +U-shape can be driven through the slots and closed by soldered +connexions at the other end.</p> + +<div class="condensed"> +<p>The first experimental determination of the shape of the E.M.F. +curve of an alternator was made by J. Joubert in 1880. A revolving +contact-maker charged a condenser with the E.M.F. +produced by the armature at a particular instant during +<span class="sidenote">Shape of E.M.F. curve.</span> +each period. The condenser was discharged through a +ballistic galvanometer, and from the measured throw the +instantaneous E.M.F. could be deduced. The contact-maker was +then shifted through a small angle, and the instantaneous E.M.F. +at the new position corresponding to a different moment in the period +was measured; this process was repeated until the E.M.F. curve +for a complete period could be traced. Various modifications of +the same principle have since been used, and a form of “oscillograph” +(<i>q.v.</i>) has been perfected which is well adapted for the +purpose of tracing the curves both of E.M.F. and of current. The +machine on which Joubert carried out his experiments was a Siemens +disk alternator having no iron in its armature, and it was found that +the curve of E.M.F. was practically identical with a sine curve. +The same law has also been found to hold true for a smooth-core +ring or drum armature, but the presence of the iron core enables +the armature current to produce greater distorting effect, so that +the curves under load may vary considerably from their shape at +no load. In toothed armatures, the broken surface of the core, +and the still greater reaction from the armature current, may +produce wide variations from the sine law, the general tendency +being to give the E.M.F. curve a more peaked form. The great +convenience of the assumption that the E.M.F. obeys the sine law +has led to its being very commonly used as the basis for the mathematical +analysis of alternator problems; but any deductions made +from this premiss require to be applied with caution if they are +likely to be modified by a different shape of the curve. Further, the +same alternator will give widely different curves even of E.M.F., +and still more so of current, according to the nature of the external +circuit to which it is connected. As will be explained later, the phase +of the current relatively to the E.M.F. depends not only on the inductance +of the alternator itself, but also upon the inductance and +capacity of the external circuit, so that the same current will produce +different effects according to the amount by which it lags or leads. +The question as to the relative advantages of differently shaped +E.M.F. curves has led to much discussion, but can only be answered +by reference to the nature of the work that the alternator has to +do—<i>i.e.</i> whether it be arc lighting, motor driving, or incandescent +lighting through transformers. The shape of the E.M.F. curve is, +however, of great importance in one respect, since upon it depends +the ratio of the maximum instantaneous E.M.F. to the effective +value, and the insulation of the entire circuit, both external and +internal, must be capable of withstanding the maximum E.M.F. +While the maximum value of the sine curve is √2 or 1.414 times +the effective value, the maximum value of a Λ curve is 1.732 times +the effective value, so that for the same effective E.M.F. the armature +wires must not only be more heavily insulated than in the continuous-current +dynamo, but also the more peaked the curve the better +must be the insulation.</p> +</div> + +<div class="condensed"> +<p>Since an alternating current cannot be used for exciting the +field-magnet, recourse must be had to some source of a direct +current. This is usually obtained from a small auxiliary +continuous-current dynamo, called an <i>exciter</i>, which may +<span class="sidenote">Excitation.</span> +be an entirely separate machine, separately driven and +used for exciting several alternators, or may be driven from the +alternator itself; in the latter case the armature of the exciter is +often coupled directly to the rotating shaft of the alternator, while +its field-magnet is attached to the bed-plate. Although separate +excitation is the more usual method, the alternator can also be made +self-exciting if a part or the whole of the alternating current is +“rectified,” and thus converted into a direct current.</p> +</div> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:405px; height:151px" src="images/img780a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 39.</td></tr></table> + +<table class="flt" style="float: right; width: 205px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:156px; height:140px" src="images/img780b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 40.</td></tr></table> + +<div class="condensed"> +<p>The general idea of the polyphase alternator giving two or more +E.M.F.’s of the same frequency, but displaced in phase, has been +already described. The several phases may be entirely +independent, and such was the case with the early polyphase +<span class="sidenote">Quarter-phase alternators.</span> +machines of Gramme, who used four independent +circuits, and also in the large two-phase alternators +designed by J.E.H. Gordon in 1883. If the phases are +thus entirely separate, each requires two collector rings and two +wires to its external circuit, <i>i.e.</i> four in all for two-phase and six +for three-phase machines. The only advantage of the polyphase +machine as thus used is that the whole of the surface of the armature +core may be efficiently covered with winding, and the output +of the alternator for a given size be thereby increased. It is, however, +also possible so to interlink the several circuits of the armature +that the necessary number of transmitting lines to the external +circuits may be reduced, and also the weight of copper in them for +a given loss in the transmission.<a name="fa21p" id="fa21p" href="#ft21p"><span class="sp">21</span></a> The condition which obviously +must be fulfilled, for such interlinking of the phases to be possible, +is that in the lines which are to meet at any common junction the +algebraic sum of the instantaneous currents, reckoned as positive +if away from such junction and as negative if towards it, must be +zero. Thus if the phases be diagrammatically represented by the +relative angular position of the coils in fig. 39, the current in the coils +A and B differs in phase from the current in the coils C and D by +a quarter of a period or 90°; hence if the two wires <i>b</i> and <i>d</i> be +replaced by the single wire <i>bd</i>, this third wire will serve as a common +path for the currents of the two phases either outwards or on their +return. At any instant the value of the current in the third wire +must be the vector sum of the two currents in the other wires, and +if the shape of the curves of instantaneous E.M.F. and current are +identical, and are assumed to be sinusoidal, the effective value +of the current in the third wire will be the vector sum of the effective +values of the currents in the other wires; in other words, if the +system is balanced, the effective current in the third wire is √2, or 1.414 +times the current in either of the two outer wires. Since the currents +of the two phases do not reach their maximum values at the same +time, the sectional area of the third wire need not be twice that of +the others; in order to secure maximum efficiency by employing +the same current density in all three wires, it need only be 40% +greater than that of either of the outer wires. The effective voltage +between the external leads may in the same way be calculated by +a vector diagram, and with the above <i>star connexion</i> the voltage +between the outer pair of wires <i>a</i> and <i>c</i> is √2, or 1.414 times the +voltage between either of the outer wires +and the common wire <i>bd</i>. Next, if the four +coils are joined up into a continuous helix, +just as in the winding of a continuous-current +machine, four wires may be attached to +equidistant points at the opposite ends of +two diameters at right angles to each other +(fig. 40). Such a method is known as the +<i>mesh connexion</i>, and gives a perfectly symmetrical +four-phase system of distribution. +Four collecting rings are necessary if the armature +rotates, and there is no saving in copper in +the transmitting lines; but the importance of the arrangement lies in +its use in connexion with rotary converters, in which it is necessary +that the winding of the armature should form a closed circuit. If +<i>e</i> = the effective voltage of one phase A, the voltage between any +pair of adjacent lines in the diagram is <i>e</i>, and between <i>m</i> and <i>o</i> or +<i>n</i> and <i>p</i> is <i>e</i> √2. The current in any line is the resultant of the +currents in the two phases connected to it, and its effective value +is <i>c</i> √2, where <i>c</i> is the current of one phase.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:324px; height:138px" src="images/img780c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 41.</td></tr></table> + +<p>When we pass to machines giving three phases differing by +120°, the same methods of star and mesh connexion find their +analogies. If the current in coil A (fig. 41) is flowing +away from the centre, and has its maximum value, the +<span class="sidenote">Three-phase alternators.</span> +currents in coils B and C are flowing towards the centre, +and are each of half the magnitude of the current in A; +the algebraic sum of the currents is therefore zero, and +this will also be the case for all other instants. Hence the three +coils can be united together at the centre, and three external wires +are alone required. In this star or “Y” connexion, if <i>e</i> be the +effective voltage of each phase, or the voltage between any one +of the three collecting rings and the common connexion, the volts +between any pair of transmitting lines will be E = <i>e</i> √3 (fig. 41); +if the load be balanced, the effective current C in each of the three +lines will be equal, and the total output in watts will be W = 3C<i>e</i> = +3CE / √3 = 1.732 EC, or 1.732 times the product of the effective +voltage between the lines and the current in any single line. Next, +if the three coils are closed upon themselves in a mesh or <i>delta</i> +fashion (fig. 42), the three transmitting wires may be connected to +the junctions of the coils (by means of collecting rings if the armature +rotates). The voltage E between any pair of wires is evidently +<span class="pagenum"><a name="page781" id="page781"></a>781</span> +that generated by one phase, and the current in a line wire is the +resultant of that in two adjacent phases; or in a balanced system, +if c be the current in each phase, the current in the line wire beyond +a collecting ring is C = c√3, hence the watts are W = 3cE = 3CE / √3 += 1.732 EC, as before. Thus any three-phase winding may be +changed over from the star to the delta connexion, and will then +give 1.732 times as much current, but only 1/1.732 times the voltage, +so that the output remains the same.</p> + +<table class="flt" style="float: right; width: 170px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:121px; height:121px" src="images/img781.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 42.</span></td></tr></table> + +<p>The “armature reaction” of the alternator, when the term is +used in its widest sense to cover all the effects of the alternating +current in the armature as linked with a magnetic circuit +or circuits, may be divided into three items which are +<span class="sidenote">Armature reaction in alternators</span> +different in their origin and consequences. In the first +place the armature current produces a self-induced flux +in local circuits independent of the main magnetic circuit, +as <i>e.g.</i> linked with the ends of the coils as they project outwards +from the armature core; such lines may be called “secondary +leakage,” of which the characteristic feature is that +its amount is independent of the position of the +coils relatively to the poles. The alternations of +this flux give rise to an inductive voltage lagging +90° behind the phase of the current, and this +leakage or reactance voltage must be directly +counterbalanced electrically by an equal component +in the opposite sense in the voltage from the +main field. The second and third elements are +more immediately magnetic and are entirely dependent +upon the position of the coils in relation to +the poles and in relation to the phase of the current which they then +carry. When the side of a drum coil is immediately under the centre +of a pole, its ampere-turns are cross-magnetizing, <i>i.e.</i> produce a +distortion of the main flux, displacing its maximum density to one +or other edge of the pole. When the coil-side is midway between the +poles and the axes of coil and pole coincide, the coil stands exactly +opposite to the pole and embraces the same magnetic circuit as the +field-magnet coils; its turns are therefore directly magnetizing, +either weakening or strengthening the main flux according to the +direction of the current. In intermediate positions the ampere-turns +of the coil gradually pass from cross to direct and vice versa. +When the instantaneous values of either the cross or direct magnetizing +effect are integrated over a period and averaged, due +account being taken of the number of slots per coil-side and of the +different phases of the currents in the polyphase machine, expressions +are obtained for the equivalent cross and direct ampere-turns of the +armature as acting upon a pair of poles. For a given winding and +current, the determining factor in either the one or the other is +found to be the relative phase angle between the axis of a coil in +its position when carrying the maximum current and the centre +of a pole, the transverse reaction being proportional to the cosine +of this angle, and the direct reaction to its sine. If the external +circuit is inductive, the maximum value of the current lags behind +the E.M.F. and so behind the centre of the pole; such a negative +angle of lag causes the direct magnetizing turns to become back +turns, directly weakening the main field and lowering the terminal +voltage. Thus, just as in the continuous-current dynamo, for a +given voltage under load the excitation between the pole-pieces +X<span class="su">p</span> must not only supply the net excitation required over the air-gaps, +armature core and teeth, but must also balance the back +ampere-turns X<span class="su">b</span> of the armature.</p> + +<p>Evidently therefore the characteristic curve connecting armature +current and terminal volts will with a constant exciting current +depend on the nature of the load, whether inductive or non-inductive, +and upon the amount of inductance already possessed by the armature +itself. With an inductive load it will fall more rapidly from its +initial maximum value, or, conversely, if the initial voltage is to be +maintained under an increasing load, the exciting current will have +to be increased more than if the load were non-inductive. In +practical working many disadvantages result from a rapid drop of +the terminal E.M.F. under increasing load, so that between no load +and full load the variation in terminal voltage with constant excitation +should not exceed 15%. Thus the output of an alternator +is limited either by its heating or by its armature reaction, just as +is the output of a continuous-current dynamo; in the case of the +alternator, however, the limit set by armature reaction is not due +to any sparking at the brushes, but to the drop in terminal voltage +as the current is increased, and the consequent difficulty in maintaining +a constant potential on the external circuit.</p> + +<p>The joint operation of several alternators so that their outputs +may be delivered into the same external circuit is sharply distinguished +from the corresponding problem in continuous-current +dynamos by the necessary condition that they +<span class="sidenote">The coupling of alternators.</span> +must be in synchronism, <i>i.e.</i> not only must they be so +driven that their frequency is the same, but their E.M.F.’s +must be in phase or, as it is also expressed, the machines +must be in step. Although in practice it is impossible to run two +alternators in series unless they are rigidly coupled together—which +virtually reduces them to one machine—two or more machines can +be run in parallel, as was first described by H. Wilde in 1868 and +subsequently redemonstrated by J. Hopkinson and W.G. Adams +in 1884. Their E.M.F.’s should be as nearly as possible in synchronism, +but, as contrasted with series connexion, parallel coupling +gives them a certain power of recovery if they fall out of step, or +are not in exact synchronism when thrown into parallel. In such +circumstances a synchronizing current passes between the two +machines, due to the difference in their instantaneous pressures; +and as this current agrees in phase more nearly with the leading +than with the lagging machine, the former machine does work as a +generator on the latter as a motor. Hence the lagging machine +is accelerated and the leading machine is retarded, until their +frequencies and phase are again the same.</p> +</div> + +<p>The chief use of the alternator has already been alluded to. +Since it can be employed to produce very high pressures either +directly or through the medium of transformers, it is +specially adapted to the electrical transmission of +<span class="sidenote">Uses of alternators.</span> +energy over long distances.<a name="fa22p" id="fa22p" href="#ft22p"><span class="sp">22</span></a> In the early days of +electric lighting, the alternate-current system was +adopted for a great number of central stations; the machines, +designed to give a pressure of 2000 volts, supplied transformers +which were situated at considerable distances and spread over +large areas, without an undue amount of copper in the transmitting +lines. While there was later a tendency to return to +the continuous current for central stations, owing to the introduction +of better means for economizing the weight of copper in +the mains, the alternating current again came into favour, +as rendering it possible to place the central station in some +convenient site far away from the district which it was to serve. +The pioneer central station in this direction was the Deptford +station of the London Electric Supply Corporation, which furnished +current to the heart of London from a distance of 7 m. +In this case, however, the alternators were single-phase and gave +the high pressure of 10,000 volts immediately, while more +recently the tendency has been to employ step-up transformers +and a polyphase system. The advantage of the latter is that +the current, after reaching the distant sub-stations, can be dealt +with by rotary converters, through which it is transformed +into a continuous current. The alternator is also used for +welding, smelting in electric furnaces, and other metallurgical +processes where heating effects are alone required; the large +currents needed therein can be produced without the disadvantage +of the commutator, and, if necessary, transformers can be +interposed to lower the voltage and still further increase the +current. The alternating system can thus meet very various +needs, and its great recommendation may be said to lie in the +flexibility with which it can supply electrical energy through +transformers at any potential, or through rotary converters in +continuous-current form.</p> + +<div class="condensed"> +<p><span class="sc">Authorities.</span>—For the further study of the dynamo, the following +may be consulted, in addition to the references already given:—</p> + +<p><i>General</i>: S.P. Thompson, <i>Dynamo-Electric Machinery—Continuous-Current +Machines</i> (1904), <i>Alternating-Current Machinery</i> +(1905, London); G. Kapp, <i>Dynamos, Alternators and Transformers</i> +(London, 1893); <i>Id., Electric Transmission of Energy</i> (London, +1894); Id., <i>Dynamo Construction; Electrical and Mechanical</i> +(London, 1899); H.F. Parshall and H.M. Hobart, <i>Electric Generators</i> +(London, 1900); C.C. Hawkins and F. Wallis, <i>The Dynamo</i> (London, +1903); E. Arnold, <i>Konstruktionstafeln für den Dynamobau</i> (Stuttgart, +1902); C.P. Steinmetz, <i>Elements of Electrical Engineering</i> +(New York, 1901).</p> + +<p><i>Continuous-Current Dynamos</i>: J. Fischer-Hinnen, <i>Continuous-Current +Dynamos</i> (London, 1899); E. Arnold, <i>Die Gleichstrommaschine</i> +(Berlin, 1902); F. Niethammer, <i>Berechnung und Konstruktion +der Gleichstrommaschinen und Gleichstrommotoren</i> (Stuttgart, +1904).</p> + +<p><i>Alternators</i>: D.C. Jackson and J.P. Jackson, <i>Alternating +Currents and Alternating Current Machinery</i> (New York, 1903); +J.A. Fleming, <i>The Alternate Current Transformer</i> (London, 1899); +C.P. Steinmetz, <i>Alternating Current Phenomena</i> (New York, 1900); +E. Arnold, <i>Die Wechselstromtechnik</i> (Berlin, 1904); S.P. Thompson, +<i>Polyphase Electric Currents</i> (London, 1900); A. Stewart, <i>Modern +Polyphase Machinery</i> (London, 1906); M. Oudin, <i>Standard Polyphase +Apparatus and Systems</i> (New York, 1904).</p> +</div> +<div class="author">(C. C. H.)</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1p" id="ft1p" href="#fa1p"><span class="fn">1</span></a> <i>Experimental Researches in Electricity</i>, series ii. § 6, pars. 256, +259-260, and series xxviii. § 34.</p> + +<p><a name="ft2p" id="ft2p" href="#fa2p"><span class="fn">2</span></a> <i>Ibid.</i> series i. § 4, pars. 84-90.</p> + +<p><a name="ft3p" id="ft3p" href="#fa3p"><span class="fn">3</span></a> “On the Physical Lines of Magnetic Force,” <i>Phil. Mag.</i>, June +1852.</p> + +<p><a name="ft4p" id="ft4p" href="#fa4p"><span class="fn">4</span></a> Faraday, <i>Exp. Res.</i> series xxviii. § 34, pars. 3104, 3114-3115.</p> + +<p><a name="ft5p" id="ft5p" href="#fa5p"><span class="fn">5</span></a> <i>Id.</i>, ib. series i. § 4, pars. 114-119.</p> + +<p><a name="ft6p" id="ft6p" href="#fa6p"><span class="fn">6</span></a> <i>Id.</i>, ib. series ii. § 6, pars. 211, 213; series xxviii. § 34, par. +3152.</p> + +<p><a name="ft7p" id="ft7p" href="#fa7p"><span class="fn">7</span></a> Invented by Nikola Tesla (<i>Elec. Eng.</i> vol. xiii. p. 83. Cf. Brit. +Pat. Spec. Nos. 2801 and 2812, 1894). Several early inventors, <i>e.g.</i> +Salvatore dal Negro in 1832 (<i>Phil. Mag.</i> third series, vol. i. p. 45), +adopted reciprocating or oscillatory motion, and this was again tried +by Edison in 1878.</p> + +<p><a name="ft8p" id="ft8p" href="#fa8p"><span class="fn">8</span></a> The advantage to be obtained by making the poles closely +embrace the armature core was first realized by Dr Werner von +Siemens in his “shuttle-wound” armature (Brit. Pat. No. 2107, +1856).</p> + +<p><a name="ft9p" id="ft9p" href="#fa9p"><span class="fn">9</span></a> <i>Nuovo Cimento</i> (1865), 19, 378.</p> + +<p><a name="ft10p" id="ft10p" href="#fa10p"><span class="fn">10</span></a> Brit. Pat. No. 1668 (1870); <i>Comptes rendus</i> (1871), 73, 175.</p> + +<p><a name="ft11p" id="ft11p" href="#fa11p"><span class="fn">11</span></a> <i>Ann. Chim. Phys.</i> l. 322.</p> + +<p><a name="ft12p" id="ft12p" href="#fa12p"><span class="fn">12</span></a> Ibid. li. 76. Since in H. Pixii’s machine the armature was +stationary, while both magnet and commutator rotated, four +brushes were used, and the arrangement was not so simple as +the split-ring described above, although the result was the same. +J. Saxton’s machine (1833) and E.M. Clarke’s machine (1835, see +Sturgeon’s <i>Annals of Electricity</i>, i. 145) were similar to one another +in that a unidirected current was obtained by utilizing every alternate +half-wave of E.M.F., but the former still employed mercury +collecting cups, while the latter employed metal brushes. W. +Sturgeon in 1835 followed Pixii in utilizing the entire wave of +E.M.F., and abandoned the mercury cups in favour of metal brushes +pressing on four semicircular disks (<i>Scientific Researches</i>, p. 252). +The simple split-ring is described by Sir C. Wheatstone and Sir W.F. +Cooke in their Patent No. 8345 (1840).</p> + +<p><a name="ft13p" id="ft13p" href="#fa13p"><span class="fn">13</span></a> By the “leading” side of the tooth or of an armature coil or +sector is to be understood that side which first enters under a pole +after passing through the interpolar gap, and the edge of the pole +under which it enters is here termed the “leading” edge as opposed +to the “trailing” edge or corner from under which a tooth or coil +emerges into the gap between the poles; cf. fig. 30, where the leading +and trailing pole-corners are marked ll and tt.</p> + +<p><a name="ft14p" id="ft14p" href="#fa14p"><span class="fn">14</span></a> Such was the arrangement of Wheatstone’s machine (Brit. Pat. +No. 9022) of 1841, which was the first to give a more nearly “continuous” +current, the number of sections and split-rings being five.</p> + +<p><a name="ft15p" id="ft15p" href="#fa15p"><span class="fn">15</span></a> Its development from the split-ring was due to Pacinotti and +Gramme (Brit. Pat. No. 1668, 1870) in connexion with their ring +armatures.</p> + +<p><a name="ft16p" id="ft16p" href="#fa16p"><span class="fn">16</span></a> And extended by G. Kapp, “On Modern Continuous-Current +Dynamo-Electric Machines,” <i>Proc. Inst. C.E.</i> vol. lxxxiii. p. 136.</p> + +<p><a name="ft17p" id="ft17p" href="#fa17p"><span class="fn">17</span></a> Drs J. and E. Hopkinson, “Dynamo-Electric Machinery,” Phil. +Trans., May 6, 1886; this was further expanded in a second paper +on “Dynamo-Electric Machinery,” <i>Proc. Roy. Soc.</i>, Feb. 15, 1892, +and both are reprinted in <i>Original Papers on Dynamo-Machinery +and Allied Subjects</i>.</p> + +<p><a name="ft18p" id="ft18p" href="#fa18p"><span class="fn">18</span></a> <i>Exp. Res.</i>, series i. § 4, par. 111. In 1845 Wheatstone and Cooke +patented the use of “voltaic” magnets in place of permanent +magnets (No. 10,655).</p> + +<p><a name="ft19p" id="ft19p" href="#fa19p"><span class="fn">19</span></a> Between Moutiers and Lyons, a distance of 115 m., energy is +transmitted on the Thury direct-current system at a maximum +pressure of 60,000 volts. Four groups of machines in series are +employed, each group consisting of four machines in series; the +rated output of each component machine is 75 amperes at 3900 +volts or 400 h.p. A water turbine drives two pairs of such machines +through an insulating coupling, and the sub-base of each pair of +machines is separately insulated from earth, the foundation being +also of special insulating materials.</p> + +<p><a name="ft20p" id="ft20p" href="#fa20p"><span class="fn">20</span></a> For experiments on high-frequency currents, Nikola Tesla constructed +an alternator having 384 poles and giving a frequency of +about 10,000 (<i>Journ. Inst. Elec. Eng.</i> 1892, 21, p. 82). The opposite +extreme is found in alternators directly coupled to the Parsons steam-turbine, +in which, with a speed of 3000 revs. per min., only two +poles are required to give a frequency of 50. By a combination +of a Parsons steam-turbine running at 12,000 revs. per min. with an +alternator of 140 poles a frequency of 14,000 has been obtained +(<i>Engineering</i>, 25th of August 1899). For description of an experimental +machine for 10,000 cycles per second when running at +3000 revs. per min., see <i>Trans. Amer. Inst. Elect. Eng.</i> vol. xxiii. +p. 417.</p> + +<p><a name="ft21p" id="ft21p" href="#fa21p"><span class="fn">21</span></a> As in the historical transmission of energy from Lauffen to +Frankfort (1891).</p> + +<p><a name="ft22p" id="ft22p" href="#fa22p"><span class="fn">22</span></a> In the pioneer three-phase transmission between Laufen and +Frankfort (<i>Electrician</i>, vol. xxvi. p. 637, and xxvii. p. 548), the +three-phase current was transformed up from about 55 to 8500 volts, +the distance being 110 m. A large number of installations driven +by water power are now at work, in which energy is transmitted +on the alternating-current system over distances of about 100 m. +at pressures ranging from 20,000 to 67,000 volts.</p> +</div> + +<p><span class="pagenum"><a name="page782" id="page782"></a>782</span></p> + + +<hr class="art" /> +<p><span class="bold">DYNAMOMETER<a name="ar8" id="ar8"></a></span> (Gr. <span class="grk" title="dynamis">δύναμις</span>, strength, and <span class="grk" title="metron">μέτρον</span>, a +measure), an instrument for measuring force exerted by men, +animals and machines. The name has been applied generally to +all kinds of instruments used in the measurement of a force, as for +example electric dynamometers, but the term specially denotes +apparatus used in connexion with the measurement of work, or +in the measurement of the horse-power of engines and motors. If +P represent the average value of the component of a force in the +direction of the displacement, s, of its point of application, the +product Ps measures the work done during the displacement. +When the force acts on a body free to turn about a fixed axis +only, it is convenient to express the work done by the transformed +product Tθ, where T is the average turning moment or +torque acting to produce the displacement θ radians. The +apparatus used to measure P or T is the dynamometer. The +factors s or θ are observed independently. Apparatus is added +to some dynamometers by means of which a curve showing the +variations of P on a distance base is drawn automatically, the +area of the diagram representing the work done; with others, +integrating apparatus is combined, from which the work done +during a given interval may be read off directly. It is convenient +to distinguish between absorption and transmission dynamometers. +In the first kind the work done is converted into +heat; in the second it is transmitted, after measurement, for +use.</p> + +<div class="condensed"> +<p><i>Absorption Dynamometers.</i>—Baron Prony’s dynamometer (<i>Ann. +Chim. Phys.</i> 1821, vol. 19), which has been modified in various +ways, consists in its original form of two symmetrically shaped +timber beams clamped to the engine-shaft. When these are held +from turning, their frictional resistance may be adjusted by means +of nuts on the screwed bolts which hold them together until the +shaft revolves at a given speed. To promote smoothness of action, +the rubbing surfaces are lubricated. A weight is moved along the +arm of one of the beams until it just keeps the brake steady midway +between the stops which must be provided to hold it when the weight +fails to do so. The general theory of this kind of brake is as +follows:-Let F be the whole frictional resistance, r the common +radius of the rubbing surfaces, W the force which holds the brake +from turning and whose line of action is at a perpendicular distance +R from the axis of the shaft, N the revolutions of the shaft per +minute, ω its angular velocity in radians per second; then, assuming +that the adjustments are made so that the engine runs steadily at a +uniform speed, and that the brake is held still, clear of the stops +and without oscillation, by W, the torque T exerted by the engine +is equal to the frictional torque Fr acting at the brake surfaces, +and this is measured by the statical moment of the weight W about +the axis of revolution; that is—</p> + +<p class="center">T = Fr = WR.</p> +<div class="author">(1)</div> + +<p class="noind">Hence WR measures the torque T.</p> + +<p>If more than one force be applied to hold the brake from turning, +Fr, and therefore T, are measured by the algebraical sum of their +individual moments with respect to the axis. If the brake is not +balanced, its moment about the axis must be included. Therefore, +quite generally,</p> + +<p class="center">T = ΣWR.</p> +<div class="author">(2)</div> + +<p class="noind">The factor θ of the product Tθ is found by means of a revolution +counter. The power of a motor is measured by the rate at which it +works, and this is expressed by Tω = T2πN / 60 in foot-pounds per second, +or T2πN / 33,000 in horse-power units. The latter is commonly referred to +as the “brake horse-power.” The maintenance of the conditions of +steadiness implied in equation (1) depends upon the constancy of +F, and therefore of the coefficient of friction μ between the rubbing +surfaces. The heating at the surfaces, the variations in their smoothness, +and the variations of the lubrication make μ continuously +variable, and necessitate frequent adjustment of W or of the nuts. +J.V. Poncelet (1788-1867) invented a form of Prony brake which +automatically adjusted its grip as μ changed, thereby maintaining +F constant.</p> + +<p>The principle of the compensating brake devised by J.G. Appold +(1800-1865) is shown in fig. 1. A flexible steel band, lined with +wood blocks, is gripped on the motor fly-wheel or pulley by a screw +A, which, together with W, is adjusted to hold the brake steady. +Compensation is effected by the lever L inserted at B. This has a +slotted end, engaged by a pin P fixed to the framing, and it will be +seen that its action is to slacken the band if the load tends to rise +and to tighten it in the contrary case. The external forces holding +the brake from turning are W, distant R from the axis, and the reaction, +W<span class="su">1</span> say, of the lever against the fixed pin P, distant R<span class="su">1</span> +from the axis. The moment of W<span class="su">1</span> may be positive or negative. +The torque T at any instant of steady running is therefore +{WR ± W<span class="su">1</span>R<span class="su">1</span>}.</p> + +<table class="flt" style="float: right; width: 330px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:283px; height:302px" src="images/img782a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 1.</span></td></tr> +<tr><td class="figright1"><img style="width:297px; height:702px" src="images/img782b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 2.</span></td></tr></table> + +<p>Lord Kelvin patented a brake in 1858 (fig. 2) consisting of a +rope or cord wrapped round the circumference of a rotating +wheel, to one end of which is applied a regulated force, the other +end being fixed to a spring +balance. The ropes are +spaced laterally by the blocks +B, B, B, B, which also serve +to prevent them from slipping +sideways. When the +wheel is turning in the direction +indicated, the forces +holding the band still are +W, and p, the observed pull +on the spring balance. Both +these forces usually act at +the same radius R, the distance +from the axis to the +centre line of the rope, in +which case the torque T is +(W − p)R, and consequently +the brake horse-power is +[(W − p)R × 2πN] / 33,000. +When μ changes the weight W rises or +falls against the action of the spring balance until a stable condition +of running is obtained. The ratio W/p is given by e<span class="sp">μθ</span>, where e = 2.718; +μ is the coefficient of friction and θ the angle, measured in radians, +subtended by the arc of contact between the rope and the wheel. In +fig. 2 θ = 2π. The ratio W/p increases very rapidly as θ is increased, +and therefore, by making θ sufficiently large, p may conveniently +be made a small fraction of W, thereby rendering errors of observation +of the spring balance negligible. Thus this kind of brake, +though cheap to make, is, when θ is large enough, an exceedingly +accurate measuring instrument, readily applied and easily controlled. +It has come into very general use in recent years, and has practically +superseded the older forms +of block brakes.</p> + +<p>It is sometimes necessary +to use water to keep the +brake wheel cool. Engines +specially designed for testing +are usually provided +with a brake wheel having +a trough-shaped rim. Water +trickles continuously into +the trough, and the centrifugal +action holds it as an +inside lining against the rim, +where it slowly evaporates.</p> + +<p>Fig. 3 shows a band-brake +invented by Professor James +Thomson, suitable for testing +motors exerting a constant +torque (see <i>Engineering</i>, +22nd October 1880). +To maintain e<span class="sp">μθ</span> constant, +compensation for variation +of μ is made by inversely +varying θ. A and B are fast +and loose pulleys, and the +brake band is placed partly +over the one and partly over +the other. Weights W and +w are adjusted to the torque. +The band turns with the fast +pulley if μ increase, thereby +slightly turning the loose +pulley, otherwise at rest, +until θ is adjusted to the +new value of μ. This form +of brake was also invented +independently by J.A.M.L. +Carpentier, and the principle +has been used in the +Raffard brake. A self-compensating +brake of another +kind, by Marcel Deprez, +was described with Carpentier’s +in 1880 (<i>Bulletin +de la société d’encouragement</i>, +Paris). W.E. Ayrton +and J. Perry used a band or rope brake in which compensation is +effected by the pulley drawing in or letting out a part of the band +or rope which has been roughened or in which a knot has been tied.</p> + +<table class="flt" style="float: left; width: 280px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:256px; height:309px" src="images/img783a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 3.</td></tr></table> + +<p>In an effective water-brake invented by W. Froude (see <i>Proc. +Inst. M. E.</i> 1877), two similar castings, A and B, each consisting +<span class="pagenum"><a name="page783" id="page783"></a>783</span> +of a boss and circumferential annular channel, are placed face to face +on a shaft, to which B is keyed, A being free (fig. 4). A ring tube of +elliptical section is thus formed. Each channel is divided into a +series of pockets by equally spaced vanes inclined at 45°. When +A is held still, and B rotated, centrifugal action sets up vortex +currents in the water in the pockets; thus a continuous circulation +is caused between B and A, and the consequent changes of momentum +give rise to oblique reactions. The moments of the components +of these actions and reactions in a plane to which the axis of rotation +is at right angles are the two +aspects of the torque acting, and +therefore the torque acting on B +through the shaft is measured by +the torque required to hold A +still. Froude constructed a brake +to take up 2000 H.P. at 90 +revs. per min. by duplicating this +apparatus. This replaced the +propeller of the ship whose +engines were to be tested, and +the outer casing was held from +turning by a suitable arrangement +of levers carried to weighing +apparatus conveniently disposed +on the wharf. The torque corresponding +to 2000 H.P. at 90 revs. +per min. is 116,772 foot-pounds, +and a brake 5 ft. in diameter +gave this resistance. Thin metal +sluices were arranged to slide between +the wheel and casing, and +by their means the range of action could be varied from 300 H.P. +at 120 revs. per min. to the maximum.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:479px; height:437px" src="images/img783b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 4.</td></tr></table> + +<p>Professor Osborne Reynolds in 1887 patented a water-brake (see +<i>Proc. Inst. C.E.</i> 99, p. 167), using Froude’s turbine to obtain the +highly resisting spiral vortices, and arranging passages in the casing +for the entry of water at the hub of the wheel and its exit at the +circumference. Water enters at E (fig. 5), and finds its way into the +interior of the wheel, A, driving the air in front of it through the air-passages +K, K. Then following into the pocketed chambers V<span class="su">1</span>, V<span class="su">2</span>, +it is caught into the vortex, and finally escapes at the circumference, +flowing away at F. The air-ways k, k, in the fixed vanes establish +communication between the cores of the vortices and the atmosphere. +From <span class="spp">1</span>⁄<span class="suu">5</span> to 30 H.P. may be measured at 100 revs. per min. +by a brake-wheel of this kind 18 in. in diameter. For other speeds +the power varies as the cube of the speed. The casing is held from +turning by weights hanging on an attached arm. The cocks regulating +the water are connected to the casing, so that any tilting +automatically regulates the flow, and therefore the thickness of the +film in the vortex. In this way the brake may be arranged to +maintain a constant torque, not withstanding variation of the speed. +In G.I. Alden’s brake (see <i>Trans. Amer. Soc. Eng.</i> vol. xi.) the +resistance is obtained by turning a cast iron disk against the frictional +resistance of two thin copper plates, which are held in a casing +free to turn upon the shaft, and are so arranged that the pressure +between the rubbing surfaces is controlled, and the heat developed +by friction carried away, by the regulated flow of water through the +casing. The torque required to hold the casing still against the action +of the disk measures the torque exerted by the shaft to which the +disk is keyed.</p> + +<table class="flt" style="float: right; width: 320px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:297px; height:453px" src="images/img783c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 5.</td></tr> +<tr><td class="figright1"><img style="width:233px; height:239px" src="images/img783d.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 6.</td></tr></table> + +<p><i>Transmission Dynamometers.</i>—The essential part of many transmission +dynamometers is a spring whose deformation indirectly +measures the magnitude of the force transmitted through it. For +many kinds of spring the change of form is practically proportional +to the force, but the relation should always be determined experimentally. +General A.J. Morin (see <i>Notice sur divers appareils +dynamométriques</i>, Paris, 1841), in his classical experiments on +traction, arranged his apparatus +so that the change in +form of the spring was continuously +recorded on a sheet +of paper drawn under a style. +For longer experiments he +used a “Compteur” or +mechanical integrator, suggested +by J.V. Poncelet, +from which the work done +during a given displacement +could be read off directly. +This device consists of a +roller of radius r, pressed +into contact with a disk. +The two are carried on a +common frame, so arranged +that a change in form of +the spring causes a relative +displacement of the disk and +roller, the point of contact +moving radially from or +towards the centre of the +disk. The radial distance x is +at any instant proportional +to the force acting through +the spring. The angular displacement, +θ, of the disk is +made proportional to the +displacement, s, of the point +of application of the force +by suitable driving gear. If dφ is the angular displacement of +the roller corresponding to displacements, dθ of the disk, and +ds of the point of application of P, a, and C constants, then +dφ = xdθ / r = (a/r) P ds = C·P ds, and therefore +φ = C <span class="f150">∫</span><span class="sp1">S2</span><span class="su1">S1</span> P ds; + that is, the angular displacement of the roller measures the work done +during the displacement from s<span class="su">1</span> to s<span class="su">2</span>. The shaft carrying the +roller is connected to a counter so that φ may be observed. The +angular velocity of the shaft is proportional to the rate of working. +Morin’s dynamometer is shown in fig. 6. The transmitting spring is +made up of two flat bars linked at their ends. Their centres s<span class="su">1</span>, s<span class="su">2</span>, +are held respectively by the pieces A, B, which together form a sliding +pair. The block A carries the disk D, B carries the roller R and +counting gear. The pulley E is driven from an axle of the carriage. +In a dynamometer used by F.W. Webb to measure the tractive +resistance of trains on the London & North-Western railway, a +tractive pull or push compresses two spiral springs by a definite +amount, which is recorded to scale by a pencil on a sheet of paper, +drawn continuously from a storage drum at the rate of 3 in. per +mile, by a roller driven from one of the carriage axles. Thus the +diagram shows the tractive force at any instant. A second pencil +electrically connected to a clock traces a time line on the diagram +with a kick at every thirty seconds. A third pencil traces an observation +line in which a kick can be made at will by pressing any one +of the electrical pushes placed about the car, and a fourth draws +a datum line. The spring of the +dynamometer car used by W. Dean +on the Great Western railway is made +up of thirty flat plates, 7 ft. 6 in. +long, 5 in. × <span class="spp">5</span>⁄<span class="suu">8</span> in. at the centre, spaced +by distance pieces nibbed into the +plates at the centre and by rollers at +the ends. The draw-bar is connected +to the buckle, which is carried on +rollers, the ends of the spring resting +on plates fixed to the under-frame. +The gear operating the paper roll is +driven from the axle of an independent +wheel which is let down into +contact with the rail when required. +This wheel serves also to measure +the distance travelled. A Morin disk +and roller integrator is connected +with the apparatus, so that the work done during a journey may +be read off. Five lines are traced on the diagram.</p> + +<table class="flt" style="float: left; width: 350px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:309px; height:366px" src="images/img784a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 7.</td></tr></table> + +<p>In spring dynamometers designed to measure a transmitted +torque, the mechanical problem of ascertaining the change of +form of the spring is complicated by the fact that the spring and +the whole apparatus are rotating together. In the Ayrton and +Perry transmission dynamometer or spring coupling of this type, +<span class="pagenum"><a name="page784" id="page784"></a>784</span> +the relative angular displacement is proportional to the radius +of the circle described by the end of a light lever operated by +mechanism between the spring-connected parts. By a device used +by W.E. Dalby (<i>Proc. Inst.C.E.</i> 1897-1898, p. 132) the change in +form of the spring is shown on a fixed indicator, which may be placed +in any convenient position. Two equal sprocket wheels Q<span class="su">1</span>, Q<span class="su">2</span>, are +fastened, the one to the spring pulley, the other to the shaft. An +endless band is placed over them to form two loops, which during +rotation remain at the same distance apart, unless relative angular +displacement occurs between +Q<span class="su">1</span> and Q<span class="su">2</span> (fig. 7) +due to a change in form +of the spring. The change +in the distance <i>d</i> is proportional +to the change +in the torque transmitted +from the shaft to the +pulley. To measure this, +guide pulleys are placed +in the loops guided by a +geometric slide, the one +pulley carrying a scale, +and the other an index. +A recording drum or integrating +apparatus may +be arranged on the pulley +frames. A quick variation, +or a periodic variation of +the magnitude of the force +or torque transmitted +through the springs, tends +to set up oscillations, and +this tendency increases +the nearer the periodic +time of the force variation +approaches a periodic time of the spring. Such vibrations may be +damped out to a considerable extent by the use of a dash-pot, +or may be practically prevented by using a relatively stiff spring.</p> + +<p>Every part of a machine transmitting force suffers elastic deformation, +and the force may be measured indirectly by measuring +the deformation. The relation between the two should in all cases +be found experimentally. G.A. Hirn (see <i>Les Pandynamomètres</i>, +Paris, 1876) employed this principle to measure the torque transmitted +by a shaft. Signor Rosio used a telephonic method to effect +the same end, and mechanical, optical and telephonic devices have +been utilized by the Rev. F.J. Jervis-Smith. (See <i>Phil. Mag.</i> +February 1898.)</p> + +<p>H. Frahm,<a name="fa1q" id="fa1q" href="#ft1q"><span class="sp">1</span></a> during an important investigation on the torsional +vibration of propeller shafts, measured the relative angular displacement +of two flanges on a propeller shaft, selected as far apart as +possible, by means of an electrical device (<i>Engineering</i>, 6th of +February 1903). These measurements were utilized in combination +with appropriate elastic coefficients of the material to find the +horse-power transmitted from the engines along the shaft to the +propeller. In this way the effective horse-power and also the +mechanical efficiency of a number of large marine engines, each of +several thousand horse-power, have been determined.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:438px; height:216px" src="images/img784b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 8.</td></tr></table> + +<p>When a belt, in which the maximum and minimum tensions +are respectively P and p ℔, drives a pulley, the torque exerted +is (P − p)r ℔ ft., r being the radius of the pulley plus half the thickness +of the belt. P and p may be measured directly by leading the +belt round two freely hanging guide pulleys, one in the tight, the +other in the slack part of the belt, and adjusting loads on them until +a stable condition of running is obtained. In W. Froude’s belt +dynamometer (see <i>Proc. Inst. M.E.</i>, 1858) (fig. 8) the guide pulleys +G<span class="su">1</span>, G<span class="su">2</span> are carried upon an arm free to turn about the axis O. H +is a pulley to guide the approaching and receding parts of the belt +to and from the beam in parallel directions. Neglecting friction, the +unbalanced torque acting on the beam is 4r {P − p} ℔ ft. If a force +Q acting at R maintains equilibrium, QR/4 = (P − p)r = T. Q is +supplied by a spring, the extensions of which are recorded on a drum +driven proportionally to the angular displacement of the driving +pulley; thus a work diagram is obtained. In the Farcot form the +guide pulleys are attached to separate weighing levers placed horizontally +below the apparatus. In a belt dynamometer built for the +Franklin Institute from the designs of Tatham, the weighing levers +are separate and arranged horizontally at the top of the apparatus. +The weighing beam in the Hefner-Alteneck dynamometer is placed +transversely to the belt (see <i>Electrotechnischen Zeitschrift</i>, 1881, 7). +The force Q, usually measured by a spring, required to maintain +the beam in its central position is proportional to (P − p). If +the angle θ<span class="su">1</span> = θ<span class="su">2</span> = 120°, Q = (P − p) neglecting friction.</p> + +<p>When a shaft is driven by means of gearing the driving torque +is measured by the product of the resultant pressure P acting +between the wheel teeth and the radius of the pitch circle of the +wheel fixed to the shaft. Fig. 9, which has been reproduced from +J. White’s <i>A New Century of Inventions</i> (Manchester, 1822), illustrates +possibly the earliest application of this principle to dynamometry. +The wheel D, keyed to the shaft overcoming the resistance +to be measured, is driven from wheel N by two bevel wheels L, L, +carried in a loose pulley K. The two shafts, though in a line, are +independent. A torque applied to the shaft A can be transmitted +to D, neglecting friction, without change only if the central pulley +K is held from turning; the torque required to do this is twice the +torque transmitted.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:437px; height:434px" src="images/img784c.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 9.</td></tr></table> + +<p>The torque acting on the armature of an electric motor is necessarily +accompanied by an equal and opposite torque acting on the +frame. If, therefore, the motor is mounted on a cradle free to turn +about knife-edges, the reacting torque is the only torque tending +to turn the cradle when it is in a vertical position, and may therefore +be measured by adjusting weights to hold the cradle in a vertical +position. The rate at which the motor is transmitting work is then +T2πn / 550 H.P., where n is the revolutions per second of the armature.</p> + +<p>See James Dredge, <i>Electric Illumination</i>, vol. ii. (London, 1885); +W.W. Beaumont, “Dynamometers and Friction Brakes,” <i>Proc. +Inst.C.E.</i> vol. xcv. (London, 1889); E. Brauer, “Über Bremsdynamometer +and verwandte Kraftmesser,” <i>Zeitschrift des Vereins +deutscher Ingenieure</i> (Berlin, 1888); J.J. Flather, <i>Dynamometers +and the Measurement of Power</i> (New York, 1893).</p> +</div> +<div class="author">(W. E. D.)</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1q" id="ft1q" href="#fa1q"><span class="fn">1</span></a> H. Frahm, “Neue Untersuchungen über die dynamischen +Vorgänge in den Wellenleitungen von Schiffsmaschinen mit besonderer +Berücksichtigung der Resonanzschwingungen,” <i>Zeitschrift +des Vereins deutscher Ingenieure</i>, 31st May 1902.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">DYNASTY<a name="ar9" id="ar9"></a></span> (Gr. <span class="grk" title="dynasteia">δυναστεία</span>, sovereignty, the position of a +<span class="grk" title="dynastês">δυνάοτης</span>, lord, ruler, from <span class="grk" title="dynasthai">δύνασθαι</span>, to be able, <span class="grk" title="dynamis">δύναμις</span>, power), +a family or line of rulers, a succession of sovereigns of a country +belonging to a single family or tracing their descent to a common +ancestor. The term is particularly used in the history of ancient +Egypt as a convenient means of arranging the chronology.</p> + + +<hr class="art" /> +<p><span class="bold">DYSART,<a name="ar10" id="ar10"></a></span> a royal and police burgh and seaport of Fifeshire, +Scotland, on the shore of the Firth of Forth, 2 m. N.E. of Kirkcaldy +by the North British railway. Pop. (1901) 3562. It has +a quaint old-fashioned appearance, many ancient houses in +High Street bearing inscriptions and dates. The public buildings +include a town hall, library, cottage hospital, mechanics’ +institute and memorial hall. Scarcely anything is left of the old +chapel dedicated to St Dennis, which for a time was used as a +<span class="pagenum"><a name="page785" id="page785"></a>785</span> +smithy; and of the chapel of St Serf, the patron saint of the +burgh, only the tower remains. The chief industries are the +manufacture of bed and table linen, towelling and woollen cloth, +shipbuilding and flax-spinning. There is a steady export of +coal, and the harbour is provided with a wet dock and patent +slip. In smuggling days the “canty carles” of Dysart were +professed “free traders.” In the 15th and 16th centuries the +town was a leading seat of the salt industry (“salt to Dysart” +was the equivalent of “coals to Newcastle”), but the salt-pans +have been abandoned for a considerable period. Nail-making, +once famous, is another extinct industry. During the time +of the alliance between Scotland and Holland, which was closer +in Fifeshire than in other counties, Dysart became known as +Little Holland. To the west of the town is Dysart House, the +residence of the earl of Rosslyn. With Burntisland and Kinghorn +Dysart forms one of the Kirkcaldy district group of parliamentary +burghs. The town is mentioned as early as 874 in +connexion with a Danish invasion. Its name is said to be a +corruption of the Latin <i>desertum</i>, “a desert,” which was applied +to a cave on the seashore occupied by St Serf. In the cave the +saint held his famous colloquy with the devil, in which Satan +was worsted and contemptuously dismissed. From James V. +the town received the rights of a royal burgh. In 1559 it was the +headquarters of the Lords of the Congregation, and in 1607 the +scene of the meetings of the synod of Fife known as the Three +Synods of Dysart. Ravensheugh Castle, on the shore to the west +of the town, is the Ravenscraig of Sir Walter Scott’s ballad of +“Rosabelle.”</p> + +<p>William Murray, a native of the place, was made earl of Dysart +in 1643, and his eldest child and heir, a daughter, Elizabeth, +obtained in 1670 a regrant of the title, which passed to the descendants +of her first marriage with Sir Lionel Tollemache, Bart., +of Helmingham; she married secondly the 1st duke of Lauderdale, +but had no children by him, and died in 1698. This countess +of Dysart (afterwards duchess of Lauderdale) was a famous +beauty of the period, and notorious both for her amours and for +her political influence. She was said to have been the mistress +of Oliver Cromwell, and also of Lauderdale before her first +husband’s death, and was a leader at the court of Charles II. +Wycherley is supposed to have aimed at her in his Widow +Blackacre in the <i>Plain Dealer</i>. Her son, Lionel Tollemache +(d. 1727), transmitted the earldom to his grandson Lionel (d. +1770), whose sons Lionel (d. 1799) and Wilbraham (d. 1821) +succeeded; they died without issue, and their sister Louisa (d. +1840), who married John Manners, an illegitimate son of the +second son of the 2nd duke of Rutland, became countess in her +own right, being succeeded by her grandson (d. 1878), and his +grandson, the 8th earl.</p> + +<p>The earldom of Dysart must not be confounded with that of +Desart (Irish), created (barony 1733) in 1793, and held in the +Cuffe family, who were originally of Creech St Michael, Somerset, +the Irish branch dating from Queen Elizabeth’s time.</p> + + +<hr class="art" /> +<p><span class="bold">DYSENTERY<a name="ar11" id="ar11"></a></span> (from the Gr. prefix <span class="grk" title="dys">δυσ</span>-, in the sense of “bad,” +and <span class="grk" title="enteron">ἔντερον</span>, the intestine), also called “bloody flux,” an infectious +disease with a local lesion in the form of inflammation +and ulceration of the lower portion of the bowels. Although +at one time a common disease in Great Britain, dysentery is +now very rarely met with there, and is for the most part confined +to warm countries, where it is the cause of a large amount of +mortality. (For the pathology see <span class="sc"><a href="#artlinks">Digestive Organs</a></span>.)</p> + +<p>Recently considerable advance has been made in our knowledge +of dysentery, and it appears that there are two distinct +types of the disease: (1) amoebic dysentery, which is due to the +presence of the amoeba histolytica (of Schaudinn) in the intestine; +(2) bacillary dysentery, which has as causative agent two +separate bacteria, (<i>a</i>) that discovered by Shiga in Japan, (<i>b</i>) +that discovered by Flexner in the Philippine Islands. With +regard to the bacillary type, at first both organisms were considered +to be identical, and the name <i>bacillus dysenteriae</i> was +given to them; but later it was shown that these bacilli are +different, both in regard to their cultural characteristics and +also in that one (Shiga) gives out a soluble toxin, whilst the +other has so far resisted all efforts to discover it. Further, the +serum of a patient affected with one of the types has a marked +agglutinative power on the variety with which he is infected +and not on the other.</p> + +<p>Clinically, dysentery manifests itself with varying degrees of +intensity, and it is often impossible without microscopical +examination to determine between the amoebic and bacillary +forms. In well-marked cases the following are the chief symptoms. +The attack is commonly preceded by certain premonitory +indications in the form of general illness, loss of appetite, and +some amount of diarrhoea, which gradually increases in severity, +and is accompanied with griping pains in the abdomen (tormina). +The discharges from the bowels succeed each other with great +frequency, and the painful feeling of pressure downwards +(tenesmus) becomes so intense that the patient is constantly +desiring to defecate. The matters passed from the bowels, +which at first resemble those of ordinary diarrhoea, soon change +their character, becoming scanty, mucous or slimy, and subsequently +mixed with, or consisting wholly of, blood, along with +shreds of exudation thrown off from the mucous membrane of +the intestine. The evacuations possess a peculiarly offensive +odour characteristic of the disease. Although the constitutional +disturbance is at first comparatively slight, it increases with the +advance of the disease, and febrile symptoms come on attended +with urgent thirst and scanty and painful flow of urine. Along +with this the nervous depression is very marked, and the state +of prostration to which the patient is reduced can scarcely be +exceeded. Should no improvement occur death may take place +in from one to three weeks, either from repeated losses of blood, +or from gradual exhaustion consequent on the continuance of +the symptoms, in which case the discharges from the bowels +become more offensive and are passed involuntarily.</p> + +<p>When, on the other hand, the disease is checked, the signs +of improvement are shown in the cessation of the pain, in the +evacuations being less frequent and more natural, and in relief +from the state of extreme depression. Convalescence is, however, +generally slow, and recovery may be imperfect—the +disease continuing in a chronic form, which may exist for a +variable length of time, giving rise to much suffering, and not +unfrequently leading to an ultimately fatal result.</p> + +<p>The dysentery poison appears to exert its effects upon the +glandular structures of the large intestine, particularly in its +lower part. In the milder forms of the disease there is simply +a congested or inflamed condition of the mucous membrane, +with perhaps some inflammatory exudation on its surface, which +is passed off by the discharges from the bowels. But in the more +severe forms ulceration of the mucous membrane takes place. +Commencing in and around the solitary glands of the large intestine +in the form of exudations, these ulcers, small at first, +enlarge and run into each other, till a large portion of the bowel +may be implicated in the ulcerative process. Should the disease +be arrested these ulcers may heal entirely, but occasionally they +remain, causing more or less disorganization of the coats of the +intestines, as is often found in chronic dysentery. Sometimes, +though rarely, the ulcers perforate the intestines, causing rapidly +fatal inflammation of the peritoneum, or they may erode a blood +vessel and produce violent haemorrhage. Even where they +undergo healing they may cause such a stricture of the calibre +of the intestinal canal as to give rise to the symptoms of obstruction +which ultimately prove fatal. One of the severest complications +of the disease is abscess of the liver, usually said to be +solitary, and known as tropical abscess of the liver, but probably +is more frequently multiple than is usually thought.</p> + +<p><i>Treatment.</i>—Where the disease is endemic or is prevailing +epidemically, it is of great importance to use all preventive +measures, and for this purpose the avoidance of all causes likely +to precipitate an attack is to be enjoined. Exposure to cold +after heat, the use of unripe fruit, and intemperance in eating +and drinking should be forbidden; and the utmost care taken +as to the quality of the food and drinking water. In houses or +hospitals where cases of the disease are under treatment, disinfectants +should be freely employed, and the evacuations of the +<span class="pagenum"><a name="page786" id="page786"></a>786</span> +patients removed as speedily as possible, having previously +been sterilized in much the same manner as is employed in +typhoid fever. In the milder varieties of this complaint, such +as those occurring sporadically, and where the symptoms are +probably due to matters in the bowels setting up the dysenteric +irritation, the employment of diaphoretic medicines is to +be recommended, and the administration of such a laxative as +castor oil, to which a small quantity of laudanum has been added, +will often, by removing the source of the mischief, arrest the +attack; but a method of treatment more to be recommended is +the use of salines in large doses, such as one drachm of sodium +sulphate from four to eight times a day. This treatment may +with advantage be combined with the internal administration +of ipecacuanha, which still retains its reputation in this disease. +Latterly, free irrigation of the bowel with astringents, such as +silver nitrate, tannalbin, &c., has been attended with success in +those cases which have been able to tolerate the injections. +In many instances they cannot be used owing to the extreme +degree of irritability of the bowel. The operation of appendicostomy, +or bringing the appendix to the surface and using it as +the site for the introduction of the irrigating fluid, has been +attended with considerable success.</p> + +<p>In those cases due to Shiga’s bacillus the ideal treatment has +been put at our disposal by the preparation of a specific antitoxin; +this has been given a trial in several grave epidemics +of late, and may be said to be the most satisfactory treatment +and offer the greatest hope of recovery. It is also of great use +as a prophylactic.</p> + +<p>The preparations of morphia are of great value in the symptomatic +treatment of the disease. They may be applied externally +as fomentations, for the relief of tormina; by rectal injection +for the relief of the tenesmus and irritability of the bowel; +hypodermically in advanced cases, for the relief of the general +distress. In amoebic dysentery, warm injections of quinine <i>per +rectum</i> have proved very efficacious, are usually well tolerated, +and are not attended with any ill effects. The diet should be +restricted, consisting chiefly of soups and farinaceous foods; +more especially is this of importance in the chronic form. For +the thirst ice may be given by the mouth. Even in the chronic +forms, confinement to bed and restriction of diet are the +most important elements of the treatment. Removal from the +hot climate and unhygienic surroundings must naturally be +attended to.</p> + +<div class="condensed"> +<p><span class="sc">Bibliography.</span>—Allbutt and Rolleston, <i>System of Medicine</i>, +vol. ii. part ii. (1907), “Dysentery,” Drs Andrew Davidson and +Simon Flexner; Davidson, <i>Hygiene and Diseases of Warm Climates</i> +(Edinburgh, 1903); Fearnside in <i>Ind. Med. Gaz.</i> (July 1905); Ford +in <i>Journal of Tropical Medicine</i> (July 15, 1904); Korentchewsky +in <i>Bulletin de l’Institut Pasteur</i> (February 1905); Shiga: Osier and +M’Crae’s <i>System of Medicine</i>, vol. ii. p. 781 (1907); Skschivan and +Stefansky in <i>Berliner klinische Wochenschrift</i> (February 11, 1907); +Vaillard and Dopter, on the treatment by antidysenteric serum, +<i>Annales de l’Institut Pasteur</i>, No. 5, p. 326 (1906); J.A. Pottinger, +“Appendicostomy in Chronic Dysentery,” <i>Lancet</i> (December 28, +1907); Robert Doerr, <i>Das Dysenterietoxin</i> (Gustav Fischer, Jena, +1907); F.M. Sandwith, “Hunterian Lecture on the Treatment of +Dysentery,” <i>Lancet</i> (December 7, 1907).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">DYSPEPSIA<a name="ar12" id="ar12"></a></span> (from the Gr. prefix <span class="grk" title="dys">δυσ</span>-, hard, ill, and <span class="grk" title="peptein">πέπτειν</span>, +to digest), or indigestion, a term vaguely given to a group of +pathological symptoms. There are comparatively few diseases +of any moment where some of the phenomena of dyspepsia are +not present as associated symptoms, and not infrequently these +exist to such a degree as to mask the real disease, of which they +are only complications. This is especially the case in many +organic diseases of the alimentary canal, in which the symptoms +of dyspepsia are often the most prominent. In its restricted +meaning, however (and it is to this that the present article +applies), the term is used to describe a functional derangement +of the natural process of digestion, apart from any structural +change in the organs concerned in the act.</p> + +<p>The causes of this trouble may be divided into (<i>a</i>) those which +concern the food, and (<i>b</i>) those which concern the organism. +Among the causes connected with the food are not only the +indulgence in indigestible articles of diet, but the too common +practice of eating too much of what may be otherwise quite +wholesome and digestible; and irregular, too frequent or too +infrequent meals. The quantity of food required by different +individuals varies between wide limits, but also the quantity +required by the same individual varies considerably according +to circumstances, more food being needed in cold than in warm +weather, and more in an active open-air occupation than in a +sedentary one. The thorough mastication of the food is a very +important precursor of digestion,<a name="fa1r" id="fa1r" href="#ft1r"><span class="sp">1</span></a> and this only too often fails, +either owing to haste over meals or because of painful or deficient +teeth. Again, the quality of the food is of importance, some +kinds of flesh being harder and more difficult of mastication +than others. This is especially the case with meat that has +been smoked or salted, and with that cooked too soon after the +death of the animal. Drinks are a common source of dyspepsia. +Beer when new and its fermentation not completed is especially +bad. Vinegar and acid wines, if taken in large quantities, tend +to produce gastric catarrh, and tea is a very fruitful source of +this trouble. Even too much water at meal-times may cause +indigestion, since the food in the mouth is apt to be softened +by the water instead of saliva, and also the gastric juice becomes +unduly diluted, rendering the digestion in the stomach too slow +and prolonged. Carious teeth and oral sepsis, from whatsoever +cause, lead to the same trouble.</p> + +<p>Of the causes which concern the organism, nervous influences +come first. Bad news may take away all power of digestion +and even provoke vomiting, and any worry or mental trouble +tends to bring on this condition. General weakness and atony +of the body affects the stomach in like degree, and, if the muscles +of the abdominal wall be much wasted, they become too weak to +support the abdominal viscera in place. Hence results a general +tendency for these organs to fall, giving rise to a condition of +visceroptosis, of which an obstinate dyspepsia is a very marked +feature. Adhesions of the intestines from old inflammatory +troubles, floating kidney and bad circulation may each be a +cause of painful digestion. Again, a dyspepsia that will not +yield to treatment is often one of the symptoms of renal disease, +or, in young people of fifteen to twenty years of age, it may +be the earliest sign of a gouty diathesis, or even of a more serious +condition still—incipient phthisis. Chronic dyspepsia, by +weakening the organism, renders it more liable to fall a prey to the +attacks of the tubercle bacillus, but, on the other hand, the +tuberculous lesion in the lung is often accompanied by a most +intractable form of dyspepsia. From this it is clear that any +condition which lessens the general well-being of the organism +as a whole, apart from its producing any permanent morbid +condition in the stomach, may yet interfere with the normal +digestive processes and so give rise to dyspepsia.</p> + +<p>The symptoms of dyspepsia, even when due to a like cause, +are so numerous and diversified in different individuals that +probably no description could exactly represent them as they +occur in any given case. All that can be here attempted is to +mention some of the more prominent morbid phenomena usually +present in greater or less degree.</p> + +<p>Very briefly, a furred tongue, foul breath, disturbance of +appetite, nausea and vomiting, oppression in the chest, pain, +flatulence and distension, acidity, pyrosis and constipation or +diarrhoea are a few of the commonest symptoms.</p> + +<p>When the attack is dependent on some error in diet, and the +dyspepsia consequently more of an acute character, there is +often pain followed with sickness and vomiting of the offensive +matters, after which the patient soon regains his former healthy +state. What are commonly known as “bilious attacks” are +frequently of this character. In the more chronic cases of +dyspepsia the symptoms are somewhat different. A sensation +of discomfort comes on shortly after a meal, and is more of the +nature of weight and distension in the stomach than of actual +pain, although this too may be present. These feelings may come +<span class="pagenum"><a name="page787" id="page787"></a>787</span> +on after each meal, or only after certain meals, and they may +arise irrespective of the kind of food taken, or only after certain +articles of diet. As in most of such cases the food is long retained +in the stomach, it is apt to undergo fermentive changes, +one of the results of which is the accumulation of gases which +cause flatulence and eructations of an acid or foul character. +Occasionally quantities of hot, sour, tasteless or bitter fluid—pyrosis—or +mouthfuls of half-digested food, regurgitate from +the stomach. Temporary relief may be obtained when another +meal is taken, but soon the uncomfortable sensations return +as before. The appetite may be craving or deficient, or desirous +of abnormal kinds of food. The tongue registers the gastric +condition with great delicacy;—a pasty white fur on the tongue +is considered a sign of weakness or atony of the digestive tract; +a clean pointed tongue with large papillae, and rather red at the +edges and tip, is a sign of gastric irritation; and a pale flabby +tongue suggests the need of stimulating treatment. Constipation +is more common in the chronic forms of dyspepsia, diarrhoea in +the acute.</p> + +<p>Numerous disagreeable and painful sensations in other parts +are experienced, and are indeed often more distressing than the +merely gastric symptoms. Pains in the chest, shortness of +breathing, palpitation, headache, giddiness, affections of vision, +coldness of the extremities, and general languor are common +accompaniments of dyspepsia; while the nervous phenomena +are specially troublesome in the form of sleeplessness, irritability, +despondency and hypochondriasis.</p> + +<p>As regards <i>treatment</i> only a few general observations can be +made. The careful arrangement of the diet is a matter of first +importance. Quantity must be regulated by the digestive +capabilities of the individual, his age, and the demands made +upon his strength by work. There is little doubt that the danger +is in most instances on the side of excess, and the rule which +enjoins the cessation from eating before the appetite is satisfied +is a safe one for dyspeptics. Due time, too, must be given for +the digestion of a meal, and from four to six hours are in general +required for this purpose. Long fasts, however, are nearly as +hurtful as too frequent meals. Of no less importance is the kind +of food taken, and on this point those who suffer from indigestion +must ever exercise the greatest care. It must be borne in mind +that idiosyncrasy often plays an important part in digestion, +some persons being unable to partake without injury of substances +which are generally regarded as wholesome and digestible. +In most cases it is found very helpful to separate the protein +from the farinaceous food, and the more severe the dyspepsia +the more thoroughly should this be done, only relaxing as the +dyspepsia yields. No fluid should be drunk at meal-times, but +from one to two tumblers of hot water should be drunk from an +hour to an hour and a half before food. This washes any remnant +of the last meal from the stomach, and also supplies material for +the free secretion of saliva and gastric juice, thus promoting +and accelerating digestion. The only exception to this is in the +case of a dilated stomach, when it is wholly contra-indicated. +With regard to mastication, Sir Andrew Clark’s rule is a very +good one, and is more easily followed than the ideal theory laid +down by Horace Fletcher, according to whom any food is digestible +if properly treated while still in the mouth. Clark’s rule is +that as the mouth normally contains thirty-two teeth, thirty-two +bites should be given before the food is swallowed. This, +of course, is a practical doctor’s concession to human weakness. +Mr Fletcher would train every one to “chew” till the contents +of the mouth were swallowed by reflex action without deliberate +act; and he applies this theory of mastication and salivation +also to drinks (except water). Again, a lack of warmth being +a source of dyspepsia, this should be attended to, the back of +the neck, the front of the abdomen and the feet being the parts +that require special attention. The feet should be raised on +a stool, the ankles protected with warm stockings and a woollen +“cummerbund” wound two or three times round the body. +Experience has shown that in this complaint no particular kind +of food or avoidance of food is absolutely to be relied on, but +that in general the best diet is one of a mixed animal and vegetable +kind, simply but well cooked. The partaking of many +dishes, of highly-seasoned or salted meats, raw vegetables, newly-baked +bread, pastry and confectionery are all well-known +common causes of dyspepsia, and should be avoided. When +even the simple diet usually taken is found to disagree, it +may be necessary to change it temporarily for a still lighter +form, such as a milk diet, and that even in very moderate +quantity.</p> + +<p>The employment of alcoholic stimulants to assist digestion +is largely resorted to, both with and without medical advice. +While it seems probable that in certain cases of atonic dyspepsia, +particularly in the feeble and aged, the moderate administration +of alcohol has the effect of stimulating the secretion of gastric +juice, and is an important adjuvant to other remedies, the +advantages of its habitual use as an aid to digestion by the young +and otherwise healthy, is more than questionable, and it will +generally be found that among them, those are least troubled +with indigestion who abstain from it. Rest should be taken +both before and after food, and general hygienic measures are +highly important, since whatever improves the state of the +health will have a favourable influence on digestion. Hence +regular exercise in the open air, early rising and the cold bath +are to be strongly recommended.</p> + +<p>The medicinal treatment of dyspepsia can only be undertaken +by a physician, but the following is a very brief résumé of the +drugs he depends on to-day. Bicarbonate of soda with some +bitter, as quassia, gentian or columba, is much in vogue as a +direct gastric stimulant. In irritable dyspepsia some form of +bismuth in solution or powder; and, to assist digestion through +the nervous system, nux vomica and strychnine can be relied +on. To give directly digestive material, hydrochloric acid, +pepsin and rennet are prescribed in many forms, but where +there is much vomiting ingluvin is more efficacious than pepsin. +When farinaceous food is badly borne, diastase is helpful, given +either before or with the meal. To prevent fermentation, phenol, +creasote and sulpho-carbolate of soda are all extremely useful +in skilled hands; and for intestinal decomposition and flatulent +distension, bismuth salicylate with salol or β-naphthol is much +used. Cyllin, and charcoal in many forms, may be taken both +for gastric and intestinal flatulence. But all these drugs, of +proved value though they are, must be modified and combined +to suit the special idiosyncrasy of the patient, and are therefore +often worse than useless in inexperienced hands. The condition +of the bowels must always have due attention.</p> + +<div class="condensed"> +<p>See also <span class="sc"><a href="#artlinks">Digestive Organs</a></span>; <span class="sc"><a href="#artlinks">Nutrition</a></span> and <span class="sc"><a href="#artlinks">Dietetics</a></span>.</p> +</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1r" id="ft1r" href="#fa1r"><span class="fn">1</span></a> This aspect of the matter—“buccal digestion”—has been +specially emphasized in recent years by Horace Fletcher of the +United States, whose experience of the results of systematic “chewing,” +confirmed by Sir M. Foster, Prof. Chittenden and others, has +almost revolutionized the science of dietetics.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">DYSTELEOLOGY,<a name="ar13" id="ar13"></a></span> a modern word invented by Haeckel +(<i>Evolution of Man</i>) for the doctrine of purposelessness, as +opposed to the philosophical doctrine of design (Teleology).</p> + + +<hr class="art" /> +<p><span class="bold">DZUNGARIA,<a name="ar14" id="ar14"></a></span> <span class="sc">Dsongaria</span>, or <span class="sc">Jungaria</span>, a former Mongolian +kingdom of Central Asia, raised to its highest pitch by Kaldan +or Bushtu Khan in the latter half of the 17th century, but +completely destroyed by Chinese invasion about 1757-1759. +It has played an important part in the history of Mongolia and +the great migrations of Mongolian stems westward. Now its +territory belongs partly to the Chinese empire (east Turkestan +and north-western Mongolia) and partly to Russian Turkestan +(provinces of Semiryechensk and Semipalatinsk). It derived +its name from the Dsongars, or Songars, who were so called +because they formed the left wing (<i>dson</i>, left; <i>gar</i>, hand) of the +Mongolian army. Its widest limit included Kashgar, Yarkand, +Khotan, the whole region of the T’ien Shan, or Tian-shan, +Mountains, and in short the greater proportion of that part of +Central Asia which extends from 35° to 50° N. and from 72° to +97° E. The name, however, is more properly applied only to +the present Chinese province of T’ien Shan-pei-lu and the country +watered by the Ili. As a political or geographical term it has +practically disappeared from the map; but the range of mountains +stretching north-east along the southern frontier of the +Land of the Seven Streams, as the district to the south-east of +the Balkhash Lake is called, preserves the name of Dzungarian +Range.</p> + + +<hr class="art" /> +<p><span class="pagenum"><a name="page788" id="page788"></a>788</span></p> +<p><span class="bold">E<a name="ar15" id="ar15"></a></span> The fifth symbol in the English alphabet occupies also +the same position in Phoenician and in the other +alphabets descended from Phoenician. As the Semitic +alphabet did not represent vowels, E was originally an +aspirate. Its earliest form, while writing is still from right to left, +is <img style="width:22px; height:21px; vertical-align: middle;" src="images/img788a.jpg" alt="" />, the upright being continued some distance below the lowest +of the cross-strokes. In some of the Greek alphabets it appears +as <img style="width:14px; height:21px; vertical-align: middle;" src="images/img788b.jpg" alt="" /> with the upright prolonged at both top and bottom, but +it soon took the form with which we are familiar, though in +the earlier examples of this form the cross-strokes are not +horizontal but drop at an angle, <img style="width:18px; height:29px; vertical-align: middle;" src="images/img788c.jpg" alt="" />. In Corinth and places +under its early influence like Megara, or colonized from it like +Corcyra, the symbol for <i>e</i> takes the form <img style="width:16px; height:24px; vertical-align: middle;" src="images/img788d.jpg" alt="" /> or <img style="width:15px; height:20px; vertical-align: middle;" src="images/img788e.jpg" alt="" />, while at Sicyon +in the 6th and 5th centuries <span class="scs">B.C.</span> it is represented by <img style="width:14px; height:22px; vertical-align: middle;" src="images/img788f.jpg" alt="" />. In +early Latin it was sometimes represented by two perpendicular +strokes of equal length, <img style="width:13px; height:19px; vertical-align: middle;" src="images/img788g.jpg" alt="" />.</p> + +<p>In the earliest Greek inscriptions and always in Latin the +symbol <img style="width:16px; height:18px; vertical-align: middle;" src="images/img788h.jpg" alt="" /> represented both the short and the long <i>e</i>-sound. +In Greek also it was often used for the close long sound which +arose either by contraction of two short <i>e</i>-sounds or by the loss +of a consonant, after a short <i>e</i>-sound, as in <span class="grk" title="phileite">φιλεῖτε</span>, “you love,” +for <span class="grk" title="phileete">φιλέετε</span>, and <span class="grk" title="phaeinos">φαεινός</span>, “bright,” out of an earlier <span class="grk" title="phaesnos">φαεσνός</span>. +The Ionian Greeks of Asia Minor, who had altogether lost the +aspirate, were the first to use the symbol <img style="width:18px; height:19px; vertical-align: middle;" src="images/img788i.jpg" alt="" /> for the long <i>e</i>-sound, +and in official documents at Athens down to 403 <span class="scs">B.C.</span>, when the +Greek alphabet as still known was adopted by the state, <img style="width:16px; height:18px; vertical-align: middle;" src="images/img788h.jpg" alt="" /> +represented ε, η and the sound arising by contraction or consonant +loss as mentioned above which henceforth was written with +two symbols, <span class="grk" title="ei">ει</span>, and being really a single sound is known as +the “spurious diphthong.” There were some minor distinctions +in usage of the symbols <img style="width:16px; height:18px; vertical-align: middle;" src="images/img788h.jpg" alt="" /> and <img style="width:18px; height:19px; vertical-align: middle;" src="images/img788i.jpg" alt="" /> which need not here be given +in detail. The ancient Greek name was <span class="grk" title="ei">εἶ</span>, not <i>Epsilon</i> as +popularly supposed; the names of the Greek letters are +given from Kallias, an earlier contemporary of Euripides, in +Athenaeus x. p. 453 d.</p> + +<p>In Greek the short <i>e</i>-sound to which <img style="width:16px; height:18px; vertical-align: middle;" src="images/img788h.jpg" alt="" /> was ultimately limited +was a close sound inclining more towards <i>i</i> than <i>a</i>; hence the +representation of the contraction of <span class="grk" title="ee">εε</span> by <span class="grk" title="ei">ει</span>. Its value in +Latin was exactly the opposite, the Latin short <i>e</i> being open, +and the long close. In English there has been a gradual +narrowing of the long vowels, <i>ā</i> becoming approximately <i>ēi</i> +and <i>ē</i> becoming <i>ī</i> (Sweet, <i>History of English Sounds</i>, §§ 781, 817 ff. +2nd ed.). In languages where the diphthong <i>ai</i> has become a +monophthong, the resulting sound is some variety of long <i>e</i>. +Often the gradual assimilation can be traced through the intermediate +stage of <i>ae</i> to <i>ē</i>, as in the Old Latin <i>aidilis</i>, which in +classical Latin is <i>aedilis</i>, and in medieval MSS. <i>edilis</i>.</p> + +<p>The variety of spelling in English for the long and short <i>e</i>-sounds +is conveniently illustrated in Miss Soames’s <i>Introduction +to the Study of Phonetics</i>, pp. 16 and 20.</p> +<div class="author">(P. Gi.)</div> + + +<hr class="art" /> +<p><span class="bold">EA<a name="ar16" id="ar16"></a></span> (written by means of two signs signifying “house” +and “water”), in the Babylonian religion, originally the patron +deity of Eridu, situated in ancient times at the head of the Persian +Gulf, but now, by reason of the constant accumulation of soil +in the Euphrates valley, at some distance from the gulf. Eridu, +meaning “the good city,” was one of the oldest settlements in +the Euphrates valley, and is now represented by the mounds +known as Abu Shahrein. In the absence of excavations on that +site, we are dependent for our knowledge of Ea on material +found elsewhere. This is, however, sufficient to enable us to +state definitely that Ea was a water-deity, and there is every +reason to believe that the Persian Gulf was the body of water +more particularly sacred to him. Whether Ea (or A-e as some +scholars prefer) represents the real pronunciation of his name +we do not know. All attempts to connect Ea with Yah and +Yahweh are idle conjectures without any substantial basis. +He is figured as a man covered with the body of a fish, and this +representation, as likewise the name of his temple E-apsu, +“house of the watery deep,” points decidedly to his character +as a god of the waters (see <span class="sc"><a href="#artlinks">Oannes</a></span>). Of his cult at Eridu, which +reverts to the oldest period of Babylonian history, nothing +definite is known beyond the fact that the name of his temple +was E-saggila, “the lofty house”—pointing to a staged tower +as in the case of the temple of Bel (<i>q.v.</i>) at Nippur, known as +E-Kur, <i>i.e.</i> “mountain house”—and that incantations, involving +ceremonial rites, in which water as a sacred element played +a prominent part, formed a feature of his worship. Whether +Eridu at one time also played an important political rôle is not +certain, though not improbable. At all events, the prominence +of the Ea cult led, as in the case of Nippur, to the survival of +Eridu as a sacred city, long after it had ceased to have any +significance as a political centre. Myths in which Ea figures +prominently have been found in Assur-bani-pal’s library, indicating +that Ea was regarded as the protector and teacher of +mankind. He is essentially a god of civilization, and it was natural +that he was also looked upon as the creator of man, and of the +world in general. Traces of this view appear in the Marduk epic +celebrating the achievements of this god, and the close connexion +between the Ea cult at Eridu and that of Marduk also follows +from two considerations: (1) that the name of Marduk’s sanctuary +at Babylon bears the same name, E-saggila, as that of Ea +in Eridu, and (2) that Marduk is generally termed the son of Ea, +who derives his powers from the voluntary abdication of the +father in favour of his son. Accordingly, the incantations +originally composed for the Ea cult were re-edited by the priests +of Babylon and adapted to the worship of Marduk, and, similarly, +the hymns to Marduk betray traces of the transfer of attributes +to Marduk which originally belonged to Ea.</p> + +<p>It is, however, more particularly as the third figure in the triad, +the two other members of which were Anu (<i>q.v.</i>) and Bel (<i>q.v.</i>), +that Ea acquires his permanent place in the pantheon. To him +was assigned the control of the watery element, and in this +capacity he becomes the <i>shar apsi</i>, <i>i.e.</i> king of the Apsu or “the +deep.” The Apsu was figured as an ocean encircling the earth, +and since the gathering place of the dead, known as Arālu, was +situated near the confines of the Apsu, he was also designated +as En-Ki, <i>i.e.</i> “lord of that which is below,” in contrast to Anu, +who was the lord of the “above” or the heavens. The cult +of Ea extended throughout Babylonia and Assyria. We find +temples and shrines erected in his honour, <i>e.g.</i> at Nippur, Girsu, +Ur, Babylon, Sippar and Nineveh, and the numerous epithets +given to him, as well as the various forms under which the god +appears, alike bear witness to the popularity which he enjoyed +from the earliest to the latest period of Babylonian-Assyrian +history. The consort of Ea, known as Damkina, “lady of that +which is below,” or Nin-Ki, having the same meaning, or +Damgal-nunna, “great lady of the waters,” represents a pale +reflection of Ea and plays a part merely in association with +her lord.</p> +<div class="author">(M. Ja.)</div> + + +<hr class="art" /> +<p><span class="bold">EABANI,<a name="ar17" id="ar17"></a></span> the name of the friend of Gilgamesh, the hero in the +Babylonian epic (see <span class="sc"><a href="#artlinks">Gilgamesh, Epic of</a></span>). Eabani, whose +name signifies “Ea creates,” pointing to the tradition which +made the god Ea (<i>q.v.</i>) the creator of mankind, is represented +in the epic as the type of the primeval man. He is a wild man +who lives with the animals of the field until lured away from his +surroundings by the charms of a woman. Created to become +a rival to Gilgamesh, he strikes up a friendship with the hero, and +together they proceed to a cedar forest guarded by Khumbaba, +whom they kill. The goddess Irnina (a form of Ishtar, <i>q.v.</i>) +in revenge kills Eabani, and the balance of the epic is taken +up with Gilgamesh’s lament for his friend, his wanderings in +quest of a remote ancestor, Ut-Napishtim, from whom he +hopes to learn how he may escape the fate of Eabani, +and his finally learning from his friend of the sad fate in +store for all mortals except the favourites of the god, like +<span class="pagenum"><a name="page789" id="page789"></a>789</span> +Ut-Napishtim, to whom immortal life is vouchsafed as a +special boon.</p> +<div class="author">(M. Ja.)</div> + + +<hr class="art" /> +<p><span class="bold">EACHARD, JOHN<a name="ar18" id="ar18"></a></span> (1636?-1697), English divine, was born in +Suffolk, and was educated at Catharine Hall, Cambridge, of +which he became master in 1675 in succession to John Lightfoot. +He was created D.D. in 1676 by royal mandate, and was twice +(in 1679 and 1695) vice-chancellor of the university. He died +on the 7th of July 1697. In 1670 he had published anonymously +a humorous satire entitled <i>The Ground and Occasions of the +Contempt of the Clergy enquired into in a letter to R. L.</i>, which +excited much attention and provoked several replies, one of them +being from John Owen. These were met by <i>Some Observations, +&c., in a second letter to R. L.</i> (1671), written in the same bantering +tone as the original work. Eachard attributed the contempt +into which the clergy had fallen to their imperfect education, +their insufficient incomes, and the want of a true vocation. +His descriptions, which were somewhat exaggerated, were +largely used by Macaulay in his <i>History of England</i>. He gave +amusing illustrations of the absurdity and poverty of the current +pulpit oratory of his day, some of them being taken from the +sermons of his own father. He attacked the philosophy of Hobbes +in his <i>Mr Hobb’s State of Nature considered; in a dialogue +between Philautus and Timothy</i> (1672), and in his <i>Some Opinions +of Mr Hobbs considered in a second dialogue</i> (1673). These were +written in their author’s chosen vein of light satire, and Dryden +praised them as highly effective within their own range. +Eachard’s own sermons, however, were not superior to those +he satirized. Swift (<i>Works</i>, xii. 279) alludes to him as a signal +instance of a successful humorist who entirely failed as a serious +writer.</p> + +<div class="condensed"> +<p>A collected edition of his works in three volumes, with a notice +of his life, was published in 1774. The <i>Contempt of the Clergy</i> was +reprinted in E. Arber’s <i>English Garner</i>. <i>A Free Enquiry into the +Causes of the very great Esteem that the Nonconforming Preachers +are generally in with their Followers</i> (1673) has been attributed to +Eachard on insufficient grounds.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EADBALD<a name="ar19" id="ar19"></a></span> (d. 640), king of Kent, succeeded to the throne +on the death of his father Æthelberht in 616. He had not been +influenced by the teaching of the Christian missionaries, and +his first step on his accession was to marry his father’s widow. +After his subsequent conversion by Laurentius, archbishop of +Canterbury, he recalled the bishops Mellitus and Justus, and built +a church dedicated to the Virgin at Canterbury. He arranged +a marriage between his sister Æthelberg and Edwin of Northumbria, +on whose defeat and death in 633 he received his sister and +Paulinus, and offered the latter the bishopric of Rochester. +Eadbald married Emma, a Frankish princess, and died on the +20th of January 640.</p> + +<div class="condensed"> +<p>See Bede, <i>Historia ecclesiastica</i> (ed. C. Plummer, Oxford, 1896); +<i>Saxon Chronicle</i> (ed. J. Earle and C. Plummer, Oxford, 1899).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EADIE, JOHN<a name="ar20" id="ar20"></a></span> (1810-1876), Scottish theologian and biblical +critic, was born at Alva, in Stirlingshire, on the 9th of May 1810. +Having taken the arts curriculum at Glasgow University, he +studied for the ministry at the Divinity Hall of the Secession +Church, a dissenting body which, on its union a few years later +with the Relief Church, adopted the title United Presbyterian. +In 1835 he became minister of the Cambridge Street Secession +church in Glasgow, and for many years he was generally regarded +as the leading representative of his denomination in Glasgow. +As a preacher, though he was not eloquent, he was distinguished +by good sense, earnestness and breadth of sympathy. In 1863 +he removed with a portion of his congregation to a new church +at Lansdowne Crescent. In 1843 Eadie was appointed professor +of biblical literature and hermeneutics in the Divinity Hall of +the United Presbyterian body. He held this appointment along +with his ministerial charge till the close of his life. Though +not a profound scholar, he was surpassed by few biblical commentators +of his day in range of learning, and in soundness of +judgment. In the professor’s chair, as in the pulpit, his strength +lay in the tact with which he selected the soundest results of +biblical criticism, whether his own or that of others, and presented +them in a clear and connected form, with a constant view +to their practical bearing. He received the degree of LL.D. +from Glasgow in 1844, and that of D.D. from St Andrews in +1850.</p> + +<p>His publications were connected with biblical criticism and +interpretation, some of them being for popular use and others +more strictly scientific. To the former class belong the <i>Biblical +Cyclopaedia</i>, his edition of <i>Cruden’s Concordance</i>, his <i>Early +Oriental History</i>, and his discourses on the <i>Divine Love</i> and on +<i>Paul the Preacher</i>; to the latter his commentaries on the Greek +text of St Paul’s epistles to the Ephesians, Colossians, Philippians +and Galatians, published at intervals in four volumes. His last +work was the <i>History of the English Bible</i> (2 vols., 1876). He +rendered good service as one of the revisers of the authorized +version. He died at Glasgow on the 3rd of June 1876. His +valuable library was bought and presented to the United Presbyterian +College.</p> + + +<hr class="art" /> +<p><span class="bold">EADMER,<a name="ar21" id="ar21"></a></span> or <span class="sc">Edmer</span> (<i>c.</i> 1060-<i>c.</i> 1124), English historian and +ecclesiastic, was probably, as his name suggests, of English, +and not of Norman parentage. He became a monk in the +Benedictine monastery of Christ Church, Canterbury, where +he made the acquaintance of Anselm, at that time visiting +England as abbot of Bec. The intimacy was renewed when +Anselm became archbishop of Canterbury in 1093; thenceforward +Eadmer was not only his disciple and follower, but his +friend and director, being formally appointed to this position +by Pope Urban II. In 1120 he was nominated to the archbishopric +of St Andrews, but as the Scots would not recognize +the authority of the see of Canterbury he was never consecrated, +and soon afterwards he resigned his claim to the archbishopric. +His death is generally assigned to the year 1124.</p> + +<p>Eadmer left a large number of writings, the most important +of which is his <i>Historiae novorum</i>, a work which deals mainly +with the history of England between 1066 and 1122. Although +concerned principally with ecclesiastical affairs scholars agree +in regarding the <i>Historiae</i> as one of the ablest and most valuable +writings of its kind. It was first edited by John Selden in 1623 +and, with Eadmer’s <i>Vita Anselmi</i>, has been edited by Martin +Rule for the “Rolls Series” (London, 1884). The <i>Vita Anselmi</i>, +first printed at Antwerp in 1551, is probably the best life of the +saint. Less noteworthy are Eadmer’s lives of St Dunstan, St +Bregwin, archbishop of Canterbury, and St Oswald, archbishop +of York; these are all printed in Henry Wharton’s <i>Anglia Sacra</i>, +part ii. (1691), where a list of Eadmer’s writings will be found. +The manuscripts of most of Eadmer’s works are preserved in +the library of Corpus Christi College, Cambridge.</p> + +<div class="condensed"> +<p>See M. Rule, <i>On Eadmer’s Elaboration of the first four Books of +“Historiae novorum”</i> (1886); and Père Ragey, <i>Eadmer</i> (Paris, 1892).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EADS, JAMES BUCHANAN<a name="ar22" id="ar22"></a></span> (1820-1887), American engineer, +was born at Lawrenceburg, Indiana, on the 23rd of May 1820. +His first engineering work of any importance was in raising +sunken steamers. In 1845 he established glass works in St Louis. +During the Civil War he constructed ironclad steamers and +mortar boats for the Federal government. His next important +engineering achievement was the construction of the great steel +arch bridge across the Mississippi at St Louis (see <span class="sc"><a href="#artlinks">Bridge</a></span>, fig. +29), upon which he was engaged from 1867 till 1874. The +work, however, upon which his reputation principally rests +was his deepening and fixing the channel at the mouths of the +Mississippi by means of jetties, whereby the narrowed stream +was made to scour out its own channel and carry the sediment +out to sea. Shortly before his death he projected a scheme for +a ship railway across the Isthmus of Tehuantepec, in lieu of an +isthmian canal. He died at Nassau, in the Bahamas, on the +8th of March 1887.</p> + + +<hr class="art" /> +<p><span class="bold">EAGLE<a name="ar23" id="ar23"></a></span> (Fr. <i>aigle</i>, from the Lat. <i>aquila</i>), the name generally +given to the larger diurnal birds of prey which are not vultures; +but the limits of the subfamily <i>Aquilinae</i> have been very variously +assigned by different writers on systematic ornithology, and there +are eagles smaller than certain buzzards. By some authorities +the <i>Laemmergeier</i> of the Alps, and other high mountains of +Europe, North Africa and Asia, is accounted an eagle, but by +others the genus <i>Gypaetus</i> is placed with the <i>Vulturidae</i> as its +<span class="pagenum"><a name="page790" id="page790"></a>790</span> +common English name (bearded vulture) shows. There are also +other forms, such as the South American <i>Harpyia</i> and its allies, +which though generally called eagles have been ranked as buzzards. +In the absence of any truly scientific definition of the family +<i>Aquilinae</i> it is best to leave these and many other more or less +questionable members of the group—such as the genera <i>Spizaetus</i>, +<i>Circaetus</i>, <i>Spilornis</i>, <i>Helotarsus</i>, and so forth—and to treat here +of those whose position cannot be gainsaid.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:408px; height:580px" src="images/img790a.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 1.</span>—Sea-Eagle.</td></tr></table> + +<p>True eagles inhabit all the regions of the world, and some seven +or eight species at least are found in Europe, of which two are +resident in the British Islands. In England and in the Lowlands +of Scotland eagles only exist as stragglers; but in the Hebrides +and some parts of the Highlands a good many may yet be found, +and their numbers appear to have rather increased of late years +than diminished; for the foresters and shepherds, finding that +a high price can be got for their eggs, take care to protect the +owners of the eyries, which are nearly all well known, and to keep +up the stock by allowing them at times to rear their young. +There are also now not a few occupiers of Scottish forests who +interfere so far as they can to protect the king of birds.<a name="fa1a" id="fa1a" href="#ft1a"><span class="sp">1</span></a> In +Ireland the extirpation of eagles seems to have been carried on +almost unaffected by the prudent considerations which in the +northern kingdom have operated so favourably for the race, and +except in the wildest parts of Donegal, Mayo and Kerry, eagles +in the sister island are almost birds of the past.</p> + +<p>Of the two British species the erne (Icel. <i>Œrn</i>) or sea-eagle +(by some called also the white-tailed and cinereous eagle)—<i>Haliaetus +albicilla</i>—affects chiefly the coast and neighbourhood +of inland waters, living in great part on the fish and refuse that is +thrown up on the shore, though it not unfrequently takes living +prey, such as lambs, hares and rabbits. On these last, indeed, +young examples mostly feed when they wander southward in +autumn, as they yearly do, and appear in England. The adults +(fig. 1) are distinguished by their prevalent greyish-brown colour, +their pale head, yellow beak and white tail—characters, however, +wanting in the immature, which do not assume the perfect +plumage for some three or four years. The eyry is commonly +placed in a high cliff or on an island in a lake—sometimes on the +ground, at others in a tree—and consists of a vast mass of sticks +in the midst of which is formed a hollow lined with <i>Luzula +sylvatica</i> (as first observed by John Wolley) or some similar +grass, and here are laid the two or three white eggs. In former +days the sea-eagle seems to have bred in several parts of England—as +the Lake district, and possibly even in the Isle of Wight +and on Dartmoor. This species inhabits all the northern part of +the Old World from Iceland to Kamchatka, and breeds in Europe +so far to the southward as Albania. In the New World, however, +it is only found in Greenland, being elsewhere replaced by the +white-headed or bald eagle, <i>H. leucocephalus</i>, a bird of similar +habits, and the chosen emblem of the United States of America. +In the far east of Asia occurs a still larger and finer sea-eagle, +<i>H. pelagicus</i>, remarkable for its white thighs and upper wing-coverts. +South-eastern Europe and India furnish a much smaller +species, <i>H. leucoryphus</i>, which has its representative, <i>H. leucogaster</i>, +in the Malay Archipelago and Australia, and, as allies in South +Africa and Madagascar, <i>H. vocifer</i> and <i>H. vociferoides</i> respectively. +All these eagles may be distinguished by their scaly tarsi, while +the group next to be treated of have the tarsi feathered to the +toes.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:512px; height:555px" src="images/img790b.jpg" alt="" /></td></tr> +<tr><td class="caption"><span class="sc">Fig. 2.</span>—Mountain-Eagle.</td></tr></table> + +<p>The golden or mountain eagle, <i>Aquila chrysaetus</i>, is the second +British species. This also formerly inhabited England, and a nest, +found in 1668 in the Peak of Derbyshire, is well described by +Willughby, in whose time it was said to breed also in the Snowdon +range. It seldom if ever frequents the coast, and is more active +on the wing than the sea-eagle, being able to take some birds +as they fly, but a large part of its sustenance is the flesh of animals +that die a natural death. Its eyry is generally placed and built +like that of the other British species,<a name="fa2a" id="fa2a" href="#ft2a"><span class="sp">2</span></a> but the neighbourhood of +<span class="pagenum"><a name="page791" id="page791"></a>791</span> +water is not requisite. The eggs, from two to four in number, +vary from a pure white to a mottled, and often highly coloured, +surface, on which appear different shades of red and purple. +The adult bird (fig. 2) is of a rich dark brown, with the elongated +feathers of the neck, especially on the nape, light tawny, in which +imagination sees a “golden” hue, and the tail marbled with +brown and ashy-grey. In the young the tail is white at the base, +and the neck has scarcely any tawny tint. The golden eagle +does not occur in Iceland, but occupies suitable situations over +the rest of the Palaearctic Region and a considerable portion of +the Nearctic—though the American bird has been, by some, +considered a distinct species. Domesticated, it has many times +been trained to take prey for its master in Europe, and to this +species is thought to belong an eagle habitually used by the +Kirghiz Tatars, who call it <i>Bergut</i> or <i>Bearcoot</i>, for the capture +of antelopes, foxes and wolves. It is carried hooded on horseback +or on a perch between two men, and released when the quarry +is in sight. Such a bird, when well trained, is valued, says +P.S. Pallas, at the price of two camels. It is quite possible, +however, that more than one kind of eagle is thus used, and the +services of <i>A. heliaca</i> (which is the imperial eagle of some +writers<a name="fa3a" id="fa3a" href="#ft3a"><span class="sp">3</span></a>) and of <i>A. mogilnik</i>—both of which are found in +central Asia, as well as in south-eastern Europe—may also be +employed.</p> + +<p>A smaller form of eagle, which has usually gone under the +name of <i>A. naevia</i>, is now thought by the best authorities to +include three local races, or, in the eyes of some, species. They +inhabit Europe, North Africa and western Asia to India, and two +examples of one of them—<i>A. clanga</i>, the form which is somewhat +plentiful in north-eastern Germany—have occurred in Cornwall. +The smallest true eagle is <i>A. pennata</i>, which inhabits southern +Europe, Africa and India. Differing from other eagles of their +genus by its wedge-shaped tail, though otherwise greatly resembling +them, is the <i>A. audax</i> of Australia. Lastly may be +noticed here a small group of eagles, characterized by their +long legs, forming the genus <i>Nisaetus</i>, of which one species, +<i>N. fasciatus</i>, is found in Europe.</p> +<div class="author">(A. N.)</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1a" id="ft1a" href="#fa1a"><span class="fn">1</span></a> Lord Breadalbane (d. 1871) was perhaps the first large landowner +who set the example that has been since followed by others. On his +unrivalled forest of Black Mount, eagles—elsewhere persecuted to +the death—were by him ordered to be unmolested so long as they +were not numerous enough to cause considerable depredations on the +farmers’ flocks. He thought that the spectacle of a soaring eagle +was a fitting adjunct to the grandeur of his Argyllshire mountain +scenery, and a good equivalent for the occasional loss of a lamb, +or the slight deduction from the rent paid by his tenantry in +consequence.</p> + +<p><a name="ft2a" id="ft2a" href="#fa2a"><span class="fn">2</span></a> As already stated, the site chosen varies greatly. Occasionally +placed in a niche in what passes for a perpendicular cliff to which +access could only be gained by a skilful cragsman with a rope, the +writer has known a nest to within 10 or 15 yds. of which he rode on +a pony. Two beautiful views of as many golden eagles’ nests, +drawn on the spot by Joseph Wolf, are given in the <i>Ootheca Wolleyana</i>, +and a fine series of eggs is also figured in the same work.</p> + +<p><a name="ft3a" id="ft3a" href="#fa3a"><span class="fn">3</span></a> Which species may have been the traditional emblem of Roman +power, and the <i>Ales Jovis</i>, is very uncertain.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EAGLEHAWK,<a name="ar24" id="ar24"></a></span> a borough of Bendigo county, Victoria, +Australia, 105 m. by rail N.N.W. of Melbourne and 4 m. from +Bendigo, with which it is connected by steam tramway. Pop. +(1901) 8130. It stands on the Bendigo gold-bearing reef, and its +mines are important.</p> + + +<hr class="art" /> +<p><span class="bold">EAGRE<a name="ar25" id="ar25"></a></span> (a word of obscure origin; the earliest form seems +to be <i>higre</i>, Latinized as <i>higra</i>, which William of Malmesbury +gives as the name of the bore in the Severn; the <i>New English +Dictionary</i> rejects the usual derivations from the O. Eng. <i>eagor</i> +or <i>egor</i>, which is seen in compounds meaning “flood,” and +also the connexion with the Norse sea-god <i>Aegir</i>), a tide wave +of great height rushing up an estuary (see <span class="sc"><a href="#artlinks">Bore</a></span>), used locally +of the Humber and Trent.</p> + + +<hr class="art" /> +<p><span class="bold">EAKINS, THOMAS<a name="ar26" id="ar26"></a></span> (1844-  ), American portrait and figure +painter, was born at Philadelphia, on the 25th of July 1844. +A pupil of J.L. Gérôme, in the École des Beaux-Arts, Paris, and +Also of Léon Bonnat, besides working in the studio of the sculptor +Dumont, he became a prolific portrait painter. He also painted +genre pictures, sending to the Centennial Exhibition at Philadelphia, +in 1876, the “Chess Players,” now in the Metropolitan +Museum of Art, New York. A large canvas, “The Surgical +Clinic of Professor Gross,” owned by Jefferson Medical College, +Philadelphia, contains many life-sized figures. Eakins, with +his pupil Samuel Murray (b. 1870), modelled the heroic +“Prophets” for the Witherspoon Building, Philadelphia, and +his work in painting has a decided sculptural quality. He was +for some years professor of anatomy at the schools of the Pennsylvania +Academy of Fine Arts in Philadelphia. A man of great +inventiveness, he experimented in many directions, depicting +on canvas modern athletic sports, the negro, and early American +life, but he is best known by his portraits. He received awards +at the Columbian (1893), Paris (1900), Pan-American (1900), +and the St Louis (1904), Expositions; and won the Temple +medal in the Pennsylvania Academy of Fine Arts, and the +Proctor prize of the National Academy of Design.</p> + + +<hr class="art" /> +<p><span class="bold">EALING,<a name="ar27" id="ar27"></a></span> a municipal borough in the Ealing parliamentary +division of Middlesex, England, suburban to London, 9 m. W. +of St Paul’s cathedral. Pop. (1891) 23,979; (1901) 33,031. +The nucleus of the town, the ancient village, lies south of the +highroad to Uxbridge, west of the open Ealing Common. The +place is wholly residential. At St Mary’s church, almost wholly +rebuilt c. 1870, are buried John Oldmixon, the historian (d. 1742), +and Horne Tooke (d. 1812). The church of All Saints (1905) commemorates +Spencer Perceval, prime minister, who was assassinated +in the House of Commons in 1812. It was erected under +the will of his daughter Frederica, a resident of Ealing. Gunnersbury +Park, south of Ealing Common, is a handsome Italian +mansion. Among former owners of the property was Princess +Amelia, daughter of George II., who lived here from 1761 till +her death in 1786. The name of Gunnersbury is said to be +traceable to the residence here of Gunilda, niece of King Canute. +The manor of Ealing early belonged to the see of London, but +it is not mentioned in Domesday and its history is obscure.</p> + + +<hr class="art" /> +<p><span class="bold">EAR<a name="ar28" id="ar28"></a></span> (common Teut.; O.E. <i>éare</i>, Ger. <i>Ohr</i>, Du. <i>oor</i>, akin to +Lat. <i>auris</i>, Gr. <span class="grk" title="ous">οὖς</span>), in anatomy, the organ of hearing. +The human ear is divided into three parts—external, middle +and internal. The external ear consists of the pinna and the +external auditory meatus. The pinna is composed of a yellow +fibro-cartilaginous framework covered by skin, and has an +external and an internal or cranial surface. Round the margin +of the external surface in its upper three quarters is a rim called +the helix (fig. 1, <i>a</i>), in which is often seen a little prominence +known as Darwin’s tubercle, representing the folded-over apex +of a prick-eared ancestor. Concentric with the helix and nearer +the meatus is the antihelix (<i>c</i>), which, above, divides into two +limbs to enclose the triangular fossa of the antihelix. Between +the helix and the antihelix is the fossa of the helix. In front +of the antihelix is the deep fossa known as the concha (fig. 1, <i>d</i>), +and from the anterior part of this the meatus passes inward +into the skull. Overlapping the meatus from in front is a flap +called the tragus, and below and behind this is another smaller +flap, the antitragus. The lower part of the pinna is the lobule +(<i>e</i>), which contains no cartilage. On the cranial surface of the +pinna elevations correspond to the concha and to the fossae +<span class="pagenum"><a name="page792" id="page792"></a>792</span> +of the helix and antihelix. The pinna can be slightly moved by +the anterior, superior and posterior auricular muscles, and in +addition to these there are four small intrinsic muscles on the +external surface, known as the helicis major and minor, the +tragicus and the antitragicus, and two on the internal surface +called the obliquus and transversus. The external auditory +meatus (fig. 1, <i>n</i>) is a tube running at first forward and upward, +then a little backward and then forward and slightly downward; +of course all the time it is also running inward until the tympanic +membrane is reached. The tube is about an inch long, its outer +third being cartilaginous and its inner two-thirds bony. It is +lined by skin in its whole length, the sweat glands of which are +modified to secrete the wax or cerumen.</p> + +<table class="pic" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter" colspan="2"><img style="width:454px; height:381px" src="images/img791.jpg" alt="" /></td></tr> +<tr><td class="caption" colspan="2"><span class="sc">Fig. 1.</span>—The Ear as seen in Section.</td></tr> + +<tr><td class="f90" style="width: 50%; vertical-align: top;"> +<p><i>a</i>, Helix.</p> +<p><i>b</i>, Antitragus.</p> +<p><i>c</i>, Antihelix.</p> +<p><i>d</i>, Concha.</p> +<p><i>e</i>, Lobule.</p> +<p><i>f</i>, Mastoid process.</p> +<p><i>g</i>, Portio dura.</p> +<p><i>h</i>, Styloid process.</p> +<p><i>k</i>, Internal carotid artery.</p> +<p><i>l</i>, Eustachian tube.</p></td> + +<td class="f90" style="width: 50%; vertical-align: top;"> +<p><i>m</i>, Tip of petrous process.</p> +<p><i>n</i>, External auditory meatus.</p> +<p><i>o</i>, Membrana tympani.</p> +<p><i>p</i>, Tympanum.</p> +<p>1, points to malleus.</p> +<p>2, to incus.</p> +<p>3, to stapes.</p> +<p>4, to cochlea.</p> +<p>5, 6, 7, the three semicircular canals.</p> +<p>8 and 9, facial and auditory nerves.</p></td></tr></table> + +<p>The middle ear or tympanum (fig. 1, <i>p</i>) is a small cavity in the +temporal bone, the shape of which may perhaps be realized by +imagining a hock bottle subjected to lateral pressure in such a +way that its circular section becomes triangular, the base of the +triangle being above. The neck of the bottle, also laterally +compressed, will represent the Eustachian tube (fig. 1, <i>l</i>), which +runs forward, inward and downward, to open into the +naso-pharynx, and so admits air into the tympanum. The bottom +of the bottle will represent the posterior wall of the tympanum, +from the upper part of which an opening leads backward into +the mastoid antrum and so into the air-cells of the mastoid +process. Lower down is a little pyramid which transmits the +stapedius muscle, and at the base of this is a small opening known +as the iter chordae posterius, for the chorda tympani to come +through from the facial nerve. The roof is formed by a very +thin plate of bone, called the tegmen tympani, which separates +the cavity from the middle fossa of the skull. Below the roof +the upper part of the tympanum is somewhat constricted off +from the rest, and to this part the term “attic” is often applied. +The floor is a mere groove formed by the meeting of the external +and internal walls. The outer wall is largely occupied by the +tympanic membrane (fig. 1, <i>o</i>), which entirely separates the +middle ear from the external auditory meatus; it is circular, +and so placed that it slopes from above, downward and inward, +and from behind, forward and inward. Externally it is lined +by skin, internally by mucous membrane, while between the +two is a firm fibrous membrane, convex inward about its centre +to form the umbo. Just in front of the membrane on the outer +wall is the Glaserian fissure leading to the glenoid cavity, and +close to this is the canal of Huguier for the chorda tympani +nerve. The inner wall shows a promontory caused by the +cochlea and grooved by the tympanic plexus of nerves; above +and behind it is the fenestra ovalis, while below and behind the +fenestra rotunda is seen, closed by a membrane. Curving round, +above and behind the promontory and fenestrae, is a ridge +caused by the aqueductus Fallopii or canal for the facial nerve. +The whole tympanum is about half an inch from before backward, +and half an inch high, and is spanned from side to side by three +small bones, of which the malleus (fig. 1, 1) is the most external. +This is attached by its handle to the umbo of the tympanic membrane, +while its head lies in the attic and articulates posteriorly +with the upper part of the next bone or incus (fig. 1, 2). The +long process of the incus runs downward and ends in a little +knob called the os orbiculare, which is jointed on to the stapes +or stirrup bone (fig. 1, 3). The two branches of the stapes are +anterior and posterior, while the footplate fits into the fenestra +ovalis and is bound to it by a membrane. It will thus be seen +that the stapes lies nearly at right angles to the long process +of the incus. From the front of the malleus a slender process +projects forward into the Glaserian fissure, while from the back +of the incus the posterior process is directed backward and is +attached to the posterior wall of the tympanum. These two +processes form a fulcrum by which the lever action of the malleus +and incus is brought about, so that when the handle of the +malleus is pushed in by the membrane the head moves out; +the top of the incus, attached to it, also moves out, and the os +orbiculare moves in, and so the stapes is pressed into the fenestra +ovalis. The stapedius and tensor tympanic muscles, the latter +of which enters the tympanum in a canal just above the +Eustachian tube to be attached to the malleus, modify the +movements of the ossicles.</p> + +<p>The mucous membrane lining the tympanum is continuous +through the Eustachian tube with that of the naso-pharynx, +and is reflected on to the ossicles, muscles and chorda tympani +nerve. It is ciliated except where it covers the membrana +tympani, ossicles and promontory; here it is stratified.</p> + +<table class="flt" style="float: right; width: 330px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:276px; height:161px" src="images/img792a.jpg" alt="" /></td></tr> +<tr><td class="caption1"><span class="sc">Fig. 2.</span>—Diagram of the Membranous +Labyrinth.</td></tr> +<tr><td class="caption1"> +<p>DC, Ductus cochlearis.</p> +<p><i>dr</i>, Ductus reuniens.</p> +<p>S, Sacculus.</p> +<p>U, Utriculus.</p> +<p><i>dv</i>, Ductus endolymphaticus.</p> +<p>SC, Semicircular canals.</p> +<p>  (After Waldeyer.)</p></td></tr></table> + +<p>The internal ear or labyrinth consists of a bony and a membranous +part, the latter of which is contained in the former. +The bony labyrinth is composed of the vestibule, the semicircular +canals and the cochlea. The vestibule lies just internal +to the posterior part of the tympanum, and there would be a +communication between the two, through the fenestra ovalis, +were it not that the footplate +of the stapes blocks the +way. The inner wall of the +vestibule is separated from +the bottom of the internal +auditory meatus by a plate +of bone pierced by many +foramina for branches of the +auditory nerve (fig. 1, 9), +while at the lower part is the +opening of the aqueductus +vestibuli, by means of which +a communication is established +with the posterior +cranial fossa. Posteriorly +the three semicircular canals +open into the vestibule; of +these the external (fig. 1, 7) has two independent openings, but +the superior and posterior (fig. 1, 5 and 6) join together at one +end and so have a common opening, while at their other ends they +open separately. The three canals have therefore five openings +into the vestibule instead of six. One end of each canal is dilated +to form its ampulla. The superior semicircular canal is vertical, +and the two pillars of its arch are nearly external and internal; +the external canal is horizontal, its two pillars being anterior and +posterior, while the convexity of the arch of the posterior canal +is backward and its two pillars are superior and inferior. +Anteriorly the vestibule leads into the +cochlea (fig. 1, 4), which is twisted two +and a half times round a central pillar +called the modiolus, the whole cochlea +forming a rounded cone something like +the shell of a snail though it is only +about 5 mm. from base to apex. Projecting +from the modiolus is a horizontal +plate which runs round it from base to +apex like a spiral staircase; this is +known as the lamina spiralis, and it +stretches nearly half-way across the canal +of the cochlea. At the summit it ends +in a little hook named the hamulus. The +modiolus is pierced by canals which +transmit branches of the auditory nerve +to the lamina spiralis.</p> + +<table class="flt" style="float: left; width: 200px;" summary="Illustration"> +<tr><td class="figleft1"><img style="width:146px; height:377px" src="images/img792b.jpg" alt="" /></td></tr> +<tr><td class="caption1"><span class="sc">Fig. 3.</span>—<i>cl</i>, Columnar +cells covering the crista acustica; <i>p</i>, peripheral, +and <i>c</i>, central processes of auditory +cells; <i>n</i>, nerve fibres. +(After Rüdinger.)</td></tr></table> + +<p>The membranous labyrinth lies in the +bony labyrinth, but does not fill it; between +the two is the fluid called perilymph, +while inside the membranous +labyrinth is the endolymph. In the bony +vestibule lie two membranous bags, +the saccule (fig. 2, S) in front, and the +utricle (fig. 2, U) behind; each of these +has a special patch or macula to which +twigs of the auditory nerve are supplied, and in the mucous +membrane of which specialized hair cells are found (fig. 3, <i>p</i>).</p> + +<p>Attached to the maculae are crystals of carbonate of lime +called otoconia. The membranous semicircular canals are very +much smaller in section than <span class="correction" title="amended from tbe">the</span> bony; in the ampulla of +each is a ridge, the crista acustica, which is covered by a mucous +<span class="pagenum"><a name="page793" id="page793"></a>793</span> +membrane containing sensory hair cells like those in the maculae. All +the canals open into the utricle. From the lower part of the saccule a +small canal called the ductus endolymphaticus (fig. 2, <i>dv</i>) runs into the +aqueductus vestibuli; it is soon joined by a small duct from the +utricle, and ends, close to the dura mater of the posterior fossa of the +cranium, as the saccus endolymphaticus, which may have minute +perforations through which the endolymph can pass. Anteriorly the +saccule communicates with the membranous cochlea or scala media by a +short ductus reuniens (fig. 2, <i>dr</i>). A section through each turn of the +cochlea shows the bony lamina spiralis, already noticed, which is +continued right across the canal by the basilar membrane (fig. 4, <i>bm</i>), +thus cutting the canal into an upper and lower half and connected with +the outer wall by the strong spiral ligament (fig. 4, <i>sl</i>). Near the free +end of the lamina spiralis another membrane called the membrane of +Reissner (fig. 4, <i>m</i>R) is attached, and runs outward and upward to the +outer wall, taking a triangular slice out of the upper half of the +section. There are now three canals seen in section, the upper of which +is the scala vestibuli (fig. 4, SV), the middle and outer the scala +media, ductus cochlearis or true membranous cochlea (fig. 4, DC), while +the lower is the scala tympani (fig. 4, ST). The scala vestibuli and +scala tympani communicate at the apex of the cochlea by an opening known +as the helicotrema, so that the perilymph can here pass from one canal +to the other. At the base of the cochlea the +perilymph in the scala vestibuli is continuous with that in the +vestibule, but that in the scala tympani bathes the inner surface of the +membrane stretched across the fenestra rotunda, and also communicates +with the subarachnoid space through the aqueductus cochleae, which opens +into the posterior cranial fossa. The scala media containing endolymph +communicates, as has been shown, with the saccule through the canalis +reuniens, while, at the apex of the cochlea, it ends in a blind +extremity of considerable morphological interest called the lagena.</p> + +<table class="pic" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter" colspan="2"><img style="width:416px; height:486px" src="images/img793a.jpg" alt="" /></td></tr> +<tr><td class="caption" colspan="2"><span class="sc">Fig.</span> 4.—Transverse Section through the Tube of the Cochlea.</td></tr> + +<tr><td class="f90" style="width: 50%; vertical-align: top;"> +<p><i>m</i>, Modiolus.</p> +<p>0, Outer wall of cochlea.</p> +<p>SV, Scala vestibuli.</p> +<p>ST, Scala tympani.</p> +<p>DC, Ductus cochlearis.</p> +<p><i>m</i>R, Membrane of Reissner.</p></td> + +<td class="f90" style="width: 50%; vertical-align: top;"> +<p><i>bm</i>, Basilar membrane.</p> +<p><i>cs</i>, Crista spiralis.</p> +<p><i>sl</i>, Spiral ligament.</p> +<p><i>sg</i>, Spiral ganglion of auditory nerve.</p> +<p><i>oc</i>, Organ of Corti.</p></td></tr></table> + +<p>The scala media contains the essential organ of hearing or organ of +Corti (fig. 4, <i>oc</i>), which lies upon the inner part of the basilar +membrane; it consists of a tunnel bounded on each side of the inner and +outer rods of Corti; on each side of these are the inner and outer hair +cells, between the latter of which are found the supporting cells of +Deiters. Most externally are the large cells of Hensen. A delicate +membrane called the lamina reticularis covers the top of all these, and +is pierced by the hairs of the hair cells, while above this is the loose +membrana tectoria attached to the periosteum of the lamina spiralis, +near its tip, internally, and possibly to some of Deiter’s cells +externally. The cochlear branch of the auditory nerve enters the lamina +spiralis, where a spiral ganglion (fig. 4, <i>sg</i>) is developed on it; after +this it is distributed to the inner and outer hair cells.</p> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:741px; height:373px" src="images/img793b.jpg" alt="" /></td></tr> +<tr><td class="tcl f80">(From R. Howden—Cunningham’s <i>Text-Book of Anatomy</i>.)</td></tr> +<tr><td class="caption"><span class="sc">Fig.</span> 5.—Transverse Section of Corti’s Organ from the Central Coil +of Cochlea (Retzius).</td></tr></table> + +<div class="condensed"> +<p>For further details see <i>Text-Book of Anatomy</i>, edited by D.J. Cunningham +(Edinburgh, 1906); Quain’s <i>Elements of Anatomy</i> (London, 1893); Gray’s +<i>Anatomy</i> (London, 1905); <i>A Treatise on Anatomy</i>, edited by H. Morris +(London, 1902); <i>A Text-Book of Human Anatomy</i>, by A. Macalister (London, +1889).</p> +</div> + +<p><i>Embryology.</i>—The pinna is formed from six tubercles which appear round +the dorsal end of the hyomandibular cleft or, more strictly speaking, +pouch. Those for the tragus and anterior part of the helix belong to the +first or mandibular arch, while those for the antitragus, antihelix and +lobule come from the second or hyoid arch. The tubercle for the helix is +dorsal to the end of the cleft where the two arches join. The external +auditory meatus, tympanum and Eustachian tube are remains of the +hyomandibular cleft, the membrana tympani being a remnant of the cleft +membrane and therefore lined by ectoderm outside and entoderm inside. +The origin of the ossicles is very doubtful. H. Gadow’s view, which is +one of the latest, is that all three are derived from the hyomandibular +plate which connects the dorsal ends of the hyoid and mandibular bars +(<i>Anatomischer Anzeiger</i>, Bd. xix., 1901, p. 396). Other papers which +should be consulted are those of E. Gaupp, <i>Anatom. Hefte, Ergebnisse</i>, +Bd. 8, 1898, p. 991, and J.A. Hammar, <i>Archiv f. mikr. Anat.</i> lix., +1902. These papers will give a clue to the immense literature of the +subject. The internal ear first appears as a pit from the cephalic +ectoderm, the mouth of which in Man and other mammals closes up, so that +a pear-shaped cavity is left. The stalk of the pear which is nearest the +point of invagination is called the recessus labyrinthi, and this, after +losing its connexion with the surface of the embryo, grows backward +toward the posterior cranial fossa and becomes the ductus +endolymphaticus. The lower part of the vesicle grows forward and becomes +the cochlea, while from the upper part three hollow circular plates grow +out, the central parts of which disappear, leaving the margin as the +semicircular canals. Subsequently constrictions appear in the vesicle +marking off the saccule and utricle. From the surrounding +<span class="pagenum"><a name="page794" id="page794"></a>794</span> +mesoderm the petrous bone is formed by a process of +chondrification and ossification.</p> + +<div class="condensed"> +<p>See W. His, Junr., <i>Archiv f. Anat. und Phys.</i>, 1889, supplement, +p. 1; also Streeter, <i>Am. Journ. of Anat.</i> vi., 1907.</p> +</div> + +<p><i>Comparative Anatomy.</i>—The ectodermal inpushing of the +internal ear has probably a common origin with the organs of +the lateral line of fish. In the lower forms the ductus endolymphaticus +retains its communication with the exterior on the +dorsum of the head, and in some Elasmobranchs the opening is +wide enough to allow the passage of particles of sand into the +saccule. It is probable that this duct is the same which, taking +a different direction and losing its communication with the skin, +abuts on the posterior cranial fossa of higher forms (see Rudolf +Krause, “Die Entwickelung des Aq. vestibuli seu d. Endelymphaticus,” +<i>Anat. Anzeiger</i>, Bd. xix., 1901, p. 49). In certain +Teleostean fishes the swim bladder forms a secondary communication +with the internal ear by means of special ossicles (see G. +Ridewood, <i>Journ. Anat. & Phys.</i> vol. xxvi.). Among the +Cyclostomata the external semicircular canals are wanting; +Petromyzon has the superior and posterior only, while in Myxine +these two appear to be fused so that only one is seen. In higher +types the three canals are constant. Concretions of carbonate of +lime are present in the internal ears of almost all vertebrates; +when these are very small they are called otoconia, but when, as +in most of the teleostean fishes, they form huge concretions, they +are spoken of as otoliths. One shark, Squatina, has sand instead +of otoconia (C. Stewart, <i>Journ. Linn. Society</i>, xxix. 409). The +utricle, saccule, semicircular canals, ductus endolymphaticus +and a short lagena are the only parts of the ear present in +fish.</p> + +<p>The Amphibia have an important sensory area at the base of +the lagena known as the macula acustica basilaris, which is +probably the first rudiment of a true cochlea. The ductus +endolymphaticus has lost its communication with the skin, but +it is frequently prolonged into the skull and along the spinal +canal, from which it protrudes, through the intervertebral +foramina, bulging into the coelom. This is the case in the common +frog (A. Coggi, <i>Anat. Anz.</i> 5. Jahrg., 1890, p. 177). In this +class the tympanum and Eustachian tube are first developed; +the membrana tympani lies flush with the skin of the side of the +head, and the sound-waves are transmitted from it to the internal +ear by a single bony rod—the columella.</p> + +<p>In the Reptilia the internal ear passes through a great range +of development. In the Chelonia and Ophidia the cochlea is as +rudimentary as in the Amphibia, but in the higher forms +(Crocodilia) there is a lengthened and slightly twisted cochlea, +at the end of which the lagena forms a minute terminal appendage. +At the same time indications of the scalae tympani and +vestibuli appear. As in the Amphibia the ductus endolymphaticus +sometimes extends into the cranial cavity and on into other +parts of the body. Snakes have no tympanic membrane. In the +birds the cochlea resembles that of the crocodiles, but the posterior +semicircular canal is above the superior where they join one +another. In certain lizards and birds (owls) a small fold of skin +represents the first appearance of an external ear. In the +monotremes the internal ear is reptilian in its arrangement, +but above them the mammals always have a spirally twisted +cochlea, the number of turns varying from one and a half in the +Cetacea to nearly five in the rodent <i>Coelogenys</i>. The lagena is +reduced to a mere vestige. The organ of Corti is peculiar to +mammals, and the single columella of the middle ear is replaced +by the three ossicles already described in Man (see Alban Doran, +“Morphology of the Mammalian Ossicula auditus,” <i>Proc. Linn. +Soc.</i>, 1876-1877, xiii. 185; also <i>Trans. Linn. Soc.</i> 2nd Ser. Zool. +i. 371). In some mammals, especially Carnivora, the middle +ear is enlarged to form the tympanic bulla, but the mastoid cells +are peculiar to Man.</p> + +<div class="condensed"> +<p>For further details see G. Retzius, <i>Das Gehörorgan der Wirbelthiere</i> +(Stockholm, 1881-1884); Catalogue of the Museum of the R. +College of Surgeons—Physiological Series, vol. iii. (London, 1906); +R. Wiedersheim’s <i>Vergleichende Anatomie der Wirbeltiere</i> (Jena, +1902).</p> +</div> +<div class="author">(F. G. P.)</div> + +<p class="pt2 center sc">Diseases of the Ear</p> + +<p>Modern scientific aural surgery and medicine (commonly +known as Otology) dates from the time of Sir William Wilde +of Dublin (1843), whose work marked a great advance in the +application of anatomical, physiological and therapeutical +knowledge to the study of this organ. Less noticeable contributions +to the subject had not long before been made by +Saunders (1827), Kramer (1833), Pilcher (1841) and Yearsley +(1841). The next important event in the history of otology +was the publication of J. Toynbee’s book in 1860 containing +his valuable anatomical and pathological observations. Von +Tröltsch of Würzburg, following on the lines of Wilde and +Toynbee, produced two well-known works in 1861 and 1862, +laying the foundation of the study in Germany. In that country +and in Austria he was followed by Hermann Schwartze, Politzer, +Gruber, Weber-Liel, Rüdinger, Moos and numerous others. +France produced Itard, de la Charrière, Menière, Loewenberg +and Bonnafont; and Belgium, Charles Delstanche, father and +son. In Great Britain the work was carried on by James Hinton +(1874), Peter Allen (1871), Patterson Cassells and Sir William +Dalby. In America we may count among the early otologists +Edward H. Clarke (1858), D.B. St John Roosa, H. Knapp, +Clarence J. Blake, Albert H. Buck and Charles Burnett. Other +workers all over the world are too numerous to mention.</p> + +<p><i>Various Diseases and Injuries.</i>—Diseases of the ear may affect +any of the three divisions, the external, middle or internal ear. +The commoner affections of the <i>auricle</i> are eczema, various +tumours (simple and malignant), and serous and sebaceous +cysts. Haematoma auris (othaematoma), or effusion of blood +into the auricle, is often due to injury, but may occur +spontaneously, especially in insane persons. The chief diseases +of the <i>external auditory canal</i> are as follows:—impacted cerumen +(or wax), circumscribed (or furuncular) inflammation, diffuse +inflammation, strictures due to inflammatory affections, bony +growths, fungi (otomycosis), malignant disease, caries and +necrosis, and foreign bodies.</p> + +<p>Diseases of the <i>middle ear</i> fall into two categories, suppurative +and non-suppurative (<i>i.e.</i> with and without the formation of pus). +Suppurative inflammation of the middle ear is either acute or +chronic, and is in either case accompanied by perforation of the +drum head and discharge from the ear. The chief importance +of these affections, in addition to the symptoms of pain, deafness, +discharge, &c., is the serious complications which may ensue +from their neglect, viz. aural polypi, caries and necrosis of the +bone, affections of the mastoid process, including the mastoid +antrum, paralysis of the facial nerve, and the still more serious +intracranial and vascular infective diseases, such as abscess in +the brain (cerebrum or cerebellum), meningitis, with subdural +and extradural abscesses, septic thrombosis of the sigmoid and +other venous sinuses, and pyaemia. It is owing to the possibility +of these complications that life insurance companies usually, +and rightly, inquire as to the presence of ear discharge before +accepting a life. Patterson Cassells of Glasgow urged this special +point as long ago as 1877. Acute suppurative disease of the +middle ear is often due to the exanthemata, scarlatina, measles +and smallpox, and to bathing and diving. It may also be caused +by influenza, diphtheria and pulmonary phthisis.</p> + +<p>Non-suppurative disease of the middle ear may be acute or +chronic. In the acute form the inflammation is less violent than +in the acute suppurative inflammation, and is rarely accompanied +by perforation. Chronic non-suppurative inflammation +may be divided into the moist form, in which the symptoms are +improved by inflation of the tympanum through the Eustachian +tube, and the dry form (including sclerosis), which is more intractable +and in which this procedure has little or no beneficial +effect. Diseases of the <i>internal ear</i> may be primary or secondary +to an affection of the tympanum or to intracranial disease.</p> + +<p>Injuries to any part of the ear may occur, among the commoner +being injuries to the auricle, rupture of the drum head (from +explosions, blows on the ear or the introduction of sharp bodies +into the ear canal), and injuries from fractured skull. Congenital +<span class="pagenum"><a name="page795" id="page795"></a>795</span> +malformations of the ear are most frequently met with in the +auricle and external canal.</p> + +<p><i>Methods of Examination.</i>—The methods of examining the ear +are roughly threefold:—(1) Testing the hearing with watch, +voice and tuning-fork. The latter is especially used to distinguish +between disease of the middle ear (conducting apparatus) and +that of the internal ear (perceptive apparatus). Our knowledge +of the subject has been brought to its present state by the labours +of many observers, notably Weber, Rinne, Schwabach, Lucae +and Gellé. (2) Examination of the canal and drum-head with +speculum and reflector, introduced by Kramer, Wilde and von +Tröltsch. (3) Examination of the drum-cavity through the +Eustachian tube by the various methods of inflation.</p> + +<p><i>Symptoms.</i>—The chief symptoms of ear diseases are deafness, +noises in the ear (tinnitus aurium), giddiness, pain and discharge. +Deafness (or other disturbance of hearing) and noises may occur +from disease in almost any part of the ear. Purulent discharge +usually comes from the middle ear. Giddiness is more commonly +associated with affections of the internal ear.</p> + +<p><i>Treatment.</i>—Ear diseases are treated on ordinary surgical and +medical lines, due regard being had to the anatomical and physiological +peculiarities of this organ of sense, and especially to its +close relationship, on the one hand to the nose and naso-pharynx, +and on the other hand to the cranium and its contents. The chief +advance in aural surgery in recent years has been in the surgery +of the mastoid process and antrum. The pioneers of this work +were H. Schwartze of Halle, and Stacke of Erfurt, who have been +followed by a host of workers in all parts of the world. This +development led to increased attention being paid to the intracranial +complications of suppurative ear disease, in the treatment +of which great strides have been made in the last few years.</p> + +<p><i>Effects of Diseases of the Nose on the Ear.</i>—The influence of +diseases of the nose and naso-pharynx on ear diseases was brought +out by Loewenberg of Paris, Voltolini of Breslau, and especially +by Wilhelm Meyer of Copenhagen, the discoverer of adenoid +vegetations of the naso-pharynx (“adenoids”), who recognized +the great importance of this disease and gave an inimitable +account of it in the <i>Trans. of the Royal Medical and Chirurgical +Society of London</i>, 1870, and the <i>Archiv für Ohrenheilkunde</i>, 1873. +Adenoid vegetations, which consist of an abnormal enlargement +of Luschka’s tonsil in the vault of the pharynx, frequently give +rise to ear disease in children, and, if not attended to, lay the +foundation of nasal and ear troubles in after life. They are often +associated with enlargement of the faucial tonsils.</p> + +<div class="condensed"> +<p><i>Journals.</i>—In 1864 the <i>Archiv für Ohrenheilkunde</i> was started by +Politzer and Schwartze, and, in 1867, the <i>Monatsschrift für Ohrenheilkunde</i> +(a monthly publication) was founded by Voltolini, Gruber, +Weber-Liel and Rüdinger. Appearing first as the <i>Archives of +Ophthalmology and Otology</i>, simultaneously in English and German, +in 1869, the <i>Archives of Otology</i> became a separate publication under +the editorship of Knapp, Moos and Roosa in 1879. Amongst other +journals now existing are <i>Annales des maladies de l’oreille et du +larynx</i> (Paris), <i>Journal of Laryngology</i> (London), <i>Centralblatt für +Ohrenheilkunde</i> (Leipzig), &c.</p> + +<p><i>Societies.</i>—The earliest society formed was the American Otological +Society (1868), which held annual meetings and published +yearly transactions. Flourishing societies for the study of otology +(sometimes combined with laryngology) exist in almost all civilized +countries, and they usually publish transactions consisting of original +papers and cases. The Otological Society of the United Kingdom +was founded in 1900.</p> + +<p><i>International Congresses.</i>—International Otological congresses +have been held at intervals of about four years at New York, Milan, +Basel, Brussels, Florence, London and Bordeaux (1904). The proceedings +of the congresses appear as substantial volumes.</p> + +<p><i>Hospitals.</i>—The earliest record of a public institution for the +treatment of ear diseases is a Dispensary for Diseases of the Eye +and Ear in London, started by Saunders and Cooper, which existed +in 1804; the aural part, however, was soon closed, so that the actual +oldest institution appears to be the Royal Ear Hospital, London, +which was founded by Curtis in 1816. Four years later there was +started the New York Eye and Ear Infirmary. At the present time +in every large town of Europe and America ear diseases are treated +either in separate departments of general hospitals or in institutions +especially devoted to the purpose.</p> + +<p>For a history of otology from the earliest times refer to <i>A Practical +Treatise on the Diseases of the Ear</i>, by D.B. St John Roosa, M.D., +LL.D. (6th edition, New York, 1885), and for a general account of +the present state of otological science to <i>A Text-Book of the Diseases +of the Ear for Students and Practitioners</i>, by Professor Dr Adam +Politzer, transl. by Milton J. Ballin, Ph.B., M.D., and Clarence J. +Heller, M.D. (4th edition, London, 1902).</p> +</div> +<div class="author">(E. C. B.*)</div> + + +<hr class="art" /> +<p><span class="bold">EARL,<a name="ar29" id="ar29"></a></span> a title and rank of nobility (corresponding to Lat. +<i>comes</i>; Fr. <i>comte</i>), now the third in order of the British peerage, +and accordingly intervening between marquess and viscount. +Earl, however, is the oldest title and rank of English nobles, +and was the highest until the year 1337, when the Black Prince +was created duke of Cornwall by Edward III.</p> + +<p>The nature of a modern earldom is readily understood, since +it is a rank and dignity of nobility which, while it confers no +official power or authority, is inalienable, indivisible, and descends +in regular succession to all the heirs under the limitation in the +grant until, on their failure, it becomes extinct.</p> + +<p>The title is of Scandinavian origin, and first appears in England +under Canute as <i>jarl</i>, which was englished as <i>eorl</i>. Like the +<i>ealdorman</i>, whose place he took, the <i>eorl</i> was a great royal officer, +who might be set over several counties, but who presided separately +in the county court of each with the bishop of the diocese. +Although there were counts in Normandy before the Norman +Conquest, they differed in character from the English earls, +and the earl’s position appears to have been but slightly modified +by the Conquest. He was still generally entitled to the “third +penny” of the county, but his office tended, under Norman +influence, to become an hereditary dignity and his sphere was +restricted by the Conqueror to a single county. The right to +the “third penny” is a question of some obscurity, but its +possession seems to have been deemed the distinctive mark of +an earl, while the girding with “the sword of the county” +formed the essential feature in his creation or investiture, as it +continued to do for centuries later. The fact that every earl +was the earl of a particular county has been much obscured +by the loose usage of early times, when the style adopted was +sometimes that of the noble’s surname (<i>e.g.</i> the Earls Ferrers), +sometimes that of his chief seat (<i>e.g.</i> the Earls of Arundel), and +sometimes that of the county. Palatine earldoms, or palatinates, +were those which possessed <i>regalia</i>, <i>i.e.</i> special privileges delegated +by the crown. The two great examples, which dated from +Norman times, were Chester and Durham, where the earl and +the bishop respectively had their own courts and jurisdiction, +and were almost petty sovereigns.</p> + +<p>The earliest known charter creating an earl is that by which +Stephen bestowed on Geoffrey de Mandeville, in or about 1140, +the earldom of Essex as an hereditary dignity. Several other +creations by Stephen and the empress Maud followed in quick +succession. From at least the time of the Conquest the earl +had a double character; he was one of the “barons,” or tenants +in chief, in virtue of the fief he held of the crown, as well as an +earl in virtue of his “belting” (with the sword) and his “third +penny” of the county. His fief would descend to the heirs of +his body; and the earliest charters creating earldoms were +granted with the same “limitation.” The dignity might thus +descend to a woman, and, in that case, like the territorial fief, +it would be held by her husband, who might be summoned to +parliament in right of it. The earldom of Warwick thus passed +through several families till it was finally obtained, in 1449, +by the Kingmaker, who had married the heiress of the former +earls. But in the case of “co-heiresses” (more daughters than +one), the king determined which, if any, should inherit the +dignity.</p> + +<p>The 14th century saw some changes introduced. The earldom +of March, created in 1328, was the first that was not named +from a county or its capital town. Under Edward III. also an +idea appears to have arisen that earldoms were connected with +the tenure of lands, and in 1337 several fresh ones were created +and large grants of lands made for their support. The first +earldom granted with limitation to the heirs male of the grantee’s +body was that of Nottingham in 1383. Another innovation +was the grant of the first earldom for life only in 1377. The +girding with the sword was the only observance at a creation till +the first year of Edward VI., when the imposition of the cap +<span class="pagenum"><a name="page796" id="page796"></a>796</span> +of dignity and a circlet of gold was added. Under James I. the +patent of creation was declared to be sufficient without any +ceremony. An earl’s robe of estate has three bars of ermine, +but possibly it had originally four.</p> + +<p>Something should be said of anomalous earldoms with Norman +or Scottish styles. The Norman styles originated either under +the Norman kings or at the time of the conquest of Normandy +by the house of Lancaster. To the former period belonged +that of Aumale, which successive fresh creations, under the +Latinized form “Albemarle” have perpetuated to the present +day (see <span class="sc"><a href="#artlinks">Albemarle, Earls and Dukes of</a></span>). The so-called +earls of Eu and of Mortain, in that period, were really holders +of Norman <i>comtés</i>. Henry V. and his son created five or six, +it is said, but really seven at least, Norman countships or +earldoms, of which Harcourt (1418), Perche (1419), Dreux (1427) +and Mortain (? 1430) were bestowed on English nobles, Eu (1419), +and Tankerville (1419) on English commoners, and Longueville +(1419) on a foreigner, Gaston de Foix. Of these the earldom of +“Eu” was assumed by the earls of Essex till the death of Robert, +the parliament’s general (1646), while the title of Tankerville +still survives under a modern creation (1714). An anomalous +royal licence of 1661 permitted the earl of Bath to use the title of +earl of Corbeil by alleged hereditary right. Of Scottish earldoms +recognized in the English parliament the most remarkable case is +that of the Lords Umfraville, who were summoned for three generations +(1297-1380), as earls of Angus; Henry, Lord Beaumont, +also was summoned as earl of Buchan from 1334 to 1339.</p> + +<p>The earldom of Chester is granted to the princes of Wales on +their creation, and the Scottish earldom of Carrick is held by +the eldest son of the sovereign under act of parliament.</p> + +<p>The premier earldom is that of Arundel (<i>q.v.</i>), but as this +is at present united with the dukedom of Norfolk, the oldest +earldom not merged in a higher title is that of Shrewsbury (1442), +the next in seniority being Derby (1485), and Huntingdon (1529). +These three have been known as “the catskin earls,” a term of +uncertain origin. The ancient earldom of Wiltshire (1397) was +unsuccessfully claimed in 1869 by Mr Scrope of Danby, and that +of Norfolk (1312), in 1906, by Lord Mowbray and Stourton.</p> + +<p>The premier earldom of Scotland as recognized by the Union +Roll (1707), is that of Crawford, held by the Lindsays since its +creation in 1398; but it is not one of the ancient “seven earldoms.” +The Decreet of Ranking (1606) appears to have recognized +the earldom of Sutherland as the most ancient in virtue +of a charter of 1347, but the House of Lords’ decision of 1771 +recognized it as having descended from at least the year 1275, +and it may be as old as 1228. It is at present united with the +dukedom of Sutherland. The original “seven earldoms” (of +which it was one) represented seven provinces, each of which +was under a “<i>mormaer</i>.” This Celtic title was rendered “<i>jarl</i>” +by the Norsemen, and under Alexander I. (<i>c.</i> 1115) began to be +replaced by earl (<i>comes</i>), owing to Anglo-Norman influence, +which also tended to make these earldoms less official and more +feudal.</p> + +<p>In Ireland the duke of Leinster is, as earl of Kildare, premier +earl as well as premier duke.</p> + +<p>An earl is “Right Honourable,” and is styled “My Lord.” +His eldest son bears his father’s “second title,” and therefore, +that second title being in most cases a viscounty, he generally +is styled “Viscount”; where, as with Devon and Huntingdon, +there is no second title, one may be assumed for convenience; +under all circumstances, however, the eldest son of an earl takes +precedence immediately after the viscounts. The younger sons +of earls are “Honourable,” but all their daughters are “Ladies.” +In formal documents and instruments, the sovereign, when +addressing or making mention of any peer of the degree of an +earl, usually designates him “trusty and well-beloved cousin,”—a +form of appellation first adopted by Henry IV., who either +by descent or alliance was actually related to every earl and +duke in the realm. The wife of an earl is a countess; she is +“Right Honourable,” and is styled “My Lady.” For the earl’s +coronet see <span class="sc"><a href="#artlinks">Crown and Coronet</a></span>.</p> + +<div class="condensed"> +<p>See Lord’s <i>Reports on the Dignity of a Peer</i>; Pike’s <i>Constitutional</i> +<i>History of the House of Lords</i>; Selden’s <i>Titles of Honour</i>; G.E. +C(okayne)’s <i>Complete Peerage</i>; Round’s <i>Geoffrey de Mandeville</i>.</p> +</div> +<div class="author">(J. H. R.)</div> + + +<hr class="art" /> +<p><span class="bold">EARLE, JOHN<a name="ar30" id="ar30"></a></span> (<i>c.</i> 1601-1665), English divine, was born at +York about 1601. He matriculated at Christ Church, Oxford, +but migrated to Merton, where he obtained a fellowship. In +1631 he was proctor and also chaplain to Philip, earl of Pembroke, +then chancellor of the university, who presented him to the +rectory of Bishopston in Wiltshire. His fame spread, and in +1641 he was appointed chaplain and tutor to Prince Charles. +In 1643 he was elected one of the Assembly of Divines at Westminster, +but his sympathies with the king and with the Anglican +Church were so strong that he declined to sit. Early in 1643 he +was chosen chancellor of the cathedral of Salisbury, but of this +preferment he was soon deprived as a “malignant.” After +Cromwell’s great victory at Worcester, Earle went abroad, and +was named clerk of the closet and chaplain to Charles II. He +spent a year at Antwerp in the house of Isaac Walton’s friend, +George Morley, who afterwards became bishop of Winchester. +He next joined the duke of York (James II.) at Paris, returning +to England at the Restoration. He was at once appointed dean +of Westminster, and in 1661 was one of the commissioners for +revising the liturgy. He was on friendly terms with Richard +Baxter. In November 1662 he was consecrated bishop of +Worcester, and was translated, ten months later, to the see of +Salisbury, where he conciliated the nonconformists. He was +strongly opposed to the Conventicle and Five Mile Acts. During +the great plague Earle attended the king and queen at Oxford, +and there he died on the 17th of November 1665.</p> + +<p>Earle’s chief title to remembrance is his witty and humorous +work entitled <i>Microcosmographie, or a Peece of the World discovered, +in Essayes and Characters</i>, which throws light on the +manners of the time. First published anonymously in 1628, +it became very popular, and ran through ten editions in the +lifetime of the author. The style is quaint and epigrammatic; +and the reader is frequently reminded of Thomas Fuller by such +passages as this: “A university dunner is a gentlemen follower +cheaply purchased, for his own money has hyr’d him.” Several +reprints of the book have been issued since the author’s death; +and in 1671 a French translation by J. Dymock appeared with +the title of <i>Le Vice ridiculé</i>. Earle was employed by Charles II. +to make the Latin translation of the <i>Eikon Basilike</i>, published +in 1649. A similar translation of R. Hooker’s <i>Ecclesiastical +Polity</i> was accidentally destroyed.</p> + +<p>“Dr Earle,” says Lord Clarendon in his <i>Life</i>, “was a man of +great piety and devotion, a most eloquent and powerful preacher, +and of a conversation so pleasant and delightful, so very innocent, +and so very facetious, that no man’s company was more desired +and loved. No man was more negligent in his dress and habit +and mien, no man more wary and cultivated in his behaviour +and discourse. He was very dear to the Lord Falkland, with +whom he spent as much time as he could make his own.”</p> + +<div class="condensed"> +<p>See especially Philip Bliss’s edition of the <i>Microcosmographie</i> +(London, 1811), and E. Arber’s Reprint (London, 1868).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EARLE, RALPH<a name="ar31" id="ar31"></a></span> (1751-1801), American historical and portrait +painter, was born at Leicester, Massachusetts, on the 11th +of May 1751. Like so many of the colonial craftsmen, Earle +was self-taught, and for many years was an itinerant painter. +He went with the Governor’s Guard to Lexington and made +battle sketches, from which in 1775 he painted four scenes, +engraved by Amos Doolittle, which are probably the first historical +paintings by an American. After the War of Independence, +Earle went to London, entered the studio of Benjamin +West, and painted the king and many notables. After his return +to America in 1786 he made portraits of Timothy Dwight, +Governor Caleb Strong, Roger Sherman, and other prominent +men. He also painted a large picture of Niagara Falls. He +died at Bolton, Connecticut, on the 16th of August 1801.</p> + + +<hr class="art" /> +<p><span class="bold">EARL MARSHAL,<a name="ar32" id="ar32"></a></span> in England, a functionary who ranks as +the eighth of the great officers of state. He is the head of the +college of arms, and has the appointment of the kings-of-arms, +heralds and pursuivants at his discretion. He attends the +sovereign in opening and closing the session of parliament, +<span class="pagenum"><a name="page797" id="page797"></a>797</span> +walking opposite to the lord great chamberlain on his or her +right hand. It is his duty to make arrangements for the order +of all state processions and ceremonials, especially for coronations +and royal marriages and funerals. Like the lord high constable +he rode into Westminster Hall with the champion after a coronation, +till the coronation banquet was abandoned, taking +his place on the left hand, and with the lord great chamberlain +he assists at the introduction of all newly-created peers into the +House of Lords.</p> + +<p>The marshal appears in the feudal armies to have been in +command of the cavalry under the constable, and to have in +some measure superseded him as master of the horse in the +royal palace. He exercised joint and co-ordinate jurisdiction +with the constable in the court of chivalry, and afterwards +became the sole judge of that tribunal till its obsolescence. +The marshalship of England was formerly believed to have been +inherited from the Clares by the Marshal family, who had only +been marshals of the household. It was held, however, by the +latter family, as the office of chief (<i>magister</i>) marshal, as early +as the days of Henry I. Through them, under Henry III., it +passed to the Bigods, as their eldest co-heirs. In 1306 it fell to +the crown on the death of the last Bigod, earl of Norfolk, who had +made Edward I. his heir, and in 1316 it was granted by Edward II. +to his own younger brother, Thomas “of Brotherton,” earl of +Norfolk. As yet the style of the office was only “marshal” +although the last Bigod holder, being an earl, was sometimes +loosely spoken of as the earl marshal. The office, having reverted +to the crown, was granted out anew by Richard II., in 1385, to +Thomas Mowbray, earl of Nottingham, the representative of +Thomas “of Brotherton.” In 1386 the style of “earl marshal” +was formally granted to him in addition. After several attainders +and partial restorations in the reigns of the Tudors and the +Stuarts, the earl marshalship was granted anew to the Howards +by Charles II. in 1672 and entailed on their male line, with many +specific remainders and limitations, under which settlement +it has regularly descended to the present duke of Norfolk. +Its holders, however, could not execute the office until the Roman +Catholic emancipation, and had to appoint deputies. The duke +is styled earl marshal “and hereditary marshal of England,” but +the double style would seem to be an error, though the Mowbrays, +with their double creation (1385, 1386) might have claimed +it. His Grace appends the letters “E.M.” to his signature, +and bears behind his shield two batons crossed in saltire, the +marshal’s rod (<i>virga</i>) having been the badge of the office from +Norman times. There appear to have been hereditary marshals +of Ireland, but their history is not well ascertained. The Keiths +were Great Marischals of Scotland from at least the days of +Robert Bruce, and were created earls marischal in or about +1458, but lost both earldom and office by the attainder of George, +the 10th earl, in 1716. (See also <span class="sc"><a href="#artlinks">Marshal</a></span>; <span class="sc"><a href="#artlinks">State, Great +Officers of</a></span>.)</p> + +<div class="condensed"> +<p>See “The Marshalship of England,” in J.H. Round, <i>Commune +of London and Other Studies</i> (London, 1899); G.E. C(okayne)’s +<i>Complete Peerage</i>.</p> +</div> +<div class="author">(J. H. R.)</div> + + +<hr class="art" /> +<p><span class="bold">EARLOM, RICHARD<a name="ar33" id="ar33"></a></span> (1742-1822), English mezzotint engraver, +was born and died in London. His natural faculty for art +appears to have been first called into exercise by admiration for +the lord mayor’s state coach, just decorated by Cipriani. He tried +to copy the paintings, and was sent to study under Cipriani. He +displayed great skill as a draughtsman, and at the same time +acquired without assistance the art of engraving in mezzotint. +In 1765 he was employed by Alderman Boydell, then one of the +most liberal promoters of the fine arts, to make a series of drawings +from the pictures at Houghton Hall; and these he afterwards +engraved in mezzotint. His most perfect works as engraver are +perhaps the fruit and flower pieces after the Dutch artists Van +Os and Van Huysum. Amongst his historical and figure subjects +are—“Agrippina,” after West; “Love in Bondage,” after +Guido Reni; the “Royal Academy,” the “Embassy of Hyderbeck +to meet Lord Cornwallis,” and a “Tiger Hunt,” the last +three after Zoffany; and “Lord Heathfield,” after Sir Joshua +Reynolds. Earlom also executed a series of 200 facsimiles of +the drawings and sketches of Claude Lorraine, which was +published in 3 vols. folio, under the title of <i>Liber veritatis</i> +(1777-1819).</p> + + +<hr class="art" /> +<p><span class="bold">EARLSTON<a name="ar34" id="ar34"></a></span> (formerly <span class="sc">Ercildoune</span>, of which it is a corruption), +a parish and market town of Berwickshire, Scotland. Pop. +(1901) 1049. It is situated on Leader Water in Lauderdale, +72½ m. S.E. of Edinburgh by the North British railway branch +line from Reston Junction to St Boswells, and about 4 m. N.E. +of Melrose. When the place was a hamlet of rude huts it was +called Arcioldun or “Prospect Fort,” with reference to Black +Hill (1003 ft.), on the top of which may yet be traced the concentric +rings of the British fort by which it was crowned. It is +said to be possible to make out the remains of the cave-dwellings +of the Ottadeni, the aborigines of the district. In the 12th and +13th centuries the Lindsays and the earls of March and Dunbar +were the chief baronial families. The particular link with the +remote past, however, is the ivy-clad ruin of the ancient tower, +“The Rhymer’s Castle,” the traditional residence of Thomas +Learmont, commonly called Thomas of Ercildoune, or Thomas +the Rhymer, poet and prophet, and friend of the Fairies, who +was born here about 1225. Rhymer’s Tower was crumbling to +pieces, and its stones were being used in the erection of dykes, +cottages and houses, when the Edinburgh Border Counties +Association acquired the relic and surrounding lands in 1895, +and took steps to prevent further spoliation and decay. The +leading manufactures are ginghams, tweeds and shirtings, and +the town is also an important agricultural centre, stock sales +taking place at regular intervals and cattle and horse fairs being +held every year. Some 3 m. away is the estate of Bemersyde, +said to have been in the possession of the Haigs for nearly 1000 +years. The prospect from Bemersyde Hill was Sir Walter +Scott’s favourite view. The castle at Bemersyde was erected +in 1535 to secure the peace of the Border.</p> + + +<hr class="art" /> +<p><span class="bold">EARLY, JUBAL ANDERSON<a name="ar35" id="ar35"></a></span> (1816-1894), American soldier +and lawyer, was born in Franklin county, Virginia, on the 3rd +of November 1816, and graduated at the U.S. Military Academy +in 1837. He served in the Seminole War of 1837-38, after which +he resigned in order to practise law in Franklin county, Va. +He also engaged in state politics, and served in the Mexican War +as a major of Virginia volunteers. He was strongly opposed to +secession, but thought it his duty to conform to the action of his +state. As a colonel in the Confederate army, he rendered conspicuous +service at the first battle of Bull Run (<i>q.v.</i>). Promoted +brigadier-general, and subsequently major-general, Early served +throughout the Virginian campaigns of 1862-63, and defended +the lines of Fredericksburg during the battle of Chancellorsville. +At Gettysburg he commanded his division of Ewell’s corps. +In the campaign of 1864 Early, who had now reached the rank +of lieutenant-general, commanded the Confederate forces in the +Shenandoah Valley. The action of Lynchburg left him free to +move northwards, his opponent being compelled to march away +from the Valley. Early promptly utilized his advantage, crossed +the Potomac, and defeated, on the Monocacy, all the troops +which could be gathered to meet him. He appeared before the +lines of Washington, put part of Maryland and Pennsylvania +under contribution, and only retired to the Valley when +threatened by heavy forces hurriedly sent up to Washington. +He then fought a successful action at Winchester, reappeared +on the Potomac, and sent his cavalry on a raid into +Pennsylvania. A greatly superior army was now formed under +General Sheridan to oppose Early. In spite of his skill and energy +the Confederate leader was defeated in the battles of Winchester +and Fisher’s Hill. Finally, on the 19th of October, after inflicting +at first a severe blow upon the Federal army in its camps +on Cedar Creek, he was decisively beaten by Sheridan. (See +<span class="sc"><a href="#artlinks">Shenandoah Valley Campaigns</a></span>.) Waynesboro (March 1865) +was his last fight, after which he was relieved from his command. +General Early was regarded by many as the ablest soldier, after +Lee and Jackson, in the Army of Northern Virginia, and one of +the ablest in the whole Confederate army. That he failed to make +headway against an army far superior in numbers, and led by a +general of the calibre of Sheridan, cannot be held to prove the +<span class="pagenum"><a name="page798" id="page798"></a>798</span> +falsity of this judgment. After the peace he went to Canada, but +in 1867 returned to resume the practice of law. For a time he +managed in conjunction with General Beauregard the Louisiana +lottery. He died at Lynchburg, Va., on the 2nd of March 1894. +General Early was for a time president of the Southern Historical +Society, and wrote, besides various essays and historical papers, +<i>A Memoir of the Last Year of the War, &c.</i> (1867).</p> + + +<hr class="art" /> +<p><span class="bold">EARLY ENGLISH PERIOD,<a name="ar36" id="ar36"></a></span> in architecture, the term given +by Rickman to the first pointed or Gothic style in England, +nominally 1189-1307, which succeeded the Romanesque or +Norman period towards the end of the 12th century, and +developed into the Decorated period in the commencement of +the 14th century. It is chiefly characterized by the almost +universal employment of the pointed arch, not only in arches of +wide span such as those of the nave arcade, but for doorways +and windows. The actual introduction of the pointed arch took +place at a much earlier date, as in the nave arcade of the Cistercian +Abbey of Buildwas (1140), though the clerestory window +above has semicircular arches. It is customary, therefore, to +make allowance for a transitional epoch from the middle of the +12th century. Although the pointed arches used are sometimes +equilateral and sometimes drop-arches, the lancet-arch is the +most characteristic. The period is best recognized in England by +the great depth given to the hollows of the mouldings, alternating +with fillets and rolls, by the decoration of the hollows with +the dog-tooth ornament, by the circular abacus of the capitals, +and the employment of slender detached shafts of Purbeck +marble which are attached to piers by circular moulded shaft-rings +(Fr. <i>anneau</i>).</p> + +<p>The arches are sometimes cusped; circles with trefoils, +quatrefoils, &c., are introduced into the tracery, and large rose +windows in the transept or nave, as at Lincoln (1220). The +conventional foliage decorating the capitals is of great beauty and +variety, and extends to spandrils, bosses, &c. In the spandrils +of the arches of the nave, transept or choir arcades, diaper work +is occasionally found, as in the transept of Westminster Abbey. +The latter is one of the chief examples of the period, to which +must be added the cathedral of Salisbury (except the tower); +the Galilee at Ely; nave and transept of Wells (1225-1240); +nave of Lincoln; west front of Peterborough; and the minster +at Beverley.</p> +<div class="author">(R. P. S.)</div> + + +<hr class="art" /> +<p><span class="bold">EARN,<a name="ar37" id="ar37"></a></span> the name of a loch and river in Perthshire, Scotland. +The loch, lying almost due east and west, is 6½ m. long and +<span class="spp">4</span>⁄<span class="suu">5</span> m. in maximum breadth, 287 ft. deep, with a mean depth of +138 ft., covers an area of nearly 4 sq. m., has a drainage basin of +over 54½ sq. m., and stands 317 ft. above the sea. Its waters are +said never to freeze. It discharges by the river Earn. The points +of interest on its shores are Lochearnhead (at the southern +extremity of Glen Ogle), which has a station on the Callander-Oban +railway, and the ruins of St Blane’s chapel; Edinample +Castle, an old turreted mansion belonging to the marquess of +Breadalbane, situated in well-wooded grounds near the pretty +falls of the Ample; Ardvorlich House, the original of Darlinvarach +in Scott’s <i>Legend of Montrose</i>, and the village of St +Fillans at the foot of the loch, once the terminus of the branch +of the Caledonian railway from Perth. The river flows out of +Loch Earn, pursues an eastward course with a gentle inclination +towards the south, and reaches the Firth of Tay, 6½ m. below +Perth, after a total run of 49 m. Its chief tributaries on the right +are the Ruchil, Machany, Ruthven, May and Farg, and on the +left, the Lednock and Turret. It is navigable by vessels of 50 +tons as far up as Bridge of Earn, and is a notable fishing stream, +abounding with salmon and trout, perch and pike being also +plentiful. On the Lednock are the falls of the Devil’s Cauldron +and on the Turret and its feeders several graceful cascades. The +principal places of interest on the banks of the Earn are Dunira, +the favourite seat of Henry Dundas, 1st Viscount Melville, who +took the title of his barony from the estate and to whose memory +an obelisk was raised on the adjoining hill of Dunmore; the +village of Comrie; the town of Crieff; the ruined castle of +Innerpeffray, founded in 1610 by the 1st Lord Maderty, close +to which is the library founded in 1691 by the 3rd Lord Maderty, +containing some rare black-letter books and the Bible that belonged +to the marquess of Montrose; Gascon Hall, now in ruins, +but with traditions reaching back to the days of Wallace; +Dupplin Castle, a fine Tudor mansion, seat of the earl of Kinnoull, +who derives from it the title of his viscounty; Aberdalgie, +Forgandenny and Bridge of Earn, a health resort situated +amidst picturesque surroundings. Strathearn, as the valley of +the Earn is called, extending from the loch to the Firth of Tay, +is a beautiful and, on the whole, fertile tract, though liable at +times to heavy floods. The earl of Perth is hereditary steward +of Strathearn.</p> + + +<hr class="art" /> +<p><span class="bold">EARNEST<a name="ar38" id="ar38"></a></span> (probably a corruption of the obsolete <i>arles</i> or <i>erles</i>, +adapted from Lat. equivalent <i>arrha</i>, due to a confusion with the +adjective “earnest,” serious, O. Eng. <i>eornust</i>, cognate with Ger. +<i>ernst</i>), the payment of a sum of money by the buyer of goods to +the seller on the conclusion of a bargain as a pledge for its due +performance. It is almost similar to the <i>arrha</i> of the Roman law, +which may be traced back in the history of legal institutions to +a period when the validity of a contract depended not so much +upon the real intention of the parties, as upon the due observance +of a prescribed ceremony. But <i>earnest</i> was never part payment, +which <i>arrha</i> might have been. Apart from its survival as a +custom, its chief importance in English law is its recognition by +the Statute of Frauds as giving validity to contracts for the sale +of goods of a value exceeding £10 (see <span class="sc"><a href="#artlinks">Sale of Goods</a></span>). It is +in that statute clearly distinguished from part payment, consequently +any sum, however small, would be sufficient as earnest, +being given as a token that the contract is binding and should +be expressly stated so by the giver. The giving of earnest, +or <i>hand-money</i>, as it is sometimes called, has now fallen into very +general disuse.</p> + + +<hr class="art" /> +<p><span class="bold">EAR-RING,<a name="ar39" id="ar39"></a></span> an ornament worn pendent from the ear, and +generally suspended (especially among the more civilized races) +by means of a ring or hook passing through the pendulous +lobe of the ear. Among savage races the impulse to decorate, +or at any rate to modify the appearance of the ear, is almost +universal. With such peoples the ear appendage is chiefly +remarkable for its extravagant dimensions. Many examples +may be seen in the ethnographic galleries of the British Museum. +The Berawan people of Borneo use plugs through the lobe of the +ear 3¾ in. in diameter. More extraordinary still is an example +of a stone ear-plug worn by a Masai, 4½ in. in diameter and +weighing 2 ℔ 14 oz. (<i>Man</i>, 1905, p. 22). It is stated that +according to the Masai standard of fashion, the lobes of the ears +should be enlarged so as to be capable of meeting above the head. +Among the superior races, though ear ornaments of extravagant +size and elaboration are not unknown, moderation in size is commonly +observed, and greater attention is paid to workmanship +and fineness of material.</p> + +<table class="flt" style="float: right; width: 220px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:103px; height:303px" src="images/img799a.jpg" alt="" /></td></tr> +<tr><td class="caption1 f80">From <i>La Grande Encyclopédie</i>.</td></tr> +<tr><td class="caption1"><span class="sc">Fig. 1.</span>—Ear-ring +from an Assyrian bas +relief.</td></tr> + +<tr><td class="figright1"><img style="width:170px; height:354px" src="images/img799b.jpg" alt="" /></td></tr> +<tr><td class="caption1 f80">From <i>La Grande Encyclopédie</i>.</td></tr> +<tr><td class="caption1"><span class="sc">Fig. 2.</span>—Thetis crossing +the sea, with the +armour of Achilles. +Ear-ring from the +Crimea, Hermitage +museum.</td></tr></table> + +<p>The general usage appears to have been to have ear-rings +worn in pairs, the two ornaments in all respects resembling each +other; in ancient times, or more recently among Oriental races, +a single ear-ring has sometimes been worn. The use of this kind +of ornament, which constantly was of great value, dates from the +remotest historical antiquity, the earliest mention of ear-rings +occurring in the book of Genesis. It appears probable that the +ear-rings of Jacob’s family, which he buried with his strange idols +at Bethel, were regarded as amulets or talismans, such unquestionably +being the estimation in which some ornaments of this class +have been held from a very early period, as they still are held in +the East. Thus in New Zealand ear-rings are decorated with the +teeth of enemies, and with talismanic sharks’ teeth. Among +all the Oriental races of whom we have any accurate knowledge, +the Hebrews and Egyptians excepted, ear-rings always have been +in general use by both sexes; while in the West, as well as by +the Hebrews and Egyptians, as a general rule they have been +considered exclusively female ornaments. By the Greeks and +Romans also ear-rings were worn only by women, and the wearing +of them by a man is often spoken of as distinctively oriental.</p> + +<p>In archaic art, ear-rings are frequently represented or their +traces are left in the perforated ear lobes of early statues. After +the 4th century such perforations occur seldom. In one instance, +<span class="pagenum"><a name="page799" id="page799"></a>799</span> +a Greek inscription records the weight of the detachable gold ornaments +on a statue, among which a pair of ear-rings is included. +Ear-rings of characteristic form are frequently discovered by +excavation. In Egypt, a system of pendent +chains is found hanging from a disk. In +Assyria the decoration consists of pendants +or knobs attached to a rigid ring. In +the early civilization represented by Dr +Schliemann’s Trojan investigations, pieces +of gold plate are suspended by parallel +chains. In the Mycenaean period, ear-rings +are infrequent in Greece, but have been +found in abundance in the Mycenaean finds +of Enkomi (Cyprus) in the form of pendent +bulls’-heads, or of decorative forms based on +the bull’s head. In the tombs of the Greek +settlers in the Crimea (4th century <span class="scs">B.C.</span>), +ear-rings are found of marvellous complexity +and beauty. The lexicographer Pollux, +speaking of the names given to ear-rings, +derived from their forms, mentions caryatids, +hippocamps and centauresses. Jewels +of the same class, of exquisite beauty and +of workmanship that is truly wonderful, have been rescued +from the sepulchres of ancient Etruria. Ear-rings of comparatively +simple forms, but set with pearls +and other stones, were the mode in +Rome. In some instances, the stones +were of fabulous value. During the +Byzantine period they once more attained +an extravagant size. Researches among +the burial places of Anglo-Saxon Britain +have led to the discovery of jewels in considerable +numbers, which among their +varieties include ear-rings executed in a +style that proves the Anglo-Saxons to +have made no inconsiderable advances +in the arts of civilization.</p> + +<p>These same ornaments, which never +have fallen into disuse, enjoy at the +present day a considerable degree of +favour, and the tide of fashion has set +towards their increased use. Like all +other modern jewels, however, the ear-rings +of our own times as works of art +can claim no historical attributes, because +they consist as well of reproductions from +all past ages and of every race as of +fanciful productions that certainly can +be assigned to no style of art whatever. +As one of the curiosities of the subject it may be mentioned +that Antonia, wife of Drusus, is said by Pliny to have attached +a pair of ear-rings to her pet lamprey.</p> + + +<hr class="art" style="clear: both;" /> +<p><span class="bold">EARTH<a name="ar40" id="ar40"></a></span> (a word common to Teutonic languages, cf. Ger. <i>Erde</i>, +Dutch <i>aarde</i>, Swed. and Dan. <i>jord</i>; outside Teutonic it appears +only in the Gr. <span class="grk" title="eraze">ἔραζε</span>, on the ground; it has been connected +by some etymologists with the Aryan root <i>ar-</i>, to plough, which +is seen in the Lat. <i>arare</i>, obsolete Eng. “ear,” and Gr. <span class="grk" title="aroun">ἀροῦν</span>, but +this is now considered very doubtful; see G. Curtius, <i>Greek +Etymology</i>, Eng. trans., i. 426; Max Müller, <i>Lectures</i>, 8th ed. +i. 294). From early times the word “earth” has been used +in several connexions—from that of soil or ground to that +of the planet which we inhabit, but it is difficult to trace +the exact historic sequence of the diverse usages. In the +cosmogony of the Pythagoreans, Platonists and other philosophers, +the term or its equivalent denoted an element or +fundamental quality which conferred upon matter the character +of earthiness; and in the subsequent development of theories +as to the ultimate composition of matter by the alchemists, +iatrochemists, and early phlogistonists an element of the same +name was retained (see <span class="sc"><a href="#artlinks">Element</a></span>). In modern chemistry, the +common term “earth” is applied to certain oxides:—the +”alkaline earths” (<i>q.v.</i>) are the oxides of calcium (lime), barium +(baryta) and strontium (strontia); the ”rare earths” (<i>q.v.</i>) are +the oxides of a certain class of rare metals.</p> + +<p class="pt2 center sc">The Earth</p> + +<p>The terrestrial globe is a member of the Solar system, the third +in distance from the Sun, and the largest within the orbit of +Jupiter. In the wider sense it may be regarded as composed +of a gaseous atmosphere (see <span class="sc"><a href="#artlinks">Meteorology</a></span>), which encircles +the crust or lithosphere (see <span class="sc"><a href="#artlinks">Geography</a></span>), and surface waters +or hydrosphere (see <span class="sc"><a href="#artlinks">Ocean and Oceanography</a></span>). The description +of the surface features is a branch of Geography, and the +discussions as to their origin and permanence belongs to Physiography +(in the narrower sense), physiographical geology, or +physical geography. The investigation of the crust belongs +to geology and of rocks in particular to petrology.</p> + +<p>In the present article we shall treat the subject matter of the +Earth as a planet under the following headings:—(1) Figure +and Size, (2) Mass and Density, (3) Astronomical Relations, +(4) Evolution and Age. These subjects will be treated summarily, +readers being referred to the article <span class="sc"><a href="#artlinks">Astronomy</a></span> and to the +cross-references for details.</p> + +<p>1. <i>Figure and Size.</i>—To primitive man the Earth was a flat +disk with its surface diversified by mountains, rivers and seas. +In many cosmogonies this disk was encircled by waters, unmeasurable +by man and extending to a junction with the sky; +and the disk stood as an island rising up through the waters from +the floor of the universe, or was borne as an immovable ship on +the surface. Of such a nature was the cosmogony of the Babylonians +and Hebrews; Homer states the same idea, naming +the encircling waters <span class="grk" title="Ôkeanos">Ὠκεανός</span>; and Hesiod regarded it as a +disk midway between the sky and the infernal regions. The +theory that the Earth extended downwards to the limit of the +universe was subjected to modification when it was seen that the +same sun and stars reappeared in the east after their setting in +the west. But man slowly realized that the earth was isolated +in space, floating freely as a balloon, and much speculation was +associated about that which supported the Earth. Tunnels +in the foundations to permit the passage of the sun and stars +were suggested; the Greeks considered twelve columns to +support the heavens, and in their mythology the god Atlas +appears condemned to support the columns; while the Egyptians +had the Earth supported by four elephants, which themselves +stood on a tortoise swimming on a sea. Earthquakes were +regarded as due to a movement of these foundations; in Japan +this was considered to be due to the motion of a great spider, +an animal subsequently replaced by a cat-fish; in Mongolia +it is a hog; in India, a mole; in some parts of South America, +a whale; and among some of the North American Indians, +a giant tortoise.</p> + +<p>The doctrine of the spherical form has been erroneously +assigned to Thales; but he accepted the Semitic conception of the +disk, and regarded the production of springs after earthquakes +as due to the inrushing of the waters under the Earth into fissures +in the surface. His pupil, Anaximander (610-547), according +to Diogenes Laërtius, believed it to be spherical (see <i>The +Observatory</i>, 1894, P. 208); and Anaximenes probably held a +similar view. The spherical form is undoubtedly a discovery +of Pythagoras, and was taught by the Pythagoreans and by the +Eleatic Parmenides. The expositor of greatest moment was +Aristotle; his arguments are those which we employ to-day:—the +ship gradually disappearing from hull to mast as it recedes +from the harbour to the horizon; the circular shadow cast by the +Earth on the Moon during an eclipse, and the alteration in the +appearance of the heavens as one passes from point to point on +the Earth’s surface.<a name="fa1b" id="fa1b" href="#ft1b"><span class="sp">1</span></a> He records attempts made to determine +the circumference; but the first scientific investigation in this +<span class="pagenum"><a name="page800" id="page800"></a>800</span> +direction was made 150 years later by Eratosthenes. The +spherical form, however, only became generally accepted after +the Earth’s circumnavigation (see <span class="sc"><a href="#artlinks">Geography</a></span>).</p> + +<p>The historical development of the methods for determining +the figure of the Earth (by which we mean a theoretical surface +in part indicated by the ocean at rest, and in other parts by the +level to which water freely communicating with the oceans +by canals traversing the land masses would rise) and the mathematical +investigation of this problem are treated in the articles +<span class="sc"><a href="#artlinks">Earth, Figure of the</a></span>, and <span class="sc"><a href="#artlinks">Geodesy</a></span>; here the results are +summarized. Sir Isaac Newton deduced from the mechanical +consideration of the figure of equilibrium of a mass of rotating +fluid, the form of an oblate spheroid, the ellipticity of a meridian +section being 1/231, and the axes in the ratio 230 : 231. Geodetic +measurements by the Cassinis and other French astronomers +pointed to a prolate form, but the Newtonian figure was +proved to be correct by the measurement of meridional arcs +in Peru and Lapland by the expeditions organized by the +French Academy of Sciences. More recent work points +to an elliptical equatorial section, thus making the earth +pear-shaped. The position of the longer axis is somewhat uncertain; +it is certainly in Africa, Clarke placing it in longitude +8° 15′ W., and Schubert in longitude 41° 4′ E.; W.J. Sollas, +arguing from terrestrial symmetry, has chosen the position +lat. 6° N., long. 28° E., <i>i.e.</i> between Clarke’s and Schubert’s +positions. For the lengths of the axes and the ellipticity of the +Earth, see <span class="sc"><a href="#artlinks">Earth, Figure of the</a></span>.</p> + +<p>2. <i>Mass and Density.</i>—The earliest scientific investigation +on the density and mass of the Earth (the problem is really single +if the volume of the Earth be known) was made by Newton, who, +mainly from astronomical considerations, suggested the limiting +densities 5 and 6; it is remarkable that this prophetic guess +should be realized, the mean value from subsequent researches +being about 5½, which gives for the mass the value 6 × 10<span class="sp">21</span> tons. +The density of the Earth has been determined by several experimenters +within recent years by methods described in the article +<span class="sc"><a href="#artlinks">Gravitation</a></span>; the most probable value is there stated to be +5.527.</p> + +<p>3. <i>Astronomical Relations.</i>—The grandest achievements of +astronomical science are undoubtedly to be associated with +the elucidation of the complex motion of our planet. The +notion that the Earth was fixed and immovable at the centre +of an immeasurable universe long possessed the minds of men; +and we find the illustrious Ptolemy accepting this view in the +2nd century <span class="scs">A.D.</span>, and rejecting the notion of a rotating Earth—a +theory which had been proposed as early as the 5th century +<span class="scs">B.C.</span> by Philolaus on philosophical grounds, and in the 3rd century +<span class="scs">B.C.</span> by the astronomer Aristarchus of Samos. He argued that +if the Earth rotated then points at the equator had the enormous +velocity of about 1000 m. per hour, and as a consequence there +should be terrific gales from the east; the fact that there were +no such gales invalidated, in his opinion, the theory. The +Ptolemaic theory was unchallenged until 1543, in which year the +<i>De Revolutionibus orbium Celestium</i> of Copernicus was published. +In this work it was shown that the common astronomical +phenomena could be more simply explained by regarding +the Earth as annually revolving about a fixed Sun, and daily +rotating about itself. A clean sweep was made of the geocentric +epicyclic motions of the planets which Ptolemy’s theory demanded, +and in place there was substituted a procession of planets +about the Sun at different distances. The development of the +Copernican theory—the corner-stone of modern astronomy—by +Johann Kepler and Sir Isaac Newton is treated in the article +<span class="sc"><a href="#artlinks">Astronomy</a></span>: <i>History</i>; here we shall summarily discuss the +motions of our planet and its relation to the solar system.</p> + +<p>The Earth has two principal motions—revolution about the +Sun, rotation about its axis; there are in addition a number +of secular motions.</p> + +<p><i>Revolution.</i>—The Earth revolves about the Sun in an +elliptical orbit having the Sun at one focus. The plane of the +orbit is termed the ecliptic; it is inclined to the Earth’s equator +at an angle termed the obliquity, and the points of intersection +of the equator and ecliptic are termed the equinoctial points. +The major axis of the ellipse is the line of apsides; when the +Earth is nearest the Sun it is said to be in perihelion, when +farthest it is in aphelion. The mean distance of the Earth from +the Sun is a most important astronomical constant, since it is +the unit of linear measurement; its value is about 93,000,000 m., +and the difference between the perihelion and aphelion distances +is about 3,000,000 m. The eccentricity of the orbit is 0.016751. +A tabular comparison of the orbital constants of the Earth and +the other planets is given in the article <span class="sc"><a href="#artlinks">Planet</a></span>. The period +of revolution with regard to the Sun, or, in other words, the time +taken by the Sun apparently to pass from one equinox to the +same equinox, is the tropical or equinoctial year; its length is +365 d. 5 hrs. 48 m. 46 secs. It is about 20 minutes shorter than +the true or sidereal year, which is the time taken for the Sun +apparently to travel from one star to it again. The difference +in these two years is due to the secular variation termed precession +(see below). A third year is named the <i>anomalistic year</i>, +which is the time occupied in the passage from perihelion to +perihelion; it is a little longer than the sidereal.</p> + +<p><i>Rotation.</i>—The Earth rotates about an axis terminating +at the north and south geographical poles, and perpendicular +to the equator; the period of rotation is termed the day (<i>q.v.</i>), +of which several kinds are distinguished according to the body +or point of reference. The rotation is performed from west to +east; this daily rotation occasions the <i>diurnal</i> motion of the +celestial sphere, the rising of the Sun and stars in the east and +their setting in the west, and also the phenomena of day and +night. The inclination of the axis to the ecliptic brings about +the presentation of places in different latitudes to the more direct +rays of the sun; this is revealed in the variation in the length of +daylight with the time of the year, and the phenomena of seasons.</p> + +<p>Although the rotation of the Earth was an accepted fact soon +after its suggestion by Copernicus, an experimental proof was +wanting until 1851, when Foucault performed his celebrated +pendulum experiment at the Pantheon, Paris. A pendulum +about 200 ft. long, composed of a flexible wire carrying a heavy +iron bob, was suspended so as to be free to oscillate in any direction. +The bob was provided with a style which passed over a +table strewn with fine sand, so that the style traced the direction +in which the bob was swinging. It was found that the oscillating +pendulum never retraced its path, but at each swing it was +apparently deviated to the right, and moreover the deviations +in equal times were themselves equal. This means that the floor +of the Pantheon was moving, and therefore the Earth was +rotating. If the pendulum were swung in the southern hemisphere, +the deviation would be to the left; if at the equator it +would not deviate, while at the poles the plane of oscillation would +traverse a complete circle in 24 hours.</p> + +<p>The rotation of the Earth appears to be perfectly uniform, +comparisons of the times of transits, eclipses, &c., point to a +variation of less than <span class="spp">1</span>⁄<span class="suu">100</span>th of a second since the time of Ptolemy. +Theoretical investigations on the phenomena of tidal friction +point, however, to a retardation, which may to some extent be +diminished by the accelerations occasioned by the shrinkage of +the globe, and some other factors difficult to evaluate (see <span class="sc"><a href="#artlinks">Tide</a></span>).</p> + +<p>We now proceed to the secular variations.</p> + +<p><i>Precession.</i>—The axis of the earth does not preserve an invariable +direction in space, but in a certain time it describes a +cone, in much the same manner as the axis of a top spinning out +of the vertical. The equator, which preserves approximately +the same inclination to the ecliptic (there is a slight variation in +the obliquity which we shall mention later), must move so that +its intersections with the ecliptic, or equinoctial points, pass in +a retrograde direction, <i>i.e.</i> opposite to that of the Earth. This +motion is termed the precession of the equinoxes, and was observed +by Hipparchus in the 2nd century <span class="scs">B.C.</span>; Ptolemy corrected the +catalogue of Hipparchus for precession by adding 2° 40′ to the +longitudes, the latitudes being unaltered by this motion, which at +the present time is 50.26″ annually, the complete circuit being +made in about 26,000 years. Owing to precession the signs of +the zodiac are traversing paths through the constellations, or, +<span class="pagenum"><a name="page801" id="page801"></a>801</span> +in other words, the constellations are continually shifting with +regard to the equinoctial points; at one time the vernal equinox +Aries was in the constellations of that name; it is now in Pisces, +and will then pass into Aquarius. The pole star, <i>i.e.</i> the star +towards which the Earth’s axis points, is also shifting owing to +precession; in about 2700 <span class="scs">B.C.</span> the Chinese observed α Draconis +as the pole star (at present α Ursae minoris occupies this position +and will do so until 3500); in 13600 Vega (α Lyrae) the brightest +star in the Northern hemisphere, will be nearest.</p> + +<p>Precession is the result of the Sun and the Moon’s attraction +on the Earth not being a single force through its centre of gravity. +If the Earth were a homogeneous sphere the attractions would +act through the centre, and such forces would have no effect +upon the rotation about the centre of gravity, but the Earth +being spheroidal the equatorial band which stands up as it were +beyond the surface of a sphere is more strongly attracted, with +the result that the axis undergoes a tilting. The precession due +to the Sun is termed the <i>solar precession</i> and that due to the +Moon the <i>lunar precession</i>; the joint effect (two-thirds of which +is due to the Moon) is the <i>luni-solar</i> precession. Solar precession +is greatest at the solstices and zero at the equinoxes; the part +of luni-solar precession due to the Moon varies with the position +of the Moon in its orbit. The obliquity is unchanged by precession +(see <span class="sc"><a href="#artlinks">Precession of the Equinoxes</a></span>).</p> + +<p><i>Nutation.</i>—In treating precession we have stated that the axis +of the Earth traces a cone, and it follows that the pole describes +a circle (approximately) on the celestial sphere, about the pole +of the ecliptic. This is not quite true. Irregularities in the +attracting forces which occasion precession also cause a slight +oscillation backwards and forwards over the mean precessional +path of the pole, the pole tracing a wavy line or nodding. Both +the Sun and Moon contribute to this effect. Solar nutation +depends upon the position of the Sun on the ecliptic; its period +is therefore 1 year, and in extent it is only 1.2″; lunar nutation +depends upon the position of the Moon’s nodes; its period is +therefore about 18.6 years, the time of revolution of the nodes, +and its extent is 9.2″. There is also given to the obliquity a small +oscillation to and fro. Nutation is one of the great discoveries +of James Bradley (1747).</p> + +<p><i>Planetary Precession.</i>—So far we have regarded the ecliptic as +absolutely fixed, and treated precession as a real motion of the +equator. The ecliptic (<i>q.v.</i>), however, is itself subject to a motion, +due to the attractions of the planets on the Earth. This effect +also displaces the equinoctial points. Its annual value is 0.13″. +The term General Precession in longitude is given to the displacement +of the intersection of the equator with the apparent +ecliptic on the latter. The standard value is 50.2453″, which +prevailed in 1850, and the value at 1850 + t, <i>i.e.</i> the constant of +precession, is 50.2453″ + 0.0002225″ t. This value is also liable +to a very small change. The nutation of the obliquity at time +1850 + t is given by the formula 23° 27′ 32.0″ − 0.47″ t. Complete +expressions for these functions are given in Newcomb’s +<i>Spherical Astronomy</i> (1908), and in the <i>Nautical Almanac</i>.</p> + +<p>The variation of the <i>line of apsides</i> is the name given to the +motion of the major axis of the Earth’s orbit along the ecliptic. +It is due to the general influence of the planets, and the revolution +is effected in 21,000 years.</p> + +<p>The variation of the eccentricity denotes an oscillation of the +form of the Earth’s orbit between a circle and ellipse. This +followed the mathematical researches of Lagrange and Leverrier. +It was suggested by Sir John Herschel in 1830 that this variation +might occasion great climatic changes, and James Croll developed +the theory as affording a solution of the glacial periods in geology +(<i>q.v.</i>).</p> + +<p><i>Variation of Latitude.</i>—Another secular motion of the Earth +is due to the fact that the axis of rotation is not rigidly fixed +within it, but its polar extremities wander in a circle of about +50 ft. diameter. This oscillation brings about a variability +in terrestrial latitudes, hence the name. Euler showed mathematically +that such an oscillation existed, and, making certain +assumptions as to the rigidity of the Earth, deduced that its +period was 305 days; S.C. Chandler, from 1890 onwards, +deduced from observations of the stars a period of 428 days; +and Simon Newcomb explained the deviation of these periods +by pointing out that Euler’s assumption of a perfectly rigid +Earth is not in accordance with fact. For details of this intricate +subject see the articles <span class="sc"><a href="#artlinks">Latitude</a></span> and <span class="sc"><a href="#artlinks">Earth, Figure of the</a></span>.</p> + +<p>4. <i>Evolution and Age.</i>—In its earliest history the mass now +consolidated as the Earth and Moon was part of a vast nebulous +aggregate, which in the course of time formed a central nucleus—our +Sun—which shed its outer layers in such a manner as to +form the solar system (see <span class="sc"><a href="#artlinks">Nebular Theory</a></span>). The moon may +have been formed from the Earth in a similar manner, but the +theory of tidal friction suggests the elongation of the Earth along +an equatorial axis to form a pear-shaped figure, and that in the +course of time the protuberance shot off to form the Moon +(see <span class="sc"><a href="#artlinks">Tide</a></span>). The age of the Earth has been investigated from +several directions, as have also associated questions related to +climatic changes, internal temperature, orientation of the land +and water (permanence of oceans and continents), &c. These +problems are treated in the articles <span class="sc"><a href="#artlinks">Geology</a></span> and <span class="sc"><a href="#artlinks">Geography</a></span>.</p> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1b" id="ft1b" href="#fa1b"><span class="fn">1</span></a> Aristotle regarded the Earth as having an upper inhabited half +and a lower uninhabited one, and the air on the lower half as tending +to flow upwards through the Earth. The obstruction of this passage +brought about an accumulation of air within the Earth, and the +increased pressure may occasion oscillations of the surface, which +may be so intense as to cause earthquakes.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EARTH, FIGURE OF THE.<a name="ar41" id="ar41"></a></span> The determination of the figure +of the earth is a problem of the highest importance in astronomy, +inasmuch as the diameter of the earth is the unit to which all +celestial distances must be referred.</p> + +<p class="pt2 center"><i>Historical.</i></p> + +<p>Reasoning from the uniform level appearance of the horizon, +the variations in altitude of the circumpolar stars as one travels +towards the north or south, the disappearance of a ship standing +out to sea, and perhaps other phenomena, the earliest astronomers +regarded the earth as a sphere, and they endeavoured +to ascertain its dimensions. Aristotle relates that the mathematicians +had found the circumference to be 400,000 stadia (about +46,000 miles). But Eratosthenes (<i>c.</i> 250 <span class="scs">B.C.</span>) appears to have +been the first who entertained an accurate idea of the principles +on which the determination of the figure of the earth really depends, +and attempted to reduce them to practice. His results +were very inaccurate, but his method is the same as that which is +followed at the present day—depending, in fact, on the comparison +of a line measured on the earth’s surface with the corresponding +arc of the heavens. He observed that at Syene in Upper Egypt, +on the day of the summer solstice, the sun was exactly vertical, +whilst at Alexandria at the same season of the year its zenith +distance was 7° 12′, or one-fiftieth of the circumference of a +circle. He assumed that these places were on the same meridian; +and, reckoning their distance apart as 5000 stadia, he inferred +that the circumference of the earth was 250,000 stadia (about +29,000 miles). A similar attempt was made by Posidonius, who +adopted a method which differed from that of Eratosthenes only +in using a star instead of the sun. He obtained 240,000 stadia +(about 27,600 miles) for the circumference. Ptolemy in his +<i>Geography</i> assigns the length of the degree as 500 stadia.</p> + +<p>The Arabs also investigated the question of the earth’s magnitude. +The caliph Abdallah al Mamun (<span class="scs">A.D.</span> 814), having fixed +on a spot in the plains of Mesopotamia, despatched one company +of astronomers northwards and another southwards, measuring +the journey by rods, until each found the altitude of the pole +to have changed one degree. But the result of this measurement +does not appear to have been very satisfactory. From this +time the subject seems to have attracted no attention until about +1500, when Jean Fernel (1497-1558), a Frenchman, measured +a distance in the direction of the meridian near Paris by counting +the number of revolutions of the wheel of a carriage. His +astronomical observations were made with a triangle used as a +quadrant, and his resulting length of a degree was very near the +truth.</p> + +<p>Willebrord Snell<a name="fa1c" id="fa1c" href="#ft1c"><span class="sp">1</span></a> substituted a chain of triangles for actual +linear measurement. He measured his base line on the frozen +surface of the meadows near Leiden, and measured the angles of +his triangles, which lay between Alkmaar and Bergen-op-Zoom, +with a quadrant and semicircles. He took the precaution of +<span class="pagenum"><a name="page802" id="page802"></a>802</span> +comparing his standard with that of the French, so that his +result was expressed in toises (the length of the toise is about +6.39 English ft.). The work was recomputed and reobserved +by P. von Musschenbroek in 1729. In 1637 an Englishman, +Richard Norwood, published a determination of the figure of the +earth in a volume entitled <i>The Seaman’s Practice, contayning +a Fundamentall Probleme in Navigation experimentally verified, +namely, touching the Compasse of the Earth and Sea and the +quantity of a Degree in our English Measures</i>. He observed on +the 11th of June 1633 the sun’s meridian altitude in London +as 62° 1′, and on the 6th of June 1635, his meridian altitude +in York as 59° 33′. He measured the distance between these +places partly with a chain and partly by pacing. By this means, +through compensation of errors, he arrived at 367,176 ft. for the +degree—a very fair result.</p> + +<p>The application of the telescope to angular instruments was +the next important step. Jean Picard was the first who in 1669, +with the telescope, using such precautions as the nature of the +operation requires, measured an arc of meridian. He measured +with wooden rods a base line of 5663 toises, and a second or base +of verification of 3902 toises; his triangulation extended from +Malvoisine, near Paris, to Sourdon, near Amiens. The angles +of the triangles were measured with a quadrant furnished with +a telescope having cross-wires. The difference of latitude of the +terminal stations was determined by observations made with a +sector on a star in Cassiopeia, giving 1° 22′ 55″ for the amplitude. +The terrestrial measurement gave 78,850 toises, whence he inferred +for the length of the degree 57,060 toises.</p> + +<p>Hitherto geodetic observations had been confined to the +determination of the magnitude of the earth considered as a +sphere, but a discovery made by Jean Richer (d. 1696) turned +the attention of mathematicians to its deviation from a spherical +form. This astronomer, having been sent by the Academy of +Sciences of Paris to the island of Cayenne, in South America, +for the purpose of investigating the amount of astronomical +refraction and other astronomical objects, observed that his +clock, which had been regulated at Paris to beat seconds, lost +about two minutes and a half daily at Cayenne, and that in order +to bring it to measure mean solar time it was necessary to shorten +the pendulum by more than a line (about <span class="spp">1</span>⁄<span class="suu">12</span>th of an in.). This +fact, which was scarcely credited till it had been confirmed by +the subsequent observations of Varin and Deshayes on the coasts +of Africa and America, was first explained in the third book of +Newton’s <i>Principia</i>, who showed that it could only be referred +to a diminution of gravity arising either from a protuberance of +the equatorial parts of the earth and consequent increase of the +distance from the centre, or from the counteracting effect of the +centrifugal force. About the same time (1673) appeared Christian +Huygens’ <i>De Horologio Oscillatorio</i>, in which for the first time +were found correct notions on the subject of centrifugal force. +It does not, however, appear that they were applied to the +theoretical investigation of the figure of the earth before the +publication of Newton’s <i>Principia</i>. In 1690 Huygens published +his <i>De Causa Gravitatis</i>, which contains an investigation of the +figure of the earth on the supposition that the attraction of every +particle is towards the centre.</p> + +<p>Between 1684 and 1718 J. and D. Cassini, starting from +Picard’s base, carried a triangulation northwards from Paris +to Dunkirk and southwards from Paris to Collioure. They +measured a base of 7246 toises near Perpignan, and a somewhat +shorter base near Dunkirk; and from the northern portion of +the arc, which had an amplitude of 2° 12′ 9″, obtained for the +length of a degree 56,960 toises; while from the southern portion, +of which the amplitude was 6° 18′ 57″, they obtained 57,097 +toises. The immediate inference from this was that, the degree +diminishing with increasing latitude, the earth must be a prolate +spheroid. This conclusion was totally opposed to the theoretical +investigations of Newton and Huygens, and accordingly the +Academy of Sciences of Paris determined to apply a decisive +test by the measurement of arcs at a great distance from each +other—one in the neighbourhood of the equator, the other in a +high latitude. Thus arose the celebrated expeditions of the French +academicians. In May 1735 Louis Godin, Pierre Bouguer and +Charles Marie de la Condamine, under the auspices of Louis XV., +proceeded to Peru, where, assisted by two Spanish officers, after +ten years of laborious exertion, they measured an arc of 3° 7′, +the northern end near the equator. The second party consisted +of Pierre Louis Moreau de Maupertuis, Alexis Claude Clairault, +Charles Étienne Louis Camus, Pierre Charles Lemonnier, and +Reginaud Outhier, who reached the Gulf of Bothnia in July 1736; +they were in some respects more fortunate than the first party, +inasmuch as they completed the measurement of an arc near the +polar circle of 57′ amplitude and returned within sixteen months +from the date of their departure.</p> + +<p>The measurement of Bouguer and De la Condamine was +executed with great care, and on account of the locality, as well +as the manner in which all the details were conducted, it has +always been regarded as a most valuable determination. The +southern limit was at Tarqui, the northern at Cotchesqui. A base +of 6272 toises was measured in the vicinity of Quito, near the +northern extremity of the arc, and a second base of 5260 toises +near the southern extremity. The mountainous nature of the +country made the work very laborious, in some cases the difference +of heights of two neighbouring stations exceeding 1 mile; +and they had much trouble with their instruments, those with +which they were to determine the latitudes proving untrustworthy. +But they succeeded by simultaneous observations of +the same star at the two extremities of the arc in obtaining very +fair results. The whole length of the arc amounted to 176,945 +toises, while the difference of latitudes was 3° 7′ 3″. In consequence +of a misunderstanding that arose between De la Condamine +and Bouguer, their operations were conducted separately, +and each wrote a full account of the expedition. Bouguer’s +book was published in 1749; that of De la Condamine in 1751. +The toise used in this measure was afterwards regarded as the +standard toise, and is always referred to as the <i>Toise of Peru</i>.</p> + +<p>The party of Maupertuis, though their work was quickly +despatched, had also to contend with great difficulties. Not +being able to make use of the small islands in the Gulf of Bothnia +for the trigonometrical stations, they were forced to penetrate +into the forests of Lapland, commencing operations at Torneå, +a city situated on the mainland near the extremity of the gulf. +From this, the southern extremity of their arc, they carried a +chain of triangles northward to the mountain Kittis, which they +selected as the northern terminus. The latitudes were determined +by observations with a sector (made by George Graham) of the +zenith distance of α and δ Draconis. The base line was measured +on the frozen surface of the river Torneå about the middle of the +arc; two parties measured it separately, and they differed by +about 4 in. The result of the whole was that the difference of +latitudes of the terminal stations was 57′ 29″ .6, and the length +of the arc 55,023 toises. In this expedition, as well as in that to +Peru, observations were made with a pendulum to determine +the force of gravity; and these observations coincided with the +geodetic results in proving that the earth was an oblate and not +prolate spheroid.</p> + +<p>In 1740 was published in the Paris <i>Mémoires</i> an account, by +Cassini de Thury, of a remeasurement by himself and Nicolas +Louis de Lacaille of the meridian of Paris. With a view to +determine more accurately the variation of the degree along the +meridian, they divided the distance from Dunkirk to Collioure +into four partial arcs of about two degrees each, by observing the +latitude at five stations. The results previously obtained by +J. and D. Cassini were not confirmed, but, on the contrary, +the length of the degree derived from these partial arcs showed +on the whole an increase with an increasing latitude. Cassini +and Lacaille also measured an arc of parallel across the mouth +of the Rhone. The difference of time of the extremities was +determined by the observers at either end noting the instant +of a signal given by flashing gunpowder at a point near the +middle of the arc.</p> + +<p>While at the Cape of Good Hope in 1752, engaged in various +astronomical observations, Lacaille measured an arc of meridian +of 1° 13′ 17″, which gave him for the length of the degree 57,037 +<span class="pagenum"><a name="page803" id="page803"></a>803</span> +toises—an unexpected result, which has led to the remeasurement +of the arc by Sir Thomas Maclear (see <span class="sc"><a href="#artlinks">Geodesy</a></span>).</p> + +<p>Passing over the measurements made between Rome and +Rimini and on the plains of Piedmont by the Jesuits Ruggiero +Giuseppe Boscovich and Giovanni Battista Beccaria, and also the +arc measured with deal rods in North America by Charles Mason +and Jeremiah Dixon, we come to the commencement of the +English triangulation. In 1783, in consequence of a representation +from Cassini de Thury on the advantages that would accrue +from the geodetic connexion of Paris and Greenwich, General +William Roy was, with the king’s approval, appointed by the +Royal Society to conduct the operations on the part of England, +Count Cassini, Méchain and Delambre being appointed on the +French side. A precision previously unknown was attained +by the use of Ramsden’s theodolite, which was the first to make +the spherical excess of triangles measurable. The wooden rods +with which the first base was measured were replaced by glass +rods, which were afterwards rejected for the steel chain of +Ramsden. (For further details see <i>Account of the Trigonometrical +Survey of England and Wales</i>.)</p> + +<p>Shortly after this, the National Convention of France, having +agreed to remodel their system of weights and measures, chose for +their unit of length the ten-millionth part of the meridian +quadrant. In order to obtain this length precisely, the remeasurement +of the French meridian was resolved on, and +deputed to J.B.J. Delambre and Pierre François André Méchain. +The details of this operation will be found in the <i>Base du système +métrique décimale</i>. The arc was subsequently extended by +Jean Baptiste Biot and Dominique François Jean Arago to +the island of Iviza. Operations for the connexion of England +with the continent of Europe were resumed in 1821 to 1823 by +Henry Kater and Thomas Frederick Colby on the English side, +and F.J.D. Arago and Claude Louis Mathieu on the French.</p> + +<p>The publication in 1838 of Friedrich Wilhelm Bessel’s <i>Gradmessung +in Ostpreussen</i> marks an era in the science of geodesy. +Here we find the method of least squares applied to the calculation +of a network of triangles and the reduction of the +observations generally. The systematic manner in which all +the observations were taken with the view of securing final +results of extreme accuracy is admirable. The triangulation, +which was a small one, extended about a degree and a half +along the shores of the Baltic in a N.N.E. direction. The +angles were observed with theodolites of 12 and 15 in. diameter, +and the latitudes determined by means of the transit instrument +in the prime vertical—a method much used in Germany. +(The base apparatus is described in the article <span class="sc"><a href="#artlinks">Geodesy</a></span>.)</p> + +<p>The principal triangulation of Great Britain and Ireland, +which was commenced in 1783 under General Roy, for the more +immediate purpose of connecting the observatories of Greenwich +and Paris, had been gradually extended, under the successive +direction of Colonel E. Williams, General W. Mudge, General +T.F. Colby, Colonel L.A. Hall, and Colonel Sir Henry James; +it was finished in 1851. The number of stations is about 250. +At 32 of these the latitudes were determined with Ramsden’s +and Airy’s zenith sectors. The theodolites used for this work +were, in addition to the two great theodolites of Ramsden which +were used by General Roy and Captain Kater, a smaller theodolite +of 18 in. diameter by the same mechanician, and another +of 24 in. diameter by Messrs Troughton and Simms. Observations +for determination of absolute azimuth were made with +those instruments at a large number of stations; the stars +α, δ, and λ Ursae Minoris and 51 Cephei being those observed +always at the greatest azimuths. At six of these stations the +probable error of the result is under 0.4″, at twelve under 0.5″, +at thirty-four under 0.7″: so that the absolute azimuth of the +whole network is determined with extreme accuracy. Of the +seven base lines which have been measured, five were by means +of steel chains and two with Colby’s compensation bars (see +<span class="sc"><a href="#artlinks">Geodesy</a></span>). The triangulation was computed by least squares. +The total number of equations of condition for the triangulation +is 920; if therefore the whole had been reduced in one mass, as +it should have been, the solution of an equation of 920 unknown +quantities would have occurred as a part of the work. To +avoid this an approximation was resorted to; the triangulation +was divided into twenty-one parts or figures; four of these, +not adjacent, were first adjusted by the method explained, and +the corrections thus determined in these figures carried into +the equations of condition of the adjacent figures. The average +number of equations in a figure is 44; the largest equation +is one of 77 unknown quantities. The vertical limb of Airy’s +zenith sector is read by four microscopes, and in the complete +observation of a star there are 10 micrometer readings and 12 +level readings. The instrument is portable; and a complete +determination of latitude, affected with the mean of the declination +errors of two stars, is effected by two micrometer readings +and four level readings. The observation consists in measuring +with the telescope micrometer the difference of zenith distances +of two stars which cross the meridian, one to the north and +the other to the south of the observer at zenith distances which +differ by not much more than 10′ or 15′, the interval of the times of +transit being not less than one nor more than twenty minutes. +The advantages are that, with simplicity in the construction of the +instrument and facility in the manipulation, refraction is eliminated +(or nearly so, as the stars are generally selected within +25° of the zenith), and there is no large divided circle. The +telescope, which is counterpoised on one side of the vertical +axis, has a small circle for finding, and there is also a small +horizontal circle. This instrument is universally used in +American geodesy.</p> + +<div class="condensed"> +<p>The principal work containing the methods and results of these +operations was published in 1858 with the title “Ordnance Trigonometrical +Survey of Great Britain and Ireland. Account of the +observations and calculations of the principal triangulation and of +the figure, dimensions and mean specific gravity of the earth as +derived therefrom. Drawn up by Captain Alexander Ross Clarke, +R.E., F.R.A.S., under the direction of Lieut.-Colonel H. James, +R.E., F.R.S., M.R.I.A., &c.” A supplement appeared in 1862: +“Extension of the Triangulation of the Ordnance Survey into +France and Belgium, with the measurement of an arc of parallel in +52° N. from Valentia in Ireland to Mount Kemmel in Belgium. +Published by ... Col. Sir Henry James.”</p> +</div> + +<p>Extensive operations for surveying India and determining +the figure of the earth were commenced in 1800. Colonel W. +Lambton started the great meridian arc at Punnae in latitude +8° 9′, and, following generally the methods of the English survey, +he carried his triangulation as far north as 20° 30′. The work +was continued by Sir George (then Captain) Everest, who carried +it to the latitude of 29° 30′. Two admirable volumes by Sir +George Everest, published in 1830 and in 1847, give the details +of this undertaking. The survey was afterwards prosecuted by +Colonel T.T. Walker, R.E., who made valuable contributions +to geodesy. The working out of the Indian chains of triangle +by the method of least squares presents peculiar difficulties, +but, enormous in extent as the work was, it has been thoroughly +carried out. The ten base lines on which the survey depends +were measured with Colby’s compensation bars.</p> + +<div class="condensed"> +<p>The survey is detailed in eighteen volumes, published at Dehra +Dun, and entitled <i>Account of the Operations of the Great Trigonometrical +Survey of India</i>. Of these the first nine were published +under the direction of Colonel Walker; and the remainder by +Colonels Strahan and St G.C. Gore, Major S.G. Burrard and others. +Vol. i., 1870, treats of the base lines; vol. ii., 1879, history and general +descriptions of the principal triangulation and of its reduction; +vol. v., 1879, pendulum operations (Captains T.P. Basevi and W.T. +Heaviside); vols. xi., 1890, and xviii., 1906, latitudes; vols. ix., 1883, +x., 1887, xv., 1893, longitudes; vol. xvii., 1901, the Indo-European +longitude-arcs from Karachi to Greenwich. The other volumes contain +the triangulations.</p> +</div> + +<p>In 1860 Friedrich Georg Wilhelm Struve published his <i>Arc du +méridien de 25° 20′ entre le Danube et la Mer Glaciale mesuré +depuis 1816 jusqu’en 1855</i>. The latitudes of the thirteen astronomical +stations of this arc were determined partly with vertical +circles and partly by means of the transit instrument in the prime +vertical. The triangulation, a great part of which, however, +is a simple chain of triangles, is reduced by the method of least +squares, and the probable errors of the resulting distances of +parallels is given; the probable error of the whole arc in length +is ± 6.2 toises. Ten base lines were measured. The sum of the +<span class="pagenum"><a name="page804" id="page804"></a>804</span> +lengths of the ten measured bases is 29,863 toises, so that the +average length of a base line is 19,100 ft. The azimuths were +observed at fourteen stations. In high latitudes the determination +of the meridian is a matter of great difficulty; nevertheless +the azimuths at all the northern stations were successfully +determined,—the probable error of the result at Fuglenaes being +± 0″.53.</p> + +<p>Before proceeding with the modern developments of geodetic +measurements and their application to the figure of the earth, +we must discuss the “mechanical theory,” which is indispensable +for a full understanding of the subject.</p> + +<p class="pt2 center"><i>Mechanical Theory.</i></p> + +<p>Newton, by applying his theory of gravitation, combined +with the so-called centrifugal force, to the earth, and assuming +that an oblate ellipsoid of rotation is a form of equilibrium for +a homogeneous fluid rotating with uniform angular velocity, +obtained the ratio of the axes 229:230, and the law of variation +of gravity on the surface. A few years later Huygens published +an investigation of the figure of the earth, supposing the attraction +of every particle to be towards the centre of the earth, +obtaining as a result that the proportion of the axes should be +578 : 579. In 1740 Colin Maclaurin, in his <i>De causa physica +fluxus et refluxus maris</i>, demonstrated that the oblate ellipsoid +of revolution is a figure which satisfies the conditions of equilibrium +in the case of a revolving homogeneous fluid mass, whose +particles attract one another according to the law of the inverse +square of the distance; he gave the equation connecting the +ellipticity with the proportion of the centrifugal force at the +equator to gravity, and determined the attraction on a particle +situated anywhere on the surface of such a body. In 1743 +Clairault published his <i>Théorie de la figure de la terre</i>, which +contains a remarkable theorem (“Clairault’s Theorem”), establishing +a relation between the ellipticity of the earth and the +variation of gravity from the equator to the poles. Assuming +that the earth is composed of concentric ellipsoidal strata having +a common axis of rotation, each stratum homogeneous in itself, +but the ellipticities and densities of the successive strata varying +according to any law, and that the superficial stratum has the +same form as if it were fluid, he proved that</p> + +<table class="math0" summary="math"> +<tr><td>g′ − g</td> <td rowspan="2">+ e =</td> +<td>5</td> <td rowspan="2">m,</td></tr> +<tr><td class="denom">g</td> <td class="denom">2</td></tr></table> + +<p class="noind">where g, g′ are the amounts of gravity at the equator and at +the pole respectively, e the ellipticity of the meridian (or “flattening”), +and m the ratio of the centrifugal force at the equator to g. +He also proved that the increase of gravity in proceeding from +the equator to the poles is as the square of the sine of the latitude. +This, taken with the former theorem, gives the means of determining +the earth’s ellipticity from observation of the relative +force of gravity at any two places. P.S. Laplace, who devoted +much attention to the subject, remarks on Clairault’s work that +“the importance of all his results and the elegance with which +they are presented place this work amongst the most beautiful +of mathematical productions” (Isaac Todhunter’s <i>History of the +Mathematical Theories of Attraction and the Figure of the Earth</i>, +vol. i. p. 229).</p> + +<p>The problem of the figure of the earth treated as a question +of mechanics or hydrostatics is one of great difficulty, and it +would be quite impracticable but for the circumstance that +the surface differs but little from a sphere. In order to express +the forces at any point of the body arising from the attraction +of its particles, the form of the surface is required, but this form +is the very one which it is the object of the investigation to +discover; hence the complexity of the subject, and even with +all the present resources of mathematicians only a partial and +imperfect solution can be obtained.</p> + +<div class="condensed"> +<p>We may here briefly indicate the line of reasoning by which some +of the most important results may be obtained. If X, Y, Z be the +components parallel to three rectangular axes of the forces acting +on a particle of a fluid mass at the point x, y, z, then, p being the +pressure there, and ρ the density,</p> + +<p class="center">dp = ρ(Xdx + Ydy + Zdz);</p> + +<p>and for equilibrium the necessary conditions are, that ρ(Xdx + +Ydy + Zdz) be a complete differential, and at the free surface Xdx + +Ydy + Zdz = 0. This equation implies that the resultant of the forces +is normal to the surface at every point, and in a homogeneous fluid +it is obviously the differential equation of all surfaces of equal pressure. +If the fluid be heterogeneous then it is to be remarked that for +forces of attraction according to the ordinary law of gravitation, +if X, Y, Z be the components of the attraction of a mass whose +potential is V, then</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Xdx + Ydy + Zdz =</td> <td>dV</td> +<td rowspan="2">dx +</td> <td>dV</td> +<td rowspan="2">dy +</td> <td>dV</td> +<td rowspan="2">dz,</td></tr> +<tr><td class="denom">dx</td> <td class="denom">dy</td> <td class="denom">dz</td></tr></table> + +<p class="noind">which is a complete differential. And in the case of a fluid rotating +with uniform velocity, in which the so-called centrifugal force enters +as a force acting on each particle proportional to its distance from +the axis of rotation, the corresponding part of Xdx + Ydy + Zdz is +obviously a complete differential. Therefore for the forces with +which we are now concerned Xdx + Ydy + Zdz = dU, where U is some +function of x, y, z, and it is necessary for equilibrium that dp = ρdU +be a complete differential; that is, ρ must be a function of U or a +function of p, and so also p a function of U. So that dU = 0 is the +differential equation of surfaces of equal pressure and density.</p> + +<p>We may now show that a homogeneous fluid mass in the form of +an oblate ellipsoid of revolution having a uniform velocity of rotation +can be in equilibrium. It may be proved that the attraction of the +ellipsoid x² + y² + z²(1 + ε²) = c²(1 + ε²); upon a particle P of its mass at +x, y, z has for components</p> + +<p class="center">X = − Ax, Y = − Ay, Z = − Cz,</p> + +<p class="noind">where</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">A = 2πk²ρ<span class="f150">(</span></td> <td>1 + ε²</td> +<td rowspan="2">tan<span class="sp">−1</span>ε −</td> <td>1</td> +<td rowspan="2"><span class="f150">)</span>,</td></tr> +<tr><td class="denom">ε³</td> <td class="denom">ε²</td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">C = 4πk²ρ<span class="f150">(</span></td> <td>1 + ε²</td> +<td rowspan="2">−</td> <td>1 + ε²</td> +<td rowspan="2">tan<span class="sp">−1</span>ε<span class="f150">)</span>,</td></tr> +<tr><td class="denom">ε²</td> <td class="denom">ε³</td></tr></table> + +<p class="noind">and k² the constant of attraction. Besides the attraction of the mass +of the ellipsoid, the centrifugal force at P has for components ++ xω², + yω², 0; then the condition of fluid equilibrium is</p> + +<p class="center">(A − ω²)xdx + (A − ω²)ydy + Czdz = 0,</p> + +<p class="noind">which by integration gives</p> + +<p class="center">(A − ω²)(x² + y²) + Cz² = constant.</p> + +<p class="noind">This is the equation of an ellipsoid of rotation, and therefore the +equilibrium is possible. The equation coincides with that of the surface +of the fluid mass if we make</p> + +<p class="center">A − ω² = C / (1 + ε²),</p> + +<p class="noind">which gives</p> + +<table class="math0" summary="math"> +<tr><td>ω²</td> <td rowspan="2">=</td> +<td>3 + ε²</td> <td rowspan="2">tan<span class="sp">−1</span>ε −</td> +<td>3</td> <td rowspan="2">.</td></tr> +<tr><td class="denom">2πk²ρ</td> <td class="denom">ε³</td> +<td class="denom">ε²</td></tr></table> + +<p>In the case of the earth, which is nearly spherical, we obtain by +expanding the expression for ω² in powers of ε², rejecting the higher +powers, and remarking that the ellipticity e = ½ε²,</p> + +<p class="center">ω² / 2πk²ρ = 4ε² / 15 = 8e / 15.</p> + +<p>Now if m be the ratio of the centrifugal force to the intensity of +gravity at the equator, and a = c(1 + e), then</p> + +<p class="center">m = aω² / <span class="spp">4</span>⁄<span class="suu">3</span>πk²ρa, ∴ ω² / 2πk²ρ = <span class="spp">2</span>⁄<span class="suu">3</span>m.</p> + +<p>In the case of the earth it is a matter of observation that +m = 1/289, hence the ellipticity</p> + +<p class="center">e = 5m / 4 = 1/231,</p> + +<p class="noind">so that the ratio of the axes on the supposition of a homogeneous +fluid earth is 230 : 231, as stated by Newton.</p> + +<p>Now, to come to the case of a heterogeneous fluid, we shall assume +that its surfaces of equal density are spheroids, concentric and +having a common axis of rotation, and that the ellipticity of these +surfaces varies from the centre to the outer surface, the density also +varying. In other words, the body is composed of homogeneous +spheroidal shells of variable density and ellipticity. On this supposition +we shall express the attraction of the mass upon a particle in +its interior, and then, taking into account the centrifugal force, form +the equation expressing the condition of fluid equilibrium. The +attraction of the homogeneous spheroid x² + y² + z²(1 + 2e) = c²(1 + 2e), +where e is the ellipticity (of which the square is neglected), on an +internal particle, whose co-ordinates are x = f, y = 0, z = h, has for its +x and z components</p> + +<p class="center">X′ = −<span class="spp">4</span>⁄<span class="suu">3</span>πk²ρf(1 − <span class="spp">2</span>⁄<span class="suu">5</span>e),   Z′ = −<span class="spp">4</span>⁄<span class="suu">3</span>πk²ρh(1 + <span class="spp">4</span>⁄<span class="suu">5</span>e),</p> + +<p class="noind">the Y component being of course zero. Hence we infer that the attraction +of a shell whose inner surface has an ellipticity e, and its +outer surface an ellipticity e + de, the density being ρ, is expressed by</p> + +<p class="center">dX′ = <span class="spp">4</span>⁄<span class="suu">3</span> · <span class="spp">2</span>⁄<span class="suu">5</span>πk²ρf de,   dZ′ = −<span class="spp">4</span>⁄<span class="suu">3</span> · <span class="spp">4</span>⁄<span class="suu">5</span>πk²ρh de.</p> + +<p class="noind">To apply this to our heterogeneous spheroid; if we put c<span class="su">1</span> for the +semiaxis of that surface of equal density on which is situated the +attracted point P, and c<span class="su">0</span> for the semiaxis of the outer surface, the +attraction of that portion of the body which is exterior to P, namely, +of all the shells which enclose P, has for components</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">X<span class="su">0</span> = <span class="spp">8</span>⁄<span class="suu">15</span>πk²f <span class="f150">∫</span><span class="sp1">c0</span><span class="su1">c1</span> ρ</td> <td>de</td> +<td rowspan="2">dc,   Z<span class="su">0</span> = <span class="spp">16</span>⁄<span class="suu">15</span>πk²h <span class="f150">∫</span><span class="sp1">c0</span><span class="su1">c1</span> ρ</td> <td>de</td> +<td rowspan="2">dc,</td></tr> +<tr><td class="denom">dc</td> <td class="denom">dc</td></tr></table> + +<p><span class="pagenum"><a name="page805" id="page805"></a>805</span></p> + +<p class="noind">both e and ρ being functions of c. Again the attraction of a homogeneous +spheroid of density ρ on an <i>external</i> point f, h has the +components</p> + +<p class="center">X″ = −<span class="spp">4</span>⁄<span class="suu">3</span>πk²ρfr<span class="sp">−3</span> {c³(1 + 2e) − λec<span class="sp">5</span>},</p> + +<p class="center">Z″ = −<span class="spp">4</span>⁄<span class="suu">3</span>πk²ρhr<span class="sp">−3</span> {c³(1 + 2e) − λ′ec<span class="sp">5</span>},</p> + +<p class="center">where λ = <span class="spp">3</span>⁄<span class="suu">5</span>(4h² − f²) / r<span class="sp">4</span>,   λ′ = <span class="spp">3</span>⁄<span class="suu">5</span>(2h² − 3f²) / r<span class="sp">4</span>,   and r² = f² + h².</p> + +<p class="noind">Now e being considered a function of c, we can at once express the +attraction of a shell (density ρ) contained between the surface defined +by c + dc, e + de and that defined by c, e upon an external point; the +differentials with respect to c, viz. dX″ dZ″, must then be integrated +with ρ under the integral sign as being a function of c. The integration +will extend from c = 0 to c = c<span class="su">1</span>. Thus the components of the +attraction of the heterogeneous spheroid upon a particle within its +mass, whose co-ordinates are f, 0, h, are</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">X = −<span class="spp">4</span>⁄<span class="suu">3</span>πk²f <span class="f150">[</span></td> <td>1</td> +<td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρ d{c³(1 + 2e)} −</td> <td>λ</td> +<td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρ d(ec<span class="sp">5</span>) + <span class="spp">2</span>⁄<span class="suu">5</span> + <span class="f150">∫</span><span class="sp1">c0</span><span class="su1">c1</span> ρ de<span class="f150">]</span>,</td></tr> +<tr><td class="denom">r<span class="sp">3</span></td> <td class="denom">r<span class="sp">3</span></td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Z = −<span class="spp">4</span>⁄<span class="suu">3</span>πk²h <span class="f150">[</span></td> <td>1</td> +<td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρ d{c³(1 + 2e)} −</td> <td>λ′</td> +<td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρ d(ec<span class="sp">5</span>) + <span class="spp">4</span>⁄<span class="suu">5</span> + <span class="f150">∫</span><span class="sp1">c0</span><span class="su1">c1</span> ρ de<span class="f150">]</span>.</td></tr> +<tr><td class="denom">r<span class="sp">3</span></td> <td class="denom">r<span class="sp">3</span></td></tr></table> + +<p class="noind">We take into account the rotation of the earth by adding the centrifugal +force fω² = F to X. Now, the surface of constant density upon +which the point f, 0, h is situated gives (1 − 2e) fdf + hdh = 0; and the +condition of equilibrium is that (X + F)df + Zdh = 0. Therefore,</p> + +<p class="center">(X + F) h = Zf (1 − 2e),</p> + +<p class="noind">which, neglecting small quantities of the order e² and putting +ω²t² = 4π²k², gives</p> + +<table class="math0" summary="math"> +<tr><td>2e</td> <td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρd{c³(1 + 2e)} −</td> +<td>6</td> <td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρd(ec<span class="sp">5</span>) −</td> +<td>6</td> <td rowspan="2"><span class="f150">∫</span><span class="sp1">c1</span><span class="su1">0</span> ρde =</td> +<td>3π</td> <td rowspan="2">.</td></tr> +<tr><td class="denom">r³</td> <td class="denom">5r<span class="sp">5</span></td> +<td class="denom">5</td> <td class="denom">t²</td></tr></table> + +<p class="noind">Here we must now put c for c<span class="su">1</span>, c for r; and 1 + 2e under the first +integral sign may be replaced by unity, since small quantities of the +second order are neglected. Two differentiations lead us to the +following very important differential equation (Clairault):</p> + +<table class="math0" summary="math"> +<tr><td>d²e</td> <td rowspan="2">+</td> +<td>2ρc²</td> <td rowspan="2">·</td> +<td>de</td> <td rowspan="2">+ <span class="f150">(</span></td> +<td>2ρc</td> <td rowspan="2">−</td> +<td>6</td> <td rowspan="2"><span class="f150">)</span> e = 0.</td></tr> +<tr><td class="denom">dc²</td> <td class="denom">∫ρc² dc</td> +<td class="denom">dc</td> <td class="denom">∫ρc² dc</td> +<td class="denom">c²</td></tr></table> + +<p>When ρ is expressed in terms of c, this equation can be integrated. +We infer then that a rotating spheroid of very small ellipticity, composed +of fluid homogeneous strata such as we have specified, will be +in equilibrium; and when the law of the density is expressed, the +law of the corresponding ellipticities will follow.</p> + +<p>If we put M for the mass of the spheroid, then</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M =</td> <td>4π</td> +<td rowspan="2"><span class="f150">∫</span><span class="sp1">c</span><span class="su2">0</span> ρd{c³(1 + 2e)};   and m =</td> <td>c³</td> +<td rowspan="2">·</td> <td>4π²</td> +<td rowspan="2">,</td></tr> +<tr><td class="denom">3</td> <td class="denom">M</td> +<td class="denom">t²</td></tr></table> + +<p class="noind">and putting c = c<span class="su">0</span> in the equation expressing the condition of equilibrium, +we find</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M(2e − m) =</td> <td>4</td> +<td rowspan="2">π ·</td> <td>6</td> +<td rowspan="2"><span class="f150">∫</span><span class="sp1">c</span><span class="su2">0</span> ρ d(ec<span class="sp">5</span>).</td></tr> +<tr><td class="denom">3</td> <td class="denom">5c²</td></tr></table> + +<p class="noind">Making these substitutions in the expressions for the forces at the +surface, and putting r/c = 1 + e − e(h/c)², we get</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">G cos φ =</td> <td>Mk²</td> +<td rowspan="2"><span class="f150">{</span>1 − e −</td> <td>3</td> +<td rowspan="2">m + <span class="f150">(</span></td> <td>5</td> +<td rowspan="2">m − 2e<span class="f150">)</span></td> <td>h²</td> +<td rowspan="2"><span class="f150">}</span></td> <td>f</td></tr> +<tr><td class="denom">ac</td> <td class="denom">2</td> +<td class="denom">2</td> <td class="denom">c²</td> +<td class="denom">c</td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">G sin φ =</td> <td>Mk²</td> +<td rowspan="2"><span class="f150">{</span>1 + e −</td> <td>3</td> +<td rowspan="2">m + <span class="f150">(</span></td> <td>5</td> +<td rowspan="2">m − 2e<span class="f150">)</span></td> <td>h²</td> +<td rowspan="2"><span class="f150">}</span></td> <td>h</td> <td rowspan="2">.</td></tr> +<tr><td class="denom">ac</td> <td class="denom">2</td> +<td class="denom">2</td> <td class="denom">c²</td> +<td class="denom">c</td></tr></table> + +<p class="noind">Here G is gravity in the latitude φ, and a the radius of the equator. +Since</p> + +<p class="center">sec φ = (c/f){1 + e + (eh²/c²)},</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">G =</td> <td>Mk²</td> +<td rowspan="2"><span class="f150">{</span>1 −</td> <td>3</td> +<td rowspan="2">m +<span class="f150">(</span></td> <td>5</td> +<td rowspan="2">m − e<span class="f150">)</span> sin² φ<span class="f150">}</span>,</td></tr> +<tr><td class="denom">ac</td> <td class="denom">2</td> +<td class="denom">2</td></tr></table> + +<p class="noind">an expression which contains the theorems we have referred to as +discovered by Clairault.</p> + +<p>The theory of the figure of the earth as a rotating ellipsoid has +been especially investigated by Laplace in his <i>Mécanique celeste</i>. +The principal English works are:—Sir George Airy, <i>Mathematical +Tracts</i>, a lucid treatment without the use of Laplace’s coefficients; +Archdeacon Pratt’s <i>Attractions and Figure of the Earth</i>; and +O’Brien’s <i>Mathematical Tracts</i>; in the last two Laplace’s coefficients +are used.</p> +</div> + +<p>In 1845 Sir G.G. Stokes (<i>Camb. Trans.</i> viii.; see also <i>Camb. +Dub. Math. Journ.</i>, 1849, iv.) proved that if the external form +of the sea—imagined to percolate the land by canals—be a +spheroid with small ellipticity, then the law of gravity is that +which we have shown above; his proof required no assumption +as to the ellipticity of the internal strata, or as to the past or +present fluidity of the earth. This investigation admits of being +regarded conversely, viz. as determining the elliptical form of +the earth from measurements of gravity; if G, the observed +value of gravity in latitude φ, be expressed in the form +G = g(1 + β sin² φ), where g is the value at the equator and β +a coefficient. In this investigation, the square and higher powers +of the ellipticity are neglected; the solution was completed +by F.R. Helmert with regard to the square of the ellipticity, +who showed that a term with sin² 2φ appeared (see Helmert, +<i>Geodäsie</i>, ii. 83). For the coefficient of this term, the gravity +measurements give a small but not sufficiently certain value; +we therefore assume a value which agrees best with the hypothesis +of the fluid state of the entire earth; this assumption is well +supported, since even at a depth of only 50 km. the pressure of +the superincumbent crust is so great that rocks become plastic, +and behave approximately as fluids, and consequently the crust +of the earth floats, to some extent, on the interior (even though +this may not be fluid in the usual sense of the word). This is +the geological theory of “Isostasis” (cf. <span class="sc"><a href="#artlinks">Geology</a></span>); it agrees +with the results of measurements of gravity (<i>vide infra</i>), and was +brought forward in the middle of the 19th century by J.H. +Pratt, who deduced it from observations made in India.</p> + +<p>The sin² 2φ term in the expression for G, and the corresponding +deviation of the meridian from an ellipse, have been analytically +established by Sir G.H. Darwin and E. Wiechert; earlier and +less complete investigations were made by Sir G.B. Airy and +O. Callandreau. In consequence of the sin² 2φ term, two parameters +of the level surfaces in the interior of the earth are to be +determined; for this purpose, Darwin develops two differential +equations in the place of the one by Clairault. By assuming +Roche’s law for the variation of the density in the interior of the +Earth, viz. ρ = ρ<span class="su">1</span> − k(c/c<span class="su">1</span>)², k being a coefficient, it is shown that +in latitude 45°, the meridian is depressed about 3¼ metres from +the ellipse, and the coefficient of the term sin²φ cos²φ (= ¼ sin²2φ) +is −0.0000295. According to Wiechert the earth is composed +of a kernel and a shell, the kernel being composed of material, +chiefly metallic iron, of density near 8.2, and the shell, about +900 miles thick, of silicates, &c., of density about 3.2. On this +assumption the depression in latitude 45° is 2¾ metres, and the +coefficient of sin²φ cos²φ is, in round numbers, −0.0000280.<a name="fa2c" id="fa2c" href="#ft2c"><span class="sp">2</span></a> +To this additional term in the formula for G, there corresponds +an extension of Clairault’s formula for the calculation of the +flattening from β with terms of the higher orders; this was first +accomplished by Helmert.</p> + +<p>For a long time the assumption of an ellipsoid with three +unequal axes has been held possible for the figure of the earth, in +consequence of an important theorem due to K.G. Jacobi, who +proved that for a homogeneous fluid in rotation a spheroid is not +the only form of equilibrium; an ellipsoid rotating round its +least axis may with certain proportions of the axes and a certain +time of revolution be a form of equilibrium.<a name="fa3c" id="fa3c" href="#ft3c"><span class="sp">3</span></a> It has been objected +to the figure of three unequal axes that it does not satisfy, in +the proportions of the axes, the conditions brought out in +Jacobi’s theorem (c : a < 1/√2). Admitting this, it has to be +noted, on the other hand, that Jacobi’s theorem contemplates a +homogeneous fluid, and this is certainly far from the actual +condition of our globe; indeed the irregular distribution of +continents and oceans suggests the possibility of a sensible +divergence from a perfect surface of revolution. We may, +however, assume the ellipsoid with three unequal axes to be an +interpolation form. More plausible forms are little adapted for +computation.<a name="fa4c" id="fa4c" href="#ft4c"><span class="sp">4</span></a> Consequently we now generally take the ellipsoid +of rotation as a basis, especially so because measurements of +gravity have shown that the deviation from it is but trifling.</p> + +<p class="pt2 center"><i>Local Attraction.</i></p> + +<p>In speaking of the figure of the earth, we mean the surface +of the sea imagined to percolate the continents by canals. That +<span class="pagenum"><a name="page806" id="page806"></a>806</span> +this surface should turn out, after precise measurements, to be +exactly an ellipsoid of revolution is <i>a priori</i> improbable. Although +it may be highly probable that originally the earth was +a fluid mass, yet in the cooling whereby the present crust has +resulted, the actual solid surface has been left most irregular +in form. It is clear that these irregularities of the visible surface +must be accompanied by irregularities in the mathematical +figure of the earth, and when we consider the general surface +of our globe, its irregular distribution of mountain masses, +continents, with oceans and islands, we are prepared to admit +that the earth may not be precisely any surface of revolution. +Nevertheless, there must exist some spheroid which agrees very +closely with the mathematical figure of the earth, and has the +same axis of rotation. We must conceive this figure as exhibiting +slight departures from the spheroid, the two surfaces cutting +one another in various lines; thus a point of the surface is +defined by its latitude, longitude, and its height above the +“spheroid of reference.” Calling this height N, then of the +actual magnitude of this quantity we can generally have no +information, it only obtrudes itself on our notice by its variations. +In the vicinity of mountains it may change sign in the space +of a few miles; N being regarded as a function of the latitude +and longitude, if its differential coefficient with respect to the +former be zero at a certain point, the normals to the two surfaces +then will lie in the prime vertical; if the differential coefficient +of N with respect to the longitude be zero, the two normals will +lie in the meridian; if both coefficients are zero, the normals +will coincide. The comparisons of terrestrial measurements with +the corresponding astronomical observations have always been +accompanied with discrepancies. Suppose A and B to be two +trigonometrical stations, and that at A there is a disturbing force +drawing the vertical through an angle δ, then it is evident that +the apparent zenith of A will be really that of some other place +A′, whose distance from A is rδ, when r is the earth’s radius; +and similarly if there be a disturbance at B of the amount δ′, +the apparent zenith of B will be really that of some other place +B′, whose distance from B is rδ′. Hence we have the discrepancy +that, while the geodetic measurements deal with the points +A and B, the astronomical observations belong to the points +A′, B′. Should δ, δ′ be equal and parallel, the displacements +AA′, BB′ will be equal and parallel, and no discrepancy will +appear. The non-recognition of this circumstance often led +to much perplexity in the early history of geodesy. Suppose +that, through the unknown variations of N, the probable error +of an observed latitude (that is, the angle between the normal +to the mathematical surface of the earth at the given point +and that of the corresponding point on the spheroid of reference) +be ε, then if we compare two arcs of a degree each in mean +latitudes, and near each other, say about five degrees of latitude +apart, the probable error of the resulting value of the ellipticity +will be approximately ±<span class="spp">1</span>⁄<span class="suu">500</span>ε, ε being expressed in seconds, +so that if ε be so great as 2″ the probable error of the resulting +ellipticity will be greater than the ellipticity itself.</p> + +<p>It is necessary at times to calculate the attraction of a +mountain, and the consequent disturbance of the astronomical +zenith, at any point within its influence. The deflection of the +plumb-line, caused by a local attraction whose amount is k²Aδ, +is measured by the ratio of k²Aδ to the force of gravity at the +station. Expressed in seconds, the deflection Λ is</p> + +<p class="center">Λ = 12″.447Aδ / ρ,</p> + +<p class="noind">where ρ is the mean density of the earth, δ that of the attracting +mass, and A = ƒs<span class="sp">−3</span>xdv, in which dv is a volume element of the +attracting mass within the distance s from the point of deflection, +and x the projection of s on the horizontal plane through this +point, the linear unit in expressing A being a mile. Suppose, +for instance, a table-land whose form is a rectangle of 12 miles by +8 miles, having a height of 500 ft. and density half that of the +earth; let the observer be 2 miles distant from the middle +point of the longer side. The deflection then is 1″.472; but at +1 mile it increases to 2″.20.</p> + +<p>At sixteen astronomical stations in the English survey the +disturbance of latitude due to the form of the ground has been +computed, and the following will give an idea of the results. +At six stations the deflection is under 2″, at six others it is +between 2″ and 4″, and at four stations it exceeds 4″. There is +one very exceptional station on the north coast of Banffshire, +near the village of Portsoy, at which the deflection amounts +to 10″, so that if that village were placed on a map in a position +to correspond with its astronomical latitude, it would be 1000 ft. +out of position! There is the sea to the north and an undulating +country to the south, which, however, to a spectator at the +station does not suggest any great disturbance of gravity. A +somewhat rough estimate of the local attraction from external +causes gives a maximum limit of 5″, therefore we have 5″ which +must arise from unequal density in the underlying strata in the +surrounding country. In order to throw light on this remarkable +phenomenon, the latitudes of a number of stations between +Nairn on the west, Fraserburgh on the east, and the Grampians +on the south, were observed, and the local deflections determined. +It is somewhat singular that the deflections diminish in all +directions, not <i>very</i> regularly certainly, and most slowly in a south-west +direction, finally disappearing, and leaving the maximum +at the original station at Portsoy.</p> + +<p>The method employed by Dr C. Hutton for computing the +attraction of masses of ground is so simple and effectual that it +can hardly be improved on. Let a horizontal plane pass through +the given station; let r, θ be the polar co-ordinates of any point +in this plane, and r, θ, z, the co-ordinates of a particle of the +attracting mass; and let it be required to find the attraction of +a portion of the mass contained between the horizontal planes +z = 0, z = h, the cylindrical surfaces r = r<span class="su">1</span>, r = r<span class="su">2</span>, and the vertical +planes θ = θ<span class="su">1</span>, θ = θ<span class="su">2</span>. The component of the attraction at the +station or origin along the line θ = 0 is</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">k²δ <span class="f150">∫</span><span class="sp1">r2</span><span class="su1">r1</span> + <span class="f150">∫</span><span class="sp1">θ2</span><span class="su1">θ1</span> + <span class="f150">∫</span><span class="sp1">h</span><span class="su2">0</span></td> <td>r²cosθ</td> +<td rowspan="2">dr dθ dz = + k²δh (sinθ<span class="su">2</span> − sinθ<span class="su">1</span>) log{r<span class="su">2</span> + (r<span class="su">2</span>² + h²)<span class="sp">1/2</span> / r<span class="su">1</span> + (r<span class="su">1</span>² + h²)<span class="sp">1/2</span>}.</td></tr> +<tr><td class="denom">(r² + z²)<span class="sp">3/2</span></td></tr></table> + +<p class="noind">By taking r<span class="su">2</span> − r<span class="su">1</span>, sufficiently small, and supposing h also small +compared with r<span class="su">1</span> + r<span class="su">2</span> (as it usually is), the attraction is</p> + +<p class="center">k²δ (r<span class="su">2</span> − r<span class="su">1</span>) (sinθ<span class="su">2</span> − sinθ<span class="su">1</span>) h/r,</p> + +<p class="noind">where r = ½ (r<span class="su">1</span> + r<span class="su">2</span>). This form suggests the following procedure. +Draw on the contoured map a series of equidistant circles, +concentric with the station, intersected by radial lines so disposed +that the sines of their azimuths are in arithmetical progression. +Then, having estimated from the map the mean heights of the +various compartments, the calculation is obvious.</p> + +<p>In mountainous countries, as near the Alps and in the Caucasus, +deflections have been observed to the amount of as much as +30″, while in the Himalayas deflections amounting to 60″ were +observed. On the other hand, deflections have been observed +in flat countries, such as that noted by Professor K.G. Schweizer, +who has shown that, at certain stations in the vicinity of Moscow, +within a distance of 16 miles the plumb-line varies 16″ in such a +manner as to indicate a vast deficiency of matter in the underlying +strata; deflections of 10″ were observed in the level regions of +north Germany.</p> + +<p>Since the attraction of a mountain mass is expressed as a +numerical multiple of δ : ρ the ratio of the density of the mountain +to that of the earth, if we have any independent means of +ascertaining the amount of the deflection, we have at once the +ratio ρ : δ, and thus we obtain the mean density of the earth, +as, for instance, at Schiehallion, and afterwards at Arthur’s +Seat. Experiments of this kind for determining the mean +density of the earth have been made in greater numbers; but +they are not free from objection (see <span class="sc"><a href="#artlinks">Gravitation</a></span>).</p> + +<p>Let us now consider the perturbation attending a spherical +subterranean mass. A compact mass of great density at a small +distance under the surface of the earth will produce an elevation +of the mathematical surface which is expressed by the formula</p> + +<p class="center">y = aμ {(1 − 2u cosθ + u²)<span class="sp">−1/2</span> − 1},</p> + +<p class="noind">where a is the radius of the (spherical) earth, a (1 − u) the distance +<span class="pagenum"><a name="page807" id="page807"></a>807</span> +of the disturbing mass below the surface, μ the ratio of the disturbing +mass to the mass of the earth, and aθ the distance of any +point on the surface from that point, say Q, which is vertically +over the disturbing mass. The maximum value of y is at Q, +where it is y = aμu (1 − u). The deflection at the distance aθ +is Λ = μu sinθ (1 − 2u cosθ + u²)<span class="sp">−3/2</span>, or since θ is small, putting +h + u = 1, we have Λ = μθ (h² + θ²)<span class="sp">−3/2</span>. The maximum deflection +takes place at a point whose distance from Q is to the +depth of the mass as 1 : √2, and its amount is 2μ/3 √<span class="ov">3h²</span>. +If, for instance, the disturbing mass were a sphere a mile +in diameter, the excess of its density above that of the surrounding +country being equal to half the density of the +earth, and the depth of its centre half a mile, the greatest deflection +would be 5″, and the greatest value of y only two inches. +Thus a large disturbance of gravity may arise from an irregularity +in the mathematical surface whose actual magnitude, as regards +height at least, is extremely small.</p> + +<p>The effect of the disturbing mass μ on the vibrations of a +pendulum would be a maximum at Q; if v be the number of +seconds of time gained per diem by the pendulum at Q, and σ +the number of seconds of angle in the maximum deflection, then +it may be shown that v/σ = π√<span class="ov">3</span>/10.</p> + +<p>The great Indian survey, and the attendant measurements of +the degree of latitude, gave occasion to elaborate investigations +of the deflection of the plumb-line in the neighbourhood of the +high plateaus and mountain chains of Central Asia. Archdeacon +Pratt (<i>Phil. Trans.</i>, 1855 and 1857), in instituting these investigations, +took into consideration the influence of the apparent +diminution of the mass of the earth’s crust occasioned by the +neighbouring ocean-basins; he concluded that the accumulated +masses of mountain chains, &c., corresponded to subterranean +mass diminutions, so that over any level surface in a fixed depth +(perhaps 100 miles or more) the masses of prisms of equal section +are equal. This is supported by the gravity measurements at +Moré in the Himalayas at a height of 4696 metres, which showed +no deflection due to the mountain chain (<i>Phil. Trans.</i>, 1871); +more recently, H.A. Faye (<i>Compt. rend.</i>, 1880) arrived at the +same conclusion for the entire continent.</p> + +<p>This compensation, however, must only be regarded as a general +principle; in certain cases, the compensating masses show marked +horizontal displacements. Further investigations, especially of +gravity measurements, will undoubtedly establish other important +facts. Colonel S.G. Burrard has recently recalculated, +with the aid of more exact data, certain Indian deviations +of the plumb-line, and has established that in the region +south of the Himalayas (lat. 24°) there is a subterranean perturbing +mass. The extent of the compensation of the high +mountain chains is difficult to recognize from the latitude +observations, since the same effect may result from different +causes; on the other hand, observations of geographical longitude +have established a strong compensation.<a name="fa5c" id="fa5c" href="#ft5c"><span class="sp">5</span></a></p> + +<p class="pt2 center"><i>Meridian Arcs.</i></p> + +<p>The astronomical stations for the measurement of the degree +of latitude will generally lie not exactly on the same meridian; +and it is therefore necessary to calculate the arcs of meridian +M which lie between the latitude of neighbouring stations. If +S be the geodetic line calculated from the triangulation with the +astronomically determined azimuths α<span class="su">1</span> and α<span class="su">2</span>, then</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M = S</td> <td>cos α</td> +<td rowspan="2"><span class="f150">{</span>1 + <span class="spp">1</span>⁄<span class="suu">12</span></td> <td>S²</td> +<td rowspan="2">sin²α ...<span class="f150">}</span>,</td></tr> +<tr><td class="denom">cos ½Δα</td> <td class="denom">α²</td></tr></table> + +<p class="noind">in which 2α = α<span class="su">1</span> + α<span class="su">2</span> − 180°, Δα = α<span class="su">2</span> − α<span class="su">1</span> − 180°.</p> + +<p>The length of the arc of meridian between the latitudes φ<span class="su">1</span> +and φ<span class="su">2</span> is</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M = <span class="f150">∫</span><span class="sp1">φ2</span><span class="su1">φ1</span> + ρdφ = α <span class="f150">∫</span><span class="sp1">φ2</span><span class="su1">φ1</span></td> <td>(1 − e²) dφ</td></tr> +<tr><td class="denom">(1 − e² sin²φ)<span class="sp">3/2</span></td></tr></table> + +<p class="noind">where a²e² = a² − b²; instead of using the eccentricity e, put the +ratio of the axes b : a = 1 − n : 1 + n, then</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M = <span class="f150">∫</span><span class="sp1">φ2</span><span class="su1">φ1</span></td> <td>b (1 + n) (1 − n²) dφ</td> +<td rowspan="2">.</td></tr> +<tr><td class="denom">(1 + 2n cos2φ + n²)<span class="sp">3/2</span></td></tr></table> + +<p class="noind">This, after integration, gives</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M/b = <span class="f150">(</span>1 + n +</td> <td>5</td> +<td rowspan="2">n² +</td> <td>5</td> +<td rowspan="2">n³<span class="f150">)</span>α<span class="su">0</span> − <span class="f150">(</span>3n + 3n² +</td> <td>21</td> +<td rowspan="2">n³<span class="f150">)</span>α<span class="su">1</span> + <span class="f150">(</span></td> <td>15</td> +<td rowspan="2">n² +</td> <td>15</td> +<td rowspan="2">n³<span class="f150">)</span>α<span class="su">2</span> − <span class="f150">(</span></td> <td>35</td> +<td rowspan="2">n³<span class="f150">)</span>α<span class="su">3</span>,</td></tr> +<tr><td class="denom">4</td> <td class="denom">4</td> +<td class="denom">8</td> <td class="denom">8</td> +<td class="denom">8</td> <td class="denom">24</td></tr></table> + +<p class="noind">where</p> + +<table class="reg" summary="poem"><tr><td> <div class="poemr"> +<p>α<span class="su">0</span> = φ<span class="su">2</span> − φ<span class="su">1</span></p> +<p>α<span class="su">1</span> = sin (φ<span class="su">2</span> − φ<span class="su">1</span>) cos (φ<span class="su">2</span> + φ<span class="su">1</span>)</p> +<p>α<span class="su">2</span> = sin 2(φ<span class="su">2</span> − φ<span class="su">1</span>) cos 2(φ<span class="su">2</span> + φ<span class="su">1</span>)</p> +<p>α<span class="su">3</span> = sin 3(φ<span class="su">2</span> − φ<span class="su">1</span>) cos 3(φ<span class="su">2</span> + φ<span class="su">1</span>).</p> +</div> </td></tr></table> + +<p class="noind">The part of M which depends on n³ is very small; in fact, if we +calculate it for one of the longest arcs measured, the Russian arc, +it amounts to only an inch and a half, therefore we omit this +term, and put for M/b the value</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2"><span class="f150">(</span>1 + n +</td> <td>5</td> +<td rowspan="2">n²<span class="f150">)</span>α<span class="su">0</span> − <span class="f150">(</span>3n + 3n²<span class="f150">)</span>α<span class="su">1</span> + <span class="f150">(</span></td> <td>15</td> +<td rowspan="2">n²<span class="f150">)</span>α<span class="su">2</span>.</td></tr> +<tr><td class="denom">4</td> <td class="denom">8</td></tr></table> + +<p class="noind">Now, if we suppose the observed latitudes to be affected with +errors, and that the true latitudes are φ<span class="su">1</span> + x<span class="su">1</span>, φ<span class="su">2</span> + x<span class="su">2</span>; and if +further we suppose that n<span class="su">1</span> + dn is the true value of a − b : a + b, +and that n<span class="su">1</span> itself is merely a very approximate numerical value, +we get, on making these substitutions and neglecting the influence +of the corrections x on the <i>position</i> of the arc in latitude, <i>i.e.</i> on +φ<span class="su">1</span> + φ<span class="su">2</span>,</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">M/b = <span class="f150">(</span>1 + n<span class="su">1</span> +</td> <td>5</td> +<td rowspan="2">n<span class="su">1</span>²<span class="f150">)</span>α<span class="su">0</span> − <span class="f150">(</span>3n<span class="su">1</span> + 3n<span class="su">1</span>²<span class="f150">)</span>α<span class="su">1</span> + <span class="f150">(</span></td> <td>15</td> +<td rowspan="2">n<span class="su">1</span>²<span class="f150">)</span>α<span class="su">2</span> + <span class="f150">{</span> <span class="f150">(</span>1 +</td> <td>5</td> +<td rowspan="2">n<span class="su">1</span><span class="f150">)</span>α<span class="su">0</span> − <span class="f150">(</span>3 + 6n<span class="su">1</span><span class="f150">)</span>α<span class="su">1</span> + <span class="f150">(</span></td> <td>15</td> +<td rowspan="2">n<span class="su">1</span><span class="f150">)</span>α<span class="su">2</span> <span class="f150">}</span>dn</td></tr> +<tr><td class="denom">4</td> <td class="denom">8</td> +<td class="denom">2</td> <td class="denom">4</td></tr></table> + +<table class="math0" summary="math"> +<tr><td rowspan="2">+ <span class="f150">{</span>1 + n<span class="su">1</span> − 3n</td> <td>dα<span class="su">1</span></td> +<td rowspan="2"><span class="f150">}</span>dα<span class="su">0</span>;</td></tr> +<tr><td class="denom">dα<span class="su">0</span></td></tr></table> + +<p class="noind">here dα<span class="su">0</span> = x<span class="su">2</span> − x<span class="su">1</span>; and as b is only known approximately, put +b = b<span class="su">1</span>(1 + u); then we get, after dividing through by the coefficient +of dα<span class="su">0</span>, which is = 1 + n<span class="su">1</span> − 3n<span class="su">1</span> cos(φ<span class="su">2</span> − φ<span class="su">1</span>) cos(φ<span class="su">2</span> + φ<span class="su">1</span>), +an equation of the form x<span class="su">2</span> = x<span class="su">1</span> + h + fu + gv, where for convenience +we put v for dn.</p> + +<p>Now in every measured arc there are not only the extreme +stations determined in latitude, but also a number of intermediate +stations so that if there be i + 1 stations there will be +i equations</p> + +<table class="reg" summary="poem"><tr><td> <div class="poemr"> +<p>x<span class="su">2</span> = x<span class="su">1</span> + f<span class="su">1</span>u + g<span class="su">1</span>v + h<span class="su">1</span></p> +<p>x<span class="su">3</span> = x<span class="su">1</span> + f<span class="su">2</span>u + g<span class="su">2</span>v + h<span class="su">2</span></p> +<p>  :   :      :</p> +<p>  :   :      :</p> +<p>x<span class="su">i</span> = x<span class="su">1</span> + f<span class="su">i</span>u + g<span class="su">i</span>v + h<span class="su">i</span></p> +</div> </td></tr></table> + +<p>In combining a number of different arcs of meridian, with +the view of determining the figure of the earth, each arc will +supply a number of equations in u and v and the corrections to +its observed latitudes. Then, according to the method of least +squares, those values of u and v are the most probable which +render the sum of the squares of <i>all</i> the errors x a minimum. +The corrections x which are here applied arise not from errors +of observation only. The mere uncertainty of a latitude, as +determined with modern instruments, does not exceed a very +small fraction of a second as far as errors of observation go, but +no accuracy in observing will remove the error that may arise +from local attraction. This, as we have seen, may amount to +some seconds, so that the corrections x to the observed latitudes +are attributable to local attraction. Archdeacon Pratt objected +to this mode of applying least squares first used by Bessel; but +Bessel was right, and the objection is groundless. Bessel found, +in 1841, from ten meridian arcs with a total amplitude of 50°.6:</p> + +<table class="reg" summary="poem"><tr><td> <div class="poemr"> +<p>a = 3272077 toises = 6377397 metres.</p> +<p>e (ellipticity) = (a − b) / a ≈ 1/299.15 (prob. error ± 3.2).</p> +</div> </td></tr></table> + +<p class="noind">The probable error in the length of the earth’s quadrant is +± 336 m.</p> + +<p>We now give a series of some meridian-arcs measurements, +which were utilized in 1866 by A.R. Clarke in the <i>Comparisons +of the Standards of Length</i>, pp. 280-287; details of the calculations +are given by the same author in his <i>Geodesy</i> (1880), pp. +311 et seq.</p> + +<p>The data of the French arc from Formentera to Dunkirk are—</p> + +<p><span class="pagenum"><a name="page808" id="page808"></a>808</span></p> + +<table class="ws" summary="Contents"> +<tr><td class="tcc">Stations.</td> <td class="tccm" colspan="3">Astronomical<br />Latitudes.</td> <td class="tccm">Distance of<br />Parallels.</td></tr> + +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td> <td class="tcc">Ft.</td></tr> +<tr><td class="tcl">Formentera</td> <td class="tcc">38</td> <td class="tcc">39</td> <td class="tcc">53.17</td> <td class="tcc">· ·</td></tr> +<tr><td class="tcl">Mountjouy</td> <td class="tcc">41</td> <td class="tcc">21</td> <td class="tcc">44.96</td> <td class="tcr">982671.04</td></tr> +<tr><td class="tcl">Barcelona</td> <td class="tcc">41</td> <td class="tcc">22</td> <td class="tcc">47.90</td> <td class="tcr">988701.92</td></tr> +<tr><td class="tcl">Carcassonne</td> <td class="tcc">43</td> <td class="tcc">12</td> <td class="tcc">54.30</td> <td class="tcr">1657287.93</td></tr> +<tr><td class="tcl">Pantheon</td> <td class="tcc">48</td> <td class="tcc">50</td> <td class="tcc">47.98</td> <td class="tcr">3710827.13</td></tr> +<tr><td class="tcl">Dunkirk</td> <td class="tcc">51</td> <td class="tcc"> 2</td> <td class="tcc"> 8.41</td> <td class="tcr">4509790.84</td></tr> +</table> + +<p>The distance of the parallels of Dunkirk and Greenwich, +deduced from the extension of the triangulation of England +into France, in 1862, is 161407.3 ft., which is 3.9 ft. greater than +that obtained from Captain Kater’s triangulation, and 3.2 ft. +less than the distance calculated by Delambre from General Roy’s +triangulation. The following table shows the data of the +English arc with the distances in standard feet from Formentera.</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td> <td class="tcc">Ft.</td></tr> +<tr><td class="tcl">Formentera</td> <td class="tcc" colspan="3">· ·</td> <td class="tcc">· ·</td></tr> +<tr><td class="tcl">Greenwich</td> <td class="tcc">51</td> <td class="tcc">28</td> <td class="tcc">38.30</td> <td class="tcc">4671198.3</td></tr> +<tr><td class="tcl">Arbury</td> <td class="tcc">52</td> <td class="tcc">13</td> <td class="tcc">26.59</td> <td class="tcc">4943837.6</td></tr> +<tr><td class="tcl">Clifton</td> <td class="tcc">53</td> <td class="tcc">27</td> <td class="tcc">29.50</td> <td class="tcc">5394063.4</td></tr> +<tr><td class="tcl">Kellie Law</td> <td class="tcc">56</td> <td class="tcc">14</td> <td class="tcc">53.60</td> <td class="tcc">6413221.7</td></tr> +<tr><td class="tcl">Stirling</td> <td class="tcc">57</td> <td class="tcc">27</td> <td class="tcc">49.12</td> <td class="tcc">6857323.3</td></tr> +<tr><td class="tcl">Saxavord</td> <td class="tcc">60</td> <td class="tcc">49</td> <td class="tcc">37.21</td> <td class="tcc">8086820.7</td></tr> +</table> + +<p>The latitude assigned in this table to Saxavord is not the +directly observed latitude, which is 60° 49′ 38.58″, for there +are here a cluster of three points, whose latitudes are astronomically +determined; and if we transfer, by means of the geodesic +connexion, the latitude of Gerth of Scaw to Saxavord, we get +60° 49′ 36.59″; and if we similarly transfer the latitude of Balta, +we get 60° 49′ 36.46″. The mean of these three is that entered +in the above table.</p> + +<p>For the Indian arc in long. 77° 40′ we have the following +data:—</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td> <td class="tcc">Ft.</td></tr> +<tr><td class="tcl">Punnea</td> <td class="tcr">8</td> <td class="tcr">9</td> <td class="tcc">31.132</td> <td class="tcc">· ·</td></tr> +<tr><td class="tcl">Putchapolliam</td> <td class="tcr">10</td> <td class="tcr">59</td> <td class="tcc">42.276</td> <td class="tcc">1029174.9</td></tr> +<tr><td class="tcl">Dodagunta</td> <td class="tcr">12</td> <td class="tcr">59</td> <td class="tcc">52.165</td> <td class="tcc">1756562.0</td></tr> +<tr><td class="tcl">Namthabad</td> <td class="tcr">15</td> <td class="tcr">5</td> <td class="tcc">53.562</td> <td class="tcc">2518376.3</td></tr> +<tr><td class="tcl">Daumergida</td> <td class="tcr">18</td> <td class="tcr">3</td> <td class="tcc">15.292</td> <td class="tcc">3591788.4</td></tr> +<tr><td class="tcl">Takalkhera</td> <td class="tcr">21</td> <td class="tcr">5</td> <td class="tcc">51.532</td> <td class="tcc">4697329.5</td></tr> +<tr><td class="tcl">Kalianpur</td> <td class="tcr">24</td> <td class="tcr">7</td> <td class="tcc">11.262</td> <td class="tcc">5794695.7</td></tr> +<tr><td class="tcl">Kaliana</td> <td class="tcr">29</td> <td class="tcr">30</td> <td class="tcc">48.322</td> <td class="tcc">7755835.9</td></tr> +</table> + +<p>The data of the Russian arc (long. 26° 40′) taken from Struve’s +work are as below:—</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td> <td class="tcc">Ft.</td></tr> +<tr><td class="tcl">Staro Nekrasovsk</td> <td class="tcr">45</td> <td class="tcr">20</td> <td class="tcr">2.94</td> <td class="tcc">· ·</td></tr> +<tr><td class="tcl">Vodu-Luy</td> <td class="tcr">47</td> <td class="tcr">1</td> <td class="tcr">24.98</td> <td class="tcr">616529.81</td></tr> +<tr><td class="tcl">Suprunkovzy</td> <td class="tcr">48</td> <td class="tcr">45</td> <td class="tcr">3.04</td> <td class="tcr">1246762.17</td></tr> +<tr><td class="tcl">Kremenets</td> <td class="tcr">50</td> <td class="tcr">5</td> <td class="tcr">49.95</td> <td class="tcr">1737551.48</td></tr> +<tr><td class="tcl">Byelin</td> <td class="tcr">52</td> <td class="tcr">2</td> <td class="tcr">42.16</td> <td class="tcr">2448745.17</td></tr> +<tr><td class="tcl">Nemesh</td> <td class="tcr">54</td> <td class="tcr">39</td> <td class="tcr">4.16</td> <td class="tcr">3400312.63</td></tr> +<tr><td class="tcl">Jacobstadt</td> <td class="tcr">56</td> <td class="tcr">30</td> <td class="tcr">4.97</td> <td class="tcr">4076412.28</td></tr> +<tr><td class="tcl">Dorpat</td> <td class="tcr">58</td> <td class="tcr">22</td> <td class="tcr">47.56</td> <td class="tcr">4762421.43</td></tr> +<tr><td class="tcl">Hogland</td> <td class="tcr">60</td> <td class="tcr">5</td> <td class="tcr">9.84</td> <td class="tcr">5386135.39</td></tr> +<tr><td class="tcl">Kilpi-maki</td> <td class="tcr">62</td> <td class="tcr">38</td> <td class="tcr">5.25</td> <td class="tcr">6317905.67</td></tr> +<tr><td class="tcl">Torneå</td> <td class="tcr">65</td> <td class="tcr">49</td> <td class="tcr">44.57</td> <td class="tcr">7486789.97</td></tr> +<tr><td class="tcl">Stuor-oivi</td> <td class="tcr">68</td> <td class="tcr">40</td> <td class="tcr">58.40</td> <td class="tcr">8530517.90</td></tr> +<tr><td class="tcl">Fuglenaes</td> <td class="tcr">70</td> <td class="tcr">40</td> <td class="tcr">11.23</td> <td class="tcr">9257921.06</td></tr> +</table> + +<p class="noind">From the are measured in Cape Colony by Sir Thomas Maclear +in long. 18° 30′, we have</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td> <td class="tcc">Ft.</td></tr> +<tr><td class="tcl">North End</td> <td class="tcr">29</td> <td class="tcr">44</td> <td class="tcr">17.66</td> <td class="tcc">· ·</td></tr> +<tr><td class="tcl">Heerenlogement Berg</td> <td class="tcr">31</td> <td class="tcr">58</td> <td class="tcr">9.11</td> <td class="tcr">811507.7</td></tr> +<tr><td class="tcl">Royal Observatory</td> <td class="tcr">33</td> <td class="tcr">56</td> <td class="tcr">3.20</td> <td class="tcr">1526386.8</td></tr> +<tr><td class="tcl">Zwart Kop</td> <td class="tcr">34</td> <td class="tcr">13</td> <td class="tcr">32.13</td> <td class="tcr">1632583.3</td></tr> +<tr><td class="tcl">Cape Point</td> <td class="tcr">34</td> <td class="tcr">21</td> <td class="tcr">6.26</td> <td class="tcr">1678375.7</td></tr> +</table> + +<p class="noind">And, finally, for the Peruvian arc, in long. 281° 0′,</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td> <td class="tcc">Ft.</td></tr> +<tr><td class="tcl">Tarqui</td> <td class="tcc">3</td> <td class="tcc">4</td> <td class="tcc">32.068</td> <td class="tcc">· ·</td></tr> +<tr><td class="tcl">Cotchesqui</td> <td class="tcc">0</td> <td class="tcc">2</td> <td class="tcc">31.387</td> <td class="tcc">1131036.3</td></tr> +</table> + +<p>Having now stated the data of the problem, we may seek that +oblate ellipsoid (spheroid) which best represents the observations. +Whatever the real figure may be, it is certain that if we suppose +it an ellipsoid with three unequal axes, the arithmetical process +will bring out an ellipsoid, which will agree better with all +the observed latitudes than any spheroid would, therefore we +do not <i>prove</i> that it is an ellipsoid; to prove this, arcs of +longitude would be required. The result for the spheroid may +be expressed thus:—</p> + +<p class="center"> +a = 20926062 ft. = 6378206.4 metres.<br /> +b = 20855121 ft. = 6356583.8 metres.<br /> + b : a = 293.98 : 294.98.</p> + +<p class="noind">As might be expected, the sum of the squares of the 40 latitude +corrections, viz. 153.99, is greater in this figure than in that of +three axes, where it amounts to 138.30. For this case, in the +Indian arc the largest corrections are at Dodagunta, + 3.87″, +and at Kalianpur, − 3.68″. In the Russian arc the largest +corrections are + 3.76″, at Torneå, and − 3.31″, at Staro Nekrasovsk. +Of the whole 40 corrections, 16 are under 1.0″, 10 +between 1.0″ and 2.0″, 10 between 2.0″ and 3.0″, and 4 over +3.0″. The probable error of an observed latitude is ± 1.42″; +for the spheroidal it would be very slightly larger. This quantity +may be taken therefore as approximately the probable amount +of local deflection.</p> + +<p>If ρ be the radius of curvature of the meridian in latitude φ, ρ′ +that perpendicular to the meridian, D the length of a degree of +the meridian, D′ the length of a degree of longitude, r the radius +drawn from the centre of the earth, V the angle of the vertical +with the radius-vector, then</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcc" colspan="2">Ft.</td> <td class="tcr"> </td> <td class="tcr"> </td> <td class="tcl"> </td></tr> +<tr><td class="tcr">ρ =</td> <td class="tcl">20890606.6</td> <td class="tcr">−</td> <td class="tcr">106411.5 cos 2φ</td> <td class="tcl">+ 225.8 cos 4φ</td></tr> +<tr><td class="tcr">ρ′ =</td> <td class="tcl">20961607.3</td> <td class="tcr">−</td> <td class="tcr">35590.9 cos 2φ</td> <td class="tcl">+ 45.2 cos 4φ</td></tr> +<tr><td class="tcr">D =</td> <td class="tcl"> 364609.87</td> <td class="tcr">−</td> <td class="tcr">1857.14 cos 2φ</td> <td class="tcl">+ 3.94 cos 4φ</td></tr> +<tr><td class="tcr">D′ =</td> <td class="tcl"> 365538.48 cos φ</td> <td class="tcr">−</td> <td class="tcr">310.17 cos 3φ</td> <td class="tcl">+ 0.39 cos 5φ</td></tr> +<tr><td class="tcr">Log r/a =</td> <td class="tcl">9.9992645</td> <td class="tcr">+</td> <td class="tcr">.0007374 cos 2φ</td> <td class="tcl">− .0000019 cos 4φ</td></tr> +<tr><td class="tcr">V =</td> <td class="tcl" colspan="4">700.44″ sin 2φ − 1.19″ sin 4φ.</td></tr> +</table> + +<p>A.R. Clarke has recalculated the elements of the ellipsoid +of the earth; his values, derived in 1880, in which he utilized +the measurements of parallel arcs in India, are particularly in +practice. These values are:—</p> + +<p class="center"> +a = 20926202 ft. = 6378249 metres,<br /> +b = 20854895 ft. = 6356515 metres,<br /> + b : a = 292.465 : 293.465.</p> + +<div class="condensed"> +<p>The calculation of the elements of the ellipsoid of rotation from +measurements of the curvature of arcs in any given azimuth by +means of geographical longitudes, latitudes and azimuths is indicated +in the article <span class="sc"><a href="#artlinks">Geodesy</a></span>; reference may be made to <i>Principal +Triangulation</i>, Helmert’s <i>Geodasie</i>, and the publications of the +Kgl. Preuss. Geod. Inst.:—<i>Lotabweichungen</i> (1886), and <i>Die europ. +Längengradmessung in 52° Br.</i> (1893). For the calculation of an +ellipsoid with three unequal axes see <i>Comparison of Standards</i>, +preface; and for non-elliptical meridians, <i>Principal Triangulation</i>, +p. 733.</p> +</div> + +<p class="pt2 center"><i>Gravitation-Measurements.</i></p> + +<p>According to Clairault’s theorem (see above) the ellipticity e +of the mathematical surface of the earth is equal to the difference +<span class="spp">5</span>⁄<span class="suu">2</span>m − β, where m is the ratio of the centrifugal force at the +equator to gravity at the equator, and β is derived from the +formula G = g(1 + β sin²φ). Since the beginning of the 19th +century many efforts have been made to determine the constants +of this formula, and numerous expeditions undertaken to +investigate the intensity of gravity in different latitudes. If m +be known, it is only necessary to determine β for the evaluation +of e; consequently it is unnecessary to determine G absolutely, +for the relative values of G at two known latitudes suffice. +Such relative measurements are easier and more exact than +absolute ones. In some cases the ordinary thread pendulum, +<i>i.e.</i> a spherical bob suspended by a wire, has been employed; +but more often a rigid metal rod, bearing a weight and a knife-edge +on which it may oscillate, has been adopted. The main +point is the constancy of the pendulum. From the formula for +the time of oscillation of the mathematically ideal pendulum, +t = 2π√<span class="ov">l/G</span>, l being the length, it follows that for two points +G<span class="su">1</span> / G<span class="su">2</span> = t<span class="su">2</span>² / t<span class="su">1</span>².</p> + +<p>In 1808 J.B. Biot commenced his pendulum observations at +several stations in western Europe; and in 1817-1825 Captain +Louis de Freycinet and L.I. Duperrey prosecuted similar +observations far into the southern hemisphere. Captain Henry +Kater confined himself to British stations (1818-1819); Captain +E. Sabine, from 1819 to 1829, observed similarly, with Kater’s +pendulum, at seventeen stations ranging from the West Indies +<span class="pagenum"><a name="page809" id="page809"></a>809</span> +to Greenland and Spitsbergen; and in 1824-1831, Captain +Henry Foster (who met his death by drowning in Central +America) experimented at sixteen stations; his observations +were completed by Francis Baily in London. Of other workers +in this field mention may be made of F.B. Lütke (1826-1829), +a Russian rear-admiral, and Captains J.B. Basevi and W.T. +Heaviside, who observed during 1865 to 1873 at Kew and at +29 Indian stations, particularly at Moré in the Himalayas at a +height of 4696 metres. Of the earlier absolute determinations we +may mention those of Biot, Kater, and Bessel at Paris, London +and Königsberg respectively. The measurements were particularly +difficult by reason of the length of the pendulums +employed, these generally being second-pendulums over 1 +metre long. In about 1880, Colonel Robert von Sterneck of +Austria introduced the half-second pendulum, which permitted +far quicker and more accurate work. The use of these pendulums +spread in all countries, and the number of gravity stations +consequently increased: in 1880 there were about 120, in 1900 +there were about 1600, of which the greater number were in +Europe. Sir E. Sabine<a name="fa6c" id="fa6c" href="#ft6c"><span class="sp">6</span></a> calculated the ellipticity to be 1/288.5, +a value shown to be too high by Helmert, who in 1884, with the +aid of 120 stations, gave the value 1/299.26,<a name="fa7c" id="fa7c" href="#ft7c"><span class="sp">7</span></a> and in 1901, with +about 1400 stations, derived the value 1/298.3.<a name="fa8c" id="fa8c" href="#ft8c"><span class="sp">8</span></a> The reason for +the excessive estimate of Sabine is that he did not take into +account the systematic difference between the values of G for +continents and islands; it was found that in consequence of +the constitution of the earth’s crust (Pratt) G is greater on small +islands of the ocean than on continents by an amount which may +approach to 0.3 cm. Moreover, stations in the neighbourhood +of coasts shelving to deep seas have a surplus, but a little smaller. +Consequently, Helmert conducted his calculations of 1901 for +continents and coasts separately, and obtained G for the coasts +0.036 cm. greater than for the continents, while the value of β +remained the same. The mean value, reduced to continents, is</p> + +<p class="center">G = 978.03 (1 + 0.005302 sin²φ − 0.000007 sin²2φ) cm/sec².</p> + +<p>The small term involving sin² 2φ could not be calculated with +sufficient exactness from the observations, and is therefore taken +from the theoretical views of Sir G.H. Darwin and E. Wiechert. +For the constant g = 978.03 cm. another correction has been +suggested (1906) by the absolute determinations made by F. +Kühnen and Ph. Furtwängler at Potsdam.<a name="fa9c" id="fa9c" href="#ft9c"><span class="sp">9</span></a></p> + +<div class="condensed"> +<p>A report on the pendulum measurements of the 19th century +has been given by Helmert in the <i>Comptes rendus des séances de +la 13<span class="sp">e</span> conférence générale de l’Association Géod. Internationale à +Paris</i> (1900), ii. 139-385.</p> +</div> + +<p>A difficulty presents itself in the case of the application of +measurements of gravity to the determination of the figure of +the earth by reason of the extrusion or standing out of the land-masses +(continents, &c.) above the sea-level. The potential +of gravity has a different mathematical expression outside the +masses than inside. The difficulty is removed by assuming +(with Sir G.G. Stokes) the vertical condensation of the masses +on the sea-level, without its form being considerably altered +(scarcely 1 metre radially). Further, the value of gravity (g) +measured at the height H is corrected to sea-level by + 2gH/R, +where R is the radius of the earth. Another correction, due +to P. Bouguer, is − <span class="spp">3</span>⁄<span class="suu">2</span>gδH/ρR, where δ is the density of the +strata of height H, and ρ the mean density of the earth. +These two corrections are represented in “Bouguer’s Rule”: +g<span class="su">H</span> = g<span class="su">s</span> (1 − 2H/R + 3δH / 2ρR), where g<span class="su">H</span> is the gravity at height +H, and g<span class="su">s</span> the value at sea-level. This is supposed to take +into account the attraction of the elevated strata or plateau; +but, from the analytical method, this is not correct; it is also +disadvantageous since, in general, the land-masses are compensated +subterraneously, by reason of the isostasis of the earth’s +crust.</p> + +<p>In 1849 Stokes showed that the normal elevations N of the +geoid towards the ellipsoid are calculable from the deviations Δg +of the acceleration of gravity, <i>i.e.</i> the differences between the +observed g and the value calculated from the normal G formula. +The method assumes that gravity is measured on the earth’s +surface at a sufficient number of points, and that it is conformably +reduced. In order to secure the convergence of the expansions +in spherical harmonics, it is necessary to assume all masses +outside a surface parallel to the surface of the sea at a depth of +21 km. (= R × ellipticity) to be condensed on this surface (Helmert, +<i>Geod.</i> ii. 172). In addition to the reduction with 2gH/R, +there still result small reductions with mountain chains and +coasts, and somewhat larger ones for islands. The sea-surface +generally varies but very little by this condensation. The +elevation (N) of the geoid is then equal to</p> + +<p class="center">N = R <span class="f150">∫</span><span class="sp1">π</span> + FG<span class="sp">−1</span>Δg<span class="su">ψ</span>ψ,</p> + +<p>where ψ is the spherical distance from the point N, and Δg<span class="su">ψ</span> +denotes the mean value of Δg for all points in the same distance +ψ around; F is a function of ψ, and has the following values:—</p> + +<table class="ws f90" summary="Contents"> +<tr><td class="tcc allb">Ψ =</td> <td class="tcc allb">0°</td> <td class="tcc allb">10°</td> <td class="tcc allb">20°</td> <td class="tcc allb">30°</td> <td class="tcc allb">40°</td> <td class="tcc allb">50°</td> <td class="tcc allb">60°</td> <td class="tcc allb">70°</td> <td class="tcc allb">80°</td> <td class="tcc allb">90°</td> <td class="tcc allb">100°</td> + <td class="tcc allb">110°</td> <td class="tcc allb">120°</td> <td class="tcc allb">130°</td> <td class="tcc allb">140°</td> <td class="tcc allb">150°</td> <td class="tcc allb">160°</td> <td class="tcc allb">170°</td> <td class="tcc allb">180°</td></tr> +<tr><td class="tcc allb">F = </td> <td class="tcc allb">1</td> <td class="tcc allb">1.22</td> <td class="tcc allb">0.94</td> <td class="tcc allb">0.47</td> <td class="tcc allb">−0.06</td> <td class="tcc allb">−0.54</td> <td class="tcc allb">−0.90</td> <td class="tcc allb">−1.08</td> <td class="tcc allb">−1.08</td> <td class="tcc allb">−0.91</td> + <td class="tcc allb">−0.62</td> <td class="tcc allb">−0.27</td> <td class="tcc allb">+0.08</td> <td class="tcc allb">0.36</td> <td class="tcc allb">0.53</td> <td class="tcc allb">0.56</td> <td class="tcc allb">0.46</td> <td class="tcc allb">0.26</td> <td class="tcc allb">0</td></tr> +</table> + +<p class="noind">H. Poincaré (<i>Bull. Astr.</i>, 1901, p. 5) has exhibited N by means +of Lamé’s functions; in this case the condensation is effected +on an ellipsoidal surface, which approximates to the geoid. +This condensation is, in practice, the same as to the geoid +itself.</p> + +<p>If we imagine the outer land-masses to be condensed on the +sea-level, and the inner masses (which, together with the outer +masses, causes the deviation of the geoid from the ellipsoid) +to be compensated in the sea-level by a disturbing stratum +(which, according to Gauss, is possible), and if these masses of +both kinds correspond at the point N to a stratum of thickness +D and density δ, then, according to Helmert (<i>Geod.</i> ii. 260) we +have approximately</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">Δg =</td> <td>3</td> +<td rowspan="2">·</td> <td>g</td> +<td rowspan="2"><span class="f150">(</span></td> <td>δD</td> +<td rowspan="2">− N<span class="f150">)</span>.</td></tr> +<tr><td class="denom">2</td> <td class="denom">R</td> <td class="denom">ρ</td></tr></table> + +<p class="noind">Since N slowly varies empirically, it follows that in restricted +regions (of a few 100 km. in diameter) Δg is a measure of the +variation of D. By applying the reduction of Bouguer to g, D is +diminished by H and only gives the thickness of the ideal +disturbing mass which corresponds to the perturbations due to +subterranean masses. Δg has positive values on coasts, small +islands, and high and medium mountain chains, and occasionally +in plains; while in valleys and at the foot of mountain ranges +it is negative (up to 0.2 cm.). We conclude from this that the +masses of smaller density existing under high mountain chains +lie not only vertically underneath but also spread out sideways.</p> + +<p class="pt2 center"><i>The European Arc of Parallel in 52° Lat.</i></p> + +<p>Many measurements of degrees of longitudes along central +parallels in Europe were projected and partly carried out as +early as the first half of the 19th century; these, however, +only became of importance after the introduction of the electric +telegraph, through which calculations of astronomical longitudes +obtained a much higher degree of accuracy. Of the greatest +moment is the measurement near the parallel of 52° lat., which +extended from Valentia in Ireland to Orsk in the southern Ural +mountains over 69° long, (about 6750 km.). F.G.W. Struve, +who is to be regarded as the father of the Russo-Scandinavian +latitude-degree measurements, was the originator of this investigation. +Having made the requisite arrangements with the +<span class="pagenum"><a name="page810" id="page810"></a>810</span> +governments in 1857, he transferred them to his son Otto, who, in +1860, secured the co-operation of England. A new connexion +of England with the continent, via the English Channel, was +accomplished in the next two years; whereas the requisite +triangulations in Prussia and Russia extended over several +decennaries. The number of longitude stations originally +arranged for was 15; and the determinations of the differences +in longitude were uniformly commenced by the Russian observers +E.I. von Forsch, J.I. Zylinski, B. Tiele and others; Feaghmain +(Valentia) being reserved for English observers. With the +concluding calculation of these operations, newer determinations +of differences of longitudes were also applicable, by which the +number of stations was brought up to 29. Since local deflections +of the plumb-line were suspected at Feaghmain, the most +westerly station, the longitude (with respect to Greenwich) of +the trigonometrical station Killorglin at the head of Dingle Bay +was shortly afterwards determined.</p> + +<div class="condensed"> +<p>The results (1891-1894) are given in volumes xlvii. and l. of the +memoirs (Zapiski) of the military topographical division of the +Russian general staff, volume li. contains a reconnexion of Orsk. +The observations made west of Warsaw are detailed in the <i>Die +europ. Längengradmessung in 52° Br.</i>, i. and ii., 1893, 1896, published +by the Kgl. Preuss. Geod. Inst.</p> +</div> + +<p>The following figures are quoted from Helmert’s report +“Die Grösse der Erde” (<i>Sitzb. d. Berl. Akad. d. Wiss.</i>, 1906, +p. 535):—</p> + +<p class="pt1 center"><i>Easterly Deviation of the Astronomical Zenith</i>.</p> + +<table class="ws f90" summary="Contents"> + +<tr><td class="tcc">Name.</td> <td class="tcc" colspan="3">Longitude.</td></tr> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td></tr> +<tr><td class="tcl">Feaghmain</td> <td class="tcr">−10</td> <td class="tcr">21</td> <td class="tcr">−3.3</td></tr> +<tr><td class="tcl">Killorglin</td> <td class="tcr">−9</td> <td class="tcr">47</td> <td class="tcr">+2.8</td></tr> +<tr><td class="tcl">Haverfordwest</td> <td class="tcr">−4</td> <td class="tcr">58</td> <td class="tcr">+1.6</td></tr> +<tr><td class="tcl">Greenwich</td> <td class="tcr">0</td> <td class="tcr">0</td> <td class="tcr">+1.5</td></tr> +<tr><td class="tcl">Rosendaël-Nieuport</td> <td class="tcr">+2</td> <td class="tcr">35</td> <td class="tcr">−1.7</td></tr> +<tr><td class="tcl">Bonn</td> <td class="tcr">+7</td> <td class="tcr">6</td> <td class="tcr">−4.4</td></tr> +<tr><td class="tcl">Göttingen</td> <td class="tcr">+9</td> <td class="tcr">57</td> <td class="tcr">−2.4</td></tr> +<tr><td class="tcl">Brocken</td> <td class="tcr">+10</td> <td class="tcr">37</td> <td class="tcr">+2.3</td></tr> +<tr><td class="tcl">Leipzig</td> <td class="tcr">+12</td> <td class="tcr">23</td> <td class="tcr">+2.7</td></tr> +<tr><td class="tcl">Rauenberg-Berlin</td> <td class="tcr">+13</td> <td class="tcr">23</td> <td class="tcr">+1.7</td></tr> +<tr><td class="tcl">Grossenhain</td> <td class="tcr">+13</td> <td class="tcr">33</td> <td class="tcr">−2.9</td></tr> +<tr><td class="tcl">Schneekoppe</td> <td class="tcr">+15</td> <td class="tcr">45</td> <td class="tcr">+0.1</td></tr> +<tr><td class="tcl">Springberg</td> <td class="tcr">+16</td> <td class="tcr">37</td> <td class="tcr">+0.8</td></tr> +<tr><td class="tcl">Breslau-Rosenthal</td> <td class="tcr">+17</td> <td class="tcr">2</td> <td class="tcr">+3.5</td></tr> +<tr><td class="tcl">Trockenberg</td> <td class="tcr">+18</td> <td class="tcr">53</td> <td class="tcr">−0.5</td></tr> +<tr><td class="tcl">Schönsee</td> <td class="tcr">+18</td> <td class="tcr">54</td> <td class="tcr">−2.9</td></tr> +<tr><td class="tcl">Mirov</td> <td class="tcr">+19</td> <td class="tcr">18</td> <td class="tcr">+2.2</td></tr> +<tr><td class="tcl">Warsaw</td> <td class="tcr">+21</td> <td class="tcr">2</td> <td class="tcr">+1.9</td></tr> +<tr><td class="tcl">Grodno</td> <td class="tcr">+23</td> <td class="tcr">50</td> <td class="tcr">−2.8</td></tr> +<tr><td class="tcl">Bobruisk</td> <td class="tcr">+29</td> <td class="tcr">14</td> <td class="tcr">+0.5</td></tr> +<tr><td class="tcl">Orel</td> <td class="tcr">+36</td> <td class="tcr">4</td> <td class="tcr">+4.4</td></tr> +<tr><td class="tcl">Lipetsk</td> <td class="tcr">+39</td> <td class="tcr">36</td> <td class="tcr">+0.2</td></tr> +<tr><td class="tcl">Saratov</td> <td class="tcr">+46</td> <td class="tcr">3</td> <td class="tcr">+6.4</td></tr> +<tr><td class="tcl">Samara</td> <td class="tcr">+50</td> <td class="tcr">5</td> <td class="tcr">−2.6</td></tr> +<tr><td class="tcl">Orenburg</td> <td class="tcr">+55</td> <td class="tcr">7</td> <td class="tcr">+1.7</td></tr> +<tr><td class="tcl">Orsk</td> <td class="tcr">+58</td> <td class="tcr">34</td> <td class="tcr">−8.0</td></tr> +</table> + +<p>These deviations of the plumb-line correspond to an ellipsoid +having an equatorial radius (<i>a</i>) of nearly 6,378,000 metres (prob. +error ± 70 metres) and an ellipticity 1/299.15. The latter was +taken for granted; it is nearly equal to the result from the +gravity-measurements; the value for a then gives Ση² a minimum +(nearly). The astronomical values of the geographical +longitudes (with regard to Greenwich) are assumed, according to +the compensation of longitude differences carried out by van de +Sande Bakhuyzen (<i>Comp. rend, des séances de la commission +permanente de l’Association Géod. Internationale à Genève, 1893, +annexe A.I.</i>). Recent determinations (Albrecht, <i>Astr. Nach.</i>, +3993/4) have introduced only small alterations in the deviations, +a being slightly increased.</p> + +<p>Of considerable importance in the investigation of the great +arc was the representation of the linear lengths found in different +countries, in terms of the same unit. The necessity for this had +previously occurred in the computation of the figure of the earth +from latitude-degree-measurements. A.R. Clarke instituted +an extensive series of comparisons at Southampton (see <i>Comparisons +of Standards of Length of England, France, Belgium, +Prussia, Russia, India and Australia, made at the Ordnance +Survey Office, Southampton, 1866</i>, and a paper in the <i>Philosophical +Transactions</i> for 1873, by Lieut.-Col. A.R. Clarke, C.B., R.E., +on the further comparisons of the standards of Austria, Spain, +the United States, Cape of Good Hope and Russia) and found +that 1 toise = 6.39453348 ft., 1 metre = 3.28086933 ft.</p> + +<p>In 1875 a number of European states concluded the metre +convention, and in 1877 an international weights-and-measures +bureau was established at Breteuil. Until this time the +metre was determined by the end-surfaces of a platinum rod +(<i>mètre des archives</i>); subsequently, rods of platinum-iridium, +of cross-section <img style="width:18px; height:19px; vertical-align: middle;" src="images/img788i.jpg" alt="" />, were constructed, having engraved lines at +both ends of the bridge, which determine the distance of a metre. +There were thirty of the rods which gave as accurately as possible +the length of the metre; and these were distributed among the +different states (see <span class="sc"><a href="#artlinks">Weights and Measures</a></span>). Careful comparisons +with several standard toises showed that the metre was +not exactly equal to 443,296 lines of the toise, but, in round numbers, +1/75000 of the length smaller. The metre according to the +older relation is called the “legal metre,” according to the new +relation the “international metre.” The values are (see <i>Europ. +Längengradmessung</i>, i. p. 230):—</p> + +<p class="center">Legal metre = 3.28086933 ft., International metre = 3.2808257 ft.</p> + +<p>The values of a given above are in terms of the international +metre; the earlier ones in legal metres, while the gravity +formulae are in international metres.</p> + +<p class="pt2 center"><i>The International Geodetic Association</i> (<i>Internationale +Erdmessung</i>).</p> + +<p>On the proposition of the Prussian lieutenant-general, Johann +Jacob Baeyer, a conference of delegates of several European +states met at Berlin in 1862 to discuss the question of a “Central +European degree-measurement.” The first general conference +took place at Berlin two years later; shortly afterwards other +countries joined the movement, which was then named “The +European degree-measurement.” From 1866 till 1886 Prussia +had borne the expense incident to the central bureau at Berlin; +but when in 1886 the operations received further extension and +the title was altered to “The International Earth-measurement” +or “International Geodetic Association,” the co-operating states +made financial contributions to this purpose. The central bureau +is affiliated with the Prussian Geodetic Institute, which, since +1892, has been situated on the Telegraphenberg near Potsdam. +After Baeyer’s death Prof. Friedrich Robert Helmert was +appointed director. The funds are devoted to the advancement +of such scientific works as concern all countries and deal with +geodetic problems of a general or universal nature. During the +period 1897-1906 the following twenty-one countries belonged to +the association:—Austria, Belgium, Denmark, England, France, +Germany, Greece, Holland, Hungary, Italy, Japan, Mexico, +Norway, Portugal, Rumania, Russia, Servia, Spain, Sweden, +Switzerland and the United States of America. At the present +time general conferences take place every three years.<a name="fa10c" id="fa10c" href="#ft10c"><span class="sp">10</span></a></p> + +<p>Baeyer projected the investigation of the curvature of the +meridians and the parallels of the mathematical surface of the +earth stretching from Christiania to Palermo for 12 degrees of +longitude; he sought to co-ordinate and complete the network +of triangles in the countries through which these meridians +passed, and to represent his results by a common unit of length. +This proposition has been carried out, and extended over the +greater part of Europe; as a matter of fact, the network has, +with trifling gaps, been carried over the whole of western and +central Europe, and, by some chains of triangles, over European +Russia. Through the co-operation of France, the network has +been extended into north Africa as far as the geographical +latitude of 32°; in Greece a network, united with those of Italy +and Bosnia, has been carried out by the Austrian colonel, Heinrich +Hartl; Servia has projected similar triangulations; Rumania +has begun to make the triangle measurements, and three base +<span class="pagenum"><a name="page811" id="page811"></a>811</span> +lines have been measured by French officers with Brunner’s +apparatus. At present, in Rumania, there is being worked a +connexion between the arc of parallel in lat. 47°/48° in Russia +(stretching from Astrakan to Kishinev) with Austria-Hungary. +In the latter country and in south Bavaria the connecting triangles +for this parallel have been recently revised, as well as the French +chain on the Paris parallel, which has been connected with the +German net by the co-operation of German and French geodesists. +This will give a long arc of parallel, really projected in the first +half of the 19th century. The calculation of the Russian section +gives, with an assumed ellipticity of 1/299.15, the value a = +6377350 metres; this is rather uncertain, since the arc embraces +only 19° in longitude.</p> + +<p>We may here recall that in France geodetic studies have +recovered their former expansion under the vigorous impulse +of Colonel (afterwards General) François Perrier. When occupied +with the triangulation of Algeria, Colonel Perrier had conceived +the possibility of the geodetic junction of Algeria to Spain, over +the Mediterranean; therefore the French meridian line, which was +already connected with England, and was thus produced to the +60th parallel, could further be linked to the Spanish triangulation, +cross thence into Algeria and extend to the Sahara, so as to form +an arc of about 30° in length. But it then became urgent to +proceed to a new measurement of the French arc, between +Dunkirk and Perpignan. In 1869 Perrier was authorized to +undertake that revision. He devoted himself to that work till +the end of his career, closed by premature death in February +1888, at the very moment when the <i>Dépôt de la guerre</i> had just +been transformed into the Geographical Service of the Army, +of which General F. Perrier was the first director. His work +was continued by his assistant, Colonel (afterwards General) +J.A.L. Bassot. The operations concerning the revision of the +French arc were completed only in 1896. Meanwhile the French +geodesists had accomplished the junction of Algeria to Spain, +with the help of the geodesists of the Madrid Institute under +General Carlos Ibañez (1879), and measured the meridian line +between Algiers and El Aghuat (1881). They have since been +busy in prolonging the meridians of El Aghuat and Biskra, so +as to converge towards Wargla, through Ghardaïa and Tuggurt. +The fundamental co-ordinates of the Panthéon have also been +obtained anew, by connecting the Panthéon and the Paris +Observatory with the five stations of Bry-sur-Marne, Morlu, +Mont Valérien, Chatillon and Montsouris, where the observations +of latitude and azimuth have been effected.<a name="fa11c" id="fa11c" href="#ft11c"><span class="sp">11</span></a></p> + +<p>According to the calculations made at the central bureau of +the international association on the great meridian arc extending +from the Shetland Islands, through Great Britain, France and +Spain to El Aghuat in Algeria, a = 6377935 metres, the ellipticity +being assumed as 1/299.15. The following table gives the difference: +astronomical-geodetic latitude. The net does not follow +the meridian exactly, but deviates both to the west and to the +east; actually, the meridian of Greenwich is nearer the mean +than that of Paris (Helmert, <i>Grösse d. Erde</i>).</p> + +<p class="pt1 center"><i>West Europe-Africa Meridian-arc.</i><a name="fa12c" id="fa12c" href="#ft12c"><span class="sp">12</span></a></p> + +<table class="ws f90" summary="Contents"> +<tr><td class="tcc">Name.</td> <td class="tcc" colspan="2">Latitude.</td> <td class="tcc">A.-G.</td></tr> +<tr><td class="tcl"> </td> <td class="tcc">°</td> <td class="tcc">′</td> <td class="tcc">″</td></tr> +<tr><td class="tcl">Saxavord</td> <td class="tcc">60</td> <td class="tcr">49.6</td> <td class="tcr">−4.0</td></tr> +<tr><td class="tcl">Balta</td> <td class="tcc">60</td> <td class="tcr">45.0</td> <td class="tcr">−6.1</td></tr> +<tr><td class="tcl">Ben Hutig</td> <td class="tcc">58</td> <td class="tcr">33.1</td> <td class="tcr">+0.3</td></tr> +<tr><td class="tcl">Cowhythe</td> <td class="tcc">57</td> <td class="tcr">41.1</td> <td class="tcr">+7.3</td></tr> +<tr><td class="tcl">Great Stirling</td> <td class="tcc">57</td> <td class="tcr">27.8</td> <td class="tcr">−2.3</td></tr> +<tr><td class="tcl">Kellie Law</td> <td class="tcc">56</td> <td class="tcr">14.9</td> <td class="tcr">−3.7</td></tr> +<tr><td class="tcl">Calton Hill</td> <td class="tcc">55</td> <td class="tcr">57.4</td> <td class="tcr">+3.5</td></tr> +<tr><td class="tcl">Durham</td> <td class="tcc">54</td> <td class="tcr">46.1</td> <td class="tcr">−0.9</td></tr> +<tr><td class="tcl">Burleigh Moor</td> <td class="tcc">54</td> <td class="tcr">34.3</td> <td class="tcr">+2.1</td></tr> +<tr><td class="tcl">Clifton Beacon</td> <td class="tcc">53</td> <td class="tcr">27.5</td> <td class="tcr">+1.3</td></tr> +<tr><td class="tcl">Arbury Hill</td> <td class="tcc">52</td> <td class="tcr">13.4</td> <td class="tcr">−3.0</td></tr> +<tr><td class="tcl">Greenwich</td> <td class="tcc">51</td> <td class="tcr">28.6</td> <td class="tcr">−2.5</td></tr> +<tr><td class="tcl">Nieuport</td> <td class="tcc">51</td> <td class="tcr">7.8</td> <td class="tcr">−0.4</td></tr> +<tr><td class="tcl">Rosendaël</td> <td class="tcc">51</td> <td class="tcr">2.7</td> <td class="tcr">−0.9</td></tr> +<tr><td class="tcl">Lihons</td> <td class="tcc">49</td> <td class="tcr">49.9</td> <td class="tcr">+0.5</td></tr> +<tr><td class="tcl">Panthéon</td> <td class="tcc">48</td> <td class="tcr">50.8</td> <td class="tcr">−0.0</td></tr> +<tr><td class="tcl">Chevry</td> <td class="tcc">48</td> <td class="tcr">0.5</td> <td class="tcr">+2.2</td></tr> +<tr><td class="tcl">Saligny le Vif</td> <td class="tcc">47</td> <td class="tcr">2.7</td> <td class="tcr">+3.0</td></tr> +<tr><td class="tcl">Arpheuille</td> <td class="tcc">46</td> <td class="tcr">13.7</td> <td class="tcr">+6.3</td></tr> +<tr><td class="tcl">Puy de Dôme</td> <td class="tcc">45</td> <td class="tcr">46.5</td> <td class="tcr">+7.0</td></tr> +<tr><td class="tcl">Rodez</td> <td class="tcc">44</td> <td class="tcr">21.4</td> <td class="tcr">+1.7</td></tr> +<tr><td class="tcl">Carcassonne</td> <td class="tcc">43</td> <td class="tcr">13.3</td> <td class="tcr">+0.7</td></tr> +<tr><td class="tcl">Rivesaltes</td> <td class="tcc">42</td> <td class="tcr">45.2</td> <td class="tcr">−0.7</td></tr> +<tr><td class="tcl">Montolar</td> <td class="tcc">41</td> <td class="tcr">38.5</td> <td class="tcr">+3.6</td></tr> +<tr><td class="tcl">Lérida</td> <td class="tcc">41</td> <td class="tcr">37.0</td> <td class="tcr">−0.2</td></tr> +<tr><td class="tcl">Javalon</td> <td class="tcc">40</td> <td class="tcr">13.8</td> <td class="tcr">−0.2</td></tr> +<tr><td class="tcl">Desierto</td> <td class="tcc">40</td> <td class="tcr">5.0</td> <td class="tcr">−4.5</td></tr> +<tr><td class="tcl">Chinchilla</td> <td class="tcc">38</td> <td class="tcr">55.2</td> <td class="tcr">+2.2</td></tr> +<tr><td class="tcl">Mola de Formentera</td> <td class="tcc">38</td> <td class="tcr">39.9</td> <td class="tcr">−1.2</td></tr> +<tr><td class="tcl">Tetíca</td> <td class="tcc">37</td> <td class="tcr">15.2</td> <td class="tcr">+3.5</td></tr> +<tr><td class="tcl">Roldan</td> <td class="tcc">36</td> <td class="tcr">56.6</td> <td class="tcr">−6.0</td></tr> +<tr><td class="tcl">Conjuros</td> <td class="tcc">36</td> <td class="tcr">44.4</td> <td class="tcr">−12.6</td></tr> +<tr><td class="tcl">Mt. Sabiha</td> <td class="tcc">35</td> <td class="tcr">39.6</td> <td class="tcr">+6.5</td></tr> +<tr><td class="tcl">Nemours</td> <td class="tcc">35</td> <td class="tcr">5.8</td> <td class="tcr">+7.4</td></tr> +<tr><td class="tcl">Bouzaréah</td> <td class="tcc">36</td> <td class="tcr">48.0</td> <td class="tcr">+2.9</td></tr> +<tr><td class="tcl">Algiers (Voirol)</td> <td class="tcc">36</td> <td class="tcr">45.1</td> <td class="tcr">−9.1</td></tr> +<tr><td class="tcl">Guelt ès Stel</td> <td class="tcc">35</td> <td class="tcr">7.8</td> <td class="tcr">−1.0</td></tr> +<tr><td class="tcl">El Aghuat</td> <td class="tcc">33</td> <td class="tcr">48.0</td> <td class="tcr">−2.8</td></tr> +</table> + +<table class="nobctr" style="clear: both;" summary="Illustration"> +<tr><td class="figcenter"><img style="width:525px; height:907px" src="images/img811.jpg" alt="" /></td></tr></table> + +<p><span class="pagenum"><a name="page812" id="page812"></a>812</span></p> + +<p>While the radius of curvature of this arc is obviously not uniform +(being, in the mean, about 600 metres greater in the northern +than in the southern part), the Russo-Scandinavian meridian arc +(from 45° to 70°), on the other hand, is very uniformly curved, +and gives, with an ellipticity of 1/299.15, a = 6378455 metres; +this arc gives the plausible value 1/298.6 for the ellipticity. But +in the case of this arc the orographical circumstances are more +favourable.</p> + +<p>The west-European and the Russo-Scandinavian meridians +indicate another anomaly of the geoid. They were connected +at the Central Bureau by means of east-to-west triangle chains +(principally by the arc of parallel measurements in lat. 52°); +it was shown that, if one proceeds from the west-European +meridian arcs, the differences between the astronomical and +geodetic latitudes of the Russo-Scandinavian arc become some +4″ greater.<a name="fa13c" id="fa13c" href="#ft13c"><span class="sp">13</span></a></p> + +<p>The central European meridian, which passes through Germany +and the countries adjacent on the north and south, is under +review at Potsdam (see the publications of the Kgl. Preuss. Geod. +Inst., <i>Lotabweichungen</i>, Nos. 1-3). Particular notice must be +made of the Vienna meridian, now carried southwards to Malta. +The Italian triangulation is now complete, and has been joined +with the neighbouring countries on the north, and with Tunis +on the south.</p> + +<p>The United States Coast and Geodetic Survey has published +an account of the transcontinental triangulation and measurement +of an arc of the parallel of 39°, which extends from Cape May +(New Jersey), on the Atlantic coast, to Point Arena (California), +on the Pacific coast, and embraces 48° 46′ of longitude, with +a linear development of about 4225 km. (2625 miles). The +triangulation depends upon ten base-lines, with an aggregate +length of 86 km. the longest exceeding 17 km. in length, which +have been measured with the utmost care. In crossing the +Rocky Mountains, many of its sides exceed 100 miles in length, +and there is one side reaching to a length of 294 km., or 183 +miles; the altitude of many of the stations is also considerable, +reaching to 4300 metres, or 14,108 ft., in the case of Pike’s Peak, +and to 14,421 ft. at Elbert Peak, Colo. All geometrical conditions +subsisting in the triangulation are satisfied by adjustment, +inclusive of the required accord of the base-lines, so that the +same length for any given line is found, no matter from what +line one may start.<a name="fa14c" id="fa14c" href="#ft14c"><span class="sp">14</span></a></p> + +<p>Over or near the arc were distributed 109 latitude stations, +occupied with zenith telescopes; 73 azimuth stations; and +29 telegraphically determined longitudes. It has thus been +possible to study in a very complete manner the deviations +of the vertical, which in the mountainous regions sometimes +amount to 25 seconds, and even to 29 seconds.</p> + +<p>With the ellipticity 1/299.15, a = 6377897 ± 65 metres (prob. +error); in this calculation, however, some exceedingly perturbed +stations are excluded; for the employed stations the mean +perturbation in longitude is ± 4.9″ (zenith-deflection east-to-west +± 3.8″).</p> + +<p>The computations relative to another arc, the “eastern +oblique arc of the United States,” are also finished.<a name="fa15c" id="fa15c" href="#ft15c"><span class="sp">15</span></a> It extends +from Calais (Maine) in the north-east, to the Gulf of Mexico, +and terminates at New Orleans (Louisiana), in the south. Its +length is 2612 km. (1623 miles), the difference of latitude 15° 1′, +and of longitude 22° 47′. In the main, the triangulation follows +the Appalachian chain of mountains, bifurcating once, so as +to leave an oval space between the two branches. It includes +among its stations Mount Washington (1920 metres) and Mount +Mitchell (2038 metres). It depends upon six base-lines, and the +adjustment is effected in the same manner as for the arc of the +parallel. The astronomical data have been afforded by 71 +latitude stations, 17 longitude stations, and 56 azimuth stations, +distributed over the whole extent of the arc. The resulting +dimensions of an osculating spheroid were found to be</p> + +<p class="center">a = 6378157 metres ± 90 (prob. error),<br /> +e (ellipticity) = 1/304.5 ± 1.9 (prob. error).</p> + +<p>With the ellipticity 1/399.15, a = 6378041 metres ± 80 (prob. er.).</p> + +<p>During the years 1903-1906 the United States Coast and +Geodetic Survey, under the direction of O.H. Tittmann and the +special management of John F. Hayford, executed a calculation +of the best ellipsoid of rotation for the United States. There were +507 astronomical determinations employed, all the stations being +connected through the net-work of triangles. The observed +latitudes, longitude and azimuths were improved by the attractions +of the earth’s crust on the hypothesis of isostasis for three +depths of the surface of 114, 121 and 162 km., where the isostasis +is complete. The land-masses, within the distance of 4126 km., +were taken into consideration. In the derivation of an ellipsoid +of rotation, the first case proved itself the most favourable, +and there resulted:—</p> + +<p class="center">a = 6378283 metres ± 74 (prob. er.), ellipticity = 1/297.8 ± 0.9 (prob. er.).</p> + +<p class="noind">The most favourable value for the depth of the isostatic surface +is approximately 114 km.</p> + +<p>The measurement of a great meridian arc, in long. 98° W., +has been commenced; it has a range of latitude of 23°, and will +extend over 50° when produced southwards and northwards by +Mexico and Canada. It may afterwards be connected with the +arc of Quito. A new measurement of the meridian arc of Quito +was executed in the years 1901-1906 by the <i>Service géographique</i> +of France under the direction of the Académie des Sciences, +the ground having been previously reconnoitred in 1899. The +new arc has an amplitude in latitude of 5° 53′ 33″, and stretches +from Tulcan (lat. 0° 48′ 25″) on the borders of Columbia and +Ecuador, through Columbia to Payta (lat. − 5° 5′ 8″) in Peru. +The end-points, at which the chain of triangles has a slight +north-easterly trend, show a longitude difference of 3°. Of the +74 triangle points, 64 were latitude stations; 6 azimuths and +8 longitude-differences were measured, three base-lines were +laid down, and gravity was determined from six points, in order +to maintain indications over the general deformation of the +geoid in that region. Computations of the attraction of the +mountains on the plumb-line are also being considered. The +work has been much delayed by the hardships and difficulties +encountered. It was conducted by Lieut.-Colonel Robert +Bourgeois, assisted by eleven officers and twenty-four soldiers +of the geodetic branch of the <i>Service géographique</i>. Of these +officers mention may be made of Commandant E. Maurain, +who retired in 1904 after suffering great hardships; Commandant +L. Massenet, who died in 1905; and Captains I. Lacombe, +A. Lallemand, and Lieut. Georges Perrier (son of General +Perrier). It is conceivable that the chain of triangles in longitude +98° in North America may be united with that of Ecuador and +Peru: a continuous chain over the whole of America is certainly +but a question of time. During the years 1899-1902 the +measurement of an arc of meridian was made in the extreme +north, in Spitzbergen, between the latitudes 76° 38′ and 80° 50′, +according to the project of P.G. Rosén. The southern part +was determined by the Russians—O. Bäcklund, Captain D.D. +Sergieffsky, F.N. Tschernychev, A. Hansky and others—during +1899-1901, with the aid of 1 base-line, 15 trigonometrical, 11 +latitude and 5 gravity stations. The northern part, which +has one side in common with the southern part, has been +determined by Swedes (Professors Rosén, father and son, E. +Jäderin, T. Rubin and others), who utilized 1 base-line, 9 azimuth +measurements, 18 trigonometrical, 17 latitude and 5 gravity +stations. The party worked under excessive difficulties, which +were accentuated by the arctic climate. Consequently, in the +first year, little headway was made.<a name="fa16c" id="fa16c" href="#ft16c"><span class="sp">16</span></a></p> + +<p><span class="pagenum"><a name="page813" id="page813"></a>813</span></p> + +<p>Sir David Gill, when director of the Royal Observatory, Cape +Town, instituted the magnificent project of working a latitude-degree +measurement along the meridian of 30° long. This +meridian passes through Natal, the Transvaal, by Lake Tanganyika, +and from thence to Cairo; connexion with the Russo-Scandinavian +meridian arc of the same longitude should be +made through Asia Minor, Turkey, Bulgaria and Rumania. +With the completion of this project a continuous arc of 105° +in latitude will have been measured.<a name="fa17c" id="fa17c" href="#ft17c"><span class="sp">17</span></a></p> + +<p>Extensive triangle chains, suitable for latitude-degree measurements, +have also been effected in Japan and Australia.</p> + +<p>Besides, the systematization of gravity measurements is of +importance, and for this purpose the association has instituted +many reforms. It has ensured that the relative measurements +made at the stations in different countries should be reduced +conformably with the absolute determinations made at Potsdam; +the result was that, in 1906, the intensities of gravitation at +some 2000 stations had been co-ordinated. The intensity of +gravity on the sea has been determined by the comparison of +barometric and hypsometric observations (Mohn’s method). +The association, at the proposal of Helmert, provided the +necessary funds for two expeditions:—English Channel—Rio +de Janeiro, and the Red Sea—Australia—San Francisco—Japan. +Dr O. Hecker of the central bureau was in charge; he successfully +overcame the difficulties of the work, and established the tenability +of the isostatic hypothesis, which necessitates that the +intensity of gravity on the deep seas has, in general, the same +value as on the continents (without regard to the proximity of +coasts).<a name="fa18c" id="fa18c" href="#ft18c"><span class="sp">18</span></a></p> + +<p>As the result of the more recent determinations, the ellipticity, +compression or flattening of the ellipsoid of the earth may +be assumed to be very nearly 1/298.3; a value determined in +1901 by Helmert from the measurements of gravity. The semi-major +axis, a, of the meridian ellipse may exceed 6,378,000 inter. +metres by about 200 metres. The central bureau have adopted, +for practical reasons, the value 1/299.15, after Bessel, for which +tables exist; and also the value a = 6377397.155 (1 + 0.0001).</p> + +<p>The methods of theoretical astronomy also permit the evaluation +of these constants. The semi-axis a is calculable from the +parallax of the moon and the acceleration of gravity on the +earth; but the results are somewhat uncertain: the ellipticity +deduced from lunar perturbations is 1/297.8 ± 2 (Helmert, +<i>Geodäsie</i>, ii. pp. 460-473); William Harkness (<i>The Solar +Parallax and its related Constants</i>, 1891) from all possible data +derived the values: ellipticity = 1/300.2 ± 3, a = 6377972 ± 125 +metres. Harkness also considered in this investigation the relation +of the ellipticity to precession and nutation; newer investigations +of the latter lead to the limiting values 1/296, 1/298 +(Wiechert). It was clearly noticed in this method of determination +that the influence of the assumption as to the density of the +strata in the interior of the earth was but very slight (Radau, +<i>Bull. astr.</i> ii. (1885) 157). The deviations of the geoid from the +flattened ellipsoid of rotation with regard to the heights (the +directions of normals being nearly the same) will scarcely +exceed ± 100 metres (Helmert).<a name="fa19c" id="fa19c" href="#ft19c"><span class="sp">19</span></a></p> + +<p>The basis of the degree- and gravity-measurements is actually +formed by a stationary sea-surface, which is assumed to be level. +However, by the influence of winds and ocean currents the mean +surface of the sea near the coasts (which one assumes as the +fundamental sea-surface) can deviate somewhat from a level +surface. According to the more recent levelling it varies at the +most by only some decimeters.<a name="fa20c" id="fa20c" href="#ft20c"><span class="sp">20</span></a></p> + +<p>It is well known that the masses of the earth are continually +undergoing small changes; the earth’s crust and sea-surface +reciprocally oscillate, and the axis of rotation vibrates relatively +to the body of the earth. The investigation of these problems +falls in the programme of the Association. By continued observations +of the water-level on sea-coasts, results have already been +obtained as to the relative motions of the land and sea (cf. +<span class="sc"><a href="#artlinks">Geology</a></span>); more exact levelling will, in the course of time, +provide observations on countries remote from the sea-coast. +Since 1900 an international service has been organized between +some astronomical stations distributed over the north parallel +of 39° 8′, at which geographical latitudes are observed whenever +possible. The association contributes to all these stations, +supporting four entirely: two in America, one in Italy, and one +in Japan; the others partially (Tschardjui in Russia, and +Cincinnati observatory). Some observatories, especially Pulkowa, +Leiden and Tokyo, take part voluntarily. Since 1906 another +station for South America and one for Australia in latitude +− 31° 55′ have been added. According to the existing data, +geographical latitudes exhibit variations amounting to ± 0.25″, +which, for the greater part, proceed from a twelve- and a fourteen-month +period.<a name="fa21c" id="fa21c" href="#ft21c"><span class="sp">21</span></a></p> +<div class="author">(A. R. C; F. R. H.)</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1c" id="ft1c" href="#fa1c"><span class="fn">1</span></a> <i>Eratosthenes Batavus, seu de terrae ambitus vera quantitate +suscitatus, a Willebrordo Snellio, Lugduni-Batavorum</i> (1617).</p> + +<p><a name="ft2c" id="ft2c" href="#fa2c"><span class="fn">2</span></a> O. <span class="correction" title="amended from Callendreau">Callandreau</span>, “Mémoire sur la théorie de la figure des +planètes,” <i>Ann. obs. de Paris</i> (1889); G.H. Darwin, “The Theory +of the Figure of the Earth carried to the Second Order of Small +Quantities,” <i>Mon. Not. R.A.S.</i>, 1899; E. Wiechert, “Über die +Massenverteilung im Innern der Erde,” <i>Nach. d. kön. G. d. W. zu +Gött.</i>, 1897.</p> + +<p><a name="ft3c" id="ft3c" href="#fa3c"><span class="fn">3</span></a> See I. Todhunter, <i>Proc. Roy. Soc.</i>, 1870.</p> + +<p><a name="ft4c" id="ft4c" href="#fa4c"><span class="fn">4</span></a> J.H. Jeans, “On the Vibrations and Stability of a Gravitating +Planet,” <i>Proc. Roy. Soc.</i> vol. 71; G.H. Darwin, “On the Figure +and Stability of a liquid Satellite,” <i>Phil. Trans.</i> 206, p. 161; A.E.H. +Love, “The Gravitational Stability of the Earth,” <i>Phil. Trans.</i> 207, +p. 237; <i>Proc. Roy. Soc.</i> vol. 80.</p> + +<p><a name="ft5c" id="ft5c" href="#fa5c"><span class="fn">5</span></a> <i>Survey of India</i>, “The Attraction of the Himalaya Mountains +upon the Plumb Line in India” (1901), p. 98.</p> + +<p><a name="ft6c" id="ft6c" href="#fa6c"><span class="fn">6</span></a> <i>Account of Experiments to Determine the Figure of the Earth by +means of a Pendulum vibrating Seconds in Different Latitudes</i> (1825).</p> + +<p><a name="ft7c" id="ft7c" href="#fa7c"><span class="fn">7</span></a> Helmert, <i>Theorien d. höheren Geod.</i> ii., Leipzig, 1884.</p> + +<p><a name="ft8c" id="ft8c" href="#fa8c"><span class="fn">8</span></a> Helmert, <i>Sitzber. d. kgl. preuss. Ak. d. Wiss. zu Berlin</i> (1901), +p. 336.</p> + +<p><a name="ft9c" id="ft9c" href="#fa9c"><span class="fn">9</span></a> “Bestimmung der absoluten Grösse der Schwerkraft zu Potsdam +mit Reversionspendeln” (<i>Veröffentlichung des kgl. preuss. Geod. Inst.</i>, +N.F., No. 27).</p> + +<p><a name="ft10c" id="ft10c" href="#fa10c"><span class="fn">10</span></a> <i>Die Königl. Observatorien für Astrophysik, Meteorologie und +Geodäsie bei Potsdam</i> (Berlin, 1890); <i>Verhandlungen der I. Allgemeinen +Conferenz der Bevollmächtigten zur mitteleurop. Gradmessung</i>, +October, 1864, in Berlin (Berlin, 1865); A. Hirsch, <i>Verhandlungen +der VIII. Allg. Conf. der Internationalen Erdmessung</i>, October, 1886, +in Berlin (Berlin, 1887); and <i>Verhandlungen der XI. Allg. Conf. +d. I. E.</i>, October, 1895, in Berlin (1896).</p> + +<p><a name="ft11c" id="ft11c" href="#fa11c"><span class="fn">11</span></a> Ibañez and Perrier, <i>Jonction géod. et astr. de l’Algérie avec +l’Espagne</i> (Paris, 1886); <i>Mémorial du dépôt général de la guerre</i>, +t. xii.: <i>Nouvelle méridienne de France</i> (Paris, 1885, 1902, 1904); +<i>Comptes rendus des séances de la 12<span class="sp">e</span>-19<span class="sp">e</span> conférence générale de l’Assoc. +Géod. Internat.</i>, 1898 at Stuttgart, 1900 at Paris, 1903 at Copenhagen, +1906 at Budapest (Berlin, 1899, 1901, 1904, 1908); A. Ferrero, +<i>Rapport sur les triangulations, prés. à la 12<span class="sp">e</span> conf. gén. 1898</i>.</p> + +<p><a name="ft12c" id="ft12c" href="#fa12c"><span class="fn">12</span></a> R. Schumann, <i>C. r. de Budapest</i>, p. 244.</p> + +<p><a name="ft13c" id="ft13c" href="#fa13c"><span class="fn">13</span></a> O. and A. Börsch, “Verbindung d. russ.-skandinav. mit der +franz.-engl. Breitengradmessung” (<i>Verhandlungen der 9. Allgem. +Conf. d. I. E. in Paris, 1889</i>, Ann. xi.).</p> + +<p><a name="ft14c" id="ft14c" href="#fa14c"><span class="fn">14</span></a> U.S. Coast and Geodetic Survey; H.S. Pritchett, superintendent. +<i>The Transcontinental Triangulation and the American Arc +of the Parallel</i>, by C.A. Schott (Washington, 1900).</p> + +<p><a name="ft15c" id="ft15c" href="#fa15c"><span class="fn">15</span></a> U.S. Coast and Geodetic Survey; O.H. Tittmann, superintendent. +<i>The Eastern Oblique Arc of the United States</i>, by C.A. +Schott (1902).</p> + +<p><a name="ft16c" id="ft16c" href="#fa16c"><span class="fn">16</span></a> <i>Missions scientifiques pour la mesure d’un arc de méridien au +Spitzberg entreprises en 1899-1902 sous les auspices des gouvernements +russe et suédois.</i> <i>Mission russe</i> (St Pétersbourg, 1904); <i>Mission +suédoise</i> (Stockholm, 1904).</p> + +<p><a name="ft17c" id="ft17c" href="#fa17c"><span class="fn">17</span></a> Sir David Gill, <i>Report on the Geodetic Survey of South Africa, +1833-1892</i> (Cape Town, 1896), vol. ii. 1901, vol. iii. 1905.</p> + +<p><a name="ft18c" id="ft18c" href="#fa18c"><span class="fn">18</span></a> O. Hecker, <i>Bestimmung der Schwerkraft a. d. Atlantischen +Ozean</i> (Veröffentl. d. Kgl. Preuss. Geod. Inst. No. 11), Berlin, +1903.</p> + +<p><a name="ft19c" id="ft19c" href="#fa19c"><span class="fn">19</span></a> F.R. Helmert. “Neuere Fortschritte in der Erkenntnis der +math. Erdgestalt” (<i>Verhandl. des VII. Internationalen Geographen-Kongresses, +Berlin, 1899</i>), London, 1901.</p> + +<p><a name="ft20c" id="ft20c" href="#fa20c"><span class="fn">20</span></a> C. Lallemand, “Rapport sur les travaux du service du nivellement +général de la France, de 1900 à 1906″ (<i>Comp. rend. de la 14<span class="sp">e</span> +conf. gén. de l’Assoc. Géod-Intern., 1903</i>, p. 178).</p> + +<p><a name="ft21c" id="ft21c" href="#fa21c"><span class="fn">21</span></a> T. Albrecht, <i>Resultate des internat. Breitendienstes</i>, i. and ii. +(Berlin, 1903 and 1906); F. Klein and A. Sommerfeld, <i>Über die +Theorie des Kreisels</i>, iii. p. 672; R. Spitaler, “Die periodischen Luftmassenverschiebungen +und ihr Einfluss auf die Lagenänderung der +Erdaxe” (<i>Petermanns Mitteilungen, Ergänzungsheft</i>, 137); S. Newcomb, +“Statement of the Theoretical Laws of the Polar Motion” +(<i>Astronomical Journal</i>, 1898, xix. 158); F.R. Helmert, “Zur +Erklärung der beobachteten Breitenänderungen” (<i>Astr. Nachr.</i> No. +3014); J. Weeder, “The 14-monthly period of the motion of the +Pole from determinations of the azimuth of the meridian marks of +the Leiden observatory” (<i>Kon. Ak. van Wetenschappen to Amsterdam</i>, +1900); A. Sokolof, “Détermination du mouvement du pôle terr. +au moyen des mires méridiennes de Poulkovo” (<i>Mél. math. et astr.</i> +vii., 1894); J. Bonsdorff, “Beobachtungen von δ Cassiopejae mit +dem grossen Zenitteleskop” (<i>Mitteilungen der Nikolai-Hauptsternwarte +zu Pulkowo</i>, 1907); J. Larmor and E.H. Hills, “The irregular +movement of the Earth’s axis of rotation: a contribution towards +the analysis of its causes” (<i>Monthly Notices R.A.S.</i>, 1906, lxvii. 22); +A.S. Cristie, “The latitude variation Tide” (<i>Phil. Soc. of Wash.</i>, +1895, <i>Bull.</i> xiii. 103); H.G. van de Sande Bakhuysen, “Über die +Änderung der Polhöhe” (<i>Astr. Nachr.</i> No. 3261); A.V. Bäcklund, +“Zur Frage nach der Bewegung des Erdpoles” (<i>Astr. Nachr.</i> +No. 3787); R. Schumann, “Über die Polhöhenschwankung” +(<i>Astr. Nachr.</i> No. 3873); “Numerische Untersuchung” (<i>Ergänzungshefte +zu den Astr. Nachr.</i> No. 11); <i>Weitere Untersuchungen</i> +(No. 4142); <i>Bull. astr.</i>, 1900, June, report of different theoretical +memoirs.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EARTH CURRENTS.<a name="ar42" id="ar42"></a></span> After the invention of telegraphy it +was soon found that telegraph lines in which the circuit is completed +by the earth are traversed by natural electric currents +which occasionally interfere seriously with their use, and which +are known as “earth currents.”</p> + +<p>1. Amongst the pioneers in investigating the subject were +several English telegraphists, <i>e.g.</i> W.H. Barlow (<b>1</b>) and C.V. +Walker (<b>2</b>), who were in charge respectively of the Midland and +South-Eastern telegraph systems. Barlow noticed the existence +of a more or less regular diurnal variation, and the result—confirmed +by all subsequent investigators—that earth currents +proper occur in a line only when both ends are earthed. Walker, +as the result of general instructions issued to telegraph clerks, +collected numerous statistics as to the phenomena during times +of large earth currents. His results and those given by Barlow +both indicate that the lines to suffer most from earth currents +in England have the general direction N.E. to S.W. As Walker +points out, it is the direction of the terminal plates relative to +one another that is the essential thing. At the same time he +noticed that whilst at any given instant the currents in parallel +lines have with rare exceptions the same direction, some lines +show normally stronger currents than others, and he suggested +that differences in the geological structure of the intervening +ground might be of importance. This is a point which seems +still somewhat obscure.</p> + +<p>Our present knowledge of the subject owes much to practical +men, but even in the early days of telegraphy the fact that +telegraph systems are commercial undertakings, and cannot allow +<span class="pagenum"><a name="page814" id="page814"></a>814</span> +the public to wait the convenience of science, was a serious +obstacle to their employment for research. Thus Walker +feelingly says, when regretting his paucity of data during a +notable earth current disturbance: “Our clerks were at their +wits’ end to clear off the telegrams.... At a time when observations +would have been very highly acceptable they were too much +occupied with their ordinary duties.” Some valuable observations +have, however, been made on long telegraph lines where +special facilities have been given.</p> + +<p>Amongst these may be mentioned the observations on French +lines in 1883 described by E.E. Blavier (<b>3</b>), and those on two +German lines Berlin-Thorn and Berlin-Dresden during 1884 to +1888 discussed by B. Weinstein (<b>4</b>).</p> + +<p>2. Of the experimental lines specially constructed perhaps +the best known are the Greenwich lines instituted by Sir G.B. +Airy (<b>5</b>), the lines at Pawlowsk due to H. Wild (<b>6</b>), and those at +Parc Saint Maur, near Paris (<b>7</b>).</p> + +<p><i>Experimental Lines.</i>—At Greenwich observations were commenced +in 1865, but there have been serious disturbances due +to artificial currents from electric railways for many years. +There are two lines, one to Dartford distant about 10 m., in a +direction somewhat south of east, the other to Croydon distant +about 8 m., in a direction west of south.</p> + +<p>Information from a single line is incomplete, and unless this +is clearly understood erroneous ideas may be derived. The times +at which the current is largest and least, or when it vanishes, in +an east-west line, tell nothing directly as to the amplitude at the +time of the resultant current. The lines laid down at Pawlowsk +in 1883 lay nearly in and perpendicular to the geographical +meridian, a distinct desideratum, but were only about 1 km. +long. The installation at Parc Saint Maur, discussed by T. +Moureaux, calls for fuller description. There are three lines, +one having terminal earth plates 14.8 km. apart in the geographical +meridian, a second having its earth plates due east and +west of one another, also 14.8 km. apart, and the third forming +a closed circuit wholly insulated from the ground. In each of +the three lines is a Deprez d’Arsonval galvanometer. Light +reflected from the galvanometer mirrors falls on photographic +paper wound round a drum turned by clockwork, and a continuous +record is thus obtained.</p> + +<p>3. Each galvanometer has a resistance of about 200 ohms, +but is shunted by a resistance of only 2 ohms. The total effective +resistances in the N.-S. and E.-W. lines are 225 and 348 ohms +respectively. If i is the current recorded, L, g and s the resistances +of the line, galvanometer and shunt respectively, then +E, the difference of potential between the two earth plates, is +given by</p> + +<p class="center">E = i (1 + g/s) {L + gs / (g + s)}.</p> + +<p class="noind">To calibrate the record, a Daniell cell is put in a circuit including +1000 ohms and the three galvanometers as shunted. +If i′ be the current recorded, e the E.M.F. of the cell, then +e = i′ (1 + g/s) {1000 + 3gs / (g + s)}. Under the conditions at Parc +Saint Maur we may write 2 for gs / (g + s), and 1.072 for e, and +thence we have approximately E = 0.240 (i / i′) for the N.-S. line, +and E = −0.371(i / i′) for the E.-W. line.</p> + +<p>The method of standardization assumes a potential difference +between earth plates which varies slowly enough to produce a +practically steady current. There are several causes producing +currents in a telegraph wire which do not satisfy this limitation. +During thunderstorms surgings may arise, at least in overhead +wires, without these being actually struck. Again, if the circuit +includes a variable magnetic field, electric currents will be +produced independently of any direct source of potential difference. +In the third circuit at Parc Saint Maur, where no earth +plates exist, the current must be mainly due to changes in the +earth’s vertical magnetic field, with superposed disturbances +due to atmospheric electricity or aerial waves. Even in the +other circuits, magnetic and atmospheric influences play some +part, and when their contribution is important, the galvanometer +deflection has an uncertain value. What a galvanometer records +when traversed by a suddenly varying current depends on other +things than its mere resistance.</p> + +<p>Even when the current is fairly steady, its exact significance +is not easily stated. In the first place there is usually an appreciable +E.M.F. between a plate and the earth in contact with it, +and this E.M.F. may vary with the temperature and the dryness +of the soil. Naturally one employs similar plates buried to the +same depth at the two ends, but absolute identity and invariability +of conditions can hardly be secured. In some cases, in +short lines (<b>8</b>), there is reason to fear that plate E.M.F.’s have +been responsible for a good deal that has been ascribed to true +earth currents. With deep earth plates, in dry ground, this +source of uncertainty can, however, enter but little into the +diurnal inequality.</p> + +<p>4. Another difficulty is the question of the resistance in the +earth itself. A given E.M.F. between plates 10 m. apart may +mean very different currents travelling through the earth, +according to the chemical constitution and condition of the +surface strata.</p> + +<p>According to Professor A. Schuster (<b>9</b>), if ρ and ρ’ be the +specific resistances of the material of the wire and of the soil, +the current i which would pass along an underground cable +formed of actual soil, equal in diameter to the wire connecting +the plates, is given by i = i′ρ / ρ′, where i′ is the observed current +in the wire. As ρ’ will vary with the depth, and be different at +different places along the route, while discontinuities may arise +from geological faults, water channels and so on, it is clear that +even the most careful observations convey but a general idea +as to the absolute intensity of the currents in the earth itself. +In Schuster’s formula, as in the formulae deduced for Parc Saint +Maur, it is regarded as immaterial whether the wire connecting +the plates is above or below ground. This view is in accordance +with records obtained by Blavier (<b>3</b>) from two lines between +Paris and Nancy, the one an air line, the other underground.</p> + +<p>5. The earliest quantitative results for the regular diurnal +changes in earth currents are probably those deduced by Airy +(<b>5</b>) from the records at Greenwich between 1865 and 1867. +Airy resolved the observed currents from the two Greenwich +lines in and perpendicular to the <i>magnetic</i> meridian (then about +21° to the west of astronomical north). The information given +by Airy as to the precise meaning of the quantities he terms +“magnetic tendency” to north and to west is somewhat +scanty, but we are unlikely to be much wrong in accepting his +figures as proportional to the earth currents from magnetic +east to west and from magnetic north to south respectively. +Airy gives mean hourly values for each month of the year. +The corresponding mean diurnal inequality for the whole +year appears in Table 1., the unit being arbitrary. In +every month the algebraic mean of the 24 hourly values +represented a current from north to south in the magnetic +meridian, and from east to west in the perpendicular direction; +in the same arbitrary units used in Table I. the mean +values of these two “constant” currents were respectively +777 and 559.</p> + +<p>6. <i>Diurnal Variation.</i>—Probably the most complete records +of diurnal variation are those discussed by Weinstein (<b>4</b>), which +depend on several years’ records on lines from Berlin to Dresden +and to Thorn. Relative to Berlin the geographical co-ordinates +of the other two places are:</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcl">Thorn</td> <td class="tcl">0° 29′ N. lat. 5° 12′ E. long.</td></tr> +<tr><td class="tcl">Dresden</td> <td class="tcl">1° 28′ S. lat. 0° 21′ E. long.</td></tr> +</table> + +<p class="noind">Thus the Berlin-Dresden line was directed about 8½° east of south, +and the Berlin-Thorn line somewhat more to the north of east. +The latter line had a length about 2.18 times that of the former. +The resistances in the two lines were made the same, so if we +suppose the difference of potential between earth plates along +a given direction to vary as their distance apart, the current +observed in the Thorn-Berlin line has to be divided by 2.18 to be +comparable with the other. In this way, resolving along and +perpendicular to the geographical meridian, Weinstein gives +as proportional to the earth currents from east to west and +from south to north respectively</p> + +<p class="center">J = 0.147i′ + 0.435i, and J′ = 0.989i′ − 0.100i,</p> + +<p><span class="pagenum"><a name="page815" id="page815"></a>815</span></p> + +<p>where i and i’ are the observed currents in the Thorn-Berlin and +Dresden-Berlin lines respectively, both being counted positive +when flowing towards Berlin.</p> + +<p>It is tacitly assumed that the average earth conductivity +is the same between Berlin and Thorn as between Berlin and +Dresden. It should also be noticed that local +time at Berlin and Thorn differs by fully 20 +minutes, while the crests of the diurnal variations +in <i>short</i> lines at the two places would probably +occur about the same local time. The result +is probably a less sharp occurrence of maxima +and minima, and a relatively smaller range, than in a short +line having the same orientation.</p> + +<p class="pt1 center sc">Table I.</p> + +<table class="ws f90" summary="Contents"> +<tr><td class="tccm allb cl" colspan="7">Mean Diurnal Inequalities for the year.</td> <td class="tccm allb cl" colspan="4">Numerical Values of resultant<br />current.</td></tr> + +<tr><td class="tccm allb" colspan="3">Greenwich.</td> <td class="tccm allb" colspan="4">Thorn-Berlin-Dresden.</td> <td class="tccm allb" colspan="4">Thorn-Berlin-Dresden.</td></tr> + +<tr><td class="tccm allb" rowspan="2">Hour.</td> <td class="tccm allb" rowspan="2">North<br />to<br />South<br />(Mag.)</td> <td class="tccm allb" rowspan="2">East<br />to<br />West<br />(Mag.)</td> + <td class="tccm allb" rowspan="2">Berlin<br />to<br />Dresden.</td> <td class="tccm allb" rowspan="2">Thorn<br />to<br />Berlin.</td> + <td class="tccm allb" rowspan="2">North<br />to<br />South<br />(Ast.)</td> <td class="tccm allb" rowspan="2">East<br />to<br />West<br />(Ast.)</td> + <td class="tccm allb" colspan="4">Mean hourly values from</td></tr> + +<tr><td class="tccm allb">Year.</td> <td class="tccm allb">Winter.</td> <td class="tccm allb">Equinox.</td> <td class="tccm allb">Summer.</td></tr> + +<tr><td class="tcc lb rb">1</td> <td class="tcr rb">−94</td> <td class="tcr rb">−41</td> <td class="tcr rb">−17</td> <td class="tcr rb">−13</td> <td class="tcr rb">−20</td> <td class="tcr rb">−10</td> <td class="tcr rb">81</td> <td class="tcr rb">94</td> <td class="tcr rb">51</td> <td class="tcr rb">98</td></tr> +<tr><td class="tcc lb rb">2</td> <td class="tcr rb">−68</td> <td class="tcr rb">−24</td> <td class="tcr rb">−6</td> <td class="tcr rb">−13</td> <td class="tcr rb">−9</td> <td class="tcr rb">−11</td> <td class="tcr rb">84</td> <td class="tcr rb">115</td> <td class="tcr rb">39</td> <td class="tcr rb">97</td></tr> +<tr><td class="tcc lb rb">3</td> <td class="tcr rb">−44</td> <td class="tcr rb">−8</td> <td class="tcr rb">−1</td> <td class="tcr rb">−1</td> <td class="tcr rb">−1</td> <td class="tcr rb">−1</td> <td class="tcr rb">84</td> <td class="tcr rb">113</td> <td class="tcr rb">31</td> <td class="tcr rb">108</td></tr> +<tr><td class="tcc lb rb">4</td> <td class="tcr rb">−18</td> <td class="tcr rb">+9</td> <td class="tcr rb">−20</td> <td class="tcr rb">+15</td> <td class="tcr rb">−17</td> <td class="tcr rb">+17</td> <td class="tcr rb">101</td> <td class="tcr rb">94</td> <td class="tcr rb">58</td> <td class="tcr rb">127</td></tr> +<tr><td class="tcc lb rb">5</td> <td class="tcr rb">−30</td> <td class="tcr rb">−1</td> <td class="tcr rb">−79</td> <td class="tcr rb">+21</td> <td class="tcr rb">−74</td> <td class="tcr rb">+32</td> <td class="tcr rb">122</td> <td class="tcr rb">58</td> <td class="tcr rb">78</td> <td class="tcr rb">230</td></tr> +<tr><td class="tcc lb rb">6</td> <td class="tcr rb">−63</td> <td class="tcr rb">−33</td> <td class="tcr rb">−139</td> <td class="tcr rb">+5</td> <td class="tcr rb">−136</td> <td class="tcr rb">+26</td> <td class="tcr rb">148</td> <td class="tcr rb">80</td> <td class="tcr rb">139</td> <td class="tcr rb">225</td></tr> +<tr><td class="tcc lb rb">7</td> <td class="tcr rb">−121</td> <td class="tcr rb">−80</td> <td class="tcr rb">−138</td> <td class="tcr rb">−36</td> <td class="tcr rb">−144</td> <td class="tcr rb">−14</td> <td class="tcr rb">166</td> <td class="tcr rb">155</td> <td class="tcr rb">206</td> <td class="tcr rb">136</td></tr> +<tr><td class="tcc lb rb">8</td> <td class="tcr rb">−175</td> <td class="tcr rb">−123</td> <td class="tcr rb">−7</td> <td class="tcr rb">−98</td> <td class="tcr rb">−28</td> <td class="tcr rb">−92</td> <td class="tcr rb">203</td> <td class="tcr rb">152</td> <td class="tcr rb">185</td> <td class="tcr rb">271</td></tr> +<tr><td class="tcc lb rb">9</td> <td class="tcr rb">−156</td> <td class="tcr rb">−137</td> <td class="tcr rb">+249</td> <td class="tcr rb">−156</td> <td class="tcr rb">+212</td> <td class="tcr rb">−184</td> <td class="tcr rb">305</td> <td class="tcr rb">67</td> <td class="tcr rb">272</td> <td class="tcr rb">575</td></tr> +<tr><td class="tcc lb rb">10</td> <td class="tcr rb">−43</td> <td class="tcr rb">−77</td> <td class="tcr rb">+540</td> <td class="tcr rb">−184</td> <td class="tcr rb">+494</td> <td class="tcr rb">−254</td> <td class="tcr rb">557</td> <td class="tcr rb">232</td> <td class="tcr rb">628</td> <td class="tcr rb">811</td></tr> +<tr><td class="tcc lb rb">11</td> <td class="tcr rb">+82</td> <td class="tcr rb">+1</td> <td class="tcr rb">+722</td> <td class="tcr rb">−165</td> <td class="tcr rb">+678</td> <td class="tcr rb">−-263</td> <td class="tcr rb">728</td> <td class="tcr rb">411</td> <td class="tcr rb">885</td> <td class="tcr rb">887</td></tr> +<tr><td class="tcc lb rb">Noon</td> <td class="tcr rb">+207</td> <td class="tcr rb">+66</td> <td class="tcr rb">+673</td> <td class="tcr rb">−107</td> <td class="tcr rb">+642</td> <td class="tcr rb">−200</td> <td class="tcr rb">675</td> <td class="tcr rb">441</td> <td class="tcr rb">848</td> <td class="tcr rb">735</td></tr> +<tr><td class="tcc lb rb">1</td> <td class="tcr rb">+245</td> <td class="tcr rb">+94</td> <td class="tcr rb">+404</td> <td class="tcr rb">−20</td> <td class="tcr rb">+395</td> <td class="tcr rb">−79</td> <td class="tcr rb">400</td> <td class="tcr rb">284</td> <td class="tcr rb">510</td> <td class="tcr rb">406</td></tr> +<tr><td class="tcc lb rb">2</td> <td class="tcr rb">+205</td> <td class="tcr rb">+113</td> <td class="tcr rb">+35</td> <td class="tcr rb">+55</td> <td class="tcr rb">+46</td> <td class="tcr rb">+47</td> <td class="tcr rb">98</td> <td class="tcr rb">68</td> <td class="tcr rb">103</td> <td class="tcr rb">125</td></tr> +<tr><td class="tcc lb rb">3</td> <td class="tcr rb">+153</td> <td class="tcr rb">+97</td> <td class="tcr rb">−261</td> <td class="tcr rb">+99</td> <td class="tcr rb">−237</td> <td class="tcr rb">+132</td> <td class="tcr rb">272</td> <td class="tcr rb">136</td> <td class="tcr rb">355</td> <td class="tcr rb">324</td></tr> +<tr><td class="tcc lb rb">4</td> <td class="tcr rb">+159</td> <td class="tcr rb">+108</td> <td class="tcr rb">−397</td> <td class="tcr rb">+114</td> <td class="tcr rb">−368</td> <td class="tcr rb">+167</td> <td class="tcr rb">404</td> <td class="tcr rb">218</td> <td class="tcr rb">503</td> <td class="tcr rb">492</td></tr> +<tr><td class="tcc lb rb">5</td> <td class="tcr rb">+167</td> <td class="tcr rb">+118</td> <td class="tcr rb">−391</td> <td class="tcr rb">+108</td> <td class="tcr rb">−363</td> <td class="tcr rb">+160</td> <td class="tcr rb">397</td> <td class="tcr rb">206</td> <td class="tcr rb">453</td> <td class="tcr rb">532</td></tr> +<tr><td class="tcc lb rb">6</td> <td class="tcr rb">+125</td> <td class="tcr rb">+95</td> <td class="tcr rb">−311</td> <td class="tcr rb">+96</td> <td class="tcr rb">−287</td> <td class="tcr rb">+137</td> <td class="tcr rb">319</td> <td class="tcr rb">176</td> <td class="tcr rb">333</td> <td class="tcr rb">446</td></tr> +<tr><td class="tcc lb rb">7</td> <td class="tcr rb">+43</td> <td class="tcr rb">+55</td> <td class="tcr rb">−237</td> <td class="tcr rb">+85</td> <td class="tcr rb">−216</td> <td class="tcr rb">+115</td> <td class="tcr rb">247</td> <td class="tcr rb">180</td> <td class="tcr rb">250</td> <td class="tcr rb">312</td></tr> +<tr><td class="tcc lb rb">8</td> <td class="tcr rb">−22</td> <td class="tcr rb">+4</td> <td class="tcr rb">−191</td> <td class="tcr rb">+74</td> <td class="tcr rb">−173</td> <td class="tcr rb">+98</td> <td class="tcr rb">201</td> <td class="tcr rb">207</td> <td class="tcr rb">217</td> <td class="tcr rb">181</td></tr> +<tr><td class="tcc lb rb">9</td> <td class="tcr rb">−115</td> <td class="tcr rb">−49</td> <td class="tcr rb">−168</td> <td class="tcr rb">+59</td> <td class="tcr rb">−153</td> <td class="tcr rb">+81</td> <td class="tcr rb">174</td> <td class="tcr rb">208</td> <td class="tcr rb">194</td> <td class="tcr rb">120</td></tr> +<tr><td class="tcc lb rb">10</td> <td class="tcr rb">−138</td> <td class="tcr rb">−74</td> <td class="tcr rb">−135</td> <td class="tcr rb">+40</td> <td class="tcr rb">−125</td> <td class="tcr rb">+58</td> <td class="tcr rb">138</td> <td class="tcr rb">155</td> <td class="tcr rb">149</td> <td class="tcr rb">111</td></tr> +<tr><td class="tcc lb rb">11</td> <td class="tcr rb">−136</td> <td class="tcr rb">−70</td> <td class="tcr rb">−84</td> <td class="tcr rb">+18</td> <td class="tcr rb">−79</td> <td class="tcr rb">+29</td> <td class="tcr rb">89</td> <td class="tcr rb">64</td> <td class="tcr rb">95</td> <td class="tcr rb">107</td></tr> +<tr><td class="tcc lb rb bb">Midnight</td> <td class="tcr rb bb">−147</td> <td class="tcr rb bb">−80</td> <td class="tcr rb bb">−43</td> <td class="tcr rb bb">−2</td> <td class="tcr rb bb">−43</td> <td class="tcr rb bb">+4</td> <td class="tcr rb bb">91</td> <td class="tcr rb bb">42</td> <td class="tcr rb bb">119</td> <td class="tcr rb bb">111</td></tr> +</table> + +<p>It was found that the average current derived from a number +of undisturbed days on either line might be regarded as made up +of a “constant part” plus a regular diurnal inequality, the constant +part representing the algebraic mean value of the 24 hourly +readings. In both lines the constant part showed a decided +alteration during the third year—changing sign in one line—in +consequence, it is believed, of alterations made in the earth +plates. The constant part was regarded as a plate effect, and was +omitted from further consideration. Table I. shows in terms +of an arbitrary unit—whose relation to that employed for +Greenwich data is unknown—the diurnal inequality in the +currents along the two lines, and the inequalities thence calculated +for ideal lines in and perpendicular to the <i>geographical</i> +meridian. Currents are regarded as positive when directed from +Berlin to Dresden and from north to south, the opposite point +of view to that adopted by Weinstein. The table also shows +the mean <i>numerical</i> value of the resultant current (the “constant” +part being omitted) for each hour of the day, for the year +as a whole, and for winter (November to February), equinox +(March, April, September, October) and summer (May to +August). There is a marked double period in both the +N.-S. and E.-W. currents. In both cases the numerically +largest currents occur from 10 <span class="scs">A.M.</span> to noon, the directions +then being from north to south and from west to east. +The currents tend to die out and change sign about 2 <span class="scs">P.M.</span>, +the numerical magnitude then rising again rapidly to 4 or +5 <span class="scs">P.M.</span> The current in the meridian is notably the larger. +The numerical values assigned to the resultant current are +arithmetic means from the several months composing the season in +question.</p> + +<p>7. The mean of the 24 hourly numerical values of the resultant current +for each month of the year a deducible from Weinstein’s data—the unit +being the same as before—are given in Table II.</p> + +<p class="pt1 center"><span class="sc">Table II</span>.—<i>Mean Numerical Value of Resultant Current.</i></p> + +<table class="ws" summary="Contents"> +<tr><td class="tcc allb">Jan.</td> <td class="tcc allb">Feb.</td> <td class="tcc allb">March</td> <td class="tcc allb">April</td> <td class="tcc allb">May</td> <td class="tcc allb">June</td> <td class="tcc allb">July</td> <td class="tcc allb">Aug.</td> <td class="tcc allb">Sep.</td> <td class="tcc allb">Oct.</td> <td class="tcc allb">Nov.</td> <td class="tcc allb">Dec.</td></tr> +<tr><td class="tcc allb">152</td> <td class="tcc allb">211</td> <td class="tcc allb">293</td> <td class="tcc allb">328</td> <td class="tcc allb">313</td> <td class="tcc allb">314</td> <td class="tcc allb">337</td> <td class="tcc allb">300</td> <td class="tcc allb">258</td> <td class="tcc allb">235</td> <td class="tcc allb">165</td> <td class="tcc allb">132</td></tr> +</table> + +<p>There is thus a conspicuous minimum at mid-winter, +and but little difference between the monthly +means from April to August. This is closely +analogous to what is seen in the daily range of +the magnetic elements in similar latitudes (see +<span class="sc"><a href="#artlinks">Magnetism, Terrestrial</a></span>). There is also considerable +resemblance between the curve whose ordinates +represent the diurnal inequality in the current +passing from north to south, and the curve showing +the hourly change in the westerly component of the +horizontal magnetic force in similar European +latitudes.</p> + +<p>8. <i>Relations with Sun-spots, Auroras and Magnetic +Storms.</i>—Weinstein gives curves representing the +mean diurnal inequality for separate years. In +both lines the diurnal amplitudes were notably +smaller in the later years which were near +sun-spot minimum. This raises a presumption that +the regular diurnal earth currents, like the +ranges of the magnetic elements, follow the +11-year sun-spot period. When we pass to the large +and irregular earth currents, which are of +practical interest in telegraphy, there is every +reason to suppose that the sun-spot period +applies. These currents are always accompanied by +magnetic disturbances, and when specially striking +by brilliant aurora. One most conspicuous example +of this occurred in the end of August and +beginning of September 1859. The magnetic +disturbances recorded were of almost unexampled +size and rapidity, the accompanying aurora was +extraordinarily brilliant, and E.M.F.’s of 700 and +800 volts are said to have been reached on +telegraph lines 500 to 600 km. long. It is +doubtful whether the disturbances of 1859 have +been equalled since, but earth current voltages of +the order of 0.5 volts per mile have been recorded +by various authorities, <i>e.g.</i> Sir W.H. Preece +(<b>10</b>).</p> + +<p>It was the practice for several years to publish +in the <i>Ann. du bureau central météorologique</i> +synchronous magnetic and earth current curves from +Parc Saint Maur corresponding to the chief +disturbances of the year. In most cases there is a +marked similarity between the curve of magnetic +declination and that of the north-south earth +current. At times there is also a distinct +resemblance between the horizontal force magnetic +curve and that of the east-west earth current, but +exceptions to this are not infrequent. Similar +phenomena appear in synchronous Greenwich records +published by Airy in 1868; these show a close +accordance between the horizontal force curves and +those of the currents from magnetic east to west. +Originally it was supposed by Airy that whilst +rapid movements in the declination and north-south +current curves sometimes +<span class="pagenum"><a name="page816" id="page816"></a>816</span> +occurred simultaneously, there was a distinct tendency for the +latter to precede the former. More recent examinations of the +Greenwich records by W. Ellis (<b>11</b>), and of the Parc St Maur +curves by Moureaux, have not confirmed this result, and it is now +believed that the two phenomena are practically simultaneous.</p> + +<p>There has also been a conflict of views as to the connexion +between magnetic and earth current disturbances. Airy’s +observations tended to suggest that the earth current was the +primary cause, and the magnetic disturbance in considerable +part at least its effect. Others, on the contrary, have supposed +earth currents to be a direct effect of changes in the earth’s +magnetic field. The prevailing view now is that both the +magnetic and the earth current disturbances are due to electric +currents in the upper atmosphere, these upper currents becoming +visible at times as aurora.</p> + +<p>9. There seems some evidence that earth currents can be +called into existence by purely local causes, notably difference +of level. Thus K.A. Brander (<b>12</b>) has observed a current +flowing constantly for a good many days from Airolo (height +1160 metres) to the Hospice St Gotthard (height 2094 metres). +In an 8-km. line from Resina to the top of Vesuvius L. Palmieri +(<b>13</b>)—observing in 1889 at three-hour intervals from 9 <span class="scs">A.M.</span> to +9 <span class="scs">P.M.</span>—always found a current running uphill so long as the +mountain was quiet. On a long line from Vienna to Graz A. +Baumgartner (<b>14</b>) found that the current generally flowed from +both ends towards intervening higher ground during the day, +but in the opposite directions at night. During a fortnight in +September and October 1885 hourly readings were taken of the +current in the telegraph cable from Fort-William to Ben Nevis +Observatory, and the results were discussed by H.N. Dickson +(<b>15</b>), who found a marked preponderance of currents up the line +to the summit. The recorded mean data, otherwise regarded, +represent a “constant” current, equal to 29 in the arbitrary +units employed by Dickson, flowing up the line, together with +the following diurnal inequality, + denoting current towards +Fort-William (<i>i.e.</i> down the hill, and nearly east to west).</p> + +<table class="ws" summary="Contents"> +<tr><td class="tcc rb">Hour</td> <td class="tcc rb">1</td> <td class="tcc rb">2</td> <td class="tcc rb">3</td> <td class="tcc rb">4</td> <td class="tcc rb">5</td> <td class="tcc rb">6</td> <td class="tcc rb">7</td> <td class="tcc rb">8</td> <td class="tcc rb">9</td> <td class="tcc rb">10</td> <td class="tcc rb">11</td> <td class="tcc">12</td></tr> + +<tr><td class="tcr rb pt1"><span class="scs">A.M.</span></td> <td class="tcr rb pt1">−21</td> <td class="tcr rb pt1">−41</td> <td class="tcr rb pt1">+13</td> <td class="tcr rb pt1">+23</td> <td class="tcr rb pt1">+55</td> <td class="tcr rb pt1">−3</td> <td class="tcr rb pt1">+25</td> <td class="tcr rb pt1">−32</td> <td class="tcr rb pt1">−59</td> <td class="tcr rb pt1">−62</td> <td class="tcr rb pt1">−46</td> <td class="tcr pt1">+6</td></tr> +<tr><td class="tcr rb"><span class="scs">P.M.</span></td> <td class="tcr rb">+24</td> <td class="tcr rb">+18</td> <td class="tcr rb">+115</td> <td class="tcr rb">+18</td> <td class="tcr rb">+75</td> <td class="tcr rb">−5</td> <td class="tcr rb">+50</td> <td class="tcr rb">−9</td> <td class="tcr rb">−56</td> <td class="tcr rb">−37</td> <td class="tcr rb">−28</td> <td class="tcr">−34</td></tr> +</table> + +<p>There is thus a diurnal inequality, which is by no means very +irregular considering the limited number of days, and it bears +at least a general resemblance to that shown by Weinstein’s +figures for an east-west line in Germany. This will serve to +illustrate the uncertainties affecting these and analogous observations. +A constant current in one direction may arise in whole or +part from plate E.M.F.’s; a current showing a diurnal inequality +will naturally arise between <i>any</i> two places some distance apart +whether they be at different levels or not. Finally, when +records are taken only for a short time, doubts must arise as +to the generality of the results. During the Ben Nevis observations, +for instance, we are told that the summit was almost +constantly enveloped in fog or mist. By having three earth +plates in the same vertical plane, one at the top of a mountain, +the others at opposite sides of it, and then observing the currents +between the summit and each of the base stations, as well as +directly between the base stations—during an adequate number +of days representative of different seasons of the year and +different climatic conditions—many uncertainties would soon +be removed.</p> + +<p>10. <i>Artificial Currents.</i>—The great extension in the applications +of electricity to lighting, traction and power transmission, +characteristic of the end of the 19th century, has led to the +existence of large artificial earth currents, which exert a disturbing +influence on galvanometers and magnetic instruments, and +also tend to destroy metal pipes. In the former case, whilst +the disturbance is generally loosely assigned to stray or “vagabond” +earth currents, this is only partly correct. The currents +used for traction are large, and even if there were a perfectly +insulated return there would be a considerable resultant magnetic +field at distances from the track which were not largely in +excess of the distance apart of the direct and return currents +(<b>16</b>). At a distance of half a mile or more from an electric tram +line the disturbance is usually largest in magnetographs recording +the vertical component of the earth’s field. The magnets are +slightly displaced from the position they would occupy if undisturbed, +and are kept in continuous oscillation whilst the +trams are running (<b>17</b>). The extent of the oscillation depends +on the damping of the magnets.</p> + +<p>The distance from an electric tram line where the disturbance +ceases to be felt varies with the system adopted. It also depends +on the length of the line and its subdivision into sections, on +the strength of the currents supplied, the amount of leakage, the +absence or presence of “boosters,” and finally on the sensitiveness +of the magnetic instruments. At the U.S. Coast and +Geodetic Survey’s observatory at Cheltenham the effect of the +Washington electric trams has been detected by highly sensitive +magnetographs, though the nearest point of the line is 12 m. +away (<b>18</b>). Amongst the magnetic observatories which have +suffered severely from this cause are those at Toronto, Washington +(Naval Observatory), Kew, Paris (Parc St Maur), Perpignan, +Nice, Lisbon, Vienna, Rome, Bombay (Colaba) and Batavia. +In some cases magnetic observations have been wholly suspended, +in others new observatories have been built on more remote sites.</p> + +<p>As regards damage to underground pipes, mainly gas and +water pipes, numerous observations have been made, especially +in Germany and the United States. When electric tramways +have uninsulated returns, and the potential of the rails is allowed +to differ considerably from that of the earth, very considerable +currents are found in neighbouring pipes. Under these conditions, +if the joints between contiguous pipes forming a main +present appreciable resistance, whilst the surrounding earth +through moisture or any other cause is a fair conductor, current +passes locally from the pipes to the earth causing electrolytic +corrosion of the pipes. Owing to the diversity of interests +concerned, the extent of the damage thus caused has been very +variously estimated. In some instances it has been so considerable +as to be the alleged cause of the ultimate failure of water +pipes to stand the pressure they are +exposed to.</p> + +<div class="condensed"> +<p><span class="sc">Bibliography.</span>—See Svante August +Arrhenius, <i>Lehrbuch der kosmischen Physik</i> +(Leipzig, 1903), pp. 984-990. For lists of references see J.E. +Burbank, <i>Terrestrial Magnetism</i>, vol. 10 (1905), p. 23, and +P. Bachmetjew (<b>8</b>). For papers descriptive of corrosion of pipes, +&c., by artificial currents see <i>Science Abstracts</i> (in recent years +in the volumes devoted to engineering) under the heading “Traction, +Electric; Electrolysis.” The following are the references +in the text:—(<b>1</b>) <i>Phil. Trans. R.S.</i> for 1849, pt. i. p. 61; (<b>2</b>) <i>Phil. +Trans. R.S.</i> vol. 151 (1861), p. 89, and vol. 152 (1862), p. 203; (<b>3</b>) +<i>Étude des courants telluriques</i> (Paris, 1884); (<b>4</b>) <i>Die Erdströme im +deutschen Reichstelegraphengebiet</i> (Braunschweig, 1900); (<b>5</b>) <i>Phil. +Trans. R.S.</i> vol. 158 (1868), p. 465, and vol. 160 (1870), p. 215; (<b>6</b>) +<i>Mém. de l’Académie St-Pétersbourg</i>, t. 31, No. 12 (1883); (<b>7</b>) T. +Moureaux, <i>Ann. du Bureau Central Mét.</i> (Année 1893), 1 Mem. p. +B 23; (<b>8</b>) P. Bachmetjew, <i>Mém. de l’Académie St-Pétersbourg</i>, vol. 12, +No. 3 (1901); (<b>9</b>) <i>Terrestrial Magnetism</i>, vol. 3 (1898), p. 130; (<b>10</b>) +<i>Journal Tel. Engineers</i> (1881); (<b>11</b>) <i>Proc. R.S.</i> vol. 52 (1892), p. 191; +(<b>12</b>) <i>Akad. Abhandlung</i> (Helsingfors, 1888); (<b>13</b>) <i>Acad. Napoli Rend.</i> +(1890), and <i>Atti</i> (1894, 1895); (<b>14</b>) <i>Pogg. Ann.</i> vol. 76, p. 135; (<b>15</b>) +<i>Proc. R.S.E.</i> vol. 13, p. 530; (<b>16</b>) A. Rücker, <i>Phil. Mag.</i> 1 (1901), p. +423, and R.T. Glazebrook, <i>ibid.</i> p. 432; (<b>17</b>) J. Edler, <i>Elektrotech. +Zeit.</i> vol. 20 (1899); (<b>18</b>) L.A. Bauer, <i>Terrestrial Magnetism</i>, vol. 11 +(1906), p. 53.</p> +</div> +<div class="author">(C. Ch.)</div> + + +<hr class="art" /> +<p><span class="bold">EARTH-NUT,<a name="ar43" id="ar43"></a></span> the English name for a plant known botanically +as <i>Conopodium denudatum</i> (or <i>Bunium flexuosum</i>), a member of +the natural order Umbelliferae, which has a brown tuber-like +root-stock the size of a chestnut. It grows in woods and fields, +has a slender flexuous smooth stem 2 to 3 ft. high, much-divided +leaves, and small white flowers in many-rayed terminal compound +umbels. Boswell Syme, in <i>English Botany</i>, iv. 114, says: “The +common names of this plant in England are various. It is +known as earth-nut, pig-nut, ar-nut, kipper-nut, hawk-nut, +jar-nut, earth-chestnut and ground-nut. Though really excellent +in taste and unobjectionable as food, it is disregarded +in England by all but pigs and children, both of whom +appreciate it and seek eagerly for it.” Dr Withering describes +the roots as little inferior to chestnuts. In Holland +<span class="pagenum"><a name="page817" id="page817"></a>817</span> +and elsewhere on the continent of Europe they are more +generally eaten.</p> + + +<hr class="art" /> +<p><span class="bold">EARTH PILLAR,<a name="ar44" id="ar44"></a></span> a pillar of soft rock, or earth, capped by +some harder material that has protected it from denudation. +The “bad lands” of western North America furnish numerous +examples. Here “the formations are often beds of sandstone +or shale alternating with unindurated beds of clay. A semi-arid +climate where the precipitation is much concentrated +seems to be most favourable to the development of this type +of formation.” The country round the Dead Sea, where loose +friable sandy clay is capped by harder rock, produces “bad-land” +topography. The cap of hard rock gives way at the joints, and +the water making its way downwards washes away the softer +material directly under the cracks, which become wider, leaving +isolated columns of clay capped with hard sandstone or limestone. +These become smaller and fewer as denudation proceeds, the +pillars standing a great height at times, until finally they all +disappear.</p> + + +<hr class="art" /> +<p><span class="bold">EARTHQUAKE.<a name="ar45" id="ar45"></a></span> Although the terrible effects which often +accompany earthquakes have in all ages forced themselves upon +the attention of man, the exact investigation of seismic phenomena +dates only from the middle of the 19th century. A new science +has been thus established under the name of <i>seismology</i> (Gr. +<span class="grk" title="seismos">σεισμός</span>, an earthquake).</p> + +<p><i>History.</i>—Accounts of earthquakes are to be found scattered +through the writings of many ancient authors, but they are, for +the most part, of little value to the seismologist. There is a +natural tendency to exaggeration in describing such phenomena, +sometimes indeed to the extent of importing a supernatural +element into the description. It is true that attempts were made +by some ancient writers on natural philosophy to offer a rational +explanation of earthquake phenomena, but the hypotheses +which their explanations involved are, as a rule, too fanciful to +be worth reproducing at the present day. It is therefore unnecessary +to dwell upon the references to seismic phenomena +which have come down to us in the writings of such historians +and philosophers as Thucydides, Aristotle and Strabo, Seneca, +Livy and Pliny. Nor is much to be gleaned from the pages of +medieval and later writers on earthquakes, of whom the most +notable are Fromondi (1527), Maggio (1571) and Travagini +(1679). In England, the earliest work worthy of mention is +Robert Hooke’s <i>Discourse on Earthquakes</i>, written in 1668, and +read at a later date before the Royal Society. This discourse, +though containing many passages of considerable merit, tended +but little to a correct interpretation of the phenomena in question. +Equally unsatisfactory were the attempts of Joseph Priestley +and some other scientific writers of the 18th century to connect +the cause of earthquakes with electrical phenomena. The great +earthquake of Lisbon in 1755 led the Rev. John Michell, professor +of mineralogy at Cambridge, to turn his attention to the subject; +and in 1760 he published in the <i>Philosophical Transactions</i> a +remarkable essay on the Cause and Phenomena of Earthquakes. +A suggestion of much scientific interest was made by Thomas +Young, when in his <i>Lectures on Natural Philosophy</i>, published +in 1807, he remarked that an earthquake “is probably propagated +through the earth nearly in the same manner as a noise +is conveyed through the air.” The recognition of the fact that +the seismologist has to deal with the investigation of wave-motion +in solids lies at the very base of his science. In 1846 +Robert Mallet communicated to the Royal Irish Academy his +first paper “On the Dynamics of Earthquakes”; and in the +following year W. Hopkins, of Cambridge, presented to the +British Association a valuable report in which earthquake +phenomena were discussed in some detail. Mallet’s labours +were continued for many years chiefly in the form of Reports to +the British Association, and culminated in his great work on +the Neapolitan earthquake of 1857. An entirely new impetus, +however, was given to the study of earthquakes by an energetic +body of observers in Japan, who commenced their investigations +about the year 1880, mainly through the influence of Prof. +John Milne, then of Tokyo. Their work, carried on by means of +new instruments of precision, and since taken up by observers +in many parts of the world, has so extended our knowledge of +earthquake-motion that seismology has now become practically +a new department of physical science.</p> + +<p>It is hardly too much to say, however, that the earliest +systematic application of scientific principles to the study of the +effects of an earthquake was made by Mallet in his investigation +of the Neapolitan earthquake mentioned above. It is true, the +great Calabrian earthquake of 1783 had been the subject of +careful inquiry by the Royal Academy of Naples, as also by +Deodat Dolomieu and some other scientific authorities; but in +consequence of the misconception which at that time prevailed +with regard to the nature of seismic activity, the results of the +inquiry, though in many ways interesting, were of very limited +scientific value. It was reserved for Mallet to undertake for +the first time an extensive series of systematic observations in +an area of great seismic disturbance, with the view of explaining +the phenomena by the application of the laws of wave-motion.</p> + +<p>The “Great Neapolitan Earthquake,” by which more than +12,300 lives were lost, was felt in greater or less degree over +all Italy south of the parallel of 42°, and has been +regarded as ranking third in order of severity among the +<span class="sidenote">Neapolitan earthquake, 1857.</span> +recorded earthquakes of Europe. The principal shock +occurred at about 10 <span class="scs">P.M.</span> on the 16th of December +1857; but, as is usually the case, it had been preceded by minor +disturbances and was followed by numerous after-shocks which +continued for many months. Early in 1858, aided by a grant +from the Royal Society, Mallet visited the devastated districts, +and spent more than two months in studying the effects of the +catastrophe, especially examining, with the eye of an engineer, +the cracks and ruins of the buildings. His voluminous report +was published in 1862, and though his methods of research and +his deductions have in many cases been superseded by the +advance of knowledge, the report still remains a memorable +work in the history of seismology.</p> + +<p>Much of Mallet’s labour was directed to the determination of +the position and magnitude of the subterranean source from +which the vibratory impulses originated. This is known variously +as the <i>seismic centre</i>, <i>centrum</i>, <i>hypocentre</i>, <i>origin</i> or <i>focus</i>. It +is often convenient to regard this centre theoretically as a point, +but practically it must be a locus or space of three dimensions, +which in different cases varies much in size and shape, and may +be of great magnitude. That part of the surface of the earth +which is vertically above the centre is called the <i>epicentre</i>; or, +if of considerable area, the epicentral or epifocal tract. A +vertical line joining the epicentre and the focus was termed by +Mallet the <i>seismic vertical</i>. He calculated that in the case of the +Neapolitan earthquake the focal cavity was a curved lamelliform +fissure, having a length of about 10 m. and a height of about +3½ m., whilst its width was inconsiderable. The central point +of this fissure, the theoretical seismic centre, he estimated to +have been at a depth of about 6½ m. from the surface. Dr C. +Davison, in discussing Mallet’s data, was led to the conclusion +that there were two distinct foci, possibly situated on a fault, +or plane of dislocation, running in a north-west and south-east +direction. Mallet located his epicentre near the village of +Caggiano, not far from Polla, while the other seems to have been +in the neighbourhood of Montemurro, about 25 m. to the south-east.</p> + +<p>The intensity, or violence, of an earthquake is greatest in or +near the epicentre, whence it decreases in all directions. A line +drawn through points of equal intensity forms a curve round the +epicentre known as an <i>isoseist</i>, an <i>isoseismal</i> or an <i>isoseismic +line</i>. If the intensity declined equally in all directions the +isoseismals would be circles, but as this is rarely if ever the case +in nature they usually become ellipses and other closed curves. +The tract which is most violently shaken was termed by Mallet +the <i>meizoseismic area</i>, whilst the line of maximum destruction +is known as the <i>meizoseismic line</i>. That isoseismal along which +the decline of energy is most rapid was called by K. von Seebach +a <i>pleistoseist</i>.</p> + +<p>In order to determine the position of the seismic centre, Mallet +made much use of the cracks in damaged buildings, especially +<span class="pagenum"><a name="page818" id="page818"></a>818</span> +in walls of masonry, holding that the direction of such fractures +must generally be at right angles to that in which the normal +earthquake-wave reached them. In this way he obtained the +“angle of emergence” of the wave. He also assumed that +free-falling bodies would be overthrown and projected in the +direction of propagation of the wave, so that the epicentre might +immediately be found from the intersection of such directions. +These data are, however, subject to much error, especially +through want of homogeneity in the rocks, but Mallet’s work +was still of great value.</p> + +<p>A different method of ascertaining the depth of the focus +was adopted by Major C.E. Dutton in his investigation of the +Charleston earthquake of the 31st of August 1886 +for the U.S. Geological Survey. This catastrophe +<span class="sidenote">Charleston earthquake, 1886.</span> +was heralded by shocks of greater or less severity a +few days previously at Summerville, a village 22 m. +north-west of Charleston. The great earthquake occurred at +9.51 <span class="scs">P.M.</span>, standard time of the 75th meridian, and in about +70 seconds almost every building in Charleston was more or +less seriously damaged, while many lives were lost. The +epicentral tract was mainly a forest region with but few +buildings, and the principal records of seismological value were +afforded by the lines of railway which traversed the disturbed +area. In many places these rails were flexured and dislocated. +Numerous fissures opened in the ground, and many of these +discharged water, mixed sometimes with sand and silt, which +was thrown up in jets rising in some cases to a height of 20 ft. +Two epicentres were recognized—one near Woodstock station +on the South Carolina railway, and the other, being the centre +of a much smaller tract, about 14 m. south-west of the first and +near the station of Rantowles on the Charleston and Savannah +line. Around these centres and far away isoseismal lines were +drawn, the relative intensity at different places being roughly +estimated by the effects of the catastrophe on various structures +and natural objects, or, where visible records were wanting, +by personal evidence, which is often vague and variable. The +Rossi-Forel scale was adopted. This is an arbitrary scale +formulated by Professor M.S. de Rossi, of Rome, and Dr F.A. +Forel, of Geneva, based mostly on the ordinary phenomena +observed during an earthquake, and consisting of ten degrees, +of which the lowest is the feeblest, viz. I. Microseismic shock; +II. Extremely feeble shock; III. Very feeble shock; IV. +Feeble; V. Shock of moderate intensity; VI. Fairly strong +shock; VII. Strong shock; VIII. Very strong shock; IX. +Extremely strong shock; X. Shock of extreme intensity. +Other conventional scales, some being less detailed, have been +drawn up by observers in such earthquake-shaken countries +as Italy and Japan. A curve, or theoretical isoseismal, drawn +through certain points where the decline of intensity on receding +from the epicentre seems to be greatest was called by Dutton +an “index-circle”; and it can be shown that the radius of such +a circle multiplied by the square root of 3 gives the focal depth +theoretically. In this way it was computed that in the Charleston +earthquake the origin under Woodstock must have had a depth +of about 12 m. and that near Rantowles a depth of nearly 8 m. +The determination of the index-circle presents much difficulty, +and the conclusions must be regarded as only approximate.</p> + +<p>It is probable, according to R.D. Oldham, that local +earthquakes may originate in the “outer skin” of the earth, +whilst a large world-shaking earthquake takes its origin in the +deeper part of the “crust,” whence such a disturbance is termed a +<i>bathyseism</i>. Large earthquakes may have very extended origins, +with no definite centre, or with several foci.</p> + +<p>The gigantic disaster known as the “Great Indian Earthquake,” +which occurred on the 12th of June 1897, was the subject of +careful investigation by the Geological Survey of +India and was described in detail by the superintendent, +<span class="sidenote">Great Indian earthquake, 1897.</span> +R.D. Oldham. It is sometimes termed +the Assam earthquake, since it was in that province +that the effects were most severe, but the shocks +were felt over a large part of India, and indeed far beyond its +boundaries. Much of the area which suffered most disturbance +was a wild country, sparsely populated, with but few buildings +of brick or stone from which the violence of the shocks could +be estimated. The epicentral tract was of great size, having +an estimated area of about 6000 sq. m., but the mischief was +most severe in the neighbourhood of Shillong, where the +stonework of bridges, churches and other buildings was absolutely +levelled to the ground. After the main disturbance, +shocks of greater or less severity continued at intervals for many +weeks. It is supposed that this earthquake was connected with +movement of subterranean rock-masses of enormous magnitude +along a great thrust-plane, or series of such planes, having a +length of about 200 m. and a maximum breadth of not less than +50 m. It is pointed out by Oldham that this may be compared +for size with the great Faille du Midi in Belgium, which is known +to extend for a distance of 120 m. The depth of the principal +focus, though not actually capable of determination, was probably +less than 5 m. from the surface. From the focus many +secondary faults and fractures proceeded, some reaching the +surface of the ground. Enormous landslips accompanied the +earthquake, and as an indirect effect of these slides the form of +the water-courses became in certain cases modified. Permanent +changes of level were also observed.</p> + +<p>Eight years after the great Assam earthquake India was +visited by another earthquake, which, though less intense, +resulted in the loss of about 20,000 lives. This catastrophe +is known as the Kangra earthquake, since its +<span class="sidenote">Kangra earthquake, 1905.</span> +centre seems to have been located in the Kangra +valley, in the north-west Himalaya. It occurred on +the 4th of April 1905, and the first great shocks were felt in the +chief epifocal district at about 6.9 a.m., Madras time. Although +the tract chiefly affected was around Kangra and Dharmsala, +there was a subordinate epifocal tract in Dehra Dun and the +neighbourhood of Mussoorie, whilst the effects of the earthquake +extended in slight measure to Lahore and other cities of the +plain. It is estimated that the earthquake was felt over an area of +about 1,625,000 m. Immediately after the calamity a scientific +examination of its effects was made by the Geological Survey +of India, and a report was drawn up by the superintendent, +C.S. Middlemiss.</p> + +<p>The great earthquake, which, with the subsequent fire, wrought +such terrible destruction in and around San Francisco on the 18th +of April 1906, was the most disastrous ever recorded in +California. It occurred between 10 and 15 minutes +<span class="sidenote">California earthquake, 1906.</span> +after 5 <span class="scs">A.M.</span>, standard time of the 120th meridian. +The moment at which the disaster began and the +duration of the shock varied at different localities in the great +area over which the earthquake was felt. At San Francisco +the main shock lasted rather more than one minute.</p> + +<p>According to the official Report, the earthquake was due +to rupture and movement along the plane of the San Andreas +fault, one of a series which runs for several hundred miles +approximately in a N.W. and S.E. direction near the coast +line. Evidence of fresh movement along this plane of dislocation +was traced for a distance of 190 m. from San Juan +on the south to Point Arena on the north. There the trace of +the fault is lost beneath the sea, but either the same fault or +another appears 75 m. to the north at Point Delgada. The belt +of disturbed country is notoriously unstable, and part of the +fault had been known as the “earthquake crack.” The direction +is marked by lines of straight cliffs, long ponds and narrow +depressions, forming a Rift, or old line of seismic disturbance. +According to Dr G.K. Gilbert the earthquake zone has a length +of 300 or 400 m. The principal displacement of rock, in 1906, +was horizontal, amounting generally to about 10 ft. (maximum +21 ft.), but there was also locally a slight vertical movement, +which towards the north end of the fault reached 3 ft. Movement +was traced for a distance of about 270 m., and it is estimated +that at least 175,000 sq. m. of country must have been disturbed. +In estimating the intensity of the earthquake in San Francisco +a new scale was introduced by H.O. Wood. The greatest +structural damage occurred on soft alluvial soil and “made +ground.” Most of the loss of property in San Francisco was +<span class="pagenum"><a name="page819" id="page819"></a>819</span> +due to the terrible fire which followed the earthquake and was +beyond control owing to the destruction of the system of water-supply.</p> + +<p>Immediately after the catastrophe a California Earthquake +Investigation Committee was appointed by the governor of +the state; and the American Association for the Advancement +of Science afterwards instituted a Seismological Committee. +The elaborate Report of the State Investigation Committee, +by the chairman, Professor A.C. Lawson, was published in 1908.</p> + +<p>On the 17th of August 1906 a disastrous earthquake occurred +at Valparaiso, and the year 1906 was marked generally by +exceptional seismic activity.</p> + +<p>The Jamaica earthquake of the 14th of January 1907 appears +to have accompanied movement of rock along an east and west +fracture or series of fractures under the sea a few miles from the +city of Kingston. The statue of Queen Victoria at Kingston +was turned upon its pedestal the eighth of a revolution.</p> + +<p>A terrible earthquake occurred in Calabria and Sicily on +December 28, 1908, practically destroying Messina and Reggio. +According to the official returns the total loss of life +was 77,283. Whilst the principal centre seems to +<span class="sidenote">Messina earthquake, 1908.</span> +have been in the Strait of Messina, whence the disturbance +is generally known as the Messina earthquake, +there were independent centres in the Calabrian peninsula, +a country which had been visited by severe earthquakes not +long previously, namely on September 8, 1905, and October +23, 1907. The principal shock of the great Messina earthquake +of 1908 occurred at 5.21 <span class="scs">A.M.</span> (4.21 Greenwich time), and had a +duration of from 30 to 40 seconds. Neither during nor immediately +before the catastrophe was there any special volcanic +disturbance at Etna or at Stromboli, but it is believed that there +must have been movement along a great plane of weakness in +the neighbourhood of the Strait of Messina, which has been +studied by E. Cortese. The sea-floor in the strait probably +suffered great disturbance, resulting in the remarkable movement +of water observed on the coast. At first the sea retired, +and then a great wave rolled in, followed by others generally +of decreasing amplitude, though at Catania the second was said +to have been greater than the first. At Messina the height of +the great wave was 2.70 metres, whilst at Ali and Giardini it +reached 8.40 metres and at San Alessio as much as 11.7 metres. +At Malta the tide-gauge recorded a wave of 0.91 metre. The +depth of the chief earthquake-centre was estimated by Dr E. +Oddone at about 9 kilometres. The earthquake and accompanying +phenomena were studied also by Professor A. Riccò, Dr M. +Baratta and Professor G. Platania and by Dr F. Omori of Tokyo. +After the great disturbance, shocks continued to affect the region +intermittently for several months. In certain respects the +earthquake of 1908 presented much resemblance to the great +Calabrian catastrophe of 1783.</p> + +<p>It has been proposed by R.D. Oldham that the disturbance +which causes the fracture and permanent displacement of the +rocks during an earthquake should be called an “earthshake,” +leaving the term earthquake especially for the vibratory motion. +The movement of the earthquake is molecular, whilst that of +the earthshake is molar. Subsequently he suggested the terms +<i>mochleusis</i> and <i>orchesis</i> (<span class="grk" title="mochleuô">μοχλέυω</span>, I heave; <span class="grk" title="orcheomai">ὀρχέομαι</span>, I dance), +to denote respectively the molar and the molecular movement, +retaining the word earthquake for use in its ordinary sense.</p> + +<p>In most earthquakes the proximate cause is generally regarded +as the fracture and sudden movement of underground rock-masses. +Disturbances of this type are known as “tectonic” +earthquakes, since they are connected with the folding and faulting +of the rocks of the earth’s crust. They indicate a relief of +the strain to which the rock-masses are subjected by mountain-making +and other crustal movements, and they are consequently +apt to occur along the steep face of a table-land or the margin +of a continent with a great slope from land to sea. In many +cases the immediate seat of the originating impulse is located +beneath the sea, giving rise to submarine disturbances which +have been called “seaquakes.” Much attention has been given +to these suboceanic disturbances by Professor E. Rudolph.</p> + +<p>Professor J.H. Jeans has pointed out that the regions of the +earth’s crust most affected by earthquakes lie on a great circle +corresponding with the equator of the slightly pear-shaped +figure that he assigns to the earth. This would represent a belt +of weakness, subject to crushing, from the tendency of the pear +to pass into a spherical or spheroidal form under the action of +internal stresses. According to the comte de Montessus de +Ballore, the regions of maximum seismic instability appear +to be arranged on two great circles, inclined to each other at +about 67°. These are the Circumpacific and Mediterranean zones.</p> + +<p>Maps of the world, showing the origins of large earthquakes +each year, accompany the Annual Reports of the Seismological +Committee of the British Association, drawn up by Professor +Milne. It is important to note that Professor Milne has shown +a relationship between earthquake-frequency and the wandering +of the earth’s pole from its mean position. Earthquakes seem +to have been most frequent when the displacement of the pole +has been comparatively great, or when the change in the direction +of movement has been marked. Valuable earthquake catalogues +have been compiled at various times by Alexis Perrey, R. and +J.W. Mallet, John Milne, T. Oldham, C.W.C. Fuchs, F. de +Montessus de Ballore and others.</p> + +<p>Such earthquakes as are felt from time to time in Great Britain +may generally be traced to the formation of faults, or rather +to incidents in the growth of old faults. The East +Anglian earthquake of the 22nd of April 1884—the +<span class="sidenote">British earthquakes.</span> +most disastrous that had occurred in the British Isles +for centuries—was investigated by Prof. R. Meldola +and W. White on behalf of the Essex Field Club. The shocks +probably proceeded from two foci—one near the villages of +Peldon and Abberton, the other near Wivenhoe and Rowhedge, +in N.E. Essex. It is believed that the superficial disturbance +resulted from rupture of rocks along a deep fault. An attempt +has been made by H. Darwin, for the Seismological Committee +of the British Association, to detect and measure any gradual +movement of the strata along a fault, by observation at the +Ridgeway fault, near Upway, in Dorsetshire. Dr C. Davison +in studying the earthquakes which have originated in Britain +since 1889 finds that several have been “twins.” A twin earthquake +has two maxima of intensity proceeding from two foci, +whereas a double earthquake has its successive impulses from +what is practically a single focus. The Hereford earthquake +of December 1896, which resulted in great structural damage, +was a twin, having one epicentre near Hereford and the other +near Ross. Davison refers it to a slip along a fault-plane between +the anticlinal areas of Woolhope and May Hill; and according +to the same authority the Inverness earthquake of the 18th of +September 1901 was referable to movement along a fault +between Loch Ness and Inverness. The South Wales earthquake +of June 27, 1906, was probably due to movement connected +with the Armorican system of folds, striking in an east and west +direction.</p> + +<p>It may be noted that when a slip occurs along a fault, the +displacement underground may be but slight and may die out +before reaching the surface, so that no scarp is formed. In +connexion, however, with a seismic disturbance of the first +magnitude the superficial features may be markedly affected. +Thus, the great Japan earthquake of October 1891—known +often as the Mino-Owari earthquake—was connected with +the formation or development of a fault which, according to +Professor B. Koto, was traced on the surface for a distance of +nearly 50 m. and presented in places a scarp with a vertical +throw of as much as 20 ft., while probably the maximum displacement +underground was very much greater.</p> + +<p>Although most earthquakes seem to be of tectonic type, +there are some which are evidently connected, directly or +indirectly, with volcanic activity (see <span class="sc"><a href="#artlinks">Volcano</a></span>). Such, it is +commonly believed, were the earthquakes which disturbed +the Isle of Ischia in 1881 and 1883, and were studied by Professor +J. Johnston-Lavis and G. Mercalli. In addition to the tectonic +and volcanic types, there are occasional earthquakes of minor +importance which may be referred to the collapse of the roof of +<span class="pagenum"><a name="page820" id="page820"></a>820</span> +caverns, or other falls of rock in underground cavities at no +great depth. According to Prof. T.J.J. See most earthquakes +are due, directly or indirectly, to the explosive action of steam, +formed chiefly by the leakage of sea-water through the ocean floor.</p> + +<p>Whatever the nature of the impulse which originates the +earthquake, it gives rise to a series of waves which are propagated +through the earth’s substance and also superficially. In +one kind, known as normal or condensational waves, +<span class="sidenote">Earthquake waves.</span> +or waves of elastic compression, the particles vibrate +to and from the centre of disturbance, moving in the +direction in which the wave travels, and therefore in a way +analogous to the movement of air in a sound-wave. Associated +with this type are other waves termed transverse waves, or +waves of elastic distortion, in which the particles vibrate across +or around the direction in which the wave is propagated. +The normal waves result from a temporary change of volume +in the medium; the transverse from a change of shape. The +distance through which an earth-particle moves from its mean +position of rest, whether radially or transversely, is called the +amplitude of the wave; whilst the double amplitude, or total +distance of movement, to and fro or up and down, like the +distance from crest to trough of a water wave, may be regarded +as the range of the wave. The period of a wave is the time +required for the vibrating particle to complete an oscillation. +As the rocks of the earth’s crust are very heterogeneous, the +earthquake-waves suffer refraction and reflection as they pass +from one rock to another differing in density and elasticity. +In this way the waves break up and become much modified in +course of transmission, thus introducing great complexity into +the phenomena. It is known that the normal waves travel +more rapidly than the transverse.</p> + +<p>Measurements of the surface speed at which earthquake-waves +travel require very accurate time-measurers, and these are +not generally available in earthquake-shaken regions. Observations +during the Charleston earthquake of 1886 were at that time +of exceptional value, since they were made over a large area +where standard time was kept. Lines drawn through places +around the epicentre at which the shock arrives at the same +moment are called coseismal lines. The motion of the wave is to +be distinguished from the movement of the vibrating particles. +The velocity of the earth-particle is its rate of movement, but +this is constantly changing during the vibration, and the rate +at which the velocity changes is technically called the acceleration +of the particle.</p> + +<p>Unfelt movements of the ground are registered in the +earthquake records, or seismograms, obtained by the delicate +instruments used by modern seismologists. From the study of +the records of a great earthquake from a distant source, sometimes +termed a teleseismic disturbance, some interesting inferences +have been drawn with respect to the constitution of +the interior of the earth. The complete record shows two phases +of “preliminary tremors” preceding the principal waves. It is +believed that while the preliminary tremors pass through the +body of the earth, the principal waves travel along or parallel to +the surface. Probably the first phase represents condensational, +and the second phase distortional, waves. Professor Milne concludes +from the speed of the waves at different depths that +materials having similar physical properties to those at the +surface may extend to a depth of about 30 m., below which they +pass into a fairly homogeneous nucleus. From the different rates +of propagation of the precursors it has been inferred by R.D. +Oldham that below the outer crust, which is probably not +everywhere of the same thickness, the earth is of practically +uniform character to a depth of about six-tenths of the radius, +but the remaining four-tenths may represent a core differing +physically and perhaps chemically from the outer part. +Oldham also suggests, from his study of oceanic and continental +wave-paths, that there is probably a difference in the constitution +of the earth beneath oceans and beneath continents.</p> + +<p>The surface waves, which are waves of great length and long +period and are propagated to great distances with practically a +constant velocity, have been regarded as quasi-elastic gravitational +waves. Further, in a great earthquake the surface of the ground +is sometimes visibly agitated in the epifocal district by undulations +which may be responsible for severe superficial damage. +(See also for elastic waves <span class="sc"><a href="#artlinks">Elasticity</a></span>, § 89.)</p> + +<p>An old classification of earthquake-shocks, traces of which still +linger in popular nomenclature, described them as “undulatory,” +when the movement of the ground was mainly in a horizontal +direction; “subsultory,” when the motion was vertical, like the +effect of a normal wave at the epicentre; and “vorticose,” +when the movement was rotatory, apparently due to successive +impulses in varying directions.</p> + +<p>The sounds which are associated with seismic phenomena, +often described as subterranean rumbling and roaring, are not +without scientific interest, and have been carefully studied by +Davison. “Isacoustic lines” are curves drawn through places +where the sound is heard by the same percentage of observers. +The sound is always low and often inaudible to many.</p> + +<p>The refined instruments which are now used by seismologists +for determining the elements of earthquake motion and for +recording earthquakes from distant origins are described in the +article <span class="sc"><a href="#artlinks">Seismometer</a></span>. These instruments were developed as a +consequence of the attention given in modern times to the study +of earthquakes in the Far East.</p> +<div class="author">(F. W. R.*)</div> + +<p class="pt1">Strange as it may appear, the advances that have been +made in the study of earthquakes and the world-wide interest +shown in their phenomena were initiated in work commenced +in Japan. When the Japanese government, +<span class="sidenote">Seismology in Japan.</span> +desiring to adopt Western knowledge, invited to +its shores bodies of men to act as its instructors, the +attention of the newcomers was naturally attracted to the +frequent shakings of the ground. Interest in these phenomena +increased more rapidly than their frequency, and at length it was +felt that something should be done for their systematic study. +At midnight on the 22nd of February 1880 movements more +violent than usual occurred; chimneys were shattered or rotated, +tiles slid down from roofs, and in the morning it was seen that +Yokohama had the appearance of a city that had suffered a +bombardment. The excitement was intense, and before the ruins +had been removed a meeting was convened and the Seismological +Society of Japan established. The twenty volumes of original +papers published by this body summarize to a large extent the +results of the later study of seismology.<a name="fa1d" id="fa1d" href="#ft1d"><span class="sp">1</span></a></p> + +<p>The attention of the students of earthquakes in Japan was +at first directed almost entirely to seismometry or earthquake +measurement. Forms of apparatus which then existed, as for +example the seismographs, seismometers and seismoscopes +of Mallet, Palmieri and others, were subjected to trial; but +inasmuch as they did little more than indicate that an earthquake +had taken place—the more elaborate forms recording also the +time of its occurrence—they were rapidly discarded, and instruments +were constructed to <i>measure</i> earthquake motion. Slightly +modified types of the new instruments devised in Japan were +adopted throughout the Italian peninsula, and it is fair to say +that the seismometry developed in Japan revolutionized the +seismometry of the world. The records obtained from the new +instruments increased our knowledge of the character of earthquake +motion, and the engineer and the architect were placed +in a position to construct so that the effects of known movements +could be minimized. It was no doubt the marked success, both +practical and scientific, attending these investigations that led +the Japanese government to establish a chair of seismology at its +university, to organize a system of nearly 1000 observing stations +throughout the country, and in 1893 to appoint a committee of +scientific and practical men to carry out investigations which +might palliate the effects of seismic disturbances. In the first +year this committee received a grant of £5000, and as liberal +sums for the same purpose appear from time to time in the +<span class="pagenum"><a name="page821" id="page821"></a>821</span> +parliamentary estimates, it may be assumed that the work has +been fraught with good results. In their publications we find not +only records of experiences and experiments in Japan, but descriptions +and comments upon earthquake effects in other countries. +In two of the volumes there are long and extremely well illustrated +accounts of the earthquake which on the 12th of June +1897 devastated Assam, to which country two members of the +above-mentioned committee were despatched to gather such +information as might be of value to the architect and builder +in earthquake-shaken districts.</p> + +<p>A great impetus to seismological investigation in Europe and +America was no doubt given by the realization of the fact that +a large earthquake originating in any one part of the +world may be recorded in almost any other. Italy +<span class="sidenote">Seismological research.</span> +for many years past has had its observatories for +recording earthquakes which can be felt, and which +are of local origin, but at the present time at all its first-class +stations we find instruments to record the unfelt movements +due to earthquakes originating at great distances, and as much +attention is now paid to the large earthquakes of the world as +to the smaller ones originating within Italian territory.<a name="fa2d" id="fa2d" href="#ft2d"><span class="sp">2</span></a> The +<i>Kaiserliche Akademie der Wissenschaften</i> of Vienna established +earthquake observatories in Austria,<a name="fa3d" id="fa3d" href="#ft3d"><span class="sp">3</span></a> and the Central Observatorium +of St Petersburg has carried out similar work in Russia. +Germany attached a seismological observatory to its university +at Strassburg, whilst provision has been made for a professorship +of Earth Physics (<i>Geophysik</i>) at Göttingen.<a name="fa4d" id="fa4d" href="#ft4d"><span class="sp">4</span></a> In accordance with +the recommendation of the British Association, seismographs +of a similar character have been installed at stations all over +the world.<a name="fa5d" id="fa5d" href="#ft5d"><span class="sp">5</span></a> The principal objects of this extended and still +extending system of stations are to determine the velocity with +which motion is propagated over the surface and through the +interior of the earth, to locate the positions of sub-oceanic earthquake +origins, and generally to extend our knowledge respecting +the physical nature of the planet on which we live.</p> + +<p>We now know that earthquakes are many times more frequent +than was previously supposed. In Japan, for example, between +1885 and 1892 no fewer than 8331 were recorded—that +is to say, on the average there were during that time +<span class="sidenote">Frequency of earthquakes.</span> +more than 1000 disturbances per year. Although +many of these did not cause a sensible shaking over +areas exceeding a few hundred square miles, many of them were +sufficiently intense to propagate vibrations round and through +the globe. If we pick out the well-marked earthquake districts +of the world, and give to each of them a seismicity or earthquake +frequency per unit area one-third of that in Japan, the conclusion +arrived at is that considerable areas of our planet are on the +average shaken every half-hour.</p> + +<p>The knowledge which we now possess respecting the localities +where earthquakes are frequent and the forms of the foci from +which they have spread, enables us to speak definitely +respecting the originating causes of many of these +<span class="sidenote">Volcanoes and earthquakes.</span> +phenomena. It is found, for example, that although +in many countries there may be displays of volcanic +and seismic activity taking place almost side by side, it is only +rarely that there is direct relationship between the two. Now +and then, however, before a volcano breaks into eruption there +may be a few ineffectual efforts to form a vent, each of which +is accompanied by no more than a slight local shaking of the +ground. This is true even for the largest and most violent +eruptions, when mountains have with practically a single effort +blown off their heads and shoulders. Thus the earthquake which +accompanied the eruption of Bandaisan, in central Japan, in +1888 was felt only over a radius of 25 m. The analyses of the +seismic registers of Japan clearly indicate that comparatively +few shakings originate near to the volcanoes of the country, the +majority of them, like those of many other countries, coming +from regions where volcanic rocks are absent. The greatest +number spread inland from the Pacific seaboard, the movement +becoming more and more feeble as it approaches the backbone +of the country, which is drilled with numerous volcanic vents. +What is true for Japan is generally true for the western coasts of +North and South America.</p> + +<p>Speaking broadly, earthquakes are most frequent along the +steeper flexures in the earth’s surface, and in those regions where +there is geological evidence to show that slow secular +movements in the earth’s crust are possibly yet in +<span class="sidenote">Origin of earthquakes.</span> +progress. With a unit distance of 2 degrees, or 120 +geographical m., we find that the slopes running +eastwards from the highlands of Japan and westwards from the +Andean ridges down into the Pacific vary from 1 in 20 to 1 in 30, +and it is on the faces or near to the bottom of these slopes that +seismic efforts are frequent. The slopes running from Australia, +eastern America and western Europe into the neighbouring +oceans vary between 1 in 70 and 1 in 250, and in these regions +earthquakes are of rare occurrence. The seismic activity met +with in the Himalayas and the Alps finds its best explanation +in the fact that these mountains are geologically recent, and +there are no reasons to doubt that the forces which brought +their folds into existence are yet in action.</p> + +<p>This peculiar association of earthquakes with pronounced +topographical configuration and certain geological conditions +evidently indicates that the origin of many of them is connected +with rock folding. Inasmuch as certain large earthquakes have +been accompanied by rock fracture, as for example in 1891, +when in central Japan a fault some 50 m. in length was created, +whilst the origins of others have been distinctly traced to the +line of an existing fault or its continuation, we may conclude +that the majority of earthquakes are spasmodic accelerations in +the secular movements which are creating (and in some instances +possibly obliterating) the more prominent features of the earth’s +surface. These secular movements, which include upheavals, +subsidences, horizontal displacements—all of which are explained +on the assumption of a crust seeking support on a nucleus +gradually contracting by loss of heat, are collectively referred +to as bradyseismical (<span class="grk" title="bradys">βραδύς</span>, slow) movements. To these may +be added movements directly attributable to the influence of +gravity. Sub-oceanic districts in a state of seismic strain may +be so far loaded by the accumulation of sediments that gentle +bending may be accompanied by sudden yieldings. This possibly +accounts for the frequency of earthquakes off the mouth of +the Tonegawa on the eastern side of Japan. The distortions so +frequently observed in fossils and pebbles, the varying thickness +of contorted strata, and the “creep” in coal-mines, together +with other phenomena, indicate that rocks may flow. Observations +of this nature lead to the supposition that high plateau-like +regions may be gradually subsiding under the influence of their +own weight, and that the process of settlement may from time +to time be spasmodic in its character. Whether the earthquakes +which originate round the submerged basal frontiers of the +continents bounding the Pacific are ever attributable to such +activities, it is impossible to say. All that we know with certainty +is that they are sometimes accompanied by such a vast displacement +of material that the ocean has been set into a state of oscillation +for periods of 24 hours, that in some instances there have +been marked changes in depth, and that enormous sub-oceanic +landslips have occurred. These phenomena are, however, equally +well explained on the assumption of sudden faulting accompanied +by violent shaking, which would dislodge steeply inclined +beds of material beneath the ocean as it does upon the land.</p> + +<p><span class="pagenum"><a name="page822" id="page822"></a>822</span></p> + +<p>Although the proximate cause of earthquake motion is traced +to sudden yieldings in the crust of the earth brought about +by some form of bradyseismical action, the existence +of at least two distinct types of seismic motion +<span class="sidenote">Two types of earthquake motion.</span> +indicates that the mechanical conditions accompanying +the fracturing of rocks are not always identical. +90 or 95% of the earthquakes which can be recorded consist +of elastic or quasi-elastic vibrations. The remainder, +including the large earthquakes, not only exhibit the elastic +movements, but are accompanied by surface undulations which +are propagated most certainly for some hundreds of miles round +their origin, and then as horizontal movements sweep over the +whole surface of the globe. The former of these may accompany +the formation of a new fault or the sudden renewal of movement +along an old one; they are cracking or rending effects, without +any great displacement. The latter are probably fracturings +accompanied by vertical and horizontal displacements of masses +of the earth’s crust sufficiently great to set up the observed +surface undulations. These shocks are so frequently followed +a few minutes later by disturbances, which from their similarity +to the movements which have preceded them may be called +earthquake echoes, that we are led to the speculation that we are +here dealing with the caving-in of ill-supported portions of the +earth’s crust, the waves from which are radiated to boundaries +and then returned to their origin to coalesce and give rise to a +second impulse not unlike the primary. Succeeding the first +repetition of motion recorded by the seismograph there is often +a rhythmical repetition of similar wave groups, suggesting the +existence within our earth of phenomena akin to multiple echoes.</p> + +<p>The introduction of new methods into seismometry quickly +revolutionized our ideas respecting the character of earthquake +motion. Although an earthquake may be strongly +felt within a distance of 50 m. from its origin, and +<span class="sidenote">Character of earthquake motion.</span> +although the movements in the upper storeys of +buildings within the shaken area may be large, the +actual range of the horizontal motion of the ground is usually +less than <span class="spp">1</span>⁄<span class="suu">10</span> of an inch. With such earthquakes ordinary seismographs +for recording vertical motion do not show any disturbance. +When the movement reaches ½ in. it becomes dangerous, and +a back-and-forth movement of an inch is usually accompanied +by destructive effects. In this latter case the amplitude of the +vertical record which indicates the existence of surface waves +will vary between ½ and <span class="spp">1</span>⁄<span class="suu">100</span> of an inch. In the earthquake which +devastated central Japan on the 26th of October 1891, nearly +every building within the epifocal district fell, the ground was +fissured, forests slipped down from mountain sides to dam up +valleys, whilst the valleys themselves were permanently compressed. +The horizontal movements seem to have reached +9 in. or 1 ft., and the surface undulations were visible to the eye.</p> + +<p>The rapidity with which the movements are performed varies +throughout a disturbance. A typical earthquake usually commences +with minute elastic vibrations, the periods +of which vary between <span class="spp">1</span>⁄<span class="suu">5</span> and <span class="spp">1</span>⁄<span class="suu">20</span> of a second. These +<span class="sidenote">Period and duration.</span> +are recorded by seismographs, and are noticed by +certain of the lower animals like pheasants, which +before the occurrence of movement perceptible to human beings +scream as if alarmed. When an earthquake is preceded by a +sound we have evidence of preliminary tremors even more +rapid than those recorded by seismographs. Following these +precursors there is a shock or shocks, the period of which will be +1 or 2 seconds. From this climax the movements, although +irregular in character, become slower and smaller until finally +they are imperceptible. The duration of a small earthquake +usually varies from a few seconds to a minute, but large earthquakes, +which are accompanied by surface undulations, may be +felt for 2 or 3 minutes, whilst an ordinary seismograph indicates +a duration of from 6 to 12 minutes. A free horizontal pendulum +tells us that with severe earthquakes the ground comes to rest +by a series of more or less rhythmical surgings, continuing over +1 or 2 hours. Although the maximum displacement has a +definite direction, the successive vibrations are frequently +performed in many different azimuths. The predominating +direction at a given station in certain instances is apparently +at right angles to the strike of the neighbouring strata, this +being the direction of easiest yielding.</p> + +<p>Earthquake motion as recorded at stations several thousands +of miles distant from its origin exhibits characteristics strikingly +different from those just described. The precursors +now show periods of from 1 to 5 seconds, whilst the +<span class="sidenote">Velocity.</span> +largest movements corresponding to the shocks may have +periods of from 20 to 40 seconds. The interval of time by +which the first tremors have outraced the maximum movement +has also become greater. Within a few hundreds of miles from +an origin this interval increases steadily, the velocity of propagation +of the first movements being about 2 km. per second, +whilst that of the latter may be taken at about 1.6 km. per +second. Beyond this distance the velocity of transmission of +the first movements rapidly increases, and for great distances, +as for example from Japan to England, it is higher than we +should expect for waves of compression passing through steel +or glass. This observation precludes the idea that these preliminary +tremors have travelled through the heterogeneous +crust of the earth, and since the average velocity of their transmission +increases with the length of the path along which they +have travelled, and we but rarely obtain certain evidence that a +seismograph has been disturbed by waves which have reached +it by travelling in opposite directions round the world, we are +led to the conclusion that earthquake precursors pass through +our earth and not round its surface. The following table relating +to earthquakes, which originated off the coast of Borneo on the +20th and 27th of September 1897, is illustrative of the velocities +here considered:—</p> + +<table class="ws" summary="Contents"> +<tr><td class="tccm allb">Localities.</td> + <td class="tccm allb">Distance<br />from<br />origin<br />in degrees.</td> + <td class="tccm allb">Velocity<br />in kms.<br />per sec. if<br />on chord.</td> + <td class="tccm tb bb">¼ <span style="font-size: 500%;">√</span></td> + <td class="tclm tb bb rb">Average<br />depth of<br />chord in<br />kms.</td></tr> + +<tr><td class="tcl lb rb">Nicolaieff</td> <td class="tcc rb">81°</td> <td class="tcc rb">8.1</td> <td class="tcc rb" colspan="2">8.0</td></tr> +<tr><td class="tcl lb rb">Potsdam</td> <td class="tcc rb">92°</td> <td class="tcc rb">8.4</td> <td class="tcc rb" colspan="2">9.1</td></tr> +<tr><td class="tcl lb rb">Catania, Ischia, Rocca di Papa, Rome</td> <td class="tcc rb">96°</td> <td class="tcc rb">9.0</td> <td class="tcc rb" colspan="2">9.5</td></tr> +<tr><td class="tcl lb rb bb">Isle of Wight</td> <td class="tcc rb bb">103°</td> <td class="tcc rb bb">9.8</td> <td class="tcc rb bb" colspan="2">10.2</td></tr> +</table> + +<p>The chords referred to here are those joining the earthquake +origins and distant observing stations, and it will be noted that +one-quarter of the square root of the average depths at which +these run closely corresponds to observed average velocities +if wave paths followed chords. This increase of velocity with +average depth shows that the paths followed through the earth +must be curved with their convexity towards the centre of the +earth. These observations do not directly tell us to what extent +a true wave path is deflected from the direction of a chord, +but they suggest as an extremely plausible assumption that +the square of the speed is a linear function of the depth below +the surface of the earth. With this assumption Dr C.G. Knott +shows that the square of the speed (v²) can be expressed +linearly in terms of the average depth of the chord d, thus: +v² = 2.9 + .026 d, the units being miles and seconds. The formula +applies with fair accuracy to moderate and high values of d, but +it gives too high a value for short chords. It follows that the +square of the speed increases 0.9% per mile of descent in the +earth. The conclusion we arrive at is that the preliminary +tremors which pass through the earth do so in the vicinity +of their origin at the rate of almost 2.3 km. per second. This +velocity increases as the wave path plunges downwards, attaining +in the central regions a velocity of 16 to 17 kms., whilst the +highest average velocity which is across a diameter lies between +10 and 12 kms. per second.</p> + +<p>The large surface waves radiating from an origin to a distant +place have velocities lying between 1.6 and 4 kms. per second, +and it has been observed that when the higher velocity has been +noted this refers to an observation at a station very remote +from the origin. One explanation of this is the assumption that +only very large waves indicating a large initial disturbance are +capable of travelling to great distances, and as pointed out by +<span class="pagenum"><a name="page823" id="page823"></a>823</span> +R.D. Oldham, large waves under the influence of gravity will +travel faster than small waves. These waves (which may be +gravitational or distortional) are recorded as slow tiltings of the +ground measured by angles of 0.5 to 10 or 15 seconds of arc, or +as horizontal displacements of 0.5 or several millimetres. Their +calculated lengths have reached 50 kms. (31 m.).</p> + +<p>In the section of this article relating to the cause of earthquakes +a little has been said about their frequency or the number of +times these phenomena are repeated during a given +interval of time. It has been shown that all countries +<span class="sidenote">Frequency.</span> +are very often moved by earthquakes which have originated +at great distances. Great Britain, for example, is crossed about +100 times a year by earthquake waves having durations of from +3 minutes to 3 hours, whilst the vibratory motions which originate +in that country are not only small but of rare occurrence. In the +earlier stages of the world’s history, because the contraction of +its nucleus was more rapid than it is at present, it is commonly +inferred that phenomena accompanying bradyseismical activity +must have been more pronounced and have shown themselves +upon a grander scale than they do at the present time. Now, +although the records of our rocks only carry us back over a certain +portion of this history, they certainly represent an interval of +time sufficiently long to furnish some evidence of such enfeeblement +if it ever existed. So far from this being the case, however, +we meet with distinct evidences in the later chapters of geological +history of plutonic awakenings much more violent than those +recorded at its commencement. During Palaeozoic times many +mountain ranges were formed, and accompanying these orogenic +processes there was marked volcanic activity. In the succeeding +Secondary period plutonic forces were quiescent, but during +the formation of the early Tertiaries, when some of the largest +mountain ranges were created, they awoke with a vigour greater +than had ever been previously exhibited. At this period it is not +improbable that Scotland was as remarkable for its volcanoes +and its earthquakes as Japan is at the present day. If the +statement relating to the general decrease in bradyseismical +changes referred merely to their frequency, and omitted reference +to their magnitude, the views of the geologist and physicist +might harmonize. One explanation for this divergence of +opinion may rest on the fact that too little attention has been +directed to all the conditions which accompany the adaptation +of the earth’s crust to its shrinking nucleus. As the latter grows +smaller the puckerings and foldings of the former should grow +larger. Each succeeding geological epoch should be characterized +by mountain formations more stupendous than those which +preceded them, whilst the fracturing, dislocation, caving-in of +ill-supported regions, and creation of lines of freedom for the +exhibition of volcanic activity which would accompany these +changes, would grow in magnitude. The written records of +many countries reflect but on a smaller scale the crystallized +records in their hills. In 1844, at Comrie, in Perthshire, as many +as twelve earthquakes were recorded in a single month, whilst +now there are but one or two per year. Earthquake frequency +varies with time. A district under the influence of hypogenic +activities reaches a condition of seismic strain which usually +is relieved rapidly at first, but subsequently more slowly.</p> + +<p>The small shocks which follow an initial large disturbance are +known as after-shocks. The first shock which in 1891 devastated +central Japan was accompanied by the formation of a large fault, +and the 3364 small shocks which succeeded this during the +following two years are regarded as due to intermittent settlements +of disjointed material. The decreasing frequency with +which after-shocks occur may be represented by a curve. Dr F. +Omori points out that the continuation of such a curve gives the +means of determining the length of time which will probably +elapse before the region to which it refers will return to the same +seismic quiescence that it had prior to the initial disturbance.</p> + +<p>The positive results that we have respecting the periodicity +of earthquakes are but few. Generally earthquakes are somewhat +more frequent during winter than during summer, and this +applies to both the northern and southern hemispheres. The +<span class="sidenote">Periodicity.</span> +annual periodicity, which, however, does not show itself if only +destructive earthquakes are considered, finds an explanation, +according to Dr Knott, in the annual periodicity of long-continued +stresses, as for example those due to the +accumulation of snow and to barometric gradients. +For certain earthquake regions there appears to be a +distinct semi-annual period for which no satisfactory explanation +has yet been adduced. Although the elaborate registers +of Japan, which have enabled us to group earthquakes according +to their respective origins and varying intensities, and to separate +after-shocks from initial disturbances, have been subjected by +Dr Knott to most careful analysis, with the object of discovering +periodicities connected with the ebb and flow of the tides, the +lunar day or lunar months, nothing of marked character has +been found. Certainly there is slight evidence of a periodicity +connected with the times of conjunction and opposition of the +sun and moon, and a maximum frequency near the time of +perigee, but the effect of lunar stresses is comparatively insignificant. +Ordinary earthquakes, and especially after-shocks, show +a diurnal period, but we cannot say that there are more earthquakes +during the night than during the day.</p> + +<p>Many experiments and investigations have been made to +determine a possible relationship between earthquakes and +electrical phenomena, but beyond drawing attention +to the fact that luminous appearances may accompany +<span class="sidenote">Magnetic phenomena.</span> +the friction of moving masses of rock, and that a +temporary current may be established in a line by the +disturbance of an earth-plate, these inquiries have yielded but +little of importance. The inquiries respecting a possible relationship +between adjustments so frequently taking place within +and beneath that region called the crust of the earth and magnetic +phenomena are, however, of a more promising nature. +We have seen that at or near the origin of earthquakes which for +several hours disturb continents, and occasionally cause oceans +to oscillate for longer periods, we sometimes have direct evidence +of the bodily displacement of many cubic miles of material. +When this material is volcanic it is almost invariably magnetic, +and we perceive in its sudden rearrangement causes which should +produce magnetic effects within an epifocal district. In Japan, +where attention is being directed to phenomena of this description, +not only have such effects been observed, but unusual +magnetic disturbances have been noted prior to the occurrence +of large earthquakes. These may, of course, be regarded as mere +coincidences, but when we consider volcanic and seismic activities +as evidences of physical and chemical changes, together with +mechanical displacements of a magnetic magma, it is reasonable +to suppose that they should have at least a local influence +upon magnetic needles. Another form of disturbance to which +magnetic needles are subjected is that which accompanies the +passage of large earth-waves beneath certain observatories +situated at great distances from earthquake origins. At Utrecht, +Potsdam and Wilhelmshaven the magnetographs are frequently +disturbed by seismic waves, whilst at many other European +observatories such effects are absent or only barely appreciable. +To explain these marked differences in the behaviour of magnetic +needles at different stations we are at present only in a position +to formulate hypotheses. They may be due to the fact that +different needles have different periodic times of oscillation; +it is possible that at one observatory the mechanical movements +of the ground are much greater than at others; we may speculate +on the existence of materials beneath and around various observatories +which are different in their magnetic characters; and, +lastly, we may picture a crust of varying thickness, which from +time to time is caused to rise and fall upon a magnetic magma, +the places nearest to this being the most disturbed.</p> + +<p>A subject to which but little attention has been directed is +the effect which displays of seismic and volcanic activities have +had upon the human mind. The effects are distinctly +dual and opposite in character. In countries like +<span class="sidenote">Effects on the human mind.</span> +England, where earthquakes are seldom experienced, +the prevailing idea is that they are associated with all +that is baneful. For certain earthquakes, which fortunately +are less than 1% of those which are annually recorded, this is +<span class="pagenum"><a name="page824" id="page824"></a>824</span> +partially true. A disastrous shock may unnerve a whole community. +Effects of this nature, however, differ in a marked +manner with different nationalities. After the shock of 1891, +when Japan lost 9960 of its inhabitants, amongst the wounded +indications of mental excitement were shown in spinal and other +trouble. Notwithstanding the lightheartedness of this particular +nation, it is difficult to imagine that the long series of seismic +effects chronicled in Japanese history, which culminated in +1896 in the loss of 29,000 lives by sea-waves, has been without +some effect upon its mental and moral character. Several +earthquakes are annually commemorated by special services +at temples. In bygone times governments have recognized +earthquakes as visitations of an angry deity, whom they have +endeavoured to appease by repealing stringent laws and taxes. +In other countries the sermons which have been preached to +show that the tremblings of the world were visitations consequent +on impiety, and the prayers which have been formulated to +ward off disasters in the future, far exceed in number the earthquakes +which gave rise to them. In 1755 many of the English +clergy held the view that Lisbon was destroyed because its +inhabitants were Catholics, whilst the survivors from that +disaster attributed their misfortune to the fact that they had +tolerated a few Protestant heretics in their midst. To avoid +a recurrence of disaster certain of these were baptized by force. +In the myths relating to underground monsters and personages +that are said to be the cause of earthquakes we see the direct +effects which exhibitions of seismic and volcanic activity have +produced upon the imagination. The beliefs, or more properly, +perhaps, the poetical fancies, thus engendered have exhibited +themselves in various forms. Beneath Japan there is said to be +a catfish, which in other countries is replaced by a mole, a hog, +an elephant or other living creature, which when it is restless +shakes the globe. The Kamchadales picture a subterranean +deity called Tuil, who in Scandinavian mythology is represented +by the evil genius Loki. We have only to think of the reference +in the Decalogue forbidding the making of graven images of that +which is in the earth beneath, to see in early Biblical history +evidence of a subterranean mythology; and it seems probable +that the same causes which led to the creation of Pluto, Vulcan +and Poseidon gave rise to practices condemned by Moses.</p> + +<p>Perhaps the greatest practical benefits derived from seismological +investigations relate to important changes and new +principles which have been introduced into the arts of +the engineer and builder when constructing in earthquake +<span class="sidenote">Building to withstand earthquakes.</span> +countries. The new rules and formulae, rather +than being theoretical deductions from hypotheses, +are the outcome of observation and experiment. True +measures of earthquake motion have been given to us by modern +seismometers, with the result that seismic destructivity can be +accurately expressed in mechanical units. From observation +we now know the greatest acceleration and maximum velocity +of an earth particle likely to be encountered; and these are +measures of the destructivity. The engineer is therefore dealing +with known forces, and he has to bear in mind that these are +chiefly applied in a horizontal direction. A formula connecting +the acceleration requisite to overturn bodies of different dimensions +has been given. The acceleration which will fracture or +shatter a column firmly fixed at its foundation to the moving +earth may be expressed as follows:—</p> + +<table class="math0" summary="math"> +<tr><td rowspan="2">a =</td> <td>1</td> +<td rowspan="2"> </td> <td>gFAB</td> +<td rowspan="2">,</td></tr> +<tr><td class="denom">6</td> <td class="denom">fw</td></tr></table> + +<p class="noind">where</p> + +<div class="list f90"> +<p>a = the acceleration per sec. per sec.</p> +<p>F = the force of cohesion, or force per unit surface, which when + gradually applied produces fracture.</p> +<p>A = area of base fractured.</p> +<p>B = thickness of the column.</p> +<p>f = height of centre of gravity of column above the fractured base.</p> +<p>w = the weight of the portion broken off.</p> +</div> + +<p>With this formula and its derivatives we are enabled to state +the height to which a wall, for example, may be built capable +of resisting any assumed acceleration. Experience has shown +that yielding first shows itself at the base of a pier, a wall or a +building, and it is therefore clear that the lower portion of such +structures should be of greater dimensions or stronger than that +above. Piers having these increased dimensions below, and +tapering upwards in a proper manner, so that every horizontal +section is sufficiently strong to resist the effects of the inertia +of its superstructure, are employed to carry railways in Japan. +In that country cast-iron piers are things of the past, whilst +piers of masonry, together with their foundations, no longer +follow the rules of ordinary engineering practice.</p> + +<p>After flood, fire, earthquake, or when opportunity presents +itself, changes are introduced in the construction of ordinary +buildings. In a so-called earthquake-proof house, although +externally it is similar to other dwellings, we find rafters running +from the ridge pole to the floor sills, an exceedingly light roof, +iron straps and sockets replacing mortices and tenons, and many +other departures from ordinary rules. Masonry arches for +bridges or arched openings in walls (unless protected by lintels), +heavy gables, ornamental copings, cappings for chimneys, +have by their repeated failure shown that they are undesirable +features for construction in earthquake countries. As sites for +buildings it is well to avoid soft ground, on which the movement +is always greater than on hard ground. Excessive movement +also takes place along the face of unsupported openings, and for +this reason the edges of scarps, bluffs, cuttings and river-banks +are localities to be avoided. In short, the rules and precautions +which have to be recognized so as to avoid or mitigate the +effects of earthquake movement are so numerous that students +of engineering and architecture in Japan receive a special course +of lectures on this subject. When it is remembered that a large +earthquake may entail a loss of life greater than that which +takes place in many wars, and that for the reconstruction of +ordinary buildings, factories and public works an expenditure +of several million pounds sterling is required, the importance +of these studies cannot be overrated. Severe earthquakes are +fortunately unknown in the British Isles, but we have simply +to turn our eyes to earthquake-shaken colonies and lands in +close commercial touch with Great Britain to realize the importance +of mitigating such disasters as much as possible, and +any endeavour to obviate the wholesale destruction of life +should appeal to the civilized communities of the world.</p> + +<p>An unexpected application of seismometry has been to record +the vibration of railway trains, bridges and steamships. An +instrument of suitable construction will give records +of the more or less violent jolting and vibratory +<span class="sidenote">Applications of seismometry.</span> +movements of a train, and so localize irregularities +due to changes in the character of ballast and sleepers, +to variation in gauge, &c. An instrument placed on a locomotive +throws considerable light upon the effects due to the methods of +balancing the wheels, and by alterations in this respect a saving +of fuel of from 1 to 5 ℔ of coal per mile per locomotive has +sometimes been effected.</p> + +<p>By mapping the centres from which earthquakes originate +off the coast of Japan, we have not only determined districts +where geological activity is pronounced, but have placed before +the cable engineer well-defined localities which it is advisable +to avoid; and in the records of unfelt earthquakes which +originate far from land similar information is being collected +for the deeper parts of the oceans. Occasionally these records +have almost immediately made clear the cause of a cable failure. +From lack of such information in 1888, when the cables connecting +Australia with the outer world were simultaneously broken, +the sudden isolation was regarded as a possible operation of +war, and the colonists called out their naval and military reserves. +Records of earthquakes originating at great distances have +also frequently enabled us to anticipate, to correct, to extend, or +to disprove telegraphic accounts of the disasters. Whatever +information a seismogram may give is certain, whilst the information +gathered from telegrams may in the process of transit +become exaggerated or minimized. Otherwise unaccountable +disturbances in records from magnetographs, barographs and +other instruments employed in observatories are frequently +<span class="pagenum"><a name="page825" id="page825"></a>825</span> +explained by reference to the traces yielded by seismometers. +Perhaps the greatest triumph in seismological investigation has +been the determination of the varying rates at which motion is +propagated through the world. These measurements have already +thrown new light upon its effective rigidity, and if we assume +that the density of the earth increases uniformly from its surface +towards its centre, so that its mean density is 5.5, then, according +to Knott, the coefficient of elasticity which governs the transmission +of preliminary tremors of an earthquake increases at a +rate of nearly 1.2% per mile of descent.</p> +<div class="author">(J. Mi.)</div> + +<div class="condensed"> +<p><span class="sc">Authorities.</span>—J. Milne, <i>Seismology</i> (London, 1898), <i>Earthquakes</i> +(London, 1898), Bakerian Lecture, “Recent Advances in Seismology,” +<i>Proc. Roy. Soc.</i>, 1906, 77, p. 365; J.A. Ewing, <i>Memoir +on Earthquake Measurement</i> (Tokyo, 1883); C.E. Dutton, <i>Earthquakes +in the Light of the New Seismology</i> (London, 1904); “The +Charleston Earthquake of Aug. 31, 1886,” Ninth Annual <i>Report</i> +of the United States Geological Survey, 1889; W.H. Hobbs, <i>Earthquakes, +an Introduction to Seismic Geology</i> (London, 1908), “The +San Francisco Earthquake and Fire, 1906,” <i>Bull. U.S. Geol. Surv.</i> +No. 324; “The California Earthquake of Ap. 18, 1906,” <i>Rep. State +Earthq. Com.</i> (Washington, D.C., 1908); R.D. Oldham, “Report on +the Great Earthquake of 12 June 1897,” <i>Mem. Geol. Surv. India</i>, xxix. +1899, “On the Propagation of Earthquake Motion to great Distances,” +<i>Phil. Trans.</i>, 1900, A, vol. 194, p. 135, “The Constitution +of the Interior of the Earth as revealed by Earthquakes,” <i>Quar. +Jour. Geol. Soc.</i>, 1906, 62, p. 456; 1907, 63, p. 344; C. Davison, <i>A +Study of Recent Earthquakes</i> (London, 1905); <i>The Hereford Earthquake +of December 17, 1896</i> (Birmingham, 1899), “The Investigation +of Earthquakes,” <i>Beiträge z. Geophysik</i>, Bd. ix., 1908, p. 201, +and papers on British earthquakes in <i>Quart. Jour. Geol. Soc.</i>; +T.J.J. See, “The Cause of Earthquakes, Mountain Formation and +Kindred Phenomena connected with the Physics of the Earth,” +<i>Proc. Amer. Phil. Soc.</i>, 1906, 45, p. 273; F. Frech, “Erdbeben und +Gebirgsbau,” <i>Petermann’s Mitteilungen</i>, Bd. 53, 1907, p. 245 (with +maps); C.G. Knott, <i>The Physics of Earthquake Phenomena</i> (Oxford, +1908); Comte F. de Montessus de Ballore, <i>Les Tremblements de terre: +géographie séismologique</i> (Paris, 1906), <i>La Science séismologique</i> +(1907); <i>Transactions of the Seismological Society of Japan; Seismological +Journal</i> (Yokohama); <i>Bollettino della Società Sismologica +Italiana</i> (Rome); <i>Reports of the British Association</i>, containing the +annual reports of the Committee for Seismological Investigations; +papers in the <i>Beiträge zur Geophysik</i> and the <i>Ergänzungsbände</i>.</p> +</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1d" id="ft1d" href="#fa1d"><span class="fn">1</span></a> The publications for 1880-1892 were termed the <i>Transactions +of the Seismological Society of Japan</i>, and for 1893-1895 the <i>Seismological +Journal of Japan</i>. The observations are now published by +the Earthquake Investigation Committee of Japan, and edited by +F. Omori, professor of seismology at the university of Tokyo.</p> + +<p><a name="ft2d" id="ft2d" href="#fa2d"><span class="fn">2</span></a> The chief Italian station is at Rocca di Papa near Rome. It is +equipped with delicate instruments designed by its director, Giovanni +Agamennone. The records since 1895 are published in the <i>Bollettino +della Società Sismologica Italiana</i>, edited by Luigi Palazzo, director +of the Central Office for Meteorology and Geodynamics at Rome.</p> + +<p><a name="ft3d" id="ft3d" href="#fa3d"><span class="fn">3</span></a> The chief Austrian publications are:—<i>Mittheilungen der Erdbebencommission +der k. Akad. der Wissen. in Wien</i> (since 1897); <i>Die +Erdbebenwarte</i> (1901-1907); and the “Neueste Erdbebennachrichten, +<i>Beilage der Monatsschrift Die Erdbebenwarte</i>.”</p> + +<p><a name="ft4d" id="ft4d" href="#fa4d"><span class="fn">4</span></a> The “International Seismological Association” was founded at +Strassburg in 1903, and publishes the <i>Beiträge zur Geophysik</i>, edited +by George Gerland, director of the Strassburg station; the papers +are printed in several languages.</p> + +<p><a name="ft5d" id="ft5d" href="#fa5d"><span class="fn">5</span></a> The records of the British Association stations are published +(since 1896) in the <i>Reports</i>. Chile has a national earthquake service +(founded after the Valparaiso earthquake of August 1906) directed +by comte de Montessus de Ballore.</p> +</div> + + +<hr class="art" /> + +<table class="flt" style="float: right; width: 220px;" summary="Illustration"> +<tr><td class="figright1"><img style="width:163px; height:148px" src="images/img825.jpg" alt="" /></td></tr> +<tr><td class="caption80"> From Strasburger’s <i>Lehrbuch der +Botanik</i>, by permission of Gustav +Fischer.</td></tr> +<tr><td class="caption1"><i>Geaster Granulosus</i>, nat. size.</td></tr></table> + +<p><span class="bold">EARTH-STAR<a name="ar46" id="ar46"></a></span> (<i>Geaster</i>), in botany, a kind of puff-ball, with a +distinct outer coat which, on separating from the inner, splits +into several divisions, which become +reflexed and spread like a +star. The inner coat enveloping +the spores is supported, like a ball, +either with or without a stalk on +the upper face of the star. The +spores escape generally by means +of a distinct aperture which appears +in the top of the ball. There +are several species in Britain found +on the ground or on decaying leaves. +They are rare or local, but more +common in the south or south-east of England than in other +parts of Britain.</p> + + +<hr class="art" style="clear: both;" /> +<p><span class="bold">EARTHWORM,<a name="ar47" id="ar47"></a></span> the common name of a chaetopod worm +found nearly all over the world. Linnaeus recognized only one +species of earthworm and named it <i>Lumbricus terrestris</i>. There +are now one thousand well-characterized species known from +different parts of the world, and the number increases almost +daily. The earthworms of England belong entirely to the three +genera <i>Lumbricus</i>, <i>Allolobophora</i> and <i>Allurus</i>, which are further +subdivided by some systematists; and these genera form the +prevalent earthworm fauna of the Palaearctic region and are +also very numerous in the Nearctic region. Elsewhere they do +not appear to be indigenous, but are replaced by the numerous +other genera of the families enumerated in the article Chaetopoda +(<i>q.v.</i>). It is a remarkable fact that these genera, comprizing a +separate family <i>Lumbricidae</i>, when introduced into tropical +and other countries, thrive abundantly and oust the indigenous +forms. In gatherings of earthworms from various extra-European +countries it is always found that if the collections have been +made in cultivated ground and near the coast the worms are of +European species; farther inland the native forms are met with. +Inasmuch as in every case the <i>Lumbricidae</i> from non-European +countries are identical with European species, since it has been +shown that these animals are very readily introduced accidentally +with plants, &c., and in view of the fact that they are impatient +of sea water, it seems clear that the presence of these <i>Lumbricidae</i> +in other continents is due to accidental transportation. Most +earthworms live in the soil, which they devour as they burrow +through it. A few, like their allies the river worms (Limicolae), +habitually frequent streams, lakes, &c. One genus, at any rate, +viz. <i>Pontodrilus</i>, seeks an unusual environment, and is found +in heaps of sea-weed cast up by the sea. The range of this genus +is therefore naturally wider than that of other genera which are +confined to land masses and cannot cross the sea by their own +efforts. It might be inferred, therefore, and the inference is +proved by facts, that truly oceanic islands have no indigenous +fauna of earthworms, but are inhabited by forms which are +identical with those of neighbouring continents, and doubtless, +therefore, accidentally introduced.</p> + +<p>Like the leeches the earthworms produce cocoons which are +a product of the glandular epithelium of the clitellum. In these +cocoons are deposited the eggs together with a certain amount +of albumen upon which the developing embryos feed. So far +as is known, the production of cocoons is universal among +earthworms and the remaining Oligochaeta of aquatic habit. +The young leave the cocoon as fully formed earthworms in which, +however, the genitalia are not fully developed. There is no +free living larval stage. Out of a single cocoon emerge a varying +number of young worms, the numbers being apparently characteristic +of the species. The work of earthworms in aiding +in the production of the subsoil and in levelling the surface was +first studied by C. Darwin, and has since been investigated by +others. This work is partly carried out beneath the surface +and partly on the surface, upon which the worms wander at +night and eject the swallowed and triturated earth; frequently +castings of some height are formed of coiled ropes of agglutinated +particles of mould. The indigenous species of Great Britain, +about twenty in number, do not grow to a greater length than +some 10 in.; but in several tropical countries there are species +which grow to a length of from 3 to 6 ft. Thus we have in +Natal the gigantic <i>Microchaeta rappi</i>, in Ceylon <i>Megascolex +coeruleus</i>, in Australia <i>Megascolides australis</i>, and an equally +large form in South America.</p> +<div class="author">(F. E. B.)</div> + + +<hr class="art" /> +<p><span class="bold">EARWIG,<a name="ar48" id="ar48"></a></span> an insect belonging to the <i>Forficulidae</i>, a family +usually referred to the Orthoptera, but sometimes regarded +as typifying a special order, to which the names Dermaptera, +Dermatoptera and Euplexoptera have been given, in allusion +to certain peculiarities in the structure of the wings in the species +that possess them. The front wings are short and horny and +when at rest meet without overlapping in the middle line, like +the wing-cases of brachelytrous (cocktail) beetles. The hind +wings, on the contrary, are for the most part membranous and, +when extended, of large size; each consists of two portions, the +distal of which, in virtue of the arrangement and jointing of its +nervures, is capable of being both doubled up and folded fanwise +beneath the proximal, which is partly horny when the wing is +tucked away under the front wing-case of the same side. Apart +from these characteristics, the most distinctive feature of +earwigs is the presence at the end of the abdomen of a pair of +pincers which are in reality modified appendages, known as +cercopods, and represent the similar limbs of <i>Japyx</i> and the +caudal feelers of <i>Campodea</i> and some other insects.</p> + +<p>The <i>Forficulidae</i> are almost cosmopolitan; but the various +species and genera differ from each other both in structure and +size to a comparatively slight extent. The length and armature +of the pincers and the presence or absence of wings are perhaps +the most important features used by systematists in distinguishing +the various kinds. Of particular zoological interest in this +connexion is a Ceylonese genus <i>Dyscritina</i>, in which the cercopods +are long, many-jointed and filiform during the early stages of +growth, and only assume at the last moult the forcipate structure +characteristic of the family. The best known earwig is the +common European species, <i>Forficula auricularia</i>. This insect +is gregarious and nocturnal. It hides by day under stones or +<span class="pagenum"><a name="page826" id="page826"></a>826</span> +the loosened bark of trees or in any crevice or hole sheltered +from the light. At night it crawls about in search of food, which +consists to a small extent of dead animal or vegetable matter, +but principally, as gardeners are aware, of the petals and other +parts of flowers of growing shoots and soft ripe fruit. During +the winter earwigs lie dormant; but in the early months of the +year females with their eggs may be found in the soil, frequently +in deserted earthworm burrows. Maternal instincts are well +developed, both the eggs, which number about fifty, and the +young being carefully brooded and watched over by the parent. +Except for the absence of wings, the young are miniature models +of the adult. As growth proceeds the integument is periodically +cast; and at the final moult the perfect winged insect appears. +Males and females are like each other in size, but may be distinguished +by the difference in the number of visible abdominal +segments, the male having nine and the female seven. In the +male, moreover, the pincers are caliper-like and toothed at the +base, whereas in the female they are untoothed and only lightly +curved at the tip. These differences suggest that the pincers +aid in the pairing of the sexes. However that may be, they +are known to be used in the folding of the wings; and their +importance as weapons of defence is attested by the precision +and effect with which they are wielded against assailants +like ants.</p> +<div class="author">(R. I. P.)</div> + + +<hr class="art" /> +<p><span class="bold">EASEMENT<a name="ar49" id="ar49"></a></span> (Fr. <i>aise</i>; O. Fr. <i>aisement</i>; Anglo-Lat. <i>aisiamentum</i>, +a privilege or convenience), in English law, a species +of “servitude” or limited right of use over land belonging to +another. It is distinguished from <i>profits à prendre</i>—another +species of servitude which involves a right to participate in the +profits of the soil of another—since an easement confers merely +a convenience (<i>aisiamentum</i>) to be exercised over the land of +another (without any participation in the profits of it), <i>i.e.</i> a +right to use the soil or produce of the soil in a way tending to the +more convenient enjoyment of another piece of land. Thus +a right of way is an easement, a right of common is a profit. An +easement is distinguishable also from a licence, which, unless it +is coupled with a grant, is personal to both grantor and grantee +and is neither binding on the licensor, nor, in general, assignable +by the licensee; while both the benefit and the burden of an +easement are annexed to land (Gale on <i>Easements</i>, 8th ed. p. 2). +With easements are sometimes classed certain closely allied +“natural rights,” such as a landowner’s right to lateral support +for his soil in its natural state, and a riparian owner’s right to the +natural flow of a stream.</p> + +<p>The essential features of an easement, in the strict sense of +the term, are therefore these: (i.) It is an incorporeal right; +a right to the use and enjoyment of land—not to the land itself; +(ii.) it is imposed upon corporeal property; (iii.) it is a right +without profit; (iv.) it requires for its constitution two distinct +tenements—the “dominant tenement” which enjoys the right, +and the “servient tenement” which submits to it. This last +characteristic excludes from the category of easements the +so-called “easements <i>in gross</i>,” such as a right of way conferred +by grant independently of the possession of any tenement by +the grantee. The true easement is an “appendant” or “appurtenant” +right, not a “right in gross.”</p> + +<p>Further classifications of easements must be noted. They +are divided into (<i>a</i>) <i>affirmative</i> or <i>positive</i>, those which authorize +the commission of an act by the dominant owner, <i>e.g.</i> rights of +way, a right to draw water from a spring, rights of aqueduct, +and <i>negative</i>, when the easement restricts the rights of the +servient owner over his own property, <i>e.g.</i> prevents him from +building on land so as to obstruct ancient lights (cf. also the +right to the support of neighbouring soil); (<i>b</i>) <i>continuous</i>, of +which the enjoyment may be continual without the interference +of man, <i>e.g.</i> access to light, and <i>discontinuous</i>, where there must +be a fresh act on each occasion of the exercise of the right, <i>e.g.</i> +a right of way, or right to draw water; (<i>c</i>) <i>apparent</i>, where +there are visible external signs of the exercise of the right, <i>e.g.</i> a +right to dam up a watercourse, and <i>non-apparent</i>, where such +signs are absent, <i>e.g.</i> a right to lateral support from land, a +prohibition to build above a certain height.</p> + +<p><i>Acquisition of Easements.</i>—Easements may be acquired (<i>a</i>) by +express grant, either by statute, or by deed <i>inter vivos</i>, or by +will; (<i>b</i>) by an implied grant; (<i>c</i>) by express or implied reservation, +<i>e.g.</i> by the owner of land in selling the fee (as to implied +reservation, see Gale on <i>Easements</i>, 8th ed. pp. 137 et seq.); +(<i>d</i>) by prescription, either at common law or under the Prescription +Act 1832. An express grant, or express reservation, of an easement +cannot be effected except by deed. An easement arises by +implied grant where a man makes one part of his tenement dependent +on another, or makes the parts mutually interdependent, +and grants any such part with the dependence attaching to it to +another person (Innes, <i>Law of Easements</i>, 7th ed. p. 10). For +example, a man builds two houses, each of which by the plan of +construction receives support from the other; this mutual +right of support is a <i>quasi</i>-easement, of which on severance of +the tenements the grantee of one will have the benefit; where +the enjoyment of the severed tenement could not be had at all +without such a right, it is said to be an “easement of necessity.”</p> + +<p>Easements are acquired by prescription at common law by +proof of “immemorial user” by the dominant owner and those +through whom he claims. At one time it was thought that +such proof must date back to the first year (1189) of Richard I. +(see preamble to Prescription Act 1832). The ground, however, +on which prescription was admitted as a means of acquiring +easements was the fiction of a “lost grant.” Long enjoyment +of the right pointed to its having had a legal origin in a grant +from the servient owner, and so any period of reasonably long +use came to be accepted. A “lost grant” may be presumed to +have been made (the question is one of fact) if 20 years’ uninterrupted +enjoyment is shown. To avoid the difficulties of proof +of prescriptive right at common law, the Prescription Act 1832 +established shorter periods of user. In the case of easements, +other than light, the periods of prescription are 20 years for a +claim that may be defeated, and 40 years for an indefeasible +claim (s. 2). The right of access of light is dealt with under s. 3 +(see <span class="sc"><a href="#artlinks">Ancient Lights</a></span>). The enjoyment to become prescriptive +must be open, <i>i.e.</i> of such a character that the owner of the +tenement said to be servient has a reasonable opportunity of +becoming aware of the adverse claim (<i>Union Lighterage Co.</i> v. +<i>London Graving Dock Co.</i>, 1902, 2 Ch. 557); and it must be +enjoyed as of right (<i>Gardner</i> v. <i>Hodgson’s Kingston Brewery Co.</i>, +1903, A.C. 229) as against the owner of the tenement affected +(<i>Kilgour</i> v. <i>Gaddes</i>, 1904, 1 K.B. 457). The periods of prescription +are to be reckoned backwards from the time when some +suit or matter involving the claim of the dominant owner has +arisen (s. 4). Nothing is to be deemed an interruption unless +the act of interruption has been submitted to, or acquiesced in, +for a year (s. 4).</p> + +<p>Easements may be extinguished (i.) by express release—here +an instrument under seal is necessary; (ii.) by “merger,” <i>i.e.</i> +where both tenements become the property of the same owner; +(iii.) by abandonment through non-user. In the case of discontinuous +easements, the shortest period of non-user may +suffice if there is direct evidence of an intention to abandon.</p> + +<p>A word may be added here as to the right to air. It is an +actionable nuisance to cause pollution of the air entering a +dwelling-house. The owner of a dwelling-house may by prescription +acquire a right to the passage of air through it by a +defined channel; and the enjoyment without interruption of +ventilation by means of air flowing in a definite channel, with the +knowledge of the owner and occupier of the adjoining premises, +creates a presumption of the grant of such an easement (see +Gale on <i>Easements</i>, 8th ed. p. 338).</p> + +<p>In <i>Scots Law</i> the term “easement” is unknown. Both the +name “servitude” and the main species of servitudes existing +in Roman law (<i>q.v.</i>) have been adopted. The classification of +servitudes into positive and negative, &c., and the modes of +their creation and extinction, are similar to those of English law. +The statutory period of prescription is 40 years (Scots Acts 1617, +c. 12), or 20 years in the case of enjoyment under any <i>ex facie</i> +valid irredeemable title duly recorded in the appropriate register +of sasines (Conveyancing [Scotland] Act 1874). There are +<span class="pagenum"><a name="page827" id="page827"></a>827</span> +certain servitudes special to Scots law, <i>e.g.</i> “thirlage,” by +which lands are “thirled” or bound to a particular mill, and +the possessors obliged to grind their grain there, for payment of +certain <i>multures</i> (quantities of grain or meal, payable to the mill-owner) +and <i>sequels</i> (small quantities given to the mill servants) +as the customary price of grinding. Statutory provision has +been made for the commutation of these duties (Thirlage Act +1799), and they have now almost disappeared.</p> + +<p>The French Code Civil (Arts. 637 et seq.) and the other +European codes (<i>e.g.</i> Belgium, arts. 637 et seq.; Holland, arts. +721 et seq.; Italy, arts. 531 et seq.; Spain, arts. 530 et seq.; +Germany, arts. 1018 et seq.) closely follow Roman law. French +law is in force in Mauritius, and has been followed in Quebec +(Civil Code, arts. 499 et seq.) and St Lucia (Civil Code, arts. +449 et seq.). In India the law is regulated, on English lines, +by the Easements Act 1882 (Act v. of 1882). The term “easements,” +however, in India includes <i>profits à prendre</i>. In the +South African colonies the law of easements is based on the +Roman Dutch law (see Maasdorp, <i>Institutes of Cape Law</i>, 1904; +Bk. ii. p. 166 et seq.). In most of the other colonies the law +of easements is similar to English law. In some, however, it +has been provided by statute that rights to the access and use of +light or water cannot be acquired by prescription: <i>e.g.</i> Victoria +(Water Act 1890, No. 1156, s. 3), Ontario (Real Property Limitation +Act, Revised Stats. Ontario, 1897; c. 133, s. 36, light).</p> + +<p>In the <i>United States</i> the law of easements is founded upon, +and substantially identical with, English law. The English +doctrine, however, as to acquisition of right of light and air by +prescription is not accepted in most of the States.</p> + +<div class="condensed"> +<p><span class="sc">Authorities.</span>—<i>English Law</i>: Gale, <i>Law of Easements</i> (8th ed., +London, 1908); Goddard, <i>Law of Easements</i> (6th ed., London, +1904); Innes, <i>Digest of the Law of Easements</i> (7th ed., London, 1903). +<i>Indian Law</i>: Peacock, <i>Easements in British India</i> (Calcutta, 1904); +Hudson and Inman, <i>Law of Light and Air</i> (2nd ed., London, 1905). +<i>Scots Law</i>: Erskine, <i>Principles of the Law of Scotland</i> (20th ed., +Edinburgh, 1903). <i>American Law</i>: Jones, <i>Law of Easements</i> +(New York, 1898); Bouvier, <i>Law Dict.</i> (Boston and London, 1897); +<i>Ruling Cases</i>, London and Boston, 1894-1901, tit. <i>Easement</i> +(American Notes).</p> +</div> +<div class="author">(A. W. R.)</div> + + +<hr class="art" /> +<p><span class="bold">EAST, ALFRED<a name="ar50" id="ar50"></a></span> (1849-  ), English painter and etcher, was +born at Kettering on the 15th of December 1849. One of the +most prominent among modern English landscape painters, he +received his art education first at the Glasgow School of Art +and then in Paris at the École des Beaux-Arts, and under +Robert-Fleury and Bouguereau. His landscapes are remarkable +for the lyrical use of colour and for the pleasing rhythm of line +which is the result of careful selection and building up of the +elements that constitute the scene. Based on keen observation of +the colour of nature and on careful studies of the details, they are +arranged with a rare and by no means obvious sense of balance +and compositional beauty which summarily discards all disturbing +accidents of nature. He also achieved distinction as +an etcher, and published an instructive and useful volume +on landscape painting (London, 1906). He began to exhibit at +the Royal Academy in 1882, and was elected an associate. In +1906 he became president of the Royal Society of British Artists. +Many of his works are to be found in the English provincial +galleries; Manchester owns “The Silent Somme” and “Autumn”; +Liverpool, “Gibraltar from Algeciras”; Leeds, “The Golden +Valley”; Birmingham, “Hayle from Lelant”; Preston, “An Idyll +of Spring”; and Hull, “Evening on the Cotswolds.” His +“Passing Storm” is at the Luxembourg; “The Nene Valley” +at the Venice gallery; and “A Haunt of Ancient Peace” at +the National gallery in Budapest. In 1903 he received the order +of the Crown of Italy in connexion with his services to the +Venice international exhibition; and he was made an honorary +member of the Japanese Meiji Bijutsu Kai.</p> + + +<hr class="art" /> +<p><span class="bold">EAST ANGLIA,<a name="ar51" id="ar51"></a></span> one of the kingdoms into which Anglo-Saxon +Britain was divided. Bede gives no information about its origin +except that its earliest settlers were Angles. The kingdom of +East Anglia comprised the two counties of Norfolk and Suffolk. +With regard to the western boundary we have no accurate +information, but it was probably formed by the fens of +Cambridgeshire.</p> + +<p>This kingdom first appears in Bede’s narrative early in the +7th century, when its power was at its height. Towards the end +of the reign of Æthelberht, who died about 616, Rædwald +of East Anglia, who had apparently spent some time at the court +of Kent, began to win for himself the chief position among the +Anglo-Saxon kings of his day. His position was assured, at least +temporarily, in 617, when he decided to espouse the cause of the +Northumbrian prince Edwin, then a fugitive at his court, and +defeated Æthelfrith of Northumbria on the banks of the Idle, +a tributary of the Trent, in Mercian territory. Rædwald had +been converted to Christianity in Kent, but after his return home +he relapsed, according to Bede, owing to the influence of his wife, +and there were to be seen in the same building a Christian and a +pagan altar. Bede states that Rædwald was the son of Tytili, +the son of Wuffa, from whom the East Anglian royal family +derived their name Wuffingas. According to the <i>Historia +Brittonum</i> Guffa (Wuffa) was the son of (Guecha) Wehha, who +first ruled the East Angles in Britain. This would put the organization +of the kingdom in the first or second quarter of the 6th +century. Eorpwald, the son of Rædwald, was converted to +Christianity by Edwin, but was soon afterwards slain by Ricberht +(627 or 628), whereupon the kingdom again became pagan for +three years, when Sigeberht, the brother of Eorpwald, became +king and founded a see for Felix at Dunwich. Sigeberht also +founded a school in East Anglia, and on the arrival of an Irish +missionary named Furšeus he built him a monastery at <i>Cnobheresburg</i>, +perhaps to be identified with Burgh Castle. Before +644, however, Sigeberht resigned the crown in favour of his +brother Ecgric and retired to a monastery. Shortly afterwards +both brothers were slain by Penda of Mercia in his invasion of +East Anglia, and Anna became king. This king was an enthusiastic +Christian, and converted Cœnwalh, king of Wessex, +who had fled to his court. Two of his daughters, Sæthryth +and Æthelberg, took the veil; while another, Sexburg, was +married to Earconberht, king of Kent; and a fourth, Æthelthryth, +after two marriages, with Tondberht of the South Gyrwe +and Ecgfrith of Northumbria, became abbess of Ely. In 654 +Anna was slain by Penda of Mercia, and was succeeded by his +brother Æthelhere, who was killed in 655 at the Winwaed, +fighting for the Mercian king against Oswio of Northumbria. +In 673 Archbishop Theodore divided the East Anglian diocese +into two, Elmham being the seat of the northern, Dunwich +that of the southern bishop. A long blank follows in the history +of this kingdom, until in 792 we find Offa of Mercia slaying +Æthelberht, king of East Anglia, who is said to have been his +son-in-law. East Anglia was subject to the supremacy of the +Mercian kings until 825, when its people slew Beornwulf of +Mercia, and with their king acknowledged Ecgberht (Egbert) +of Wessex as their lord. In 870 Edmund, king of East Anglia, +was killed by the Danes under I′varr and Ubbi, the sons of +Ragnar Loðbrok.</p> + +<p>The following is a list of the kings of East Anglia of whom there +is record:—Wehha; Wuffa; Rædwald, son of Tytili and grandson +of Wuffa (reigning 617); Eorpwald, son of Rædwald (d. 627 +or 628); Sigeberht, brother of Eorpwald; Ecgric, brother of +Sigeberht (both slain before 644); Anna, son of Ene and grandson +of Tytili (d. 654); Æthelhere, brother of Anna (d. 655); Æthelwald, +a third brother; Aldwulf (succ. 663, d. 713), son of +Æthelric and grandson of Ene; Elfwald, son of Aldwulf (d. 749); +Hun Beonna and Alberht; Æthelberht (792); Edmund (870).</p> + +<p>After the death of Ragnar Loðbrok’s sons East Anglia was +occupied by the Danish king Guthrum, who made a treaty +with Alfred settling their respective boundaries, probably about +880. Guthrum died in 890. A later king named Eohric took up +the cause of Æthelwald, the son of Æthelred I., and was slain in +the fight with the Kentish army at the Holm in 905. A war +broke out with King Edward the Elder in 913; in 921 a king +whose name is unknown was killed at the fall of Tempsford, +and in the same year the Danes of East Anglia submitted to +Edward the Elder. From this time, probably, East Anglia was +governed by English earls, the most famous of whom were +Æthelstan, surnamed Half-King (932-956) and his sons, +<span class="pagenum"><a name="page828" id="page828"></a>828</span> +Æthelwold (956-962), and Æthelwine, surnamed <i>Dei amicus</i> +(962-992).</p> + +<div class="condensed"> +<p>See Bede, <i>Hist. Eccl.</i> (ed. C. Plummer, Oxford. 1896), ii. 5, 15, +iii. 7, 8, 18-20, 22, iv. 3, 5, 23; <i>Saxon Chronicle</i> (ed. Earle and +Plummer, Oxford, 1899), s. a. 823, 838, 866, 870, 880, 885, 890, 894, +905, 921; <i>Historia Brittonum</i> (San-Marte, 1844), s. 59; H. Sweet, +<i>Oldest English Texts</i>, p. 171 (London, 1885).</p> +</div> +<div class="author">(F. G. M. B.)</div> + + +<hr class="art" /> +<p><span class="bold">EASTBOURNE<a name="ar52" id="ar52"></a></span>, a municipal borough (1883) in the Eastbourne +parliamentary division of Sussex, England, 61 m. S.S.E. of +London by the London, Brighton & South Coast railway. Pop. +(1891) 34,969; (1901) 43,344; (local census, 1909) 49,286. It +is situated 3 m. N.E. of Beachy Head, the loftiest headland on the +English Channel coast. It once consisted of three parts—the +village of East Bourne, a mile inland; South Bourne, lying back +from the shore; and Seahouses, facing the beach. The church +of St Mary, the ancient parish church of East Bourne, is a +fine transitional Norman building; and there are numerous +modern churches and chapels. The principal buildings and +institutions are the town hall and municipal buildings, the +Princess Alice Memorial and other hospitals, a free library and, +among many high-class schools, Eastbourne College for boys, +founded in 1867. There is a fine pier with pavilion, and a marine +parade nearly 3 m. in extent, arranged in terraced promenades. +Devonshire Park of 13 acres is pleasantly laid out, and contains +a pavilion and a theatre. The duke of Devonshire is the principal +landowner. Golf links are laid out on the neighbouring downs. +A Roman villa was formerly seen close to the shore, but it is +not now visible. The corporation consists of a mayor, 8 aldermen +and 24 councillors. In 1910 the corporation promoted a bill in +parliament to add the Hampden Park district in the parish of +Willingdon to the borough and to make Eastbourne, with this +extension, a county borough.</p> + + +<hr class="art" /> +<p><span class="bold">EAST CHICAGO<a name="ar53" id="ar53"></a></span>, a city of Lake county, Indiana, U.S.A., on +Lake Michigan, about 19 m. S.E. of the business centre of Chicago. +Pop. (1890) 1255; (1900) 3411 (1331 foreign-born); (1910) 19,098. +It is served by several railways, including the Pennsylvania, the +Wabash, the Chicago Terminal Transfer (whose shops are here), +the Lake Shore & Michigan Southern, the Chicago, Indiana & +Southern, and the Indiana Harbor railways. East Chicago +covers an area whose greatest dimensions are 4 by 3½ m. That +part of the city along the lake, known as Indiana Harbor, dates +from 1901 and has grown very rapidly because of its position at +the southernmost part of the Calumet District, and because of the +meeting here of railway and lake commerce. A good harbour +has been constructed, a new ship canal connecting the harbour +with the Calumet river. East Chicago is industrially virtually +a part of “Greater” Chicago; among its manufactures are iron +and steel, cement, lumber, boilers, hay presses, chains, chemicals +and foundry products. East Chicago was chartered as a city in +1893.</p> + + +<hr class="art" /> +<p><span class="bold">EASTER<a name="ar54" id="ar54"></a></span>, the annual festival observed throughout Christendom +in commemoration of the resurrection of Jesus Christ. +The name Easter (Ger. <i>Ostern</i>), like the names of the days +of the week, is a survival from the old Teutonic mythology. +According to Bede (<i>De Temp. Rat.</i> c. xv.) it is derived from +<i>Eostre</i>, or <i>Ostâra</i>, the Anglo-Saxon goddess of spring, to whom +the month answering to our April, and called <i>Eostur-monath</i>, +was dedicated. This month, Bede says, was the same as the +<i>mensis paschalis</i>, “when the old festival was observed with the +gladness of a new solemnity.”</p> + +<p>The name of the festival in other languages (as Fr. <i>pâques</i>; +Ital. <i>pasqua</i>; Span. <i>pascua</i>; Dan. <i>paaske</i>; Dutch <i>paasch</i>; Welsh +<i>pasg</i>) is derived from the Lat. <i>pascha</i> and the Gr. <span class="grk" title="pascha">πάσχα</span>. +These in turn come from the Chaldee or Aramaean form <span title="pascha">פסהא</span> +<i>pascha’</i>, of the Hebrew name of the Passover festival <span title="pesach">פסח</span> +<i>pesach</i>, from <span title="pasach">פסח</span> “he passed over,” in memory of the great +deliverance, when the destroying angel “passed over the houses, +of the children of Israel in Egypt when he smote the Egyptians” +(Exod. xii. 27).</p> + +<p>An erroneous derivation of the word <i>pascha</i> from the Greek +<span class="grk" title="paschein">πάσχειν</span>, “to suffer,” thus connected with the sufferings or +passion of the Lord, is given by some of the Fathers of the Church, +as Irenaeus, Tertullian and others, who were ignorant of Hebrew. +St Augustine (<i>In Joann. Tract.</i> 55) notices this false etymology, +shows how similarity of sound had led to it, and gives the +correct derivation.</p> + +<p>There is no indication of the observance of the Easter festival +in the New Testament, or in the writings of the apostolic Fathers. +The sanctity of special times was an idea absent from the minds +of the first Christians. “The whole of time is a festival unto +Christians because of the excellency of the good things which +have been given” is the comment of St Chrysostom on 1 Cor. v. 7, +which has been erroneously supposed to refer to an apostolic +observance of Easter. The ecclesiastical historian Socrates +(<i>Hist. Eccl.</i> v. 22) states, with perfect truth, that neither the +Lord nor his apostles enjoined the keeping of this or any other +festival. He says: “The apostles had no thought of appointing +festival days, but of promoting a life of blamelessness and +piety”; and he attributes the observance of Easter by the +church to the perpetuation of an old usage, “just as many other +customs have been established.”</p> + +<p>This is doubtless the true statement of the case. The first +Christians continued to observe the Jewish festivals, though in a +new spirit, as commemorations of events which those festivals +had foreshadowed. Thus the Passover, with a new conception +added to it of Christ as the true Paschal Lamb and the first +fruits from the dead, continued to be observed, and became the +Christian Easter.</p> + +<p>Although the observance of Easter was at a very early period +the practice of the Christian church, a serious difference as to +the day for its observance soon arose between the Christians +of Jewish and those of Gentile descent, which led to a long and +bitter controversy. The point at issue was when the Paschal +fast was to be reckoned as ending. With the Jewish Christians, +whose leading thought was the death of Christ as the Paschal +Lamb, the fast ended at the same time as that of the Jews, on the +fourteenth day of the moon at evening, and the Easter festival +immediately followed, without regard to the day of the week. +The Gentile Christians, on the other hand, unfettered by Jewish +traditions, identified the first day of the week with the Resurrection, +and kept the preceding Friday as the commemoration of the +crucifixion, irrespective of the day of the month. With the one +the observance of the day of the month, with the other the +observance of the day of the week, was the guiding principle.</p> + +<p>Generally speaking, the Western churches kept Easter on the +first day of the week, while the Eastern churches followed the +Jewish rule, and kept Easter on the fourteenth day. St Polycarp, +the disciple of St John the Evangelist and bishop of Smyrna, +visited Rome in 159 to confer with Anicetus, the bishop of that +see, on the subject; and urged the tradition, which he had +received from the apostle, of observing the fourteenth day. +Anicetus, however, declined to admit the Jewish custom in the +churches under his jurisdiction, but readily communicated with +Polycarp and those who followed it. About forty years later +(197) the question was discussed in a very different spirit between +Victor, bishop of Rome, and Polycrates, metropolitan of proconsular +Asia. That province was the only portion of Christendom +which still adhered to the Jewish usage, and Victor demanded +that all should adopt the usage prevailing at Rome. This +Polycrates firmly refused to agree to, and urged many weighty +reasons to the contrary, whereupon Victor proceeded to excommunicate +Polycrates and the Christians who continued the +Eastern usage. He was, however, restrained from actually +proceeding to enforce the decree of excommunication, owing to +the remonstrance of Irenaeus and the bishops of Gaul. Peace was +thus maintained, and the Asiatic churches retained their usage +unmolested (Euseb. <i>H.E.</i> v. 23-25). We find the Jewish usage +from time to time reasserting itself after this, but it never +prevailed to any large extent.</p> + +<p>A final settlement of the dispute was one among the other +reasons which led Constantine to summon the council of Nicaea +in 325. At that time the Syrians and Antiochenes were the +solitary champions of the observance of the fourteenth day. +The decision of the council was unanimous that Easter was to be +kept on Sunday, and on the same Sunday throughout the world, +<span class="pagenum"><a name="page829" id="page829"></a>829</span> +and “that none should hereafter follow the blindness of the +Jews” (Socrates, <i>H.E.</i> i. 9). The correct date of the Easter +festival was to be calculated at Alexandria, the home of astronomical +science, and the bishop of that see was to announce it +yearly to the churches under his jurisdiction, and also to the +occupant of the Roman see, by whom it was to be communicated +to the Western churches. The few who afterwards separated +themselves from the unity of the church, and continued to keep +the fourteenth day, were named <i>Quartodecimani</i>, and the dispute +itself is known as the <i>Quarto-deciman</i> controversy. Although +measures had thus been taken to secure uniformity of observance, +and to put an end to a controversy which had endangered +Christian unity, a new difficulty had to be encountered owing +to the absence of any authoritative rule by which the paschal +moon was to be ascertained. The subject is a very difficult and +complex one (see also <span class="sc"><a href="#artlinks">Calendar</a></span>). Briefly, it may be explained +here that Easter day is the first Sunday after the full moon +following the vernal equinox. This, of course, varies in different +longitudes, while a further difficulty occurred in the attempt to +fix the correct time of Easter by means of cycles of years, when +the changes of the sun and moon more or less exactly repeat +themselves. At first an eight years’ cycle was adopted, but it +was found to be faulty, then the Jewish cycle of 84 years was +used, and remained in force at Rome till the year 457, when a +more accurate calculation of a cycle of 532 years, invented by +Victorius of Acquitaine, took its place. Ultimately a cycle of +19 years was accepted, and it is the use of this cycle which makes +the Golden Number and Sunday Letter, explained in the preface +to the Book of Common Prayer, necessary. Owing to this lack +of decision as to the accurate finding of Easter, St Augustine +tells us (<i>Epist.</i> 23) that in the year 387 the churches of Gaul kept +Easter on the 21st of March, those of Italy on the 18th of April, +and those of Egypt on the 25th of April; and it appears from +a letter of Leo the Great (<i>Epist.</i> 64, <i>ad Marcian.</i>) that in 455 there +was a difference of eight days between the Roman and the +Alexandrine Easter. Gregory of Tours relates that in 577 “there +was a doubt about Easter. In Gaul we with many other cities +kept Easter on the fourteenth calends of May, others, as the +Spaniards, on the twelfth calends of April.”</p> + +<p>The ancient British and Celtic churches followed the cycle of +84 years which they had originally received from Rome, and +their stubborn refusal to abandon it caused much bitter controversy +in the 8th century between their representatives and +St Augustine of Canterbury and the Latin missionaries. These +latter unfairly attempted to fix the stigma of the Quartodeciman +observance on the British and Celtic churches, and they are even +now sometimes ignorantly spoken of as having followed the +Asiatic practice as to Easter. This, however, is quite erroneous. +The British and Celtic churches always kept Easter according +to the Nicene decree on a Sunday. The difference between +them and the Roman Church, at this period, was that they still +followed the 84 years’ cycle in computing Easter, which had +been abandoned at Rome for the more accurate cycle of 532 years. +This difference of calculation led to Easter being observed on +different Sundays, in certain years, in England, by the adherents +of the two churches. Thus Bede records that in a certain year +(which must have been 645, 647, 648 or 651) Queen Eanfleda, +who had received her instruction from a Kentish priest of the +Roman obedience, was fasting and keeping Palm Sunday, while +her husband, Oswy, king of Northumbria, following the rule of +the British church, was celebrating the Easter festival. This +diversity of usage was ended, so far as the kingdom of Northumbria +was concerned, by the council of Streaneshalch, or Whitby, +in 654. To Archbishop Theodore is usually ascribed the credit +of ending the difference in the rest of England in 669.</p> + +<p>The Gregorian correction of the calendar in 1582 has once more +led to different days being observed. So far as Western Christendom +is concerned the corrected calendar is now universally +accepted, and Easter is kept on the same day, but it was not until +1752 that the Gregorian reformation of the calendar was adopted +in Great Britain and Ireland. Jealousy of everything emanating +from Rome still keeps the Eastern churches from correcting the +calendar according to the Gregorian reformation, and thus their +Easter usually falls before, or after, that of the Western churches, +and only very rarely, as was the case in 1865, do the two coincide.</p> + +<p>Easter, as commemorating the central fact of the Christian +religion, has always been regarded as the chief festival of the +Christian year, and according to a regulation of Constantine it +was to be the first day of the year. This reckoning of the year +as beginning at Easter lingered in France till 1565, when, by +an ordinance of Charles IX., the 1st of January finally took +its place.</p> + +<p>Four different periods may be mentioned as connected with +the observance of Easter, viz. (1) the preparatory fast of the +forty days of Lent; (2) the fifteen days, beginning with the +Sunday before and ending with the Sunday after Easter, during +which the ceremonies of Holy Week and the services of the +Octave of Easter were observed; this period, called by the +French the <i>Quinzaine de Pâques</i>, was specially observed in that +country; (3) the Octave of Easter, during which the newly-baptized +wore their white garments, which they laid aside on +the Sunday after Easter, known as <i>Dominica in albis depositis</i> +from this custom; another name for this Sunday was <i>Pascha +clausum</i>, or the close of Easter, and from a clipping of the word +“close” the English name of “Low” Sunday is believed to be +derived; (4) Eastertide proper, or the paschal season beginning +at Easter and lasting till Whit Sunday, during the whole of which +time the festival character of the Easter season was maintained +in the services of the church.</p> + +<p>Many ecclesiastical ceremonies, growing up from early times, +clustered round the celebration of the Easter festival. One of +the most notable of these was the use of the paschal candle. +This was a candle of very large dimensions, set in a candlestick +big enough to hold it, which was usually placed on the north +side, just below the first ascent to the high altar. It was kept +alight during each service till Whitsuntide. The Paschal, as it +was called at Durham cathedral, was one of the chief sights of +that church before the Reformation. It was an elaborate construction +of polished brass, and, contrary to the usual custom, +seems to have been placed in the centre of the altar-step, long +branches stretching out towards the four cardinal points, bearing +smaller candles. The central stem of the candlestick was about +38 ft. high, and bore the paschal candle proper, and together +they reached a combined height of about 70 ft., the candle being +lighted from an opening above. Other paschal candles seem to +have been of scarcely less size. At Lincoln, c. 1300, the candle +was to weigh three stones of wax; at Salisbury in 1517 it was +to be 36 ft. long; and at Westminster in 1558 it weighed no less +than 3 cwt. of wax. After Whitsuntide what remained was made +into smaller candles for the funerals of the poor. In the ancient +churches at Rome the paschal candlesticks were fixtures, but +elsewhere they were usually movable, and were brought into the +church and set up on the Thursday before Easter. At Winchester +the paschal candlestick was of silver, and was the gift of Canute. +Others of more or less importance are recorded as having been +at Canterbury, Bury St Edmunds, Hereford and York. The +burning of the paschal candle still forms part of the Easter ceremonial +of the Roman Catholic Church (see <span class="sc"><a href="#artlinks">Lights, Ceremonial</a></span>).</p> + +<p>The liturgical colour for Easter was everywhere white, as the +sign of joy, light and purity, and the churches and altars were +adorned with the best ornaments that each possessed. Flowers +and shrubs no doubt in early times were also used for this +purpose, but what evidence there is goes against the medieval +use of such decorations, which are so popular at the present day.</p> + +<p>It is not the purpose of this article to enter on the wide subject +of the popular observances, such as the giving and sending of +Pasch or Easter eggs as presents. For such the reader may consult +Brand’s <i>Popular Antiquities</i>, Hone’s <i>Every-Day Book</i>, and +Chambers’s <i>Book of Days</i>.</p> + +<div class="condensed"> +<p><span class="sc">Authorities.</span>—Bingham, <i>Antiquities of the Christian Church</i>; +Bede, <i>Ecclesiastical History of England</i>; Procter and Frere, <i>A New +History of the Book of Common Prayer</i> (London, 1901); Surtees +Society, <i>Rites of Durham</i>, ed. J.T. Fowler (1903); De Morgan, +<i>Companion to the Almanac</i> (1845); De Moleon, <i>Voyages liturgiques</i> +(Paris, 1718).</p> +</div> +<div class="author">(T. M. F.)</div> + +<p><span class="pagenum"><a name="page830" id="page830"></a>830</span></p> + + +<hr class="art" /> +<p><span class="bold">EASTER ISLAND<a name="ar55" id="ar55"></a></span> (Rapanui, <i>i.e.</i> Great Rapa), an island in +the eastern part of the South Pacific ocean, belonging to Chile +(since 1888), in 27° 8′ S. and 109° 28′ W., 1400 m. E. of Pitcairn, +and 2000 m. from the South American coast. It is roughly +triangular in shape, with its hypotenuse 12 m. long running +north-east and south-west, and its three angles marked by +three volcanic peaks, of which the north-eastern reaches 1768 ft. +of altitude. The area of the island is 45 sq. m. The coast has +no good natural harbour, and landing is difficult. There is no lack +of fertile soil, and the climate is moist enough to make up for the +absence of running water. Formerly the island appears to have +been wooded, but it now presents only a few bushes (<i>Edwardsia</i>, +<i>Broussonetia</i>, &c.), ferns, grasses, sedges, &c. The natives grow +bananas in the shelter of artificial pits, also sugar-canes and +sweet potatoes, and keep a few goats and a large stock of domestic +fowls, and a Tahitian commercial house breeds cattle and sheep +on the island.</p> + +<p>It is doubtful whether Rapanui was discovered by Davis in +1686, though it is sometimes marked Davis Island on maps. +Admiral Roggeveen reached it on Easter day 1722; in 1774 +Captain Cook discovered it anew and called it Teapi or Waihu. +It was subsequently visited by La Pérouse (1776), Kotzebue +(1816), &c. At the time of Roggeveen’s discovery the island +probably contained from 2000 to 3000 inhabitants of Polynesian +race, who, according to their own tradition, came from Rapa Iti +(Little Rapa) or Oparo, one of the Tubuai or Austral group. +In 1863 a large proportion of the inhabitants were kidnapped +by the Peruvians and transported to work at the guano diggings +on the Chincha Islands. The next year a Jesuit mission from +Tahiti reached the island and succeeded in the task of civilization. +The natives, who number scarcely one hundred, are all Christians.</p> + +<p>Easter Island is famous for its wonderful archaeological +remains. Here are found immense platforms built of large cut +stones fitted together without cement. They are generally built +upon headlands, and on the slope towards the sea. The walls +on the seaside are, in some of the platforms, nearly 30 ft. high +and from 200 to 300 ft. long, by about 30 ft. wide. Some of the +squared stones are as much as 6 ft. long. On the land side of the +platforms there is a broad terrace with large stone pedestals upon +which once stood colossal stone images carved somewhat into +the shape of the human trunk. On some of the platforms there +are upwards of a dozen images, now thrown from their pedestals +and lying in all directions. Their usual height is from 14 to 16 ft., +but the largest are 37 ft., while some are only about 4 ft. They +are formed from a grey trachytic lava found at the east end +of the island. The top of the heads of the images is cut flat to +receive round crowns made of a reddish vesicular tuff found at +a crater about 8 m. distant from the quarry where the images +were cut. A number of these crowns still lie at the crater +apparently ready for removal, some of the largest being over 10 ft. +in diameter. In the atlas illustrating the voyage of La Pérouse +a plan of the island is given, with the position of several of the +platforms. Two of the images are also represented in a plate. +One statue, 8 ft. in height and weighing 4 tons, was brought to +England, and is now in the British Museum. In one part of the +island are the remains of stone houses nearly 100 ft. long by +about 20 ft. wide. These are built in courses of large flat stones +fitted together without cement, the walls being about 5 ft. +thick and over 5 ft. high. They are lined on the inside with +upright slabs, on which are painted geometrical figures and +representations of animals. The roofs are formed by placing +slabs so that each course overlaps the lower one until the opening +becomes about 5 ft. wide, when it is covered with flat slabs +reaching from one side to the other. The lava rocks near the +houses are carved into the resemblance of various animals and +human faces, forming, probably, a kind of picture writing. +Wooden tablets covered with various signs and figures have also +been found. The only ancient implement discovered on the +island is a kind of stone chisel, but it seems impossible that such +large and numerous works could have been executed with such +a tool. The present inhabitants of Easter Island know nothing +of the construction of these remarkable works; and the entire +subject of their existence in this small and remote island is a +mystery.</p> + + +<hr class="art" /> +<p><span class="bold">EASTERN BENGAL AND ASSAM<a name="ar56" id="ar56"></a></span>, a province of British India, +which was constituted out of Assam and the eastern portion of +Bengal on the 16th of October 1905. Area 111,569 sq. m.; pop. +(1901) 30,961,459. It is situated between 20° 45′ and 28° 17′ N., +and between 87° 48′ and 97° 5′ E. The province, as thus reconstituted, +consists of the Bengal districts of Dacca, Mymensingh, +Faridpur, Backergunje, Tippera, Noakhali, Chittagong, +Chittagong Hill Tracts, Rajshahi, Dinajpur, Jalpaiguri, Rangpur, +Bogra, Pabna, Malda, and the native states of Kuch Behar +and Hill Tippera; and the whole of the former area of Assam +consisting of the districts of Goalpara, Kamrup, Darrang, +Nowgong, Sibsagar, Lakhimpur, Sylhet, Cachar, Garo Hills, +Khasi and Jaintia Hills, Naga Hills and Lushai Hills. It is +bounded on the N. by Bhutan, on the W. by Burma, on the S. by +Burma and the Bay of Bengal, and on the E. by Bengal. The +line of demarcation between Bengal and the new province begins +at the frontier of Bhutan, east of Darjeeling, runs south-west to +Sahibganj on the Ganges and thence follows the course of the +Ganges down to the deltaic branch, called the Haringhata, +which leaves the main stream above Goalanda, and the course of +the latter, which runs south into the Bay of Bengal. The capital +of the province is Dacca, and its chief port is Chittagong.</p> + +<p>The Bengal districts which were transferred to Eastern Bengal +and Assam comprised northern and eastern Bengal, the most +prosperous and least overcrowded portion of Bengal. The land +there is less densely populated, wages are higher and food +cheaper, and the rainfall more copious and more regular, while +the staple crops of jute, tobacco and rice command a higher price +relative to the rent of the land than in Behar or other parts of +Bengal. The population are largely Mahommedans and of a more +virile stock than the Bengali proper. Northern Bengal corresponds +almost exactly with the Rajshahi division and lies within +the boundaries of the Ganges and Brahmaputra rivers. It +contains much high land of a stiff red clay, with an undulating +surface covered for the most part with scrub jungle. The +inhabitants are Indo-Chinese, not Indo-Aryans as in Bengal +proper, and are Mahommedan by religion instead of Hindu. +Eastern Bengal consists of the Dacca and Chittagong divisions +which are mainly Bengali in race and Hindu in religion. For the +Assamese districts see <span class="sc"><a href="#artlinks">Assam</a></span>. The province as a whole contains +18,036,688 Mahommedans and 12,036,538 Hindus. In language +27,272,895 of the inhabitants speak Bengali, 1,349,784 speak +Assamese, and the remainder Hindi and various hill dialects, +Manipuri, Bodo, Khasi and Garo. The administration is in the +hands of a lieutenant-governor, assisted by a legislative council +of fifteen members. Under him are five commissioners, and +financial matters are regulated by a board of revenue consisting +of two members.</p> + +<p>The constitution of the new province arose out of the fact that +Bengal had grown too unwieldy for the administration of a single +lieutenant-governor. In 1868 Sir Stafford Northcote drew +attention to the greatly augmented demands that the outlying +portions of Bengal made on the time and labour of the government. +At that time the population of the province was between +40 and 50 millions, and the question was left in abeyance until +1903, when the population had risen to 78½ millions. In the +meantime the importance of rendering Assam a self-contained +and independent administration with a service of its own, and +of providing for its future commercial expansion, had arisen. +These two considerations led Lord Curzon to propose that Bengal +should be lopped of territory both on its eastern and western +borders, and that all the districts east of the Brahmaputra should +be constituted into a separate province. This proposal was +bitterly opposed by the Hindus of Bengal on the ground that it +would destroy the unity of the Bengali race; and their agitation +was associated with the <i>Swadeshi</i> (own country) movement for +the boycott of British goods.</p> + +<p>After the constitution of the province in October 1905, the +agitation in Eastern Bengal increased. Public meetings of protest +were held, vernacular broadsheets containing scandalous +<span class="pagenum"><a name="page831" id="page831"></a>831</span> +attacks on the British authorities were circulated, schoolboys +and others were organized and drilled as so-called “national +volunteers,” and employed as pickets to prevent the sale of +British goods. Such was the state of things when Sir J. Bampfylde +Fuller entered on his office as first lieutenant-governor of +Eastern Bengal in January 1906. His reception was ominous. +Representative bodies that were dominated by Hindus refused +to vote the usual addresses of welcome, and non-official Hindus +abstained from paying the customary calls. There were, however, +no further overt signs of objection to the lieutenant-governor +personally, and after a month or two—in spite of, or perhaps +because of, his efforts to restrain sedition and to keep discipline +in the schools—there was a decided change in the attitude of +Hindu opinion. At Dacca, in July, for instance, the reception at +Government House was attended by large numbers of Bengali +gentlemen, who assured the lieutenant-governor that “the +trouble was nearly ended.” The agitation was, in fact, largely +artificial, the work of Calcutta lawyers, journalists and +schoolmasters; the mass of the people, naturally law-abiding, +was unmoved by it so long as the government showed a firm +hand; while the Mussulmans, who formed a large proportion of +the whole, saw in the maintenance of the partition and of the +prestige of the British government the guarantees of their own +security.</p> + +<p>All seemed to be going well when an unfortunate difference of +opinion occurred between the lieutenant-governor and the +central government, resulting in the resignation of Sir Bampfylde +Fuller (August 1906) and in ulterior consequences destined +to be of far-reaching import. The facts are briefly as follows. +Acting on a report of Dr P. Chatterji, inspector of schools, dated +January 2, 1906, the lieutenant-governor, on the 10th of February, +addressed a letter to the registrar of Calcutta University recommending +that the privilege of affiliation to the university should +be withdrawn from the Banwarilal and Victoria high schools at +Sirajganj in Pabna, as a punishment for the seditious conduct +of both pupils and teachers. Apart from numerous cases of +illegal interference with trade and of disorder in the streets +reported against the students, two specific outrages of a serious +character were instanced as having occurred on the 15th of +November: the raiding of a cart laden with English cloth +belonging to Marwari traders, and a cowardly assault by some +40 or 50 lads on the English manager of the Bank of Bengal. +These outrages “were not the result of thoughtlessness or sudden +excitement, but were the outcome of a regularly organized +scheme, set on foot and guided by the masters of these schools, +for employing the students in enforcing a boycott.” All attempts +to discover and punish the offenders had been frustrated by the +refusal of the school authorities to take action, and in the opinion +of the lieutenant-governor the only course open was to apply the +remedy suggested in the circular letter addressed to magistrates +and collectors (October 10, 1905) by Mr R.W. Carlyle, the officiating +chief secretary to the government of Bengal, directing them, +in the event of students taking any part in political agitation, +boycotting and the like, to inform the heads of schools or colleges +concerned that, unless they prevented such action being taken +by the boys attending their institutions, their grant-in-aid and the +privilege of competing for scholarships and of receiving scholarship-holders +would be withdrawn, and that the university would +be asked to disaffiliate their institutions.</p> + +<p>The reply, dated July 5th, from the secretary in the home +department of the government of India, was—to use Sir +Bampfylde’s own later expression—to throw him over. It was +likely that a difference of opinion in the syndicate of the university +would arise as to the degree of culpability that attached +to the proprietors of the schools; in the event of the syndicate +taking any “punitive action,” the matter was certain to be raised +in the senate, and would lead to an acrimonious public discussion, +in which the partition of Bengal and the administration of the +new province would be violently attacked; and in the actual +state of public opinion in Bengal it seemed to the government of +India highly inexpedient that such a debate should take place. +“Collective punishment,” too, “would be liable to be misconstrued +in England,” and the government preferred to rely +on the gradual effect of the new university regulations, which +aimed “at discouraging the participation of students in political +movements by enforcing the responsibility of masters and the +managing committees of schools for maintaining discipline.”</p> + +<p>On receipt of this communication Sir Bampfylde Fuller at +once tendered his resignation to the viceroy (July 15). He +pointed out that to withdraw from the position taken up would +be “concession, not in the interests of education, but to those +people in Calcutta who have been striving to render my government +impossible, in order to discredit the partition”; that +previous concessions had had merely provocative effects, and +that were he to give way in this matter his authority would be so +weakened that he would be unable to maintain order in the +country. On the 3rd of August, after some days of deliberation, +the viceroy telegraphed saying that he was “unable to reconsider +the orders sent,” and accepting Sir Bampfylde’s resignation. +By the Anglo-Indian press the news was received with something +like consternation, the <i>Times of India</i> describing the resignation +as one of the gravest blunders ever committed in the history of +British rule in India, and as a direct incentive to the forces of +disquiet, disturbance and unrest. Equally emphatic was the +verdict of the Mussulman community forming two-thirds of the +population of Eastern Bengal. On the 7th of August, the day of +Sir Bampfylde Fuller’s departure from Dacca, a mass-meeting +of 30,000 Mahommedans was held, which placed on record their +disapproval of a system of government “which maintains no +continuity of policy,” and expressed its feeling that the lowering +of British prestige must “alienate the sympathy of a numerically +important and loyal section of His Majesty’s subjects”; and +many meetings of Mussulmans subsequently passed resolutions +to the same general effect. The <i>Akhbar-i-Islam</i>, the organ of +Bombay Mussulman opinion, deplored the “unwise step” +taken by the government, and ascribed it to Lord Minto’s fear +of the Babu press, a display of weakness of which the Babus +would not be slow to take advantage.</p> + +<p>This latter prophecy was not slow in fulfilling itself. So early +as the 8th of August Calcutta was the scene of several large +demonstrations at which the Swadeshi vow was renewed, and +at which resolutions were passed declining to accept the partition +as a settled fact, and resolving on the continuance of the agitation. +The tone of the Babu press was openly exultant: “We have +read the familiar story of the Russian traveller and the wolves,” +said a leading Indian newspaper in Calcutta. “The British +government follows a similar policy. First the little babies +were offered up in the shape of the <i>Bande Mataram</i> circular +and the Carlyle circular. Now a bigger boy has gone in the +person of our own Joseph. Courage, therefore, O wolves! +Press on and the horse will soon be yours to devour! Afterwards +the traveller himself will alone be left.”<a name="fa1e" id="fa1e" href="#ft1e"><span class="sp">1</span></a> The task before the +new lieutenant-governor of Eastern Bengal, the Hon. L. Hare, +was obviously no easy one. The encouragement given to sedition +by the weakness of the government in this case was shown by +later events in Bengal and elsewhere (see <span class="sc"><a href="#artlinks">India</a></span>: <i>History, ad fin.</i>).</p> + +<p>For the early history of the various portions of the province see +<span class="sc"><a href="#artlinks">Bengal</a></span> and <span class="sc"><a href="#artlinks">Assam</a></span>.</p> + +<div class="condensed"> +<p>See Sir James Bourdillon, <i>The Partition of Bengal</i> (Society of Arts, +1905); official blue-books on <i>The Reconstitution of the Provinces of +Bengal and Assam</i> (Cd. 2658 and 2746), and <i>Resignation of Sir J. +Bampfylde Fuller</i>, lieutenant-governor, &c. (Cd. 3242). A long +letter from Sir J.B. Fuller, headed <i>J’accuse</i>, attacking the general +policy of the Indian government in regard to the seditious propaganda, +appeared in <i>The Times</i> of June 6, 1908.</p> +</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1e" id="ft1e" href="#fa1e"><span class="fn">1</span></a> Quoted by Mr F.S.P. Lely in <i>The Times</i> of November 22, 1906.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EASTERN QUESTION, THE<a name="ar57" id="ar57"></a></span>, the expression used in diplomacy +from about the time of the congress of Verona (1822) to comprehend +the international problems involved in the decay of the +Turkish empire and its supposed impending dissolution. The +essential questions that are involved are so old that historians +commonly speak of the “Eastern Question” in reference to +events that happened long before the actual phrase was coined. +But, wherever used, it is always the Turkish Question, the +<span class="pagenum"><a name="page832" id="page832"></a>832</span> +generic term in which subsidiary issues, <i>e.g.</i> the Greek, Armenian +or Macedonian questions, are embraced. That a phrase of so +wide and loose a nature should have been stereotyped in so +narrow a sense is simply the outcome of the conditions under +which it was invented. To the European diplomatists of the +first half of the 19th century the Ottoman empire was still the +only East with which they were collectively brought into contact. +The rivalry of Great Britain and Russia in Persia had not +yet raised the question of the Middle East; still less any +ambitions of Germany in the Euphrates valley. The immense +and incalculable problems involved in the rise of Japan, the +awakening of China, and their relations to the European powers +and to America—known as the Far Eastern Question—are +comparatively but affairs of yesterday.</p> + +<p>The Eastern Question, though its roots are set far back in +history—in the ancient contest between the political and intellectual +ideals of Greece and Asia, and in the perennial rivalry +of the powers for the control of the great trade routes to the +East—dates in its modern sense from the treaty of Kuchuk +Kainarji in 1774, which marked the definitive establishment of +Russia as a Black Sea power and formed the basis of her special +claims to interfere in the affairs of the Ottoman empire. The +compact between Napoleon and the emperor Alexander I. at +Tilsit (1807) marked a new phase, which culminated in 1812 in +the treaty of Bucharest, in which Russia definitely appeared +as the protector of the Christian nationalities subject to the +Ottoman sultan.</p> + +<p>The attitude of the various powers in the Eastern Question +was now defined. Russia, apart from her desire to protect the +Orthodox nationalities subject to the Ottoman power, aimed +at owning or controlling the straits by which alone she could +find an outlet to the Mediterranean and the ocean beyond. +Austria, once the champion of Europe against the Turk, saw in +the Russian advance on the Danube a greater peril than any to +be feared from the moribund Ottoman power, and made the +maintenance of the integrity of Turkey a prime object of her +policy. She was thus brought into line with Great Britain, +whose traditional friendship with Turkey was strengthened by +the rise of a new power whose rapid advance threatened the +stability of British rule in India. But though Austria, Great +Britain and presently France, were all equally interested in +maintaining the Ottoman empire, the failure of the congress of +Vienna in 1815 to take action in the matter of a guarantee of +Turkey, and the exclusion of the Sultan from the Holy +Alliance, seemed to endorse the claim of Russia to regard +the Eastern Question as “her domestic concern” in which +“Europe” had no right to interfere. The revolt of the Greeks +(1821) put this claim to the test; by the treaty of Adrianople +(1829) Russia stipulated for their autonomy as part of the price +of peace, but the powers assembled in conference at London +refused to recognize this settlement, and the establishment +of Greece as an independent kingdom (1832) was really aimed +at the pretensions and the influence of Russia. These reached +their high-water mark in the treaty of Unkiar Skelessi (July 8th, +1832). It was no longer a question of the partition of Turkey +or of a Russian conquest of Constantinople, but of the deliberate +degradation by Russia of the Ottoman empire into a weak state +wholly dependent upon herself. The ten years’ crisis (1831-1841) +evoked by the revolt of Mehemet Ali, pasha of Egypt, thus +resolved itself into a diplomatic struggle between Russia and the +other powers to maintain or to recover influence at Constantinople. +The Russian experiment of maintaining the integrity of Turkey +while practically treating her as a vassal state, ended with the +compromise of 1841; and the emperor Nicholas I. reverted to +the older idea of expelling the Turks from Europe. The Eastern +Question, however, slumbered until, in 1851, the matter of the +Holy Places was raised by Napoleon III., involving the whole +question of the influence in Ottoman affairs of France under +the capitulations of 1740 and of Russia under the treaty of 1774. +The Crimean War followed and in 1856 the treaty of Paris, by +which the powers hoped to stem the tide of Russian advance and +establish the integrity of a reformed Ottoman state. Turkey +was now for the first time solemnly admitted to the European +concert. The next critical phase was opened in 1871, when +Russia took advantage of the collapse of France to denounce the +Black Sea clauses of the treaty of 1856. The renewal of an +aggressive policy thus announced to the world soon produced +a new crisis in the Eastern Question, which had meanwhile +become complicated by the growth of Pan-Slav ideals in eastern +Europe. In 1875 a rising in Herzegovina gave evidence of a state +of feeling in the Balkan peninsula which called for the intervention +of Europe, if a disastrous war were to be prevented. But this +intervention, embodied in the “Andrassy Note” (December 1875) +and the Berlin memorandum (May 1876), met with the stubborn +opposition of Turkey, where the “young Turks” were beginning +to oppose a Pan-Islamic to the Pan-Slav ideal. The Russo-Turkish +War of 1877-78 followed, concluded by the treaty of San +Stefano, the terms of which were modified in Turkey’s favour by +the congress of Berlin (1878), which marks the beginning of the +later phase of the Eastern Question. Between Russia and Turkey +it interposed, in effect, a barrier of independent (Rumania, Servia) +and quasi-independent (Bulgaria) states, erected with the counsel +and consent of collective Europe. It thus, while ostensibly +weakening, actually tended to strengthen the Ottoman power of +resistance.</p> + +<p>The period following the treaty of Berlin is coincident with the +reign of Sultan Abd-ul-Hamid II. The international position of +the Ottoman empire was strengthened by the able, if Machiavellian, +statecraft of the sultan; while the danger of disruption from +within was lessened by the more effective central control made +possible by railways, telegraphs, and the other mechanical improvements +borrowed from western civilization. With the +spread of the Pan-Islamic movement, moreover, the undefined +authority of the sultan as caliph of Islam received a fresh +importance even in countries beyond the borders of the Ottoman +empire, while in countries formerly, or nominally still, subject +to it, it caused, and promised to cause, incalculable trouble.</p> + +<p>The Eastern Question thus developed, in the latter years of +the 19th century, from that of the problems raised by the impending +break-up of a moribund empire, into the even more complex +question of how to deal with an empire which showed vigorous +evidence of life, but of a type of life which, though on all sides +in close touch with modern European civilization, was incapable +of being brought into harmony with it. The belief in the imminent +collapse of the Ottoman dominion was weakened almost +to extinction; so was the belief, which inspired the treaty of +1856, in the capacity of Turkey to reform and develop itself +on European lines. But the Ottoman empire remained, the +mistress of vast undeveloped wealth. The remaining phase of the +Eastern Question, if we except the concerted efforts to impose +good government on Macedonia in the interests of European +peace, or the side issues in Egypt and Arabia, was the rivalry +of the progressive nations for the right to exploit this wealth. +In this rivalry Germany, whose interest in Turkey even so late +as the congress of Berlin had been wholly subordinate, took a +leading part, unhampered by the traditional policies or the +humanitarian considerations by which the interests of the older +powers were prejudiced. The motives of German intervention +in the Eastern Question were ostensibly commercial; but the +Bagdad railway concession, postulating for its ultimate success +the control of the trade route by way of the Euphrates valley, +involved political issues of the highest moment and opened up a +new and perilous phase of the question of the Middle East.</p> + +<p>This was the position when in 1908 an entirely new situation +was created by the Turkish revolution. As the result of the +patient and masterly organization of the “young Turks,” combined +with the universal discontent with the rule of the sultan +and the palace <i>camarilla</i>, the impossible seemed to be achieved, +and the heterogeneous elements composing the Ottoman empire +to be united in the desire to establish a unified state on the constitutional +model of the West. The result on the international +situation was profound. Great Britain hastened to re-knit the +bonds of her ancient friendship with Turkey; the powers, +without exception, professed their sympathy with the new régime. +<span class="pagenum"><a name="page833" id="page833"></a>833</span> +The establishment of a united Turkey on a constitutional and +nationalist basis was, however, not slow in producing a fresh +complication in the Eastern Question. Sooner or later the +issue was sure to be raised of the status of those countries, still +nominally part of the Ottoman empire, but in effect independent, +like Bulgaria, or subject to another state, like Bosnia and +Herzegovina. The cutting of the Gordian knot by Austria’s +annexation of Bosnia and Herzegovina, and by the proclamation +of the independence of Bulgaria, and of Prince Ferdinand’s +assumption of the old title of tsar (king), threatened to raise the +Eastern Question once more in its acutest form. The international +concert defined in the treaty of Berlin had been rudely +shaken, if not destroyed; the denunciation by Austria, without +consulting her co-signatories, of the clauses of the treaty affecting +herself seemed to invalidate all the rest; and in the absence of +the restraining force of a united concert of the great powers, free +play seemed likely once more to be given to the rival ambitions +of the Balkan nationalities, the situation being complicated by +the necessity for the dominant party in the renovated Turkish +state to maintain its prestige. During the anxious months +that followed the Austrian <i>coup</i>, the efforts of diplomacy were +directed to calming the excitement of Servians, Montenegrins +and the Young Turks, and to considering a European conference +in which the <i>fait accompli</i> should be regularized in accordance +with the accepted canons of international law. The long delay +in announcing the assembly of the conference proved the extreme +difficulty of arriving at any satisfactory basis of settlement; +and though the efforts of the powers succeeded in salving the +wounded pride of the Turks, and restraining the impetuosity +of the Serbs and Montenegrins, warlike preparations on the part +of Austria continued during the winter of 1908-1909, being +justified by the agitation in Servia, Montenegro and the annexed +provinces. It was not till April 1909 (see <span class="sc"><a href="#artlinks">Europe</a></span>: <i>ad fin.</i>) +that the crisis was ended, through the effectual backing given +by Germany to Austria; and Russia, followed by England and +France, gave way and assented to what had been done.</p> + +<div class="condensed"> +<p>See <span class="sc"><a href="#artlinks">Turkey</a></span>: <i>History</i>, where cross-references to the articles on +the various phases of the Eastern Question will be found, together +with a bibliography. See also E. Driault, <i>La Question d’orient depuis +son origine</i> (Paris, 1898), a comprehensive sketch of the whole subject, +including the Middle and Far East.</p> +</div> +<div class="author">(W. A. P.)</div> + + +<hr class="art" /> +<p><span class="bold">EAST GRINSTEAD<a name="ar58" id="ar58"></a></span>, a market town in the East Grinstead +parliamentary division of Sussex, England, 30 m. S. by E. from +London by the London, Brighton & South Coast railway. Pop. of +urban district (1901) 6094. St Swithin’s church contains, among +numerous ancient memorials, one of the iron memorial slabs +(1507) peculiar to certain churches of Sussex, and recalling the +period when iron was extensively worked in the district. There +may be noticed Sackville College (an almshouse founded in 1608), +and St Margaret’s home and orphanage, founded by the Rev. +John Mason Neale (1818-1866), warden of Sackville College. +Brewing and brick and tile making are carried on. In the +vicinity (near Forest Row station) is the golf course of the Royal +Ashdown Forest Golf Club.</p> + +<p>The hundred of East Grinstead (Grenestede, Estgrensted) +was in the possession of the count of Mortain in 1086, but no +mention of a vill or manor of East Grinstead is made in the +Domesday Survey. In the reign of Henry III. the hundred was +part of the honour of Aquila, then in the king’s hands. The +honour was granted by him to Peter of Savoy, through whom +it passed to his niece Queen Eleanor. In the next reign the +king’s mother held the borough of East Grinstead as parcel of +the honour of Aquila. East Grinstead was included in a grant +by Edward III. to John of Gaunt, duke of Lancaster, and it +remained part of the duchy of Lancaster until James I. granted +the borough to Sir George Rivers, through whom it was obtained +by the Sackvilles, earls of Dorset. East Grinstead was a borough +by prescription. In the 16th century it was governed by an +alderman, bailiff and constable. It returned two members to +parliament from 1307 until 1832, but was disenfranchised by +the Reform Act. In 1285 the king ordered that his market at +Grenestede should be held on Saturday instead of Sunday, and +in 1516 the inhabitants of the town were granted a market each +week on Saturday and a fair every year on the eve of St Andrew +and two days following. Charles I. granted the earl of Dorset +a market on Thursday instead of the Saturday market, and fairs +on the 16th of April and the 26th of September every year. +Thursday is still the market-day, and cattle-fairs are now held +on the 21st of April and the 11th of December.</p> + + +<hr class="art" /> +<p><span class="bold">EAST HAM<a name="ar59" id="ar59"></a></span>, a municipal borough in the southern parliamentary +division of Essex, England, contiguous to West Ham, +and thus forming geographically part of the eastward extension of +London. Pop. (1901) 96,018. Its modern growth has been very +rapid, the population being in the main of the artisan class. +There are some chemical and other factories. The ancient +parish church of St Mary Magdalen retains Norman work in the +chancel, which terminates in an eastern apse. There is a monument +for Edmund Neville who claimed the earldom of Westmorland +in the 17th century, and William Stukeley, the antiquary, +was buried in the churchyard. East Ham was incorporated +in 1904, and among its municipal undertakings is a technical +college (1905). The corporation consists of a mayor, 6 aldermen +and 18 councillors. Area, 3320½ acres.</p> + + +<hr class="art" /> +<p><span class="bold">EASTHAMPTON<a name="ar60" id="ar60"></a></span>, a township of Hampshire county, Mass., +U.S.A., in the Connecticut Valley. Pop. (1900) 5603, of whom +1731 were foreign-born; (1905) 6808; (1910) 8524. It is served by +the Boston & Maine, and the New York, New Haven & Hartford +railways, and by interurban electric railways. The township +is generally level, and is surrounded by high hills. In Easthampton +are a free public library and Williston Seminary; the +latter, one of the oldest and largest preparatory schools in New +England, was founded in 1841 by the gifts of Samuel Williston +(1795-1874) and Emily Graves Williston (1797-1885). Mr and +Mrs Williston built up the industry of covering buttons with +cloth, at first doing the work by hand, then (1827) experimenting +with machinery, and in 1848 building a factory for making and +covering buttons. As the soil was fertile and well watered, the +township had been agricultural up to this time. It is now chiefly +devoted to manufacturing. Among its products are cotton goods, +especially mercerised goods, for the manufacture of which it has +one of the largest plants in the country; rubber, thread, elastic +fabrics, suspenders and buttons. Parts of Northampton and +Southampton were incorporated as the “district” of Easthampton +in 1785; it became a township in 1809, and in 1841 +and 1850 annexed parts of Southampton.</p> + + +<hr class="art" /> +<p><span class="bold">EAST HAMPTON<a name="ar61" id="ar61"></a></span>, a township of Suffolk county, New York, +in the extreme S.E. part of Long Island, occupying the peninsula +of Montauk, and bounded on the S. and E. by the Atlantic Ocean, +and on the N. by Block Island Sound, Gardiner’s Bay and +Peconic Bay. Pop. (1900) 3746; (1905) 4303; (1910) 4722. +The township, 25 m. long and 8 m. at its greatest width from +north to south, has an irregular north coast-line and a very +regular south coast-line. The surface is rougher to the west +where there are several large lakes, notably Great Pond, 2 m. +long. The scenery is picturesque and the township is much +frequented by artists. Montauk Lighthouse, on Turtle Hill, +was first built in 1795. At Montauk, after the Spanish-American +War, was Camp Wikoff, a large U.S. military camp. The +township is served by the southern division of the Long Island +railway, the terminus of which is Montauk. Other villages of +the township, all summer resorts, are: Promised Land, Amagansett, +East Hampton and Sag Harbor; the last named, only partly +in the township, was incorporated in 1803 and had a population +of 1969 in 1900, and 3084 in 1910. Silverware and watch cases +are manufactured here. From Sag Harbor, which is a port of +entry, a daily steamer runs to New York city. The village +received many gifts in 1906-1908 from Mrs Russell Sage. Most +of the present township was bought from the Indians (Montauks, +Corchaugs and Shinnecocks) in 1648 for about £30, through the +governors of Connecticut and New Haven, by nine Massachusetts +freemen, mostly inhabitants of Lynn, Massachusetts. +With twenty other families they settled here in 1649, calling the +place Maidstone, from the old home of some of the settlers in +Kent; but as early as 1650 the name East Hampton was used +in reference to the earlier settlement of South Hampton. Until +<span class="pagenum"><a name="page834" id="page834"></a>834</span> +1664, when all Long Island passed to the duke of York, the +government was by town meeting, autonomous and independent +except for occasional appeals to Connecticut. In 1683 Gardiner’s +Island, settled by Lion Gardiner in 1639 and so one of the first +English settlements in what is now New York state, was made +a part of Long Island and of East Hampton township. The +English settlements in East Hampton were repeatedly threatened +by pirates and privateers, and there are many stories of treasure +buried by Captain Kidd on Gardiner’s Island and on Montauk +Point. The Clinton Academy, opened in East Hampton village +in 1785, was long a famous school. Of the church built here +in 1653 (first Congregational and after 1747 Presbyterian in +government), Lyman Beecher was pastor in 1799-1810; and in +East Hampton were born his elder children. Whale fishing was +begun in East Hampton in 1675, when four Indians were engaged +by whites in off-shore whaling; but Sag Harbor, which was first +settled in 1730 and was held by the British after the battle of +Long Island as a strategic naval and shipping point, became the +centre of the whaling business. The first successful whaling +voyage was made from Sag Harbor in 1785, and although the +Embargo ruined the fishing for a time, it revived during 1830-1850. +Cod and menhaden fishing, the latter for the manufacture +of fish-oil and guano, were important for a time, but in the +second half of the 19th century Sag Harbor lost its commercial +importance.</p> + + +<hr class="art" /> +<p><span class="bold">EAST INDIA COMPANY<a name="ar62" id="ar62"></a></span>, an incorporated company for exploiting +the trade with India and the Far East. In the 17th +and 18th centuries East India companies were established by +England, Holland, France, Denmark, Scotland, Spain, Austria +and Sweden. By far the most important of these was the +English East India Company, which became the dominant +power in India, and only handed over its functions to the British +Government in 1858 (see also <span class="sc"><a href="#artlinks">Dutch East India Company</a></span>, +<span class="sc"><a href="#artlinks">Ostend Company</a></span>).</p> + +<p>The English East India Company was founded at the end of +the 16th century in order to compete with the Dutch merchants, +who had obtained a practical monopoly of the trade +with the Spice Islands, and had raised the price of +<span class="sidenote">English East India Co.</span> +pepper from 3s. to 8s. per ℔. Queen Elizabeth incorporated +it by royal charter, dated December 31, 1600, +under the title of “The Governor and Company of Merchants +of London, trading into the East Indies.” This charter conferred +the sole right of trading with the East Indies, <i>i.e.</i> with all countries +lying beyond the Cape of Good Hope or the Straits of Magellan, +upon the company for a term of 15 years. Unauthorized interlopers +were liable to forfeiture of ships and cargo. There were +125 shareholders in the original East India Company, with a +capital of £72,000: the first governor was Sir Thomas Smythe. +The early voyages of the company, from 1601 to 1612, are distinguished +as the “separate voyages,” because the subscribers +individually bore the cost of each voyage and reaped the whole +profits, which seldom fell below 100%. After 1612 the voyages +were conducted on the joint stock system for the benefit of the +company as a whole. These early voyages, whose own narratives +may be read in Purchas, pushed as far as Japan, and established +friendly relations at the court of the Great Mogul. In +1610-1611 Captain Hippon planted the first English factories +on the mainland of India, at Masulipatam and at Pettapoli in +the Bay of Bengal. The profitable nature of the company’s +trade had induced James I. to grant subsidiary licences to private +traders; but in 1609 he renewed the company’s charter “for +ever,” though with a proviso that it might be revoked on three +years’ notice if the trade should not prove profitable to the realm.</p> + +<p>Meanwhile friction was arising between the English and +Dutch East India Companies. The Dutch traders considered +that they had prior rights in the Far East, and their +ascendancy in the Indian Archipelago was indeed +<span class="sidenote">English and Dutch disputes.</span> +firmly established on the basis of territorial dominion +and authority. In 1613 they made advances to the +English company with a suggestion for co-operation, but the +offer was declined, and the next few years were fertile in disputes +between the armed traders of both nations. In 1619 was ratified +a “treaty of defence” to prevent disputes between the English +and Dutch companies. When it was proclaimed in the East, +hostilities solemnly ceased for the space of an hour, while the +Dutch and English fleets, dressed out in all their flags and with +yards manned, saluted each other; but the treaty ended in the +smoke of that stately salutation, and perpetual and fruitless +contentions between the Dutch and English companies went on +just as before. In 1623 these disputes culminated in the “massacre +of Amboyna,” where the Dutch governor tortured and +executed the English residents on a charge of conspiring to seize +the fort. Great and lasting indignation was aroused in England, +but it was not until the time of Cromwell that some pecuniary +reparation was exacted for the heirs of the victims. The +immediate result was that the English company tacitly admitted +the Dutch claims to a monopoly of the trade in the Far East, +and confined their operations to the mainland of India and the +adjoining countries.</p> + +<p>The necessity of good ships for the East Indian trade had +led the company in 1609 to construct their dockyard at Deptford, +from which, as Monson observes, dates “the increase +of great ships in England.” Down to the middle of the +<span class="sidenote">The East Indiamen.</span> +19th century, the famous “East Indiamen” held +unquestioned pre-eminence among the merchant vessels of the +world. Throughout the 17th century they had to be prepared +at any moment to fight not merely Malay pirates, but the armed +trading vessels of their Dutch, French and Portuguese rivals. +Many such battles are recorded in the history of the East India +Company, and usually with successful results.</p> + +<p>It was not until it had been in existence for more than a century +that the English East India Company obtained a practical +monopoly of the Indian trade. In 1635, a year after +the Great Mogul had granted it the liberty of trading +<span class="sidenote">The acquisition of territory.</span> +throughout Bengal, Charles I. issued a licence to +Courten’s rival association, known as “the Assada +Merchants,” on the ground that the company had neglected +English interests. The piratical methods of their rivals disgraced +the company with the Mogul officials, and a <i>modus vivendi</i> was +only reached in 1649. In 1657 Cromwell renewed the charter of +1609, providing that the Indian trade should be in the hands of +a single joint stock company. The new company thus formed +bought up the factories, forts and privileges of the old one. It +was further consolidated by the fostering care of Charles II., +who granted it five important charters. From a simple trading +company, it grew under his reign into a great chartered company—to +use the modern term—with the right to acquire territory, +coin money, command fortresses and troops, form alliances, make +war and peace, and exercise both civil and criminal jurisdiction. +It is accordingly in 1689, when the three presidencies of Bengal, +Madras and Bombay had lately been established, that the ruling +career of the East India Company begins, with the passing by +its directors of the following resolution for the guidance of the +local governments in India:—“The increase of our revenue +is the subject of our care, as much as our trade; ’tis that must +maintain our force when twenty accidents may interrupt our +trade; ’tis that must make us a nation in India; without that +we are but a great number of interlopers, united by His Majesty’s +royal charter, fit only to trade where nobody of power thinks +it their interest to prevent us; and upon this account it is that +the wise Dutch, in all their general advices that we have seen, +write ten paragraphs concerning their government, their civil +and military policy, warfare, and the increase of their revenue, +for one paragraph they write concerning trade.” From this +moment the history of the transactions of the East India Company +becomes the history of British India (see <span class="sc"><a href="#artlinks">India</a></span>: <i>History</i>). +Here we shall only trace the later changes in the constitution and +powers of the ruling body itself.</p> + +<p>The great prosperity of the company under the Restoration, +and the immense profits of the Indian trade, attracted a number +of private traders, both outside merchants and dismissed +or retired servants of the company, who came +<span class="sidenote">The interlopers.</span> +to be known as “interlopers.” In 1683 the case of +Thomas Sandys, an interloper, raised the whole question of the +<span class="pagenum"><a name="page835" id="page835"></a>835</span> +royal prerogative to create a monopoly of the Indian trade. +The case was tried by Judge Jeffreys, who upheld the royal +prerogative; but in spite of his decision the custom of interloping +continued and laid the foundation of many great fortunes. +By 1691 the interlopers had formed themselves into a new +society, meeting at Dowgate, and rivalling the old company; +the case was carried before the House of Commons, which declared +in 1694 that “all the subjects of England have equal +right to trade to the East Indies unless prohibited by act of +parliament.” This decision led up to the act of 1698, which +created a new East India Company in consideration of a loan +of two millions to the state. The old company subscribed +£315,000 and became the dominant factor in the new body; +while at the same time it retained its charter for three years, +its factories, forts and assured position in India. The rivalry +between the two companies continued both in England and in +India, until they were finally amalgamated by a tripartite indenture +between the companies and Queen Anne (1702), which +was ratified under the Godolphin Award (1708). Under this +award the company was to lend the nation £3,200,000, and its +exclusive privileges were to cease at three years’ notice after +this amount had been repaid. But by this time the need for +permanence in the Indian establishment began to be felt, while +parliament would not relinquish its privilege of “milking” +the company from time to time. In 1712 an act was passed continuing +the privileges of the company even after their fund should +be redeemed; in 1730 the charter was prolonged until 1766, +and in 1742 the term was extended until 1783 in return for the +loan of a million. This million was required for the war with +France, which extended to India and involved the English and +French companies there in long-drawn hostilities, in which the +names of Dupleix and Clive became prominent.</p> + +<p>So long as the company’s chief business was that of trade, it +was left to manage its own affairs. The original charter of +Elizabeth had placed its control in the hands of a +governor and a committee of twenty-four, and this +<span class="sidenote">The company and the crown.</span> +arrangement subsisted in essence down to the time of +George III. The chairman and court of directors in +London exercised unchecked control over their servants in India. +But after Clive’s brilliant victory at Plassey (1757) had made +the company a ruling power in India, it was felt to be necessary +that the British government should have some control over the +territories thus acquired. Lord North’s Regulating Act (1773) +raised the governor of Bengal—Warren Hastings—to the rank +of governor-general, and provided that his nomination, though +made by a court of directors, should in future be subject to the +approval of the crown; in conjunction with a council of four, +he was entrusted with the power of peace and war; a supreme +court of judicature was established, to which the judges were +appointed by the crown; and legislative power was conferred +on the governor-general and his council. Next followed Pitt’s +India Bill (1784), which created the board of control, as a +department of the English government, to exercise political, +military and financial superintendence over the British possessions +in India. This bill first authorized the historic phrase +“governor-general in council.” From this date the direction +of Indian policy passed definitely from the company to the +governor-general in India and the ministry in London. In 1813 +Lord Liverpool passed a bill which further gave the board of +control authority over the company’s commercial transactions, +and abolished its monopoly of Indian trade, whilst leaving it +the monopoly of the valuable trade with China, chiefly in tea. +Finally, under Earl Grey’s act of 1833, the company was deprived +of this monopoly also. Its property was then secured on the +Indian possessions, and its annual dividends of ten guineas per +£100 stock were made a charge upon the Indian revenue. Henceforward +the East India Company ceased to be a trading concern +and exercised only administrative functions. Such a position +could not, in the nature of things, be permanent, and the great +cataclysm of the Indian Mutiny was followed by the entire +transference of Indian administration from the company to the +crown, on the 2nd of August 1858.</p> + +<div class="condensed"> +<p>See <i>Purchas his Pilgrimes</i> (ed. 1905), vols. 2, 3, 4, 5, for the charter +of Elizabeth and the early voyages; Sir W.W. Hunter, <i>History +of British India</i> (1899); Beckles Willson, <i>Ledger and Sword</i> (1903); +Sir George Birdwood, <i>Report on the Old Records of the India Office</i> +(1879); <i>The East India Company’s First Letter Book</i> (1895), <i>Letters +Received by the East India Company from its Servants in the East</i>, +ed. Foster, (1896 ff.). See also the interesting memorial volume +<i>Relics of the Honourable East India Company</i> (ed. Griggs, 1909), +letterpress by Sir G. Birdwood and W. Foster.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EAST INDIES<a name="ar63" id="ar63"></a></span>, a name formerly applied vaguely, in its widest +sense, to the whole area of India, Further India and the Malay +Archipelago, in distinction from the West Indies, which, at the +time of their discovery, were taken to be the extreme parts of +the Indian region. The term “East Indies” is still sometimes +applied to the Malay Archipelago (<i>q.v.</i>) alone, and the phrase +“Dutch East Indies” is commonly used to denote the Dutch +possessions which constitute the greater part of that archipelago. +The Dutch themselves use the term <i>Nederlandsch-Indië</i>.</p> + + +<hr class="art" /> +<p><span class="bold">EASTLAKE, SIR CHARLES LOCK<a name="ar64" id="ar64"></a></span> (1793-1865), English +painter, was born on the 17th of November 1793 at Plymouth, +where his father, a man of uncommon gifts but of indolent +temperament, was solicitor to the admiralty and judge advocate +of the admiralty court. Charles was educated (like Sir Joshua +Reynolds) at the Plympton grammar-school, and in London at +the Charterhouse. Towards 1809, partly through the influence +of his fellow-Devonian Haydon, of whom he became a pupil, +he determined to be a painter; he also studied in the Royal +Academy school. In 1813 he exhibited in the British Institution +his first picture, a work of considerable size, “Christ restoring +life to the Daughter of Jairus.” In 1814 he was commissioned +to copy some of the paintings collected by Napoleon in the +Louvre; he returned to England in 1815, and practised portrait-painting +at Plymouth. Here he saw Napoleon a captive on +the “Bellerophon”; from a boat he made some sketches of +the emperor, and he afterwards painted, from these sketches +and from memory, a life-sized full-length portrait of him (with +some of his officers) which was pronounced a good likeness; +it belongs to the marquess of Lansdowne. In 1817 Eastlake +went to Italy; in 1819 to Greece; in 1820 back to Italy, where +he remained altogether fourteen years, chiefly in Rome and in +Ferrara.</p> + +<p>In 1827 he exhibited at the Royal Academy his picture of the +Spartan Isidas, who (as narrated by Plutarch in the life of +Agesilaus), rushing naked out of his bath, performed prodigies +of valour against the Theban host. This was the first work that +attracted much notice to the name of Eastlake, who in consequence +obtained his election as A.R.A.; in 1830, when he +returned to England, he was chosen R.A. In 1850 he succeeded +Shee as president of the Royal Academy, and was knighted. +Prior to this, in 1841, he had been appointed secretary to the +royal commission for decorating the Houses of Parliament, and +he retained this post until the commission was dissolved in 1862. +In 1843 he was made keeper of the National Gallery, a post +which he resigned in 1847 in consequence of an unfortunate +purchase that roused much animadversion, a portrait erroneously +ascribed to Holbein; in 1855, director of the same institution, +with more extended powers. During his directorship he purchased +for the gallery 155 pictures, mostly of the Italian schools. +He became also a D.C.L. of Oxford, F.R.S., a chevalier of the +Legion of Honour, and member of various foreign academies.</p> + +<p>In 1849 he married Miss Elizabeth Rigby, who had already then +become known as a writer (<i>Letters from the Baltic</i>, 1841; <i>Livonian +Tales</i>, 1846; <i>The Jewess</i>, 1848) and as a contributor to the +<i>Quarterly Review</i>. Lady Eastlake (1809-1893) had for some years +been interested in art subjects, and after her marriage she +naturally devoted more attention to them, translating Waagen’s +<i>Treasures of Art in Great Britain</i> (1854-1857), and completing +Mrs Jameson’s <i>History of our Lord in Works of Art</i>. In 1865 +Sir Charles Eastlake fell ill at Milan; and he died at Pisa on the +24th of December in the same year. Lady Eastlake, who survived +him for many years, continued to play an active part as a +writer on art (<i>Five Great Painters</i>, 1883, &c.), and had a large +circle of friends among the most interesting men and women of +the day. In 1880 she published a volume of <i>Letters from France</i> +<span class="pagenum"><a name="page836" id="page836"></a>836</span> +(describing events in Paris during 1789), written by her father, +Edward Rigby (1747-1821), a distinguished Norwich doctor +who was known also for his practical interest in agriculture, and +who is said to have made known the flying shuttle to Norwich +manufacturers.</p> + +<p>As a painter, Sir Charles Eastlake was gentle, harmonious, +diligent and correct; lacking fire of invention or of execution; +eclectic, without being exactly imitative; influenced rather by a +love of ideal grace and beauty than by any marked bent of +individual power or vigorous originality. Among his principal +works (which were not numerous, 51 being the total exhibited in +the Academy) are: 1828, “Pilgrims arriving in sight of Rome” +(repeated in 1835 and 1836, and perhaps on the whole his +<i>chef-d’œuvre</i>); 1829, “Byron’s Dream” (in the Tate Gallery); +1834, the “Escape of Francesco di Carrara” (a duplicate in +the Tate Gallery); 1841, “Christ Lamenting over Jerusalem” +(ditto); 1843, “Hagar and Ishmael”; 1845, “Comus”; 1849, +“Helena”; 1851, “Ippolita Torelli”; 1853, “Violante”; +1855, “Beatrice.” These female heads, of a refined semi-ideal +quality, with something of Venetian glow of tint, are the most +satisfactory specimens of Eastlake’s work to an artist’s eye. +He was an accomplished and judicious scholar in matters of art, +and published, in 1840, a translation of Goethe’s <i>Theory of +Colours</i>; in 1847 (his chief literary work) <i>Materials for a History +of Oil-Painting</i>, especially valuable as regards the Flemish school; +in 1848, <i>Contributions to the Literature of the Fine Arts</i> (a second +series was edited by Lady Eastlake in 1870, and accompanied by a +Memoir from her pen); in 1851 and 1855, translated editions of +Kugler’s <i>History of the Italian School of Painting</i>, and <i>Handbook +of Painting</i> (new edition, by Lady Eastlake, 1874).</p> + +<div class="condensed"> +<p>See W. Cosmo Monkhouse, <i>Pictures by Sir Charles Eastlake, with +biographical and critical Sketch</i> (1875).</p> +</div> +<div class="author">(W. M. R.)</div> + + +<hr class="art" /> +<p><span class="bold">EAST LIVERPOOL<a name="ar65" id="ar65"></a></span>, a city of Columbiana county, Ohio, U.S.A., +on the Ohio river, about 106 m. S.E. of Cleveland. Pop. (1890) +10,956; (1900) 16,485, of whom 2112 were foreign-born; (1910 +census) 20,357. It is served by the Pennsylvania railway, by +river steamboats, and by interurban electric lines. Next to +Trenton, New Jersey, East Liverpool is the most important +place in the United States for the manufacture of earthenware +and pottery, 4859 out of its 5228 wage-earners, or 92.9%, +being employed in this industry in 1905, when $5,373,852 (83.5% +of the value of all its factory products) was the value of the +earthenware and pottery. No other city in the United States +is so exclusively devoted to the manufacture of pottery; in 1908 +there were 32 potteries in the city and its immediate vicinity. +The manufacture of white ware, begun in 1872, is the most +important branch of the industry—almost half of the “cream-coloured,” +white granite ware and semivitreous porcelain produced +in the United States in 1905 (in value, $4,344,468 out of +$9,195,703) being manufactured in East Liverpool. Though +there are large clay deposits in the vicinity, very little of it can be +used for crockery, and most of the clay used in the city’s potteries +is obtained from other states; some of it is imported from Europe. +After 1872 a large number of skilled English pottery-workers +settled in the city. The city’s product of pottery, terra-cotta +and fireclay increased from $2,137,063 to $4,105,200 from 1890 +to 1900, and in the latter year almost equalled that of Trenton, +N.J., the two cities together producing more than half (50.9%) +of the total pottery product of the United States; in 1905 East +Liverpool and Trenton together produced 42.1% of the total +value of the country’s pottery product. The municipality owns +and operates its water-works. East Liverpool was settled in +1798, and was incorporated in 1834.</p> + + +<hr class="art" /> +<p><span class="bold">EAST LONDON<a name="ar66" id="ar66"></a></span>, a town of the Cape province, South Africa, at +the mouth of the Buffalo river, in 33° 1′ S. 27° 55′ E., 543 m. +E.N.E. of Cape Town by sea and 666 m. S. of Johannesburg by +rail. Pop. (1904) 25,220, of whom 14,674 were whites. The town +is picturesquely situated on both sides of the river, which is +spanned by a combined road and railway bridge. The railway +terminus and business quarter are on the east side on the top of +the cliffs, which rise 150 ft. above the river. In Oxford Street, +the chief thoroughfare, is the town hall, a handsome building +erected in 1898. Higher up a number of churches and a school +are grouped round Vincent Square, a large open space. In consequence +of the excellent sea bathing, and the beauty of the river +banks above the town, East London is the chief seaside holiday +resort of the Cape province. The town is the entrepot of a rich +agricultural district, including the Transkei, Basutoland and the +south of Orange Free State, and the port of the Cape nearest +Johannesburg. It ranks third among the ports of the province. +The roadstead is exposed and insecure, but the inner harbour, +constructed at a cost of over £2,000,000, is protected from all +winds. A shifting sand bar lies at the mouth of the river, but +the building of training walls and dredging have increased the +minimum depth of water to 22 ft. From the east bank of the +Buffalo a pier and from the west bank a breakwater project into +the Indian Ocean, the entrance being 450 ft. wide, reduced +between the training walls to 250 ft. There is extensive wharf +accommodation on both sides of the river, and steamers of over +8000 tons can moor alongside. There is a patent slip capable +of taking vessels of 1000 tons dead weight. An aerial steel +ropeway from the river bank to the town greatly facilitates the +delivery of cargo. The imports are chiefly textiles, hardware +and provisions, the exports mainly wool and mohair. The +rateable value of the town in 1908 was £4,108,000, and the +municipal rate 1<span class="spp">5</span>⁄<span class="suu">8</span>d.</p> + +<p>East London owes its foundation to the necessities of the +Kaffir war of 1846-1847. The British, requiring a port nearer +the scene of war than those then existing, selected a site at the +mouth of the Buffalo river, and in 1847 the first cargo of military +stores was landed. A fort, named Glamorgan, was built, and the +place permanently occupied. Around this military post grew +up the town, known at first as Port Rex. Numbers of its inhabitants +are descendants of German immigrants who settled in +the district in 1857. The prosperity of the town dates from the +era of railway and port development in the last decade of the +19th century. In 1875 the value of the exports was £131,803 +and that of the imports £552,033. In 1904 the value of the +exports was £1,165,938 and that of the imports £4,688,415. In +1907 the exports, notwithstanding a period of severe trade +depression, were valued at £1,475,355, but the imports had fallen +to £3,354,633.</p> + + +<hr class="art" /> +<p><span class="bold">EASTON<a name="ar67" id="ar67"></a></span>, a city and the county-seat of Northampton county, +Pennsylvania, U.S.A., at the confluence of the Lehigh river and +Bushkill Creek with the Delaware, about 60 m. N. of Philadelphia. +Pop. (1890) 14,481; (1900) 25,238, of whom 2135 were foreign-born; +(1910 census) 28,523. Easton is served by the Central +of New Jersey, the Lehigh Valley, the Lehigh & Hudson River +and the Delaware, Lackawanna & Western railways, and is +connected by canals with the anthracite coal region to the +north-west and with Bristol, Pa. A bridge across the Delaware +river connects it with Phillipsburg, New Jersey, which is served +by the Pennsylvania railway. The city is built on rolling ground, +commanding pleasant views of hill and river scenery. Many +fine residences overlook city and country from the hillsides, and +a Carnegie library is prominent among the public buildings. +Lafayette College, a Presbyterian institution opened in 1832, +is finely situated on a bluff north of the Bushkill and Delaware. +The college provides the following courses of instruction: +graduate, classical, Latin scientific, general scientific, civil +engineering, electrical engineering, mining engineering and +chemical; in 1908 it had 38 instructors and 442 students, 256 +of whom were enrolled in the scientific and engineering courses. +Overlooking the Bushkill is the Easton Cemetery, in which is +the grave of George Taylor (1716-1781), a signer of the Declaration +of Independence, with a monument of Italian marble to +his memory. Among the city’s manufactures are silk, hosiery +and knit goods, flour, malt liquors, brick, tile, drills, lumber and +planing mill products and organs; in 1905 the value of all the +factory products was $5,654,594, of which $2,290,598, or 40.5%, +was the value of the silk manufactures. Easton is the commercial +centre of an important mining region, which produces, in particular, +iron ore, soapstone, cement, slate and building stone. +The municipality owns and operates an electric-lighting plant. +<span class="pagenum"><a name="page837" id="page837"></a>837</span> +Easton was a garden spot of the Indians, and here, because they +would not negotiate elsewhere, several important treaties were +made between 1756 and 1762 during the French and Indian War. +The place was laid out in 1752, and was made the county-seat +of the newly erected county. It was incorporated as a borough +in 1789, received a new borough charter in 1823, and in 1887 was +chartered as a city. South Easton was annexed in 1898.</p> + + +<hr class="art" /> +<p><span class="bold">EAST ORANGE<a name="ar68" id="ar68"></a></span>, a city of Essex county, New Jersey, U.S.A., +in the north-eastern part of the state, adjoining the city of Newark, +and about 12 m. W. of New York city. Pop. (1890) 13,282; +(1900) 21,506, of whom 3950 were foreign-born and 1420 were +negroes; (1910 census) 34,371. It is served by the Morris & +Essex division of the Delaware, Lackawanna & Western railway +and by the Orange branch of the Erie (the former having +four stations—Ampere, Grove Street, East Orange and Brick +Church), and is connected with Newark, Orange and West +Orange by electric line. The city covers an area of about 4 sq. m., +and has broad, well-paved streets, bordered with fine shade trees +(under the jurisdiction of a “Shade Tree Commission”). It is +primarily a residential suburb of New York and Newark, and +has many beautiful homes; with Orange, West Orange and +South Orange it forms virtually one community, popularly +known as “the Oranges.” The public school system is excellent, +and the city has a Carnegie library (1903), with more than +22,000 volumes in 1907. Among the principal buildings are +several attractive churches, the city hall, and the club-house of +the Woman’s Club of Orange. The principal manufactures of +East Orange are electrical machinery, apparatus, and supplies +(the factory of the Crocker-Wheeler Co. being here—in a part +of the city known as “Ampere”) and pharmaceutical materials. +The total value of the city’s factory products in 1905 was +$2,326,552. East Orange has a fine water-works system, which +it owns and operates; the water supply is obtained from artesian +wells at White Oaks Ridge, in the township of Milburn (about +10 m. from the city hall); thence the water is pumped to a steel +reinforced reservoir (capacity 5,000,000 gallons) on the mountain +back of South Orange. In 1863 the township of East Orange +was separated from the township of Orange, which, in turn, had +been separated from the township of Newark in 1806. An act +of the New Jersey legislature in 1895 created the office of township +president, with power of appointment and veto. Four years +later East Orange was chartered as a city.</p> + +<div class="condensed"> +<p>See H. Whittemore, <i>The Founders and Builders of the Oranges</i> +(Newark, 1896).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EASTPORT<a name="ar69" id="ar69"></a></span>, a city and port of entry of Washington county, +Maine, U.S.A., co-extensive with Moose Island in Passamaquoddy +Bay, about 190 m. E.N.E. of Portland. Pop. (1890) 4908; (1900) +5311 (1554 foreign-born); (1910) 4961. It is served by the +Washington County railway, and by steamboat lines to Boston, +Portland and Calais. It is the most eastern city of the United +States, and is separated from the mainland by a narrow +channel, which is spanned by a bridge. The harbour is well +protected from the winds, and the tide, which rises and falls +here about 25 ft., prevents it from being obstructed with ice. +The city is built on ground sloping gently to the water’s edge, +and commands delightful views of the bay, in which there are +several islands. Its principal industry is the canning of sardines; +there are also clam canneries. Shoes, mustard, decorated tin, +and shooks are manufactured, and fish and lobsters are shipped +from here in the season. The city is the port of entry for the +customs district of Passamaquoddy; in 1908 its imports were +valued at $994,961, and its exports at $1,155,791. Eastport +was first settled about 1782 by fishermen; it became a port of +entry in 1790, was incorporated as a town in 1798, and was +chartered as a city in 1893. It was a notorious place for +smuggling under the Embargo Acts of 1807 and 1808. On the +11th of July 1814, during the war of 1812, it was taken by the +British. As the British government claimed the islands of +Passamaquoddy Bay under the treaty of 1783, the British +forces retained possession of Eastport after the close of the war +and held it under martial law until July 1818, when it was +surrendered in accordance with the decision rendered in +November 1817 by commissioners appointed under Article IV. +of the treaty of Ghent (1814), this decision awarding Moose +Island, Dudley Island and Frederick Island to the United States +and the other islands, including the Island of Grand Manan in +the Bay of Fundy, to Great Britain.</p> + + +<hr class="art" /> +<p><span class="bold">EAST PROVIDENCE<a name="ar70" id="ar70"></a></span>, a township of Providence county, +Rhode Island, U.S.A., on the E. side of Providence river, opposite +Providence. Pop. (1890) 8422; (1900) 12,138, of whom 2067 +were foreign-born; (1910 census) 15,808. Area, 12½ sq. m. +It is served by the New York, New Haven & Hartford railway. +It has a rolling surface and contains several villages, one of which, +known as Rumford, has important manufactories of chemicals +and electrical supplies. South of this village, along the river +bank, are several attractive summer resorts, Hunt’s Mills, +Silver Spring, Riverside, Vanity Fair, Kettle Point and Bullock’s +Point being prominent among them. In 1905 the factory +products of the township were valued at $5,035,288. The +oyster trade is important. It was within the present limits of +this township that Roger Williams established himself in the +spring of 1636, until he learned that the place was within the +jurisdiction of the Plymouth Colony. About 1644 it was settled +by a company from Weymouth as a part of a town of Rehoboth. +In 1812 Rehoboth was divided, and the west part was made the +township of Seekonk. Finally, in 1861, it was decided that the +west part of Seekonk belonged to Rhode Island, and in the +following year that part was incorporated as the township of +East Providence.</p> + + +<hr class="art" /> +<p><span class="bold">EAST PRUSSIA<a name="ar71" id="ar71"></a></span> (<i>Ost-Preussen</i>), the easternmost province of +the kingdom of Prussia, bounded on the N. by the Baltic, on the +E. and S.W. by Russia and Russian Poland, and on the W. by +the Prussian province of West Prussia. It has an area of 14,284 +sq. m., and had, in 1905, a population of 2,025,741. It shares in +the general characteristics of the great north German plain, +but, though low, its surface is by no means absolutely flat, as the +southern half is traversed by a low ridge or plateau, which attains +a height of 1025 ft. at a point near the western boundary of the +province. This plateau, here named the Prussian Seenplatte, is +thickly sprinkled with small lakes, among which is the Spirding +See, 46 sq. m. in extent and the largest inland lake in the Prussian +monarchy. The coast is lined with low dunes or sandhills, in +front of which lie the large littoral lakes or lagoons named the +Frisches Haff and the Kurisches Haff. The first of these receives +the waters of the Nogat and the Pregel, and the other those +of the Memel or Niemen. East Prussia is the coldest part of +Germany, its mean annual temperature being about 44° F., +while the mean January temperature of Tilsit is only 25°. The +rainfall is 24 in. per annum. About half the province is under +tillage; 18% is occupied by forests, and about 23% by meadows +and pastures. The most fertile soil is found in the valleys of the +Pregel and the Memel, but the southern slopes of the Baltic +plateau and the district to the north of the Memel consist in +great part of sterile moor, sand and bog. The chief crops are rye, +oats and potatoes, while flax is cultivated in the district of +Ermeland, between the Passarge and the upper Alle. East +Prussia is the headquarters of the horse-breeding of the country, +and contains the principal government stud of Trakehnen; +numerous cattle are also fattened on the rich pastures of the river-valleys. +The extensive woods in the south part of the province +harbour a few wolves and lynxes, and the elk is still preserved +in the forest of Ibenhorst, near the Kurisches Haff. The fisheries +in the lakes and haffs are of some importance; but the only +mineral product of note is amber, which is found in the peninsula +of Samland in greater abundance than in any other part of the +world. Manufactures are almost confined to the principal towns, +though linen-weaving is practised as a domestic industry. +Commerce is facilitated by canals connecting the Memel and +Pregel and also the principal lakes, but is somewhat hampered +by the heavy dues exacted at the Russian frontier. A brisk +foreign trade is carried on through the seaports of Königsberg, +the capital of the province, and Memel, the exports consisting +mainly of timber and grain.</p> + +<p>The population of the province was in 1900 1,996,626, and +<span class="pagenum"><a name="page838" id="page838"></a>838</span> +included 1,698,465 Protestants, 269,196 Roman Catholics and +13,877 Jews. The Roman Catholics are mainly confined to the +district of Ermeland, in which the ordinary proportions of the +confessions are completely reversed. The bulk of the inhabitants +are of German blood, but there are above 400,000 Protestant +Poles (Masurians or Masovians) in the south part of the province, +and 175,000 Lithuanians in the north. As in other provinces +where the Polish element is strong, East Prussia is somewhat +below the general average of the kingdom in education. There +is a university at Königsberg.</p> + +<div class="condensed"> +<p>See Lohmeyer, <i>Geschichte von Ost- und West-Preussen</i> (Gotha, +1884); Brünneck, <i>Zur Geschichte des Kirchen-Patronats in Ost- und +West-Preussen</i> (Berlin, 1902), and <i>Ost-Preussen, Land und Volk</i> +(Stuttgart, 1901-1902).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EASTWICK, EDWARD BACKHOUSE<a name="ar72" id="ar72"></a></span> (1814-1883), British +Orientalist, was born in 1814, a member of an Anglo-Indian +family. Educated at Charterhouse and at Oxford, he joined +the Bombay infantry in 1836, but, owing to his talent for +languages, was soon given a political post. In 1843 he translated +the Persian <i>Kessahi Sanján</i>, or <i>History of the Arrival of the +Parsees in India</i>; and he wrote a <i>Life of Zoroaster</i>, a <i>Sindhi</i> +vocabulary, and various papers in the transactions of the +Bombay Asiatic Society. Compelled by ill-health to return to +Europe, he went to Frankfort, where he learned German and +translated Schiller’s <i>Revolt of the Netherlands</i> and Bopp’s <i>Comparative +Grammar</i>. In 1845 he was appointed professor of +Hindustani at Haileybury College. Two years later he published +a Hindustani grammar, and, in subsequent years, a new edition +of the <i>Gulistán</i>, with a translation in prose and verse, also an +edition with vocabulary of the Hindi translation by Lallú Lál of +Chatur Chuj Misr’s <i>Prem Sagár</i>, and translations of the <i>Bagh-o-Bahar</i>, +and of the <i>Anvár-i Suhaili</i> of Bídpáí. In 1851 he was +elected a Fellow of the Royal Society. In 1857-1858 he edited +<i>The Autobiography of Lútfullah</i>. He also edited for the Bible +Society the Book of Genesis in the Dakhani language. From +1860 to 1863 he was in Persia as secretary to the British Legation, +publishing on his return <i>The Journal of a Diplomate</i>. In 1866 +he became private secretary to the secretary of state for India, +Lord Cranborne (afterwards marquess of Salisbury), and in +1867 went, as in 1864, on a government mission to Venezuela. +On his return he wrote, at the request of Charles Dickens, for +<i>All the Year Round</i>, “Sketches of Life in a South American +Republic.” From 1868 to 1874 he was M.P. for Penryn and +Falmouth. In 1875 he received the degree of M.A. with the +franchise from the university of Oxford, “as a slight recognition +of distinguished services.” At various times he wrote several +of Murray’s Indian hand-books. His last work was the <i>Kaisarnamah-i-Hind</i> +(“the lay of the empress”), in two volumes +(1878-1882). He died at Ventnor, Isle of Wight, on the 16th of +July 1883.</p> + + +<hr class="art" /> +<p><span class="bold">EATON, DORMAN BRIDGMAN<a name="ar73" id="ar73"></a></span> (1823-1899), American lawyer, +was born at Hardwick, Vermont, on the 27th of June 1823. He +graduated at the university of Vermont in 1848 and at the +Harvard Law School in 1850, and in the latter year was admitted +to the bar in New York city. There he became associated in +practice with William Kent, the son of the great chancellor, an +edition of whose <i>Commentaries</i> he assisted in editing. Eaton +early became interested in municipal and civil service reform. +He was conspicuous in the fight against Tweed and his followers, +by one of whom he was assaulted; he required a long period of +rest, and went to Europe, where he studied the workings of +the civil service in various countries. From 1873 to 1875 he +was a member of the first United States Civil Service Commission. +In 1877, at the request of President Hayes, he made a careful +study of the British civil service, and three years later published +<i>Civil Service in Great Britain</i>. He drafted the Pendleton Civil +Service Act of 1883, and later became a member of the new +commission established by it. He resigned in 1885, but was +almost immediately reappointed by President Cleveland, and +served until 1886, editing the 3rd and 4th <i>Reports</i> of the commission. +He was an organizer (1878) of the first society for +the furtherance of civil service reform in New York, of the +National Civil Service Reform Association, and of the National +Conference of the Unitarian Church (1865). He died in New York +city on the 23rd of December 1899, leaving $100,000 each to +Harvard and Columbia universities for the establishments of +professorships in government. He was a legal writer and editor, +and a frequent contributor to the leading reviews. In addition +to the works mentioned he published <i>Should Judges be Elected?</i> +(1873), <i>The Independent Movement in New York</i> (1880), <i>Term +and Tenure of Office</i> (1882), <i>The Spoils System and Civil Service +Reform</i> (1882), <i>Problems of Police Legislation</i> (1895) and <i>The +Government of Municipalities</i> (1899).</p> + +<div class="condensed"> +<p>See the privately printed memorial volume, <i>Dorman B. Eaton</i>, +1823-1899 (New York, 1900).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EATON, MARGARET O’NEILL<a name="ar74" id="ar74"></a></span> (1796-1879), better known +as <span class="sc">Peggy O’Neill</span>, was the daughter of the keeper of a popular +Washington tavern, and was noted for her beauty, wit and +vivacity. About 1823, she married a purser in the United +States navy, John B. Timberlake, who committed suicide while +on service in the Mediterranean in 1828. In the following year +she married John Henry Eaton (1790-1856), a Tennessee politician, +at the time a member of the United States Senate. +Senator Eaton was a close personal friend of President Jackson, +who in 1829 appointed him secretary of war. This sudden +elevation of Mrs Eaton into the cabinet social circle was resented +by the wives of several of Jackson’s secretaries, and charges +were made against her of improper conduct with Eaton previous +to her marriage to him. The refusal of the wives of the cabinet +members to recognize the wife of his friend angered President +Jackson, and he tried in vain to coerce them. Eventually, and +partly for this reason, he almost completely reorganized his +cabinet. The effect of the incident on the political fortunes +of the vice-president, John C. Calhoun, whose wife was one of +the recalcitrants, was perhaps most important. Partly on this +account, Jackson’s favour was transferred from Calhoun to +Martin Van Buren, the secretary of state, who had taken Jackson’s +side in the quarrel and had shown marked attention to +Mrs Eaton, and whose subsequent elevation to the vice-presidency +and presidency through Jackson’s favour is no doubt +partly attributable to this incident. In 1836 Mrs Eaton accompanied +her husband to Spain, where he was United States +minister in 1836-1840. After the death of her husband she +married a young Italian dancing-master, Antonio Buchignani, +but soon obtained a divorce from him. She died in Washington +on the 8th of November 1879.</p> + +<div class="condensed"> +<p>See James Parton’s <i>Life of Andrew Jackson</i> (New York, 1860).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EATON, THEOPHILUS<a name="ar75" id="ar75"></a></span> (<i>c.</i> 1590-1658), English colonial governor +in America, was born at Stony Stratford, Buckinghamshire, +about 1590. He was educated in Coventry, became a +successful merchant, travelled widely throughout Europe, and +for several years was the financial agent of Charles I. in Denmark. +He subsequently settled in London, where he joined the Puritan +congregation of the Rev. John Davenport, whom he had known +since boyhood. The pressure upon the Puritans increasing, +Eaton, who had been one of the original patentees of the Massachusetts +Bay colony in 1629, determined to use his influence and +fortune to establish an independent colony of which his pastor +should be the head. In 1637 he emigrated with Davenport to +Massachusetts, and in the following year (March 1638) he and +Davenport founded New Haven. In October 1639 a form of +government was adopted, based on the <span class="correction" title="amended from Mosiac">Mosaic</span> Law, and Eaton +was elected governor, a post which he continued to hold by annual +re-election, first over New Haven alone, and after 1643 over the +New Haven Colony or Jurisdiction, until his death at New Haven +on the 7th of January 1658. His administration was embarrassed +by constantly recurring disputes with the neighbouring +Dutch settlements, especially after Stamford (Conn.) and Southold +(Long Island) had entered the New Haven Jurisdiction, but his +prudence and diplomacy prevented an actual outbreak of hostilities. +He was prominent in the affairs of the New England +Confederation, of which he was one of the founders (1643). In +1655 he and Davenport drew up the code of laws, popularly +known as the “Connecticut Blue Laws,” which were published +<span class="pagenum"><a name="page839" id="page839"></a>839</span> +in London in 1656 under the title <i>New Haven’s Settling in New +England and some Lawes for Government published for the Use of +that Colony</i>.</p> + +<div class="condensed"> +<p>A sketch of his life appears in Cotton Mather’s <i>Magnalia</i> (London, +1702); see also J.B. Moore’s “Memoir of Theophilus Eaton” in the +<i>Collections</i> of the New York Historical Society, second series, vol. ii. +(New York, 1849).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EATON, WILLIAM<a name="ar76" id="ar76"></a></span> (1764-1811), American soldier, was born +in Woodstock, Connecticut, on the 23rd of February 1764. As +a boy he served for a short time in the Continental army. He +was a school teacher for several years, graduated at Dartmouth +College in 1790, was clerk of the lower house of the Vermont +legislature in 1791-1792, and in 1792 re-entered the army as a +captain, later serving against the Indians in Ohio and Georgia. +In 1797 he was appointed consul to Tunis, where he arrived in +February 1799. In March 1799, with the consuls to Tripoli and +Algiers, he negotiated alterations in the treaty of 1797 with +Tunis. He rendered great service to Danish merchantmen by +buying on credit several Danish prizes in Tunis and turning +them over to their original owners for the redemption of his +notes. In 1803 he quarrelled with the Bey, was ordered from +the country, and returned to the United States to urge American +intervention for the restoration of Ahmet Karamanli to the +throne of Tripoli, arguing that this would impress the Barbary +States with the power of the United States. In 1804 he returned +to the Mediterranean as United States naval agent to the Barbary +States with Barron’s fleet. On the 23rd of February 1805 he +agreed with Ahmet that the United States should undertake to +re-establish him in Tripoli, that the expenses of the expedition +should be repaid to the United States by Ahmet, and that Eaton +should be general and commander-in-chief of the land forces in +Ahmet’s campaign; as the secretary of the navy had given the +entire matter into the hands of Commodore Barron, and as +Barron and Tobias Lear (1762-1816), the United States consul-general +at Algiers and a diplomatic agent to conduct negotiations, +had been instructed to consider the advisability of making +arrangements with the existing government in Tripoli, Eaton far +exceeded his authority. On the 8th of March he started for +Derna across the Libyan desert from the Arab’s Tower, 40 m. W. +of Alexandria, with a force of about 500 men, including a few +Americans, about 40 Greeks and some Arab cavalry. In the +march of nearly 600 m. the camel-drivers and the Arab chiefs +repeatedly mutinied, and Ahmet Pasha once put himself at the +head of the Arabs and ordered them to attack Eaton. Ahmet +more than once wished to give up the expedition. There were +practically no provisions for the latter part of the march. On +the 27th of April with the assistance of three bombarding cruisers +Eaton captured Derna—an exploit commemorated by Whittier’s +poem <i>Derne</i>. On the 13th of May and on the 10th of June he +successfully withstood the attacks of Tripolitan forces sent to +dislodge him. On the 12th of June he abandoned the town upon +orders from Commodore Rodgers, for Lear had made peace +(4th June) with Yussuf, the <i>de facto</i> Pasha of Tripoli. Eaton +returned to the United States, and received a grant of 10,000 +acres in Maine from the Massachusetts legislature. According to +a deposition which he made in January 1807 he was approached +by Aaron Burr (<i>q.v.</i>), who attempted to enlist him in his “conspiracy,” +and wished him to win over the marine corps and to +sound Preble and Decatur. As he received from the government, +soon after making this deposition, about $10,000 to liquidate +claims for his expense in Tripoli, which he had long pressed in +vain, his good faith has been doubted. At Burr’s trial at Richmond +in 1807 Eaton was one of the witnesses, but his testimony +was unimportant. In May 1807 he was elected a member of the +Massachusetts House of Representatives, and served for one term. +He died on the 1st of June 1811 in Brimfield, Massachusetts.</p> + +<div class="condensed"> +<p>See the anonymously published <i>Life of the Late Gen. William Eaton</i> +(Brookfield, Massachusetts, 1813) by Charles Prentiss; C.C. Felton, +“Life of William Eaton” in Sparks’s <i>Library of American Biography</i>, +vol. ix. (Boston, 1838); and Gardner W. Allen’s <i>Our Navy and the +Barbary Corsairs</i> (Boston, 1905).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EATON, WYATT<a name="ar77" id="ar77"></a></span> (1849-1896), American portrait and figure +painter, was born at Philipsburg, Canada, on the 6th of May 1849. +He was a pupil of the schools of the National Academy of Design, +New York, and in 1872 went to Paris, where he studied in the +École des Beaux-Arts under J.L. Gérôme. He made the +acquaintance of J.F. Millet at Barbizon, and was also influenced +by his friend Jules Bastien-Lepage. After his return to the +United States in 1876 he became a teacher in Cooper Institute +and opened a studio in New York city. He was one of the +organizers (and the first secretary) of the Society of American +Artists. Among his portraits are those of William Cullen +Bryant and Timothy Cole, the wood engraver (“The Man with +the Violin”). Eaton died at Newport, Rhode Island, on the 7th +of June 1896.</p> + + +<hr class="art" /> +<p><span class="bold">EAU CLAIRE<a name="ar78" id="ar78"></a></span>, a city and the county-seat of Eau Claire +county, Wisconsin, U.S.A., on the Chippewa river, at the mouth +of the Eau Claire, about 87 m. E. of St Paul. Pop. (1890) +17,415; (1900) 17,517, of whom 4996 were foreign-born; (1910 census) +18,310. It is served by the Chicago & North-Western, +the Chicago, Milwaukee & St Paul, and the Wisconsin Central +railways, and is connected by an electric line with Chippewa +Falls (12 m. distant). The city has a Carnegie library with +17,200 volumes in 1908, a Federal building, county court house, +normal school and insane asylum. It has abundant water-power, +and is an important lumber manufacturing centre; +among its other manufactures are flour, wooden-ware, agricultural +machinery, saw-mill machinery, logging locomotives, +wood pulp, paper, linen, mattresses, shoes and trunks. The +total value of factory products in 1905 was $3,601,558. The +city is the principal wholesale and jobbing market for the prosperous +Chippewa Valley. Eau Claire was first settled about +1847, and was chartered as a city in 1872; its growth dates from +the development of the north-western lumber trade in the decade +1870-1880. In 1881 a serious strike necessitated the calling out of +state militia for its suppression and the protection of property.</p> + + +<hr class="art" /> +<p><span class="bold">EAU DE COLOGNE<a name="ar79" id="ar79"></a></span> (Ger. <i>Kölnisches Wasser</i>, “Cologne +water”), a perfume, so named from the city of Cologne, where +its manufacture was first established by an Italian, Johann (or +Giovanni) Maria Farina (1685-1766), who settled at Cologne +in 1709. The perfume gained a high reputation by 1766, and +Farina associated himself with his nephew, to whose grandson +the secret was ultimately imparted; the original perfume is +still manufactured by members of this family under the name +of the founder. The manufacture is, however, carried on at +Cologne, and also in Italy, by other firms bearing the name +Farina, and the scent has become part of the regular output of +perfumers. The discovery has also been ascribed to a Paul de +Feminis, who is supposed to have brought his recipe from Milan +to Cologne, of which he became a citizen in 1690, and sold the +perfume under the name <i>Eau admirable</i>, leaving the secret at +his death to his nephew Johann Maria Farina. Certain of the +Farinas claim to use his process. It was originally prepared +by making an alcoholic infusion of certain flowers, pot-herbs, +drugs and spices, distilling and then adding definite quantities +of several vegetable essences. The purity and thorough blending +of the ingredients are of the greatest importance. The original +perfume is simulated and even excelled by artificial preparations. +The oils of lemon, bergamot and orange are employed, together +with the oils of neroli and rosemary in the better class. The +common practice consists in dissolving the oils, in certain definite +proportions based on experience, in pure alcohol and distilling, +the distillate being diluted by rose-water.</p> + + +<hr class="art" /> +<p><span class="bold">EAUX-BONNES<a name="ar80" id="ar80"></a></span>, a watering-place of south-western France, +in the department of Basses-Pyrénées, 3½ m. S.E. of the small +town of Laruns, the latter being 24 m. S. of Pau by rail. Pop. +(1906) 610. Eaux-Bonnes is situated at a height of 2460 ft. +at the entrance of a fine gorge, overlooking the confluence of +two torrents, the Valentin and the Sourde. The village is well +known for its sulphurous and saline mineral waters (first mentioned +in the middle of the 14th century), which are beneficial +in affections of the throat and lungs. They vary between +50° and 90° F. in temperature, and are used for drinking and +bathing. There are two thermal establishments, a casino and +fine promenades.</p> + +<p><span class="pagenum"><a name="page840" id="page840"></a>840</span></p> + +<p>The watering-place of <span class="sc">Les Eaux-Chaudes</span> is 5 m. by road +south-west of Eaux-Bonnes, in a wild gorge on the Gave d’Ossau. +The springs are sulphurous, varying in temperature from 52° to +97° F., and are used in cases of rheumatism, certain maladies of +women, &c. The thermal establishment is a handsome marble +building.</p> + +<p>There is fine mountain scenery in the neighbourhood of both +places, the Pic de Ger near Eaux-Bonnes, commanding an +extensive view. The valley of Ossau, one of the most beautiful in +the Pyrenees, before the Revolution formed a community which, +though dependent on Béarn, had its own legal organization, +manners and costumes, the last of which are still to be seen on +holidays.</p> + + +<hr class="art" /> +<p><span class="bold">EAVES<a name="ar81" id="ar81"></a></span> (not a plural form as is sometimes supposed, but +singular; O. Eng. <i>efes</i>, in Mid. High Ger. <i>obse</i>, Gothic <i>ubizwa</i>, a +porch; connected with “over”), in architecture, the projecting +edge of a sloping roof, which overhangs the face of the wall so +as to throw off the water.</p> + + +<hr class="art" /> +<p><span class="bold">EAVESDRIP<a name="ar82" id="ar82"></a></span>, or <span class="sc">Eavesdrop</span>, that width of ground around +a house or building which receives the rain water dropping from +the eaves. By an ancient Saxon law, a landowner was forbidden +to erect any building at less than 2 ft. from the boundary of his +land, and was thus prevented from injuring his neighbour’s house +or property by the dripping of water from his eaves. The law +of Eavesdrip has had its equivalent in the Roman <i>stillicidium</i>, +which prohibited building up to the very edge of an estate.</p> + +<p>From the Saxon custom arose the term “eavesdropper,” +<i>i.e.</i> any one who stands within “the eavesdrop” of a house, +hence one who pries into others’ business or listens to secrets. +At common law an eavesdropper was regarded as a common +nuisance, and was presentable at the court leet, and indictable +at the sheriff’s tourn and punishable by fine and finding sureties +for good behaviour. Though the offence of eavesdropping still +exists at common law, there is no modern instance of a prosecution +or indictment.</p> + + +<hr class="art" /> +<p><span class="bold">EBBW VALE<a name="ar83" id="ar83"></a></span>, an urban district in the western parliamentary +division of Monmouthshire, England, 21 m. N.W. of Newport +on the Great Western, London & North-Western and Rhymney +railways. Pop. (1891) 17,312; (1901) 20,994. It lies near the +head of the valley of the river Ebbw, at an elevation of nearly +1000 ft., in a wild and mountainous mining district, which contains +large collieries and important iron and steel works.</p> + + +<hr class="art" /> +<p><span class="bold">EBEL, HERMANN WILHELM<a name="ar84" id="ar84"></a></span> (1820-1875), German philologist, +was born at Berlin on the 10th of May 1820. He displayed +in his early years a remarkable capacity for the study of +languages, and at the same time a passionate fondness for music +and poetry. At the age of sixteen he became a student at the +university of Berlin, applying himself especially to philology, +and attending the lectures of Böckh. Music continued to be the +favourite occupation of his leisure hours, and he pursued the +study of it under the direction of Marx. In the spring of 1838 +he passed to the university of Halle, and there began to apply +himself to comparative philology under Pott. Returning in the +following year to his native city, he continued this study as a +disciple of Bopp. He took his degree in 1842, and, after spending +his year of probation at the French Gymnasium of Berlin, he +resumed with great earnestness his language studies. About +1847 he began to study Old Persian. In 1852 he accepted a +professorship at the Beheim-Schwarzbach Institution at Filehne, +which post he held for six years. It was during this period that +his studies in the Old Slavic and Celtic languages began. In +1858 he removed to Schneidemühl, and there he discharged the +duties of first professor for ten years. He was afterwards called +to the chair of comparative philology at the university of Berlin. +He died at Misdroy on the 19th of August 1875. The most +important work of Dr Ebel in the field of Celtic philology is his +revised edition of the <i>Grammatica Celtica</i> of Professor Zeuss, +completed in 1871. This had been preceded by his treatises—<i>De +verbi Britannici futuro ac conjunctivo</i> (1866), and <i>De Zeussii curis +positis in Grammatica Celtica</i> (1869). He made many learned +contributions to Kühn’s <i>Zeitschrift für vergleichende Sprachforschung</i>, +and to A. Schleicher’s <i>Beiträge zur vergleichenden +Sprachforschung</i>; and a selection of these contributions was +translated into English by Sullivan, and published under the +title of <i>Celtic Studies</i> (1863). Ebel contributed the Old Irish +section to Schleicher’s <i>Indogermanische Chrestomathie</i> (1869). +Among his other works must be named <i>Die Lehnwörter der +deutschen Sprache</i> (1856).</p> + + +<hr class="art" /> +<p><span class="bold">EBEL, JOHANN GOTTFRIED<a name="ar85" id="ar85"></a></span> (1764-1830), the author of the +first real guide-book to Switzerland, was born at Züllichau +(Prussia). He became a medical man, visited Switzerland for +the first time in 1790, and became so enamoured of it that he +spent three years exploring the country and collecting all kinds +of information relating to it. The result was the publication +(Zürich, 1793) of his <i>Anleitung auf die nützlichste und genussvollste +Art in der Schweitz zu reisen</i> (2 vols.), in which he gave a complete +account of the country, the General Information sections being +followed by an alphabetically arranged list of places, with +descriptions. It at once superseded all other works of the +kind, and was the best Swiss guide-book till the appearance of +“Murray” (1838). It was particularly strong on the geological +and historical sides. The second (1804-1805) and third (1809-1810) +editions filled four volumes, but the following (the 8th +appeared in 1843) were in a single volume. The work was translated +into French in 1795 (many later editions) and into English +(by 1818). Ebel also published a work (2 vols., Leipzig, 1798-1802) +entitled <i>Schilderungen der Gebirgsvölker der Schweiz</i>, +which deals mainly with the pastoral cantons of Glarus and +Appenzell. In 1801 he was naturalized a Swiss citizen, and +settled down in Zürich. In 1808 he issued his chief geological +work, <i>Über den Bau der Erde im Alpengebirge</i> (Zürich, +2 vols.). He took an active share in promoting all that could +make his adopted country better known, <i>e.g.</i> Heinrich Keller’s +map (1813), the building of a hotel on the Rigi (1816), and the +preparation of a panorama from that point (1823). From +1810 onwards he lived at Zürich, with the family of his friend, +Conrad Escher von der Linth (1767-1823), the celebrated +engineer.</p> +<div class="author">(W. A. B. C.)</div> + + +<hr class="art" /> +<p><span class="bold">EBER, PAUL<a name="ar86" id="ar86"></a></span> (1511-1569), German theologian, was born +at Kitzingen in Franconia, and was educated at Nuremberg +and Wittenberg, where he became the close friend of Philip +Melanchthon. In 1541 he was appointed professor of Latin +grammar at Wittenberg, and in 1557 professor of the Old Testament. +His range of learning was wide, and he published a +handbook of Jewish history, a historical calendar intended to +supersede the Roman Saints’ Calendar, and a revision of the +Latin Old Testament. In the theological conflict of the time he +played a large part, doing what he could to mediate between +the extremists. From 1559 to the close of his life he was +superintendent-general of the electorate of Saxony. He attained +some fame as a hymn-writer, his best-known composition being +“Wenn wir in höchsten Nöthen sein.” He died at Wittenberg +on the 10th of December 1569.</p> + + +<hr class="art" /> +<p><span class="bold">EBERBACH<a name="ar87" id="ar87"></a></span>, a town of Germany, in the grand-duchy of Baden, +romantically situated on the Neckar, at the foot of the Katzenbuckel, +19 m. E. of Heidelberg by the railway to Würzburg. +Pop. (1900) 5857. It contains an Evangelical and a Roman +Catholic church, a commercial and a technical school, and, in +addition to manufacturing cigars, leather and cutlery, carries +on by water an active trade in timber and wine. Eberbach was +founded in 1227 by the German king Henry VII., who acquired +the castle (the ruins of which overhang the town) from the +bishop of Worms. It became an imperial town and passed later +to the Palatinate.</p> + +<div class="condensed"> +<p>See Wirth, <i>Geschichte der Stadt Eberbach</i> (Stuttgart, 1864).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBERBACH<a name="ar88" id="ar88"></a></span>, a famous Cistercian monastery of Germany, in +the Prussian province of Hesse-Nassau, situated near Hattenheim +in the Rheingau, 10 m. N.W. from Wiesbaden. Founded in +1116 by Archbishop Adalbert of Mainz, as a house of Augustinian +canons regular, it was bestowed by him in 1131 upon the Benedictines, +but was shortly afterwards repurchased and conferred +upon the Cistercian order. The Romanesque church (consecrated +in 1186) contains numerous interesting monuments and tombs, +notable among them being those of the archbishop of Mainz, +<span class="pagenum"><a name="page841" id="page841"></a>841</span> +Gerlach (d. 1371) and Adolph II. of Nassau (d. 1475). It was +despoiled during the Thirty Years’ War, was secularized in 1803, +and now serves as a house of correction. Its cellars contain some +of the finest vintages of the Rhine wines of the locality.</p> + +<div class="condensed"> +<p>See Bär, <i>Diplomatische Geschichte der Abtei Eberbach</i> (Wiesb., 1851-1858 +and 1886, 3 vols.), and Schäfer, <i>Die Abtei Eberbach im Mittelalter</i> +(Berlin, 1901).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBERHARD<a name="ar89" id="ar89"></a></span>, surnamed <span class="sc">Im Bart</span> (<i>Barbatus</i>), count and +afterwards duke of Württemberg (1445-1496), was the second +son of Louis I., count of Württemberg-Urach (d. 1450), and +succeeded his elder brother Louis II. in 1457. His uncle Ulrich V., +count of Württemberg-Stuttgart (d. 1480), acted as his guardian, +but in 1459, assisted by Frederick I., elector palatine, he threw +off this restraint, and undertook the government of the district +of Urach as Count Eberhard V. He neglected his duties as a +ruler and lived a reckless life until 1468, when he made a pilgrimage +to Jerusalem. He visited Italy, became acquainted with +some famous scholars, and in 1474 married Barbara di Gonzaga, +daughter of Lodovico III., marquis of Mantua, a lady distinguished +for her intellectual qualities. In 1482 he brought about +the treaty of Münsingen with his cousin Eberhard VI., count of +Württemberg-Stuttgart. By this treaty the districts of Urach +and Stuttgart into which Württemberg had been divided in +1437 were again united, and for the future the county was +declared indivisible, and the right of primogeniture established. +The treaty led to some disturbances, but in 1492 the sanction +of the nobles was secured for its provisions. In return for this +Eberhard agreed to some limitations on the power of the count, +and so in a sense founded the constitution of Württemberg. +At the diet of Worms in 1495 the emperor Maximilian I. +guaranteed the treaty, confirmed the possessions and prerogatives +of the house of Württemberg, and raised Eberhard to the rank +of duke. Eberhard, although a lover of peace, was one of the +founders of the Swabian League in 1488, and assisted to release +Maximilian, then king of the Romans, from his imprisonment +at Bruges in the same year. He gave charters to the towns of +Stuttgart and Tübingen, and introduced order into the convents +of his land, some of which he secularized. He took a keen interest +in the new learning, founded the university of Tübingen in 1476, +befriended John Reuchlin, whom he made his private secretary, +welcomed scholars to his court, and is said to have learned Latin +in later life. In 1482 he again visited Italy and received the +Golden Rose from Pope Sixtus IV. He won the esteem of the +emperors Frederick III. and Maximilian I. on account of his +wisdom and fidelity, and his people held him in high regard. +His later years were mainly spent at Stuttgart, but he died at +Tübingen on the 25th of February 1496, and in 1537 his ashes +were placed in the choir of the Stiftskirche there. Eberhard +left no children, and the succession passed to his cousin Eberhard, +who became Duke Eberhard II.</p> + +<div class="condensed"> +<p>See Rösslin, <i>Leben Eberhards im Barte</i> (Tübingen, 1793); Bossert, +<i>Eberhard im Bart</i> (Stuttgart, 1884).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBERHARD, CHRISTIAN AUGUST GOTTLOB<a name="ar90" id="ar90"></a></span> (1769-1845), +German miscellaneous writer, was born at Belzig, near Wittenberg, +on the 12th of January 1769. He studied theology at +Leipzig; but, a story he contributed to a periodical having +proved successful, he devoted himself to literature. With the +exception of <i>Hannchen und die Küchlein</i> (1822), a narrative +poem in ten parts, and an epic on the Creation, <i>Der erste Mensch +und die Erde</i> (1828), Eberhard’s work was ephemeral in character +and is now forgotten. He died at Dresden on the 13th of May +1845.</p> + +<div class="condensed"> +<p>His collected works (<i>Gesammelte Schriften</i>) appeared in 20 volumes +in 1830-1831.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBERHARD, JOHANN AUGUSTUS<a name="ar91" id="ar91"></a></span> (1739-1809), German +theologian and philosopher, was born at Halberstadt in Lower +Saxony, where his father was singing-master at the church of +St Martin’s, and teacher of the school of the same name. He +studied theology at the university of Halle, and became tutor +to the eldest son of the baron von der Horst, to whose family +he attached himself for a number of years. In 1763 he was +appointed con-rector of the school of St Martin’s, and second +preacher in the hospital church of the Holy Ghost; but he soon +afterwards resigned these offices and followed his patron to +Berlin. There he met Nicolai and Moses Mendelssohn, with +whom he formed a close friendship. In 1768 he became preacher +or chaplain to the workhouse at Berlin and the neighbouring +fishing village of Stralow. Here he wrote his <i>Neue Apologie des +Socrates</i> (1772), a work occasioned by an attack on the fifteenth +chapter of Marmontel’s <i>Belisarius</i> made by Peter Hofstede, a +clergyman of Rotterdam, who maintained the patristic view +that the virtues of the noblest pagans were only <i>splendida peccata</i>. +Eberhard stated the arguments for the broader view with +dignity, acuteness and learning, but the liberality of the reasoning +gave great offence to the strictly orthodox divines, and is +believed to have obstructed his preferment in the church.</p> + +<p>In 1774 he was appointed to the living of Charlottenburg. +A second volume of his <i>Apologie</i> appeared in 1778. In this he +not only endeavoured to obviate some objections which were +taken to the former part, but continued his inquiries into the +doctrines of the Christian religion, religious toleration and the +proper rules for interpreting the Scriptures. In 1778 he accepted +the professorship of philosophy at Halle. As an academical +teacher, however, he was unsuccessful. His powers as an original +thinker were not equal to his learning and his literary gifts, as +was shown in his opposition to the philosophy of Kant. In 1786 +he was admitted a member of the Berlin Academy of Sciences; +in 1805 the king of Prussia conferred upon him the honorary title +of a privy-councillor. In 1808 he obtained the degree of doctor +in divinity, which was given him as a reward for his theological +writings. He died on the 6th of January 1809. He was master +of the learned languages, spoke and wrote French with facility +and correctness, and understood English, Italian and Dutch. +He possessed a just and discriminating taste for the fine arts, and +was a great lover of music.</p> + +<div class="condensed"> +<p>Works:—<i>Neue Apologie des Socrates</i>, &c. (2 vols., 1772-1778); +<i>Allgemeine Theorie des Denkens und Empfindens</i>, &c. (Berlin, 1776), an +essay which gained the prize assigned by the Royal Society of Berlin +for that year; <i>Von dem Begriff der Philosophie und ihren Theilen</i> +(Berlin, 1778)—a short essay, in which he announced the plan of his +lectures on being appointed to the professorship at Halle; <i>Lobschrift +auf Herrn Johann Thunmann Prof. der Weltweisheit und Beredsamkeit +auf der Universität zu Halle</i> (Halle, 1779); <i>Amyntor, eine +Geschichte in Briefen</i> (Berlin, 1782)—written with the view of +counteracting the influence of those sceptical and Epicurean principles +in religion and morals then so prevalent in France, and rapidly +spreading amongst the higher ranks in Germany; <i>Über die Zeichen +der Aufklärung einer Nation</i>, &c. (Halle, 1783); <i>Theorie der schönen +Künste und Wissenschaften</i>, &c. (Halle, 1783, 3rd ed. 1790); <i>Vermischte +Schriften</i> (Halle, 1784); <i>Neue vermischte Schriften</i> (<i>ib.</i> 1786); +<i>Allgemeine Geschichte der Philosophie</i>, &c. (Halle, 1788), 2nd ed. +with a continuation and chronological tables (1796); <i>Versuch einer +allgemeinen-deutschen Synonymik</i> (Halle and Leipzig, 1795-1802, +6 vols., 4th ed. 1852-1853), long reckoned the best work on the +synonyms of the German language (an abridgment of it was published +by the author in one large volume, Halle, 1802); <i>Handbuch der +Aesthetik</i> (Halle, 1803-1805, 2nd ed. 1807-1820). He also edited +the <i>Philosophisches Magazin</i> (1788-1792) and the <i>Philosophisches +Archiv</i> (1792-1795).</p> + +<p>See F. Nicolai, <i>Gedächtnisschrift auf J.A. Eberhard</i> (Berlin and Stettin, +1810); also K.H. Jördens, <i>Lexicon deutscher Dichter und Prosaisten</i>.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBERLIN, JOHANN ERNST<a name="ar92" id="ar92"></a></span> (1702-1762), German musician +and composer, was born in Bavaria, and became afterwards +organist in the cathedral at Salzburg, where he died. Most of +his compositions were for the church (oratorios, &c.), but he also +wrote some important fugues, sonatas and preludes; and his +pieces were at one time highly valued by Mozart.</p> + + +<hr class="art" /> +<p><span class="bold">EBERS, GEORG MORITZ<a name="ar93" id="ar93"></a></span> (1837-1898), German Egyptologist +and novelist, was born in Berlin on the 1st of March 1837. At +Göttingen he studied jurisprudence, and at Berlin oriental +languages and archaeology. Having made a special study of +Egyptology, he became in 1865 <i>docent</i> in Egyptian language and +antiquities at Jena, and in 1870 he was appointed professor in +these subjects at Leipzig. He had made two scientific journeys +to Egypt, and his first work of importance, <i>Ägypten und die +Bücher Moses</i>, appeared in 1867-1868. In 1874 he edited the +celebrated medical papyrus (“Papyrus Ebers”) which he had +discovered in Thebes (translation by H. Joachim, 1890). Ebers +early conceived the idea of popularizing Egyptian lore by means +of historical romances. <i>Eine ägyptische Königstochter</i> was +<span class="pagenum"><a name="page842" id="page842"></a>842</span> +published in 1864, and obtained great success. His subsequent +works of the same kind—<i>Uarda</i> (1877), <i>Homo sum</i> (1878), <i>Die +Schwestern</i> (1880), <i>Der Kaiser</i> (1881), of which the scene is laid +in Egypt at the time of Hadrian, <i>Serapis</i> (1885), <i>Die Nilbraut</i> +(1887), and <i>Kleopatra</i> (1894), were also well received, and did +much to make the public familiar with the discoveries of Egyptologists. +Ebers also turned his attention to other fields of +historical fiction—especially the 16th century (<i>Die Frau Bürgermeisterin</i>, +1882; <i>Die Gred</i>, 1887)—without, however, attaining +the success of his Egyptian novels. Apart from their antiquarian +and historical interest, Ebers’s books have not a very high literary +value. His other writings include a descriptive work on Egypt +(<i>Ägypten in Wort und Bild</i>, 2nd ed., 1880), a guide to Egypt +(1886) and a life (1885) of his old teacher, the Egyptologist +Karl Richard Lepsius. The state of his health led him in 1889 +to retire from his chair at Leipzig on a pension. He died at +Tutzing in Bavaria, on the 7th of August 1898.</p> + +<div class="condensed"> +<p>Ebers’s <i>Gesammelte Werke</i> appeared in 25 vols. at Stuttgart (1893-1895). +Many of his books have been translated into English. For +his life see his <i>Die Geschichte meines Lebens</i> (Stuttgart, 1893); also +R. Gosche, <i>G. Ebers, der Forscher und Dichter</i> (2nd ed., Leipzig, +1887).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBERSWALDE<a name="ar94" id="ar94"></a></span>, a town of Germany, in the kingdom of Prussia, +28 m. N.E. of Berlin by rail; on the Finow canal. Pop. (1905) +23,876. The town has a Roman Catholic and two Evangelical +churches, a school of forestry, a gymnasium, a higher-grade girls’ +school and two schools of domestic economy. It possesses a +mineral spring, which attracts numerous summer visitors, and +has various industries, which include iron-founding and the +making of horse-shoe nails, roofing material and bricks. A +considerable trade is carried on in grain, wood and coals. In +the immediate neighbourhood are one of the chief brass-foundries +in Germany and an extensive government paper-mill, in which +the paper for the notes of the imperial bank is manufactured.</p> + +<p>Eberswalde received its municipal charter in 1257. It was +taken and sacked during the Thirty Years’ War. In 1747 +Frederick the Great brought a colony of Thuringian cutlers to the +town, but this branch of industry has entirely died out. About +4 m. to the north lies the old Cistercian monastery of Chorin, +the fine Gothic church of which contains the tombs of several +margraves of Brandenburg.</p> + + +<hr class="art" /> +<p><span class="bold">EBERT, FRIEDRICH ADOLF<a name="ar95" id="ar95"></a></span> (1791-1834), German bibliographer, +was born at Taucha, near Leipzig, on the 9th of July +1791, the son of a Lutheran pastor. At the age of fifteen he was +appointed to a subordinate post in the municipal library of +Leipzig. He studied theology for a short time at Leipzig, and +afterwards philology at Wittenberg, where he graduated doctor in +philosophy in 1812. While still a student he had already published, +in 1811, a work on public libraries, and in 1812 another +work entitled <i>Hierarchiae in religionem ac literas commoda</i>. In +1813 he was attached to the Leipzig University library, and in +1814 was appointed secretary to the Royal library of Dresden. +The same year he published <i>F. Taubmanns Leben und Verdienste</i>, +and in 1819 <i>Torquato Tasso</i>, a translation from Pierre Louis +Ginguené with annotations. The rich resources open to him in +the Dresden library enabled him to undertake the work on which +his reputation chiefly rests, the <i>Allgemeines bibliographisches +Lexikon</i>, the first volume of which appeared in 1821 and the second +in 1830. This was the first work of the kind produced in Germany, +and the most scientific published anywhere. From 1823 to 1825 +Ebert was librarian to the duke of Brunswick at Wolfenbüttel, +but returning to Dresden was made, in 1827, chief librarian of +the Dresden Royal library. Among his other works are—<i>Die +Bildung des Bibliothekars</i> (1820), <i>Geschichte und Beschreibung der +königlichen öffentlichen Bibliothek in Dresden</i> (1822), <i>Zur Handschriftenkunde</i> +(1825-1827), and <i>Culturperioden des obersächsischen +Mittelalters</i> (1825). Ebert was a contributor to various +journals and took part in the editing of Ersch and Gruber’s great +encyclopaedia. He died at Dresden on the 13th of November +1834, in consequence of a fall from the ladder in his library.</p> + +<div class="condensed"> +<p>See the article in <i>Ersch und Grubers Encyclopädie</i>, and that in the +<i>Allg. deutsche Biog.</i> by his successor in the post of chief librarian in +Dresden, Schnorr von Carolsfeld.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBINGEN<a name="ar96" id="ar96"></a></span>, a town of Germany, in the kingdom of Württemberg, +on the Schmiecha, a left-hand tributary of the Danube, +22 m. S. of Tübingen and 37 m. W. of Ulm by rail. It manufactures +velvet and cotton-velvet (“Manchester”) goods, stockings, +stays, hats, needles, tools, &c. There are also tanneries. +Pop. 9000.</p> + + +<hr class="art" /> +<p><span class="bold">EBIONITES<a name="ar97" id="ar97"></a></span> (Heb. <span title="ebyonim">אביונם</span>, “poor men”), a name given to the +ultra-Jewish party in the early Christian church. It is first met +with in Irenaeus (<i>Adv. Haer.</i> i. 26. 2), who sheds no light on the +origin of the Ebionites, but says that while they admit the world +to have been made by the true God (in contrast to the Demiurge +of the Gnostics), they held Cerinthian views on the person of +Christ, used only the Gospel of Matthew (probably the Gospel +according to the Hebrews—so Eusebius), and rejected Paul as an +apostate from the Mosaic Law, to the customs and ordinances of +which, including circumcision, they steadily adhered. A similar +account is given by Hippolytus (<i>Haer.</i> vii. 35), who invents a +founder named Ebion. Origen (<i>Contra Celsum</i>, v. 61; <i>In Matt.</i> +tom. xvi. 12) divides the Ebionites into two classes according to +their acceptance or rejection of the virgin birth of Jesus, but +says that all alike reject the Pauline epistles. This is confirmed +by Eusebius, who adds that even those who admitted the virgin +birth did not accept the pre-existence of Jesus as Logos and +Sophia. They kept both the Jewish Sabbath and the Christian +Lord’s day, and held extreme millenarian ideas in which Jerusalem +figured as the centre of the coming Messianic kingdom. Epiphanius +with his customary confusion makes two separate sects, +Ebionites and Nazarenes. Both names, however, refer to the +same people<a name="fa1f" id="fa1f" href="#ft1f"><span class="sp">1</span></a> (the Jewish Christians of Syria), the latter going +back to the designation of apostolic times (Acts xxiv. 5), and the +former being the term usually applied to them in the ecclesiastical +literature of the 2nd and 3rd centuries.</p> + +<p>The origin of the Nazarenes or Ebionites as a distinct sect is +very obscure, but may be dated with much likelihood from the +edict of Hadrian which in 135 finally scattered the old church of +Jerusalem. While Christians of the type of Aristo of Pella and +Hegesippus, on the snapping of the old ties, were gradually +assimilated to the great church outside, the more conservative +section became more and more isolated and exclusive. “It may +have been then that they called themselves the Poor Men, probably +as claiming to be the true representatives of those who had +been blessed in the Sermon on the Mount, but possibly adding +to the name other associations.” Out of touch with the main +stream of the church they developed a new kind of pharisaism. +Doctrinally they stood not so much for a theology as for a refusal +of theology, and, rejecting the practical liberalism of Paul, became +the natural heirs of those early Judaizers who had caused the +apostle so much annoyance and trouble.</p> + +<p>Though there is insufficient justification for dividing the +Ebionites into two separate and distinct communities, labelled +respectively Ebionites and Nazarenes, we have good evidence, +not only that there were grades of Christological thought among +them, but that a considerable section, at the end of the 2nd +century and the beginning of the 3rd, exchanged their simple +Judaistic creed for a strange blend of Essenism and Christianity. +These are known as the Helxaites or Elchasaites, for they accepted +as a revelation the “book of Elchasai,” and one Alcibiades of +Apamea undertook a mission to Rome about 220 to propagate +its teaching. It was claimed that Christ, as an angel 96 miles +high, accompanied by the Holy Spirit, as a female angel of the +same stature, had given the revelation to Elchasai in the 3rd year +of Trajan (<span class="scs">A.D.</span> 100), but the book was probably quite new in +Alcibiades’ time. It taught that Christ was an angel born of +human parents, and had appeared both before (<i>e.g.</i> in Adam +and Moses) and after this birth in Judea. His coming did not +annul the Law, for he was merely a prophet and teacher; Paul +was wrong and circumcision still necessary. Baptism must be +repeated as a means of purification from sin, and proof against +disease; the sinner immerses himself “in the name of the mighty +<span class="pagenum"><a name="page843" id="page843"></a>843</span> +and most high God,” invoking the “seven witnesses” (sky, water, +the holy spirits, the angels of prayer, oil, salt and earth), and +pledging himself to amendment. Abstinence from flesh was +also enjoined, and a good deal of astrological fancy was interwoven +with the doctrinal and practical teaching. It is highly +probable, too, that from these Essene Ebionites there issued the +fantastical and widely read “Clementine” literature (<i>Homilies</i> +and <i>Recognitions</i>) of the 3rd century. Ebionite views lingered +especially in the country east of the Jordan until they were +absorbed by Islam in the 7th century.</p> + +<div class="condensed"> +<p>In addition to the literature cited see R.C. Ottley, <i>The Doctrine +of the Incarnation</i>, part iii. § ii.; W. Moeller, <i>Hist. of the Christian +Church</i>, i. 99; art. in Herzog-Hauck, <i>Realencyklopädie</i>, s.v. +“Ebioniten”; also <span class="sc"><a href="#artlinks">Clementine Literature</a></span>.</p> +</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1f" id="ft1f" href="#fa1f"><span class="fn">1</span></a> So A. Harnack, <i>Hist. of Dogma</i>, i. 301, and F.J.A. Hort, <i>Judaistic +Christianity</i>, p. 199. Th. Zahn and J.B. Lightfoot (“St. Paul and +the Three,” in <i>Commentary on Galatians</i>) maintain the distinction.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBNER-ESCHENBACH, MARIE,<a name="ar98" id="ar98"></a></span> <span class="sc">Freifrau von</span> (1830-  ), +Austrian novelist, was born at Zdislavič in Moravia, on +the 13th of September 1830, the daughter of a Count Dubsky. +She lost her mother in early infancy, but received a careful +intellectual training from two stepmothers. In 1848 she married +the Austrian captain, and subsequent field-marshal, Moritz +von Ebner-Eschenbach, and resided first at Vienna, then at +Klosterbruck, where her husband had a military charge, and +after 1860 again at Vienna. The marriage was childless, and +the talented wife sought consolation in literary work. In her +endeavours she received assistance and encouragement from +Franz Grillparzer and Freiherr von Münch-Bellinghausen. +Her first essay was with the drama <i>Maria Stuart in Schottland</i>, +which Philipp Eduard Devrient produced at the Karlsruhe +theatre in 1860. After some other unsuccessful attempts in the +field of drama, she found her true sphere in narrative. Commencing +with <i>Die Prinzessin von Banalien</i> (1872), she graphically +depicts in <i>Božena</i> (Stuttgart, 1876, 4th ed. 1899) and <i>Das +Gemeindekind</i> (Berlin, 1887, 4th ed. 1900) the surroundings of her +Moravian home, and in <i>Lotti, die Uhrmacherin</i> (Berlin, 1883, 4th +ed. 1900), <i>Zwei Comtessen</i> (Berlin, 1885, 5th ed. 1898), <i>Unsühnbar</i> +(1890, 5th ed. 1900) and <i>Glaubenslos?</i> (1893) the life of the +Austrian aristocracy in town and country. She also published +<i>Neue Erzählungen</i> (Berlin, 1881, 3rd ed. 1894), <i>Aphorismen</i> +(Berlin, 1880, 4th ed. 1895) and <i>Parabeln, Märchen und Gedichte</i> +(2nd ed., Berlin, 1892). Frau von Ebner-Eschenbach’s elegance +of style, her incisive wit and masterly depiction of character +give her a foremost place among the German women-writers of +her time. On the occasion of her seventieth birthday the +university of Vienna conferred upon her the degree of doctor of +philosophy, <i>honoris causa</i>.</p> + +<div class="condensed"> +<p>An edition of Marie von Ebner-Eschenbach’s <i>Gesammelte Schriften</i> +began to appear in 1893 (Berlin). See A. Bettelheim, <i>Marie von +Ebner-Eschenbach: biographische Blätter</i> (Berlin, 1900), and M. +Necker, <i>Marie von Ebner-Eschenbach, nach ihren Werken geschildert</i> +(Berlin, 1900).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">EBOLI<a name="ar99" id="ar99"></a></span> (anc. <i>Eburum</i>), a town of Campania, Italy, in the +province of Salerno, from which it is 16 m. E. by rail, situated +470 ft. above sea-level, on the S. edge of the hills overlooking +the valley of the Sele. Pop. (1901) 9642 (town), 12,423 (commune). +The sacristy of St Francesco contains two 14th-century +pictures, one by Roberto da Oderisio of Naples. The ancient +Eburum was a Lucanian city, mentioned only by Pliny and in +inscriptions, not far distant from the Campanian border. It +lay above the Via Popillia, which followed the line taken by the +modern railway. Some scanty remains of its ancient polygonal +walls may still be seen.</p> +<div class="author">(T. As.)</div> + + +<hr class="art" /> +<p><span class="bold">EBONY<a name="ar100" id="ar100"></a></span> (Gr. <span class="grk" title="ebenos">ἔβενος</span>), the wood of various species of trees of +the genus <i>Diospyros</i> (natural order Ebenaceae), widely distributed +in the tropical parts of the world. The best kinds are very +heavy, are of a deep black, and consist of heart-wood only. +On account of its colour, durability, hardness and susceptibility +of polish, ebony is much used for cabinet work and inlaying, +and for the manufacture of pianoforte-keys, knife-handles and +turned articles. The best Indian and Ceylon ebony is furnished +by <i>D. Ebenum</i>, a native of southern India and Ceylon, which +grows in great abundance throughout the flat country west of +Trincomalee. The tree is distinguished from others by the +inferior width of its trunk, and its jet-black, charred-looking +bark, beneath which the wood is perfectly white until the heart +is reached. The wood is stated to excel that obtained from +<i>D. reticulata</i> of the Mauritius and all other varieties of ebony in +the fineness and intensity of its dark colour. Although the centre +of the tree alone is employed, reduced logs 1 to 3 ft. in diameter +can readily be procured. Much of the East Indian ebony is +yielded by the species <i>D. Melanoxylon</i> (Coromandel ebony), +a large tree attaining a height of 60 to 80 ft., and 8 to 10 ft. in +circumference, with irregular rigid branches, and oblong or +oblong-lanceolate leaves. The bark of the tree is astringent, +and mixed with pepper is used in dysentery by the natives of +India. The wood of <i>D. tomentosa</i>, a native of north Bengal, is +black, hard and of great weight. <i>D. montana</i>, another Indian +species, produces a yellowish-grey soft but durable wood. +<i>D. quaesita</i> is the tree from which is obtained the wood known +in Ceylon by the name <i>Calamander</i>, derived by Pridham from +the Sinhalee <i>kalumindrie</i>, black-flowing. Its closeness of grain, +great hardness and fine hazel-brown colour, mottled and striped +with black, render it a valuable material for veneering and +furniture making. <i>D. Dendo</i>, a native of Angola, is a valuable +timber tree, 25 to 35 ft. high, with a trunk 1 to 2 ft. in diameter. +The heart-wood is very black and hard and is known as black +ebony, also as billet-wood, and Gabun, Lagos, Calabar or Niger +ebony. What is termed Jamaica or West Indian ebony, and +also the green ebony of commerce, are produced by <i>Brya Ebenus</i>, +a leguminous tree or shrub, having a trunk rarely more than +4 in. in diameter, flexible spiny branches, and orange-yellow, +sweet-scented flowers. The heart-wood is rich dark brown in +colour, heavier than water, exceedingly hard and capable of +receiving a high polish.</p> + +<p>From the book of Ezekiel (xxvii. 15) we learn that ebony +was among the articles of merchandise brought to Tyre; and +Herodotus states (iii. 97) that the Ethiopians every three years +sent a tribute of 200 logs of it to Persia. Ebony was known +to Virgil as a product of India (<i>Georg.</i> ii. 116), and was displayed +by Pompey the Great in his Mithradatic triumph at Rome. +By the ancients it was esteemed of equal value for durability +with the cypress and cedar (see Pliny, <i>Nat. Hist.</i> xii. 9, xvi. 79). +According to Solinus (<i>Polyhistor</i>, cap. lv. p. 353, Paris, 1621), +it was employed by the kings of India for sceptres and images, +also, on account of its supposed antagonism to poison, for drinking-cups. +The hardness and black colour of the wood appear to +have given rise to the tradition related by Pausanias, and alluded +to by Southey in <i>Thalaba</i>, i. 22, that the ebony tree produced +neither leaves nor fruit, and was never seen exposed to the sun.</p> + + +<hr class="art" /> +<p><span class="bold">EBRARD, JOHANNES HEINRICH AUGUST<a name="ar101" id="ar101"></a></span> (1818-1888), +German theologian, was born at Erlangen on the 18th of January +1818. He was educated in his native town and at Berlin, +and after teaching in a private family became <i>Privatdocent</i> at +Erlangen (1841) and then professor of theology at Zürich (1844). +In 1847 he was appointed professor of theology at Erlangen, a +chair which he resigned in 1861; in 1875 he became pastor of +the French reformed church in the same city. As a critic Ebrard +occupied a very moderate standpoint; as a writer his chief +works were <i>Christliche Dogmatik</i> (2 vols., 1851), <i>Vorlesungen über +praktische Theologie</i> (1864), <i>Apologetik</i> (1874-1875, Eng. trans. +1886). He also edited and completed H. Olshausen’s commentary, +himself writing the volumes on the Epistle to the +Hebrews, the Johannine Epistles, and Revelation. In the +department of belles-lettres he wrote a good deal under such +pseudonyms as Christian Deutsch, Gottfried Flammberg and +Sigmund Sturm. He died at Erlangen on the 23rd of July 1888.</p> + + +<hr class="art" /> +<p><span class="bold">EBRO<a name="ar102" id="ar102"></a></span> (anc. <i>Iberus</i> or <i>Hiberus</i>), the only one of the five great +rivers of the Iberian Peninsula (Tagus, Douro, Ebro, Guadalquivir, +Guadiana) which flows into the Mediterranean. The +Ebro rises at Fuentibre, a hamlet among the Cantabrian Mountains, +in the province of Santander; at Reinosa, 4 m. east, it is +joined on the right by the Hijar, and thus gains considerably +in volume. It flows generally east by south through a tortuous +valley as far as Miranda de Ebro, passing through the celebrated +Roman bridge known as La Horadada (“the perforated”), near +Oña in Burgos. From Miranda it winds south-eastward through +<span class="pagenum"><a name="page844" id="page844"></a>844</span> +the wide basin enclosed on the right by the highlands of Old +Castile and western Aragon, and on the left by the Pyrenees. +The chief cities on its banks are Logroño, Calahorra, Tudela, +Saragossa and Caspe. Near Mora in Catalonia it forces a way +through the coastal mountains, and, passing Tortosa, falls into +the Mediterranean about 80 m. south-west of Barcelona, after +forming by its delta a conspicuous projection on the otherwise +regular coast line. In its length, approximately 465 m., the Ebro +is inferior to the Tagus, Guadiana and Douro; it drains an area +of nearly 32,000 sq. m. Its principal tributaries are—from the +right hand the Jalon with its affluent the Jiloca, the Huerva, +Aguas, Martin, Guadalope and Matarraña; from the left the +Ega, Aragon, Arba, Gallego, and the Segre with its intricate +system of confluent rivers. The Ebro and its tributaries have +been utilized for irrigation since the Moorish conquest; the +main stream becomes navigable by small boats about Tudela; +but its value as a means of communication is almost neutralized +by the obstacles in its channel, and seafaring vessels cannot +proceed farther up than Tortosa. The great Imperial Canal, +begun under the emperor Charles V. (1500-1558), proceeds along +the right bank of the river from a point about 3 m. below Tudela, +to El Burgo de Ebro, 5 m. below Saragossa; the irrigation canal +of Tauste skirts the opposite bank for a shorter distance; and the +San Carlos or New Canal affords direct communication between +Amposta at the head of the delta and the harbour of Los +Alfaques. From Miranda to Mora the Bilbao-Tarragona railway +follows the course of the Ebro along the right bank.</p> + + +<hr class="art" /> +<p><span class="bold">EBROÏN<a name="ar103" id="ar103"></a></span> (d. 681), Frankish “mayor of the palace,” was a +Neustrian, and wished to impose the authority of Neustria over +Burgundy and Austrasia. In 656, at the moment of his accession +to power, Sigebert III., the king of Austrasia, had just died, and +the Austrasian mayor of the palace, Grimoald, was attempting +to usurp the authority. The great nobles, however, appealed to +the king of Neustria, Clovis II., and unity was re-established. +But in spite of a very firm policy Ebroïn was unable to maintain +this unity, and while Clotaire III., son of Clovis II., reigned in +Neustria and Burgundy, he was obliged in 660 to give the +Austrasians a special king, Childeric II., brother of Clotaire III., +and a special mayor of the palace, Wulfoald. He endeavoured +to maintain at any rate the union of Neustria and Burgundy, +but the great Burgundian nobles wished to remain independent, +and rose under St Leger (Leodegar), bishop of Autun, defeated +Ebroïn, and interned him in the monastery of Luxeuil (670). +A proclamation was then issued to the effect that each kingdom +should keep its own laws and customs, that there should be no +further interchange of functionaries between the kingdoms, and +that no one should again set up a tyranny like that of Ebroïn. +Soon, however, Leger was defeated by Wulfoald and the Austrasians, +and was himself confined at Luxeuil in 673. In the same +year, taking advantage of the general anarchy, Ebroïn and Leger +left the cloister and soon found themselves once more face to face. +Each looked for support to a different Merovingian king, Ebroïn +even proclaiming a false Merovingian as sovereign. In this +struggle Leger was vanquished; he was besieged in Autun, was +forced to surrender and had his eyes put out, and, on the 12th +of October 678, he was put to death after undergoing prolonged +tortures. The church honours him as a saint. After his death +Ebroïn became sole and absolute ruler of the Franks, imposing +his authority over Burgundy and subduing the Austrasians, +whom he defeated in 678 at Bois-du-Fay, near Laon. His +triumph, however, was short-lived; he was assassinated in 681, +the victim of a combined attack of his numerous enemies. He +was a man of great energy, but all his actions seem to have been +dictated by no higher motives than ambition and lust of power.</p> + +<div class="condensed"> +<p>See <i>Liber historiae Francorum</i>, edited by B. Krusch, in <i>Mon. +Germ. hist. script. rer. Merov.</i> vol. ii.; <i>Vita sancti Leodegarii</i>, by +Ursinus, a monk of St Maixent (Migne, <i>Patr. Latina</i>, vol. xcvi.); +“Vita metrica” in <i>Poetae Latini aevi Carolini</i>, vol. iii. (<i>Mon. Germ. +hist.</i>); J.B. Pitra, <i>Histoire de Saint Léger</i> (Paris, 1846); and +J. Friedrich, “Zur Gesch. des Hausmeiers Ebroïn,” in the <i>Proceedings +of the Academy of Munich</i> (1887, pp. 42-61).</p> +</div> +<div class="author">(C. Pf.)</div> + +<hr class="art" /> +<p><span class="bold">EBURĀCUM,<a name="ar104" id="ar104"></a></span> or <span class="sc">Eborācum</span> (probably a later variant), the +Roman name of York (<i>q.v.</i>) in England. Established about <span class="scs">A.D.</span> +75-80 as fortress of the Ninth legion and garrisoned (after the annihilation +of that legion about <span class="scs">A.D.</span> 118) by the Sixth legion, it developed +outside its walls a town of civil life, which later obtained +Roman municipal rank and in the 4th century was the seat of a +Christian bishop. The fortress and town were separated by the +Ouse. On the left bank, where the minster stands, was the fortress, +of which the walls can still be partly traced, and one corner +(the so-called Multangular Tower) survives. The municipality +occupied the right bank near the present railway station. The +place was important for its garrison and as an administrative +centre, and the town itself was prosperous, though probably +never very large. The name is preserved in the abbreviated +form Ebor in the official name of the archbishop of York, but the +philological connexion between Eboracum and the modern name +York is doubtful and has probably been complicated by Danish +influence.</p> +<div class="author">(F. J. H.)</div> + + +<hr class="art" /> +<p><span class="bold">EÇA DE QUEIROZ, JOSÉ MARIA<a name="ar105" id="ar105"></a></span> (1843-1900), Portuguese +writer, was born at the northern fishing town of Povoa de +Varzim, his father being a retired judge. He went through the +university of Coimbra, and on taking his degree in law was +appointed Administrador de Concelho at Leiria, but soon tired +of the narrow mental atmosphere of the old cathedral town and +left it. He accompanied the Conde de Rezende to Egypt, where +he assisted at the opening of the Suez Canal, and to Palestine, +and on his return settled down to journalism in Lisbon and began +to evolve a style, at once magical and unique, which was to +renovate his country’s prose. Though he spent much of his +days with the philosopher sonneteer Anthero de Quental, and +the critic Jayme Batalha Reis, afterwards consul-general in +London, he did not restrict his intimacy to men of letters, but +frequented all kinds of society, acquiring a complete acquaintance +with contemporary Portuguese life and manners. Entering +the consular service in 1872, he went to Havana, and, after a tour +in the United States, was transferred two years later to Newcastle-on-Tyne +and in 1876 to Bristol. In 1888 he became Portuguese +consul-general in Paris, and there died in 1900.</p> + +<p>Queiroz made his literary début in 1870 by a sensational story, +<i>The Mystery of the Cintra Road</i>, written in collaboration with the +art critic Ramalho Ortigão, but the first publication which +brought him fame was <i>The Farpas</i>, a series of satirical and +humorous sketches of various phases of social life, which, to quote +the poet Guerra Junqueiro, contain “the epilepsy of talent.” +These essays, the joint production of the same partners, criticized +and ridiculed the faults and foibles of every class in turn, mainly +by a comparison with the French, for the education of Queiroz +had made him a Frenchman in ideas and sympathies. His +Brazilian friend, Eduardo Prado, bears witness that at this +period French literature, especially Hugo’s verse, and even +French politics, interested Queiroz profoundly, while he altogether +ignored the <i>belles-lettres</i> of his own country and its public +affairs. This phase lasted for some years, and even when he +travelled in the East he was inclined to see it with the eyes of +Flaubert, though the publication of <i>The Relic</i> and that delightful +prose poem <i>Sweet Miracle</i> afterwards showed that he had been +directly impressed and deeply penetrated by its scenery, poetry +and mysticism. The Franco-German War of 1870, however, by +lowering the prestige of France, proved the herald of a national +Portuguese revival, and had a great influence on Queiroz, as +also had his friend Oliveira Martins (<i>q.v.</i>), the biographer of the +patriot kings of the Aviz dynasty. He founded the Portuguese +Realist-Naturalist school, of which he remained for the rest of +his life the chief exponent, by a powerful romance, <i>The Crime +of Father Amaro</i>, written in 1871 at Leiria but only issued in 1875. +Its appearance then led to a baseless charge that he had +plagiarized <i>La Faute de l’Abbé Mouret</i>, and ill-informed critics +began to name Queiroz the Portuguese Zola, though he clearly +occupied an altogether different plane in the domain of art. +During his stay in England he produced two masterpieces, +<i>Cousin Basil</i> and <i>The Maias</i>, but they show no traces of English +influence, nor again are they French in tone, for, living near to +France, his disillusionment progressed and was completed when +he went to Paris and had to live under the régime of the Third +<span class="pagenum"><a name="page845" id="page845"></a>845</span> +Republic. Settling at Neuilly, the novelist became chronicler, +critic, and letter-writer as well, and in all these capacities +Queiroz displayed a spontaneity, power and artistic finish +unequalled in the literature of his country since the death of +Garrett. A bold draughtsman, he excelled in freshness of +imagination and careful choice and collocation of words, while +his warmth of colouring and brilliance of language speak of the +south. Many of his pages descriptive of natural scenery, such +for instance as the episode of the return to Tormes in <i>The City +and the Mountains</i>, have taken rank as classic examples of +Portuguese prose, while as a creator of characters he stood +unsurpassed by any writer of his generation in the same field. +He particularly loved to draw and judge the middle class, and +he mocks at and chastises its hypocrisy and narrowness, its +veneer of religion and culture, its triumphant lying, its self-satisfied +propriety, its cruel egotism. But though he manifested +a predilection for middle-class types, his portrait gallery comprises +men and women of all social conditions. <i>The Maias</i>, +his longest book, treats of <i>fidalgos</i>, while perhaps his most remarkable +character study is of a servant, Juliana, in <i>Cousin Basil</i>. +At least two of his books, this latter and <i>The Crime of Father +Amaro</i>, are <i>chroniques scandaleuses</i> in their plots and episodes; +these volumes, however, mark not only the high-water line of the +Realist-Naturalist school in Portugal, but are in themselves, leaving +aside all accidentals, creative achievements of a high order.</p> + +<p>Though Queiroz was a keen satirist of the ills of society, his +pages show hardly a trace of pessimism. <i>The City and the +Mountains</i>, and in part <i>The Relic</i> also, reveal the apostle of +Realism as an idealist and dreamer, a true representative of +that Celtic tradition which survives in the race and has permeated +the whole literature of Portugal. <i>The Mandarin</i>, a fantastic +variation on the old theme of a man self-sold to Satan, and <i>The +Illustrious House of Ramires</i>, are the only other writings of his +that require mention, except <i>The Correspondence of Fradique +Mendes</i>. In conjunction with Anthero de Quental and Jayme +Batalha Reis, Queiroz invented under that name a smart man +of the world who had something of himself and something of +Eduardo Prado, and made him correspond on all sorts of subjects +with imaginary friends and relatives to the delight of the public, +many of whom saw in him a mysterious new writer whose identity +they were eager to discover. These sparkling and humorous +letters are an especial favourite with admirers of Queiroz, because +they reveal so much of his very attractive personality, and +perhaps the cleverest of the number, that on Pacheco, has +received an English dress. In addition to his longer and more +important works, Queiroz wrote a number of short stories, +some of which have been printed in a volume under the title of +<i>Contos</i>. The gems of this remarkable collection are perhaps +<i>The Peculiarities of a Fair-haired Girl</i>, <i>A Lyric Poet</i>, <i>José +Matthias</i>, <i>The Corpse</i>, and <i>Sweet Miracle</i>.</p> + +<div class="condensed"> +<p>Most of his books have gone through many editions, and they are +even more appreciated in the Brazils than in Portugal. It should be +mentioned that the fourth edition of <i>Father Amaro</i> is entirely different +in form and action from the first, the whole story having been rewritten. +One of Queiroz’s romances and two of his short stories +have been published in English. An unsatisfactory version of +<i>Cousin Basil</i>, under the title <i>Dragon’s Teeth</i>, appeared at Boston, +U.S.A., in 1889, while <i>Sweet Miracle</i> has had three editions in England +and one in America, and there is also a translation of <i>O Defunto</i> (<i>The +Corpse</i>) under the name of <i>Our Lady of the Pillar</i>.</p> + +<p>An admirable critical study of the work of Queiroz will be found +in <i>A Geração Nova—Os Novellistas</i>, by J. Pereira de Sampaio (<i>Bruno</i>), +(Oporto, 1886). The <i>Revista moderna</i> of the 20th of November 1897 +was entirely devoted to him. Senhor Batalha Reis gives interesting +reminiscences of the novelist’s early days in his preface to some +prose fragments edited by him and named <i>Prosas Barbaras</i> (Oporto, +1903).</p> +</div> +<div class="author">(E. Pr.)</div> + + +<hr class="art" /> +<p><span class="bold">ÉCARTÉ<a name="ar106" id="ar106"></a></span> (Fr. for “separated,” “discarded”), a game at +cards, of modern origin, probably first played in the Paris <i>salons</i> +in the first quarter of the 19th century. It is a development of +a very old card game called <i>la triomphe</i> or <i>French-ruff</i>. Écarté +is generally played by two persons, but a pool of three may be +formed, the player who is out taking the place of the loser, and +the winner of two consecutive games winning the pool. At +French écarté (but not at English) bystanders who are betting +may advise the players, but only by pointing to the cards they +desire them to play, and the loser of the game goes out, one of +the <i>rentrants</i> taking his place, unless the loser is playing <i>la +chouette</i>, <i>i.e.</i> playing single-handed against two, and taking +all bets.</p> + +<p>The small cards (from the two to the six, both inclusive) are +removed from an ordinary pack. The players cut for deal, the +highest having the choice. The king is the highest card, the ace +ranking after the knave. The dealer gives five cards to his +adversary, and five to himself, by two at a time to each and by +three at a time to each, or vice versa. The eleventh card is +turned up for trumps. If it is a king, the dealer scores one, at +any time before the next deal. The non-dealer then looks at +his cards. If satisfied with them he plays, and there is no discarding; +if not satisfied he “proposes.” The dealer may either +accept or refuse. If he accepts, each player discards face downwards +as many cards as he thinks fit, and fresh ones are given +from the undealt cards or “stock,” first to complete the non-dealer’s +hand to five, then to complete the dealer’s. To ask for +“a book” is to ask for five cards. Similarly a second proposal +may be made, and so on, until one player is satisfied with his +hand. If the dealer refuses, the hand is played without discarding. +If the non-dealer announces that he holds the king +of trumps, he scores one; and similarly, if the dealer holds the +king and announces it, he scores one. The announcement +must be made before playing one’s first card, or if that card be +the king, on playing it. The non-dealer, being satisfied with +his hand, leads a card. The dealer plays a card to it, the two +cards thus played forming a trick. The winner of the trick leads +to the next, and so on. The second to play to a trick must follow +suit if able, and must win the trick if he can.</p> + +<p>The scores are for the king and for the majority of tricks. +The player who wins three tricks scores one for the “point”; +if he wins all five tricks, he scores two for the “vole.” If the +non-dealer plays without proposing, or the dealer refuses the +first proposal, and fails to win three tricks, the adversary scores +two, but no more even if he wins the vole. The game is five up. +The points are conveniently marked with a three-card and a +two-card, as at euchre. The three is put face upwards with the +two face downwards on the top of it. When one or two or three +points are scored the top card is moved so as to expose them. +At four, one pip of the two-card is put under the other card. +Games may be recorded similarly.</p> + +<div class="condensed"> +<p><i>Hints to Players.</i>—The following hints may be of service to beginners:—</p> + +<p>Shuffle thoroughly after every deal.</p> + +<p>Do not announce the king until in the act of playing your first +card.</p> + +<p>The hands which should be played without proposing, called +<i>jeux de règle</i> (standard hands), ought to be thoroughly known. They +are as follows:—</p> + +<p>1. All hands with three or more trumps, whatever the other cards.</p> + +<p>2. Hands with <i>two trumps</i> which contain also—</p> + +<div class="list"> +<p>(<i>a</i>) Any three cards of one plain suit;</p> + +<p>(<i>b</i>) Two cards of one plain suit, one being as high as a queen;</p> + +<p>(<i>c</i>) Two small cards of one suit, the fifth card being a king +of another suit;</p> + +<p>(<i>d</i>) Three high cards of different suits.</p> +</div> + +<p>3. Hands with <i>one trump</i>, which contain also—</p> + +<div class="list"> +<p>(<i>a</i>) King, queen, knave of one suit, and a small card of another;</p> + +<p>(<i>b</i>) Four cards of one suit headed by king;</p> + +<p>(<i>c</i>) Three cards of one suit headed by queen, and queen of +another suit.</p> +</div> + +<p>4. Hands with <i>no trump</i>, which contain three queens or cards of +equal value in different suits, <i>e.g.</i>, four court cards.</p> + +<p>5. Hands from which only two cards can be discarded without +throwing a king or a trump.</p> + +<p>Holding cards which make the point certain, propose. If you +hold a <i>jeu de règle</i>, and one of the trumps is the king, propose, as +your adversary cannot then take in the king.</p> + +<p>When discarding, throw out all cards except trumps and kings.</p> + +<p>If your adversary proposes you should accept, unless you are +guarded in three suits (a queen being a sufficient guard), or in two +suits with a trump, or in one suit with two trumps. Hence the +rule not to discard two cards, unless holding the king of trumps, +applies to the dealer.</p> + +<p>The hands with which to refuse are the same as those with which +to play without proposing, except as follows:—</p> + +<p><span class="pagenum"><a name="page846" id="page846"></a>846</span></p> + +<p>1. Two trumps and three cards of one plain suit should not be +played unless the plain suit is headed by a court card.</p> + +<p>2. One trump and a tierce major is too weak, unless the fifth +card is a court card. With similar hands weaker in the tierce major +suit, accept unless the fifth card is a queen.</p> + +<p>3. One trump and four cards of a plain suit is too weak to play.</p> + +<p>4. One trump and two queens is too weak, unless both queens are +singly guarded.</p> + +<p>5. One trump, queen of one suit, and knave guarded of another +should not be played unless the queen is also guarded, or the card +of the fourth suit is a court card.</p> + +<p>6. One trump, a king and a queen, both unguarded, should not +be played, unless the fourth suit contains a card as high as an ace.</p> + +<p>7. Four court cards without a trump are too weak to play, unless +they are of three different suits.</p> + +<p>Refuse with three queens, if two are singly guarded; otherwise, +accept.</p> + +<p>Lead from your guarded suit, and lead the highest.</p> + +<p>If the strong suit led is not trumped, persevere with it, unless with +king of trumps, or queen (king not having been announced), or knave +ace, when lead a trump before continuing your suit.</p> + +<p>You should not lead trumps at starting, unless you hold king or +queen, knave, or knave ace, with court cards out of trumps.</p> + +<p>The score has to be considered. If the dealer is at four, and the +king is not in your hand nor turned up, play any cards without +proposing which give an even chance of three tricks, <i>e.g.</i> a queen, +a guarded knave, and a guarded ten. The same rule applies to the +dealer’s refusal.</p> + +<p>At the adverse score of four, and king not being in hand or turned +up, any hand with one trump should be played, unless the plain +cards are very small and of different suits.</p> + +<p>If the non-dealer plays without proposing when he is four to +three, and the dealer holds the king he ought not to mark it. The +same rule applies to the non-dealer after a refusal, if the dealer is +four to three.</p> + +<p>At the score of non-dealer three, dealer four, the dealer should +refuse on moderate cards, as the player proposing at this score must +have a very bad hand.</p> + +<p>At four a forward game should not be played in trumps, as there +is no advantage in winning the vole.</p> + +<p><i>Laws of Écarté.</i>—The following laws are abridged from the revised +code adopted by the Turf Club:—A cut must consist of at least two +cards. Card exposed in cutting, fresh cut. Order of distribution of +cards, whether by three and two, or vice versa, once selected, dealer +must not change it during game. Player announcing king when he +has not got it, and playing a card without declaring error, adversary +may correct score and have hand played over again. If offender +wins point or vole that hand, he scores one less than he wins. Proposal, +acceptance, or refusal made cannot be retracted. Cards discarded +must not be looked at. Cards exposed in giving cards to +non-dealer, he has option of taking them or of having next cards; +dealer exposing his own cards, no penalty. Dealer turning up top +card after giving cards, cannot refuse second discard. Dealer +accepting when too few cards in stock to supply both, non-dealer +may take cards, and dealer must play his hand. Card led in turn +cannot be taken up again. Card played to a lead can only be taken +up prior to another lead, to save revoke or to correct error of not +winning trick. Card led out of turn may be taken up prior to its +being played to. Player naming one suit and leading another, +adversary has option of requiring suit named to be led. If offender +has none, no penalty. Player abandoning hand, adversary is deemed +to win remaining tricks, and scores accordingly. If a player revokes +or does not win trick when he can do so, the adversary may correct +score and have hand replayed.</p> + +<p>See <i>Académie des jeux</i> (various editions after the first quarter of +the 19th century); Hoyle’s <i>Games</i> (various editions about the same +dates); Ch. Van-Tenac et Louis Delanoue, <i>Traité du jeu de l’écarté</i> +(Paris, 1845; translated in Bohn’s <i>Handbook of Games</i>, London, +1850); “Cavendish,” <i>The Laws of Écarté, adopted by the Turf Club, +with a Treatise on the Game</i> (London, 1878); <i>Pocket Guide to Écarté</i> +(“Cavendish,” 1897); Foster’s <i>Encyclopaedia of Indoor Games</i> +(1903).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECBATANA<a name="ar107" id="ar107"></a></span> (<i>Agbatana</i> in Aeschylus, <i>Haňgmatāna</i> in Old +Persian, written <i>Agamtanu</i> by Nabonidos, and <i>Agamatanu</i> at +Behistun, mod. <i>Hamadān</i>), the capital of Astyages (Istuvegu), +which was taken by Cyrus in the sixth year of Nabonidos +(549 <span class="scs">B.C.</span>). The Greeks supposed it to be the capital of Media, +confusing the Manda, of whom Astyages was king, with the Madā +or Medes of Media Atropatene, and ascribed its foundation to +Deioces (the <i>Daiukku</i> of the cuneiform inscriptions), who is said +to have surrounded his palace in it with seven concentric walls of +different colours. Under the Persian kings, Ecbatana, situated +at the foot of Mount Elvend, became a summer residence; and +was afterwards the capital of the Parthian kings. Sir H. +Rawlinson attempted to prove that there was a second and older +Ecbatana in Media Atropatene, on the site of the modern Takht-i-Suleiman, +midway between Hamadan and Tabriz (<i>J.R.G.S.</i> +x. 1841), but the cuneiform texts imply that there was only one +city of the name, and Takht-i-Suleiman is the Gazaca of classical +geography. The Ecbatana at which Cambyses is said by +Herodotus (iii. 64) to have died is probably a blunder for Hamath.</p> + +<div class="condensed"> +<p>See Perrot and Chipiez, <i>History of Art in Persia</i> (Eng. trans., 1892); +M. Dieulafoy, <i>L’Art antique de la Perse</i>, pt. i. (1884); J. de Morgan, +<i>Mission scientifique en Perse</i>, ii. (1894). See <span class="sc"><a href="#artlinks">Hamadan</a></span> and <span class="sc"><a href="#artlinks">Persia</a></span>: +<i>Ancient History</i>, § v. 2.</p> +</div> +<div class="author">(A. H. S.)</div> + + +<hr class="art" /> +<p><span class="bold">ECCARD, JOHANN<a name="ar108" id="ar108"></a></span> (1553-1611), German composer of church +music, was born at Mühlhausen on the Unstrut, Prussia, in 1553. +At the age of eighteen he went to Munich, where he became the +pupil of Orlando Lasso. In his company Eccard is said to have +visited Paris, but in 1574 we find him again at Mühlhausen, +where he resided for four years, and edited, together with Johann +von Burgk, his first master, a collection of sacred songs, called +<i>Crepundia sacra Helmboldi</i> (1577). Soon afterwards he obtained +an appointment as musician in the house of Jacob Fugger, the +Augsburg banker. In 1583 he became assistant conductor, and +in 1599 conductor, at Königsberg, to Georg Friedrich, margrave +of Brandenburg-Anspach, the administrator of Prussia. In 1608 +he was called by the elector Joachim Friedrich to Berlin as chief +conductor, but this post he held only for three years, owing to +his premature death at Königsberg in 1611. Eccard’s works +consist exclusively of vocal compositions, such as songs, sacred +cantatas and chorales for four or five, and sometimes for seven, +eight, or even nine voices. Their polyphonic structure is a +marvel of art, and still excites the admiration of musicians. At +the same time his works are instinct with a spirit of true religious +feeling. His setting of the beautiful words “Ein’ feste Burg ist +unser Gott” is still regarded by the Germans as their representative +national hymn. Eccard and his school are inseparably connected +with the history of the Reformation.</p> + +<div class="condensed"> +<p>Of Eccard’s songs a great many collections are extant; see +K.G.A. von Winterfeld, <i>Der Evangelische Kirchengesang</i> (1843); +Döring (<i>Choralkunde</i>, p. 47).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECCELINO<a name="ar109" id="ar109"></a></span> [or <span class="sc">Ezzelino</span>] <b>DA ROMANO</b> (1194-1259), Ghibelline +leader, and supporter of the emperor Frederick II., was born on +the 25th of April 1194. He belonged to a family descended from +a German knight named Eccelin, who followed the emperor +Conrad II. to Italy about 1036, and received the fief of Romano +near Padua. Eccelin’s grandson was Eccelino III., surnamed +the Monk, who divided his lands between his two sons in 1223, +and died in 1235. The elder of these two sons was Eccelino, +who in early life began to take part in family and other feuds, +and in 1226, at the head of a band of Ghibellines, seized Verona +and became <i>podestà</i> of the city. He soon lost Verona, but regained +it in 1230; and about this time came into relations with +Frederick II., who in 1232 issued a charter confirming him in his +possessions. In 1236 when besieged in Verona he was saved by +the advance of the emperor, who in November of the same year +took Vicenza and entrusted its government to Eccelino. In +1237 he obtained authority over Padua and Treviso; and on the +27th of November in that year he shared in the victory gained +by the emperor over the Lombards at Cortenuova. In 1238 he +married Frederick’s natural daughter, Selvaggia; in 1239 was +appointed imperial vicar of the march of Treviso; but in the +same year was excommunicated by Pope Gregory IX. He was +constantly engaged in increasing his possessions; was present +at the siege of Parma in 1247, and after Frederick’s death in +1250 he supported his son, the German king Conrad IV. His +cruelties had, however, aroused general disgust, and in 1254 he +was again excommunicated. In 1256 Pope Alexander IV. +proclaimed a crusade against him, and a powerful league was +soon formed under the leadership of Philip, archbishop of +Ravenna. Padua was taken from Eccelino, but on the 1st of +September 1258 he defeated his enemies at Torricella. He then +made an attempt on Milan, and the rival forces met at Cassano +on the 27th of September 1259, when Eccelino was wounded and +taken prisoner. Enraged at his capture, he tore the bandages +from his wounds, refused to take nourishment, and died at +Soncino on the 7th of October 1259. In the following year his +brother Albert was put to death, and the Romano family became +<span class="pagenum"><a name="page847" id="page847"></a>847</span> +extinct. Eccelino, who is sometimes called the <i>tyrant</i>, acquired +a terrible reputation on account of his cruelties, a reputation +that won for him the immortality of inclusion in Dante’s <i>Inferno</i>; +but his unswerving loyalty to Frederick II. forms a marked +contrast to the attitude of many of his contemporaries.</p> + +<p>Eccelino is the subject of a novel by Cesare Cantu and of a +drama by J. Eichendorff.</p> + +<div class="condensed"> +<p>See J.M. Gittermann, <i>Ezzelino da Romano</i> (Freiburg, 1890); +S. Mitis, <i>Storia d’ Ezzelino IV. da Romano</i> (Maddaloni, 1896); and +F. Stieve, <i>Ezzelino von Romano</i> (Leipzig, 1909).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECCENTRIC<a name="ar110" id="ar110"></a></span> (from Gr. <span class="grk" title="ek">ἐκ</span>, out of, and <span class="grk" title="kentron">κέντρον</span>, centre), literally +“out from the centre,” and thus used to connote generally any +deviation from the normal. In astronomy the word denotes a +circle round which a body revolves, but whose centre is displaced +from the visible centre of motion. In the ancient astronomy the +ellipses in which it is now known that the planets revolve around +the sun could not be distinguished from circles, but the unequal +angular motion due to ellipticity was observed. The theory of +the eccentric was that the centre of the epicycle of each planet +moved uniformly in a circle, the centre of which was displaced +from that of the earth by an amount double the eccentricity of +the actual ellipse, as the case is now understood. When measured +around this imaginary centre, which is so situated on the major +axis of the ellipse that the focus, or place of the real sun, is +midway between it and the centre of the ellipse, the motion is +approximately uniform. In engineering, an eccentric is a +mechanical device for converting rotary into reciprocating +motion (see <span class="sc"><a href="#artlinks">Steam-engine</a></span>). For eccentric angle see <span class="sc"><a href="#artlinks">Ellipse</a></span>.</p> + + +<hr class="art" /> +<p><span class="bold">ECCHELLENSIS<a name="ar111" id="ar111"></a></span> (or <span class="sc">Echellensis</span>), <b>ABRAHAM</b> (d. 1664), a +learned Maronite, whose surname is derived from Eckel in Syria, +where he was born towards the close of the 16th century. He +was educated at the Maronite college in Rome, and, after taking +his doctor’s degree in theology and philosophy, returned for a +time to his native land. He then became professor of Arabic +and Syriac in the college of the Propaganda at Rome. Called to +Paris in 1640 to assist Le Jay in the preparation of his polyglot +Bible, he contributed to that work the Arabic and Latin versions +of the book of Ruth and the Arabic version of the third book of +Maccabees. In 1646 he was appointed professor of Syriac and +Arabic at the Collège de France. Being invited by the Congregation +of the Propaganda to take part in the preparation of an +Arabic version of the Bible, Ecchellensis went again in 1652 or +1653 to Rome. He published several Latin translations of Arabic +works, of which the most important was the <i>Chronicon Orientale</i> +of Ibnar-Rāhib (Paris, 1653), a history of the patriarchs of +Alexandria. He was engaged in an interesting controversy with +John Selden as to the historical grounds of episcopacy, in the +course of which he published his <i>Eutychius vindicatus, sive +Responsio ad Seldeni Origines</i> (Rome, 1661). Conjointly with +Giovanni Borelli he wrote a Latin translation of the 5th, 6th +and 7th books of the <i>Conics</i> of Apollonius of Perga (1661). He +died at Rome in 1664.</p> + + +<hr class="art" /> +<p><span class="bold">ECCLES,<a name="ar112" id="ar112"></a></span> a municipal borough in the Eccles parliamentary +division of Lancashire, England, 4 m. W. of Manchester, of which +it forms practically a suburb. Pop. (1901) 34,369. It is served +by the London & North-Western railway and by the Birkenhead +railway (North-Western and Great Western joint). The Manchester +Ship Canal passes through. The church of St Mary is +believed to date from the 12th century, but has been enlarged +and wholly restored in modern times. There are several handsome +modern churches and chapels, a town hall, and numerous +cotton mills, while silk-throwing and the manufacture of fustians +and ginghams are also among the industries, and there are also +large engine works. A peculiar form of cake is made here, +taking name from the town, and has a wide reputation. Eccles +was incorporated in 1892, and the corporation consists of a mayor, +6 aldermen and 18 councillors. The borough maintains the +tramway service, &c., but water and gas are supplied from +Manchester and Salford respectively. Area, 2057 acres.</p> + +<p>Before the Reformation the monks of Whalley Abbey had a +grange here at what is still called Monks’ Hall; and in 1864 +many thousands of silver pennies of Henry III. and John of +England and William I. of Scotland were discovered near the +spot. Robert Ainsworth, the author of the Latin and English +dictionary so long familiar to English students, was born at Eccles +in 1660; and it was at the vicarage that William Huskisson +expired on the 15th of September 1830 from injuries received at +the opening of the Liverpool & Manchester railway. From early +times “wakes” were held at Eccles, and bull-baiting, bear-baiting +and cock-fighting were carried on. Under Elizabeth +these festivals, which had become notoriously disorderly, were +abolished, but were revived under James I., and maintained +until late in the 19th century on public ground. The cockpit +remained on the site of the present town hall. A celebration +on private property still recalls these wakes.</p> + + +<hr class="art" /> +<p><span class="bold">ECCLESFIELD,<a name="ar113" id="ar113"></a></span> a township in the Hallamshire parliamentary +division of the West Riding of Yorkshire, England, 5 m. N. of +Sheffield, on the Great Central and Midland railways. The +church of St Mary is Perpendicular, with a central tower, and contains +excellent woodwork. It formerly bore, and must have +deserved, the familiar title of the “Minster of the Moors.” +Ecclesfield was the seat of a Benedictine priory, which passed to +the Carthusians in the 14th century. Cutlery and tools are +largely manufactured, and there are coal-mines, paper mills and +iron and fire-clay works. After the inclusion within the county +borough of Sheffield of part of the civil parish of Ecclesfield in +1901, the population was 18,324.</p> + + +<hr class="art" /> +<p><span class="bold">ECCLESHALL,<a name="ar114" id="ar114"></a></span> a market town in the north-western parliamentary +division of Staffordshire, England; 7 m. N.W. from +Stafford, and 4 W. of Norton Bridge station on the London & +North-Western main line. Pop. (1901) 3799. The church of the +Holy Trinity, one of the most noteworthy in Staffordshire, is +principally Early English, and has fine stained glass. Several +bishops of Lichfield are buried here, as Eccleshall Castle was the +episcopal residence from the 13th century until 1867. Of this the +ancient remains include a picturesque tower and bridge. To the +west on the borders of Shropshire is Blore Heath, the scene of a +defeat of the Lancastrians by the Yorkists in 1459.</p> + + +<hr class="art" /> +<p><span class="bold">ECCLESIA<a name="ar115" id="ar115"></a></span> (Gr. <span class="grk" title="ekklêsia">ἐκκλησία</span>, from <span class="grk" title="ek">ἐκ</span>, out, and <span class="grk" title="kalein">καλεῖν</span>, to call), in +ancient Athens, the general assembly of all the freemen of the +state. In the primitive unorganized state the king was theoretically +absolute, though his great nobles meeting in the Council +(see <span class="sc"><a href="#artlinks">Boulē</a></span>) were no doubt able to influence him considerably. +There is, however, no doubt that in the earliest times the free +people, <i>i.e.</i> the fighting force of the state, were called together to +ratify the decisions of the king, and that they were gradually able +to enforce their wishes against those of the nobles. In Athens, +as in Rome, where the Plebs succeeded in their demand for the +codification of the laws (the Twelve Tables), it was no doubt +owing to the growing power of the people meeting in the Agora +that Draco was entrusted with the task of publishing a code of +law and so putting an end to the arbitrary judicature of the +aristocratic party. But there is no evidence that the Ecclesia +had more than a <i>de facto</i> existence before Solon’s reforms.</p> + +<p>The precise powers which Solon gave the people are not known. +It is clear that the executive power in the state (see <span class="sc"><a href="#artlinks">Archon</a></span>) was +still vested in the Eupatrid class. It is obvious, therefore, that a +moderate reformer would endeavour to give to the people some +control over the magistracy. Now in speaking of the Thetes +(the lowest of the four Solonian classes; see <span class="sc"><a href="#artlinks">Solon</a></span>), Aristotle’s +<i>Constitution of Athens</i> says that Solon gave them merely “a +share in the Ecclesia and the Law Courts,” and in the <i>Politics</i> we +find that he gave them the right of electing the magistrates and +receiving their accounts at the end of the official year. Thus it +seems that the “mixed” character of Solon’s constitution +consisted in the fact that though the officials of the state were +still necessarily Eupatrid, the Ecclesia elected those of the +Eupatrids whom they could trust, and further had the right of +criticizing their official actions. Secondly, all our accounts agree +that Solon admitted the Thetes to the Ecclesia, thus recognizing +them as citizens. Under Cleisthenes the Ecclesia remained the +sovereign power, but the Council seems to have become to +some extent a separate administrative body. The relation of +Boulē and Ecclesia in the Cleisthenic democracy was of the +<span class="pagenum"><a name="page848" id="page848"></a>848</span> +greatest importance. The Ecclesia alone, a heterogeneous body of +untrained citizens, could not have passed, nor even have drawn +up intelligible measures; all the preliminary drafting was done +by the small committee of the Boulē which was in session at any +particular time. In the 5th century the functions of the Ecclesia +and the popular courts of justice were vastly increased by the +exigencies of empire. At the beginning of the 4th century <span class="scs">B.C.</span> +the system of payment was introduced (see below). In 308 <span class="scs">B.C.</span> +Demetrius of Phalerum curtailed the power of the Ecclesia by the +institution of the <i>Nomophylaces</i> (Guardians of the Law), who +prevented the Ecclesia from voting on an illegal or injurious +motion. Under Roman rule the powers of the Ecclesia and the +popular courts were much diminished, and after 48 <span class="scs">B.C.</span> (the +franchise being frequently sold to any casual alien) the Demos +(people) was of no importance. They still assembled to pass +psephisms in the theatre and to elect strategi, and, under Hadrian, +had some small judicial duties, but as a governing body the +Ecclesia died when Athens became a <i>civitas libera</i> under Roman +protection.</p> + +<p><i>Constitution and Functions.</i>—Throughout the period of +Athenian greatness the Ecclesia was the sovereign power, not only +in practice but also in theory. The assembly met in early times +near the sanctuary of Aphrodite Pandemus (<i>i.e.</i> south of the +Acropolis), but, in the 5th and 4th centuries, the regular place of +meeting was the Pnyx. From the 5th century it met sometimes +in the theatre, which in the 3rd century was the regular place. +From Demosthenes we learn that in his time special meetings +were held at Peiraeus, and, in the last centuries <span class="scs">B.C.</span>, meetings +were held at Athens and Peiraeus alternately. Certain meetings, +however, for voting ostracism (<i>q.v.</i>) and on questions affecting +individual status took place in the Agora. Meetings were +(1) ordinary, (2) extraordinary, and (3) convened by special +messengers (<span class="grk" title="kyriai">κύριαι</span>, <span class="grk" title="synklêtoi">σύγκλητοι</span> and <span class="grk" title="kataklêtoi">κατάκλητοι</span>), these last +being called when it was desirable that the country people should +attend. At ordinary meetings the attendance was practically +confined to Athenian residents. According to Aristotle there +were four regular meetings in each prytany (see <span class="sc"><a href="#artlinks">Boulē</a></span>); probably +only the first of these was called <span class="grk" title="kyria">κυρία</span>. It is certain, however, +that the four meetings did not fall on regular days, owing to +the occurrence of feast days on which no meeting could take place. +In the <span class="grk" title="kyria ekklêsia">κυρία ἐκκλησία</span> of each month took place the <i>Epicheirotonia</i> +(monthly inquiry) of the state officials, and if it proved +unsatisfactory a trial before the Heliaea was arranged; the +council reported on the general security and the corn-supply, +and read out lists of vacant inheritances and unmarried +heiresses. In the sixth prytany of each year at the <span class="grk" title="kyria ekklêsia">κυρία ἐκκλησία</span> +the question whether ostracism should take place that year was +put to the vote. For all meetings it was usual that the Prytaneis +should give five days’ notice in the form of a <i>programma</i> (agenda). +On occasions of sudden importance the herald of the council +summoned the people with a trumpet, and sometimes special +messengers were despatched to “bring in” the country people +(<span class="grk" title="katakalein">κατακαλεῖν</span>).</p> + +<p>After the archonship of Solon all Athenians over the age of +eighteen were eligible to attend the assembly, save those who +for some reason had suffered <i>atimia</i> (loss of civil rights). To +prevent the presence of any disqualified persons, six <i>lexiarchs</i> +with thirty assistants were present with the deme-rolls in their +hands. These officers superintended the payment in the +4th century and probably the <i>toxotae</i> (police) also, whose duty +it was before the introduction of pay to drive the people out +of the Agora into the Ecclesia with a rope steeped in red dye +which they stretched out and used as a draw net (see +Aristoph. <i>Acharn.</i> 22 and <i>Eccles.</i> 378). The introduction +of pay, which belongs to the early years of the 4th century +and by the <i>Constitution</i> (<i>c.</i> 41 ad fin.) is attributed to Agyrrhius, +a statesman of the restored democracy, was a device to secure +a larger attendance. The rate rose from one to two obols and +then to three obols (Aristoph. <i>Eccles.</i> 300 sqq.), while at the time +of Aristotle it was one and a half drachmas for the <span class="grk" title="kyria ekklêsia">κυρία ἐκκλησία</span> +and one drachma for other meetings. Probably those who were +late did not receive payment.</p> + +<p><i>Procedure.</i>—The proceedings opened with formalities: the +purification by the <i>peristiarchs</i>, who carried round slain sucking +pigs; the curse against all who should deceive the people; the +appointment (in the 4th century) of the <i>proedri</i> and their +<i>epistates</i> (see <span class="sc"><a href="#artlinks">Boulē</a></span>); the report as to the weather-omens. The +assembly was always dismissed if there were thunder, rain or +an eclipse. These formalities over, the Prytaneis communicated +the <i>probouleuma</i> of the council, without which the Ecclesia could +not debate. This recommendation either submitted definite +proposals or merely brought the agenda before the assembly. +Its importance lay largely in the fact that it <i>explained</i> the business +in hand, which otherwise must often have been beyond the +grasp of a miscellaneous assembly. After the reading, a preliminary +vote was taken as to whether the council’s report should +be accepted <i>en bloc</i>. If it was decided to discuss, the herald called +upon people to speak. Any person, without distinction of age +or position, might obtain leave to speak, but it seems probable +that the man who had moved the recommendation previously +in the council would advocate it in the assembly. The council +was, therefore, a check on the assembly, but its powers were to +some extent illusory, because any member of the assembly (1) +might propose an amendment, (2) might draw up a new resolution +founded on the principal motion, (3) might move the rejection +of the motion and the substitution of another, (4) might bring +in a motion asking the council for a recommendation on a +particular matter, (5) might petition the council for leave to +speak on a given matter to the assembly. Voting usually was +by show of hands, but in special cases (ostracism, &c.) by ballot +(<i>i.e.</i> by casting pebbles into one of two urns). The decision of +the assembly was called a <i>psephism</i> and had absolute validity. +These decisions were deposited in the Metroön where state +documents were preserved; peculiarly important decrees were +inscribed also on a column (<i>stēlē</i>) erected on the Acropolis. +It has been shown that the power of the council was far from +sufficient. The real check on the vagaries of amateur legislators +was the Graphē Paranomōn. Any man was at liberty to give +notice that he would proceed against the mover of a given +resolution either before or after the voting in the Ecclesia. A +trial in a Heliastic court was then arranged, and the plaintiff +had to prove that the resolution in question contravened an +existing law. If this contention were upheld by the court, when +the case was brought to it by the Thesmothetae, the resolution +was annulled, and the defendant had to appear in a new trial +for the assessment of the penalty, which was usually a fine, +rarely death. Three convictions under this law, however, involved +a certain loss of rights; the loser could no longer move +a resolution in the Ecclesia. After the lapse of a year the mover +of a resolution could not be attacked. In the 4th century the +Graphē Paranomōn took the place of Ostracism (<i>q.v.</i>). In the +5th century it was merely an arrangement whereby the people +sitting as sworn juries ratified or annulled their own first decision +in the Ecclesia.</p> + +<p><i>Revision of Laws.</i>—In the 4th century, the assembly annually, +on the eleventh day of Hecatombaeon (the first day of the +official year), took a general vote on the laws, to decide whether +revision was necessary. If the decision was in favour of alteration, +it was open to any private citizen to put up notice of amendments. +The Nomothetae, a panel selected by the Prytaneis from the +Heliaea, heard arguments for and against the changes proposed +and voted accordingly. Against all new laws so passed, there +lay the Graphē; Paranomōn. Thus the Nomothetae, not the +Ecclesia, finally passed the law.</p> + +<p><i>Judicial Functions.</i>—The Ecclesia heard cases of Probolē +and Eisangelia (see <span class="sc"><a href="#artlinks">Greek Law</a></span>). The Probolē was an action +against sycophants and persons who had not kept their promises +to the people, or had disturbed a public festival. The verdict +went by show of hands, but no legal consequences ensued; if +the plaintiff demanded punishment he had to go to the Heliaea +which were not at all bound by the previous vote in the Ecclesia. +Cases of Eisangelia in which the penalty exceeded the legal +competence of the council came before the Ecclesia in the form +of a <i>probouleuma</i>. To prevent vexatious accusations, it was +<span class="pagenum"><a name="page849" id="page849"></a>849</span> +(at some date unknown) decided that the accuser who failed +to obtain one-fifth of the votes should be fined 1000 drachmas +(£40). (For the procedure in case of <span class="sc"><a href="#artlinks">Ostracism</a></span> see that article.)</p> + +<p><i>Summary.</i>—Thus it will be seen that the Ecclesia, with no +formal organization, had absolute power save for the Graphē +Paranomōn (which, therefore, constituted the dicasteries in one +sense the sovereign power in the state). It dealt with all matters +home and foreign. Every member could initiate legislation, +and, as has been shown, the power of the council was merely +formal. As against this it must be pointed out that it was +by no means a representative assembly in practice. The phrase +used to describe a very special assembly (<span class="grk" title="kataklêtos ekklêsia">κατάκλητος ἐκκλησία</span>) +shows that ordinarily the country members did not attend +(<span class="grk" title="katakalein">κατακαλεῖν</span> always involving the idea of motion from a distance +towards Athens), and Thucydides says that 5000 was the maximum +attendance, though it must be remembered that he is +speaking of the time when the number of citizens had been much +reduced owing to the plague and the Sicilian expedition. From +this we understand the necessity of payment in the 4th century, +although in that period the Ecclesia was supreme (<i>Constitution +of Athens</i>, xli. 2). The functions of the Ecclesia thus differed +in two fundamental respects from those which are in modern +times associated with a popular assembly. (1) It did not exercise, +at least in the period as to which we are best instructed, the power +of law-making (<span class="grk" title="nomothesia">νομοθεσία</span>) in the strict sense. It must be +remembered, however, in qualification of this statement that it +possessed the power of passing <i>psephismata</i> which would in many +cases be regarded as law in the modern sense. (2) The Ecclesia +was principally concerned with the supervision of administration. +Much of what we regard as executive functions were discharged +by the Ecclesia.</p> + +<div class="condensed"> +<p>With this article compare those on <span class="sc"><a href="#artlinks">Solon</a></span>; <span class="sc"><a href="#artlinks">Boule</a></span>; <span class="sc"><a href="#artlinks">Areopagus</a></span>; +<span class="sc"><a href="#artlinks">Greek Law</a></span>, and, for other ancient popular assemblies, <span class="sc"><a href="#artlinks">Apella</a></span>; +<span class="sc"><a href="#artlinks">Comitia</a></span>. See also A.H.J. Greenidge, <i>Handbook of Greek Constitutional +History</i> (1896); Gilbert, <i>Greek Constitutional Antiquities</i> +(trans. Brooks and Nicklin, 1895); Schömann, <i>De comitiis Atheniensium</i>; +L. Schmidt, “De Atheniensis reipublicae indole democratica” +in <i>Ind. Lect.</i> (Marburg, 1865); J.W. Headlam, <i>Election by Lot at +Athens</i> (Cambridge, 1891). See also the histories of Greece by Meyer, +Busolt, Grote, Evelyn Abbott, and J.E. Sandys’ edition of the <i>Constitution +of Athens</i> (1892); for a comparative study, E.A. Freeman, +<i>Comparative Politics</i>.</p> +</div> +<div class="author">(J. M. M.)</div> + + +<hr class="art" /> +<p><span class="bold">ECCLESIASTES<a name="ar116" id="ar116"></a></span> (Heb. <span title="Kohelet">קהלת</span>, <i>Kohelet</i>, “Koheleth”; Sept. +<span class="grk" title="ekklêsiastês">ἐκκλησιαστής</span>; Jerome <i>concionator</i>), one of the Wisdom Books +of the Old Testament (see <span class="sc"><a href="#artlinks">Wisdom Literature</a></span>). The book, as +it stands, is a collection of the discourses, observations and +aphorisms of a sage called Koheleth, a term the precise meaning +of which is not certain. The Greek <i>ecclesiastes</i> means one who +takes part in the deliberations of an assembly (<i>ecclesia</i>), a debater +or speaker in an assembly (Plato, <i>Gorgias</i>, 452 E), and this is the +general sense of the Hebrew word. Its form (singular feminine) +has been supposed to be the adoption or imitation of the Arabic +employment of a fem. sing. as the designation of a high official +person, as is the case in the title <i>caliph</i> (whence the rendering +in the margin of the Revised Version, “Great orator”); but +the adoption of an Arabic idiom is not probable. This usage is +not Hebrew; it is not found either in the Old Testament or in +the later (Mishnaic) Hebrew. The form may have been suggested +by that of the Hebrew word for “wisdom.” <i>Koheleth</i>, however, +is employed in the book not as a title of wisdom (for “wisdom” +is never the speaker), but as the independent name of the sage. +It is intended to represent him as a member of an assembly +(<i>Kahal</i>)—not the Jewish congregation, but a body of students +or inquirers, such as is referred to in xii. 9-11, a sort of collegium, +of which he was the head; and as instructor of this body +he gives his criticism of life. The author begins, indeed, +with identifying his sage with King Solomon (i. 12-ii. 11, 12b); +but he soon abandons this literary device, and speaks in his +own name. The rendering “preacher” has a misleading +connotation.</p> + +<p>In the book as we have it there is no orderly exposition of a +theory; it rather has the appearance of a collection of remarks +jotted down by a pupil (somewhat after the manner of Xenophon’s +<i>Memorabilia</i>), or of extracts from a sage’s notebook. It +is, however, characterized throughout (except in some scribal +additions) by a definite thought, and pervaded by a definite tone +of feeling. The keynote is given in the classic phrase with which +the discussion opens and with which it closes: “Vanity of +vanities (<i>i.e.</i> absolute vanity), all<a name="fa1g" id="fa1g" href="#ft1g"><span class="sp">1</span></a> is vanity!” Life, says the +author, has nothing of permanent value to offer. His attitude +is one not of bitterness but of calm hopelessness, with an occasional +tinge of disgust or contempt. He fancies that he has tried +or observed everything in human experience, and his deliberate +conclusion is that nothing is worth doing. He believes in an all-powerful +but indifferent God, and is himself an observer of +society, standing aloof from its passions and ambitions, and +interested only in pointing out their emptiness.</p> + +<p>This general view is set forth in a number of particular +observations.</p> + +<p>1. His fundamental proposition is that there is a fixed, +unchangeable order in the world, a reign of inflexible law (i. 4-11, +iii. 1-11, 14, 15, vii. 13, viii. 5-9): natural phenomena, such as +sunrise and sunset, recur regularly; for everything in human +experience a time has been set; birth and death, building up +and destroying, laughing and weeping, silence and speech, love +and hate, war and peace, are to be regarded not as utterances +of a living, self-directing world, but as incidents in the work of a +vast machine that rolls on for ever; there is an endless repetition—nothing +is new, nothing is lost; if one thinks he has found +something new, inquiry shows that it was in existence long ago; +God, the author of all, seeks out the past in order to make it once +more present; it is impossible to add to or take from the content +of the world, impossible to change the nature of things, to effect +any radical betterment of life; the result is unspeakable weariness—a +depressing series of sights and sounds. No goal or +purpose is discoverable in this eternal round; if the sun rises +and goes on his journey through the sky, it is merely to come +back to the place where he rose; rivers flow for ever into the +sea without filling it. To what end was the world created? +It is impossible to say. Such is Koheleth’s view of life, and it is +obvious that such a conception of an aimless cosmos is thoroughly +non-Jewish, if we may judge Jewish thought by the great body +of the extant literature.</p> + +<p>2. Further, says Koheleth, man is impelled to study the world, +but under the condition that he shall never comprehend it +(iii. 11, vii. 23, 24, viii. 16, 17). As to the meaning of the +Hebrew term <i>olam</i> in iii. 11, there are various opinions, but +“world” appears to be the rendering favoured by the connexion: +“God has made everything beautiful in its time, and +has put the <i>olam</i> into men’s minds, yet so that they cannot understand +His work”: the <i>olam</i>, the sum of phenomena, is God’s +work. The word is not found in this sense elsewhere in the Old +Testament, but it so occurs in the Mishna (<i>Pirke Aboth</i>, iv. 7), +and the vocabulary of Ecclesiastes is admittedly similar to that +of the Mishna. Only here in the Old Testament does it stand +as a simple isolated noun; elsewhere it is the definition of a +noun (in “everlasting covenant,” &c.), or it is preceded by a +preposition, in the phrases “for ever,” “of old,” or it stands +alone (sing. or plur.) in the same adverbial sense, “for ever.” +The word means first a remote point in past or future, then a +future point without limit of time, then a period of history, and +finally the world considered as a mass of human experiences +(cf. <span class="grk" title="aiôn">αἰών</span>). The renderings “eternity” and “future” in +the present passage are unsatisfactory; the former has an +inappropriate metaphysical connotation, and yields no distinct +sense; the latter does not suit the connexion, though there is +reference to the future elsewhere (ix. 1). God, the text here +declares, has made the world an object of man’s thought, yet +so that man can never find out the work that God has done +(iii. 11). The reference seems to be not so much to the variety +and complexity of phenomena as to the impossibility of construing +them rationally or in such a way that man may foresee and +provide for his future. Man is in the clutches of fate (ix. 11, 12): +there is no observable relation between exertion and result in +life: the race is not to the swift nor the battle to the strong; +<span class="pagenum"><a name="page850" id="page850"></a>850</span> +success does not attend wisdom, knowledge and skill; men are +like fish taken in a net or birds caught in a snare.</p> + +<p>3. Human life, Koheleth declares, is unsatisfying. He +inquired, he says, into everything that is done by men under +the sun (i. 12-16): God has inflicted on men a restless desire for +movement and work<a name="fa2g" id="fa2g" href="#ft2g"><span class="sp">2</span></a>, yet life is but a catalogue of fruitless +struggles. He gives a number of illustrations. In his character +of king he tried all the bodily pleasures of life (ii. 1-11): he had +houses, vineyards, gardens, parks, ponds, forests, servants, +flocks and herds, treasures of gold and silver, singers, wives; +all these he set himself to enjoy in a rational way—indeed, he +found a certain pleasure in carrying out his designs, but, when all +was done, he surveyed it only to see that it was weary and unprofitable. +Dropping the rôle of Solomon and speaking as an +observer of life, the author declares (iv. 4) that the struggle for +success is the result of rivalry among men, which has no worthy +outcome. The securing of riches is a fallacious achievement, +for often wealth perishes by some accident (v. 13 f.), or its +possessor is unable to enjoy it (vi. 1-3<i>a</i>), or he has no one to +whom to leave it, and he cannot keep it—naked man comes into +the world, naked he goes out. He does not consider the possibility +of deriving enjoyment from wealth by helping the poor or +encouraging learning (this latter, indeed, he looks on as vanity), +and in general he recognizes no obligation on the part of a man +to his fellows. A noteworthy survival of an old belief is found +in vi. 3: though a man have the great good fortune to live long +and to have many children, yet, if he have not proper burial +the blank darkness of an untimely birth is better than he: this +latter is merely the negation of existence; the former, it appears +to be held, is positive misfortune, the loss of a desirable place in +Sheol, though elsewhere (ix. 5) existence in Sheol is represented +as the negation of real life. It is not necessary to suppose that +the writer has here any particular case in mind.</p> + +<p>If wealth be thus a vain thing, yet a sage might be supposed +to find satisfaction in wisdom, that is, practical good sense and +sagacity; but this also the author puts aside as bringing no +lasting advantage, since a wise man must finally give up the fruit +of his wisdom to someone else, who may be a fool, and in any +case the final result for both fools and wise men is the same—both +are forgotten (ii. 12-23). A particular instance is mentioned +(ix. 13-15) of a <span class="correction" title="amended from beleagured">beleaguered</span> city saved by a wise man; but the +man happened to be poor, and no one remembered him. The +whole constitution of society, in fact, seems to the sage a lamentable +thing: the poor are oppressed, the earth is full of their cries, +and there is no helper (iv. 1); strange social upheavals may be +seen: the poor<a name="fa3g" id="fa3g" href="#ft3g"><span class="sp">3</span></a> set in high places, the rich cast down, slaves +on horseback, princes on foot (x. 5-7). He permits himself a +sweeping generalization (vii. 25-28): human beings as a rule are +bad: one may occasionally find a good man, never a good +woman—woman is a snare and a curse. He (or an editor) adds +(vii. 29) that this condition of things is due to social development: +man was created upright (Gen. i. 27; Enoch lxix. 11), but in the +course of history has introduced corrupting complications into +life.</p> + +<p>4. The natural outcome of these experiences of the author is +that he cannot recognize a moral government of the world. +He finds, like Job, that there are good men who die prematurely +notwithstanding their goodness, and bad men who live long +notwithstanding their badness (vii. 15), though long life, it is +assumed, is one of the great blessings of man’s lot; and in +general there is no moral discrimination in the fortunes of men +(viii. 14, ix. 2).</p> + +<p>5. There is no sacredness or dignity in man or in human life: +man has no pre-eminence over beasts, seeing that he and they +have the same final fate, die and pass into the dust, and no one +knows what becomes of the spirit, whether in man’s case it goes +up to heaven, and in the case of beasts goes down into Sheol—death +is practically the end-all; and so poor a thing is life that +the dead are to be considered more fortunate than the living, +and more to be envied than either class is he who never came +into existence (iv. 2, 3). It is a special grievance that the wicked +when they die are buried with pomp and ceremony, while men +who have acted well are forgotten<a name="fa4g" id="fa4g" href="#ft4g"><span class="sp">4</span></a> in the city (viii. 10).</p> + +<p>6. That the author does not believe in a happy or active future +life appears in the passage (iv. 2, 3) quoted above. The old +Hebrew view of the future excluded from Sheol the common +activities of life and also the worship of the national god (Isa. +xxxviii. 18); he goes even beyond this in his conception of the +blankness of existence in the underworld. The living, he says, +at least know that they shall die, but the dead know nothing—the +memory of them, their love, hate and envy, perishes, they +have no reward, no part in earthly life (ix. 5, 6); there is +absolutely no knowledge and no work in Sheol (ix. 10). His +conclusion is that men should do now with all their might what +they have to do; the future of man’s vital part, the spirit, is +wholly uncertain.</p> + +<p>7. His conception of God is in accord with these views. +God for him is the creator and ruler of the world, but hardly +more; he is the master of a vast machine that grinds out human +destinies without sympathy with man and without visible +regard for what man deems justice—a being to be acknowledged +as lord, not one to be loved. There can thus be no social contact +between man and God, no communion of soul, no enthusiasm +of service. Moral conduct is to be regulated not by divine law +(of this nothing is said) but by human experience. The author’s +theism is cold, spiritless, without influence on life.</p> + +<p>If now the question be asked what purpose or aim a man can +have, seeing that there is nothing of permanent value in human +work, an answer is given which recurs, like a refrain, from the +beginning to the end of the book, and appears to be from the +hand of the original author: after every description of the vanity +of things comes the injunction to enjoy such pleasures as may fall +to one’s lot (ii. 24, 25, iii. 12, 13, 22, v. 18, 19, viii. 15, +ix. 7-10, xi. 7-xii. 7). Elsewhere (ii.), it is true, it is said that +there is no lasting satisfaction in pleasure; but the sage may +mean to point out that, though there is no permanent outcome +to life, it is the part of common-sense to enjoy what one has. +The opportunity and the power to enjoy are represented as being +the gift of God; but this statement is not out of accord with +the author’s general position, which is distinctly theistic. All the +passages just cited, except the last (xi. 7-xii. 7), are simple and +plain, but the bearing of the last is obscured by interpolations. +Obviously the purpose of the paragraph is to point out the +wisdom of enjoying life in the time of youth while the physical +powers are fresh and strong, and the impotency of old age has +not yet crept in. Omitting xi. 8<i>c</i>, 9<i>b</i>, 10<i>b</i>, xii. 1<i>a</i>, the passage +will read: “Life is pleasant in the bright sunshine—however +long a man may live, he must be cheerful always, only remembering +that dark days will come. Let the young man enjoy all the +pleasures of youth, putting away everything painful, before the +time comes when his bodily powers decay and he can enjoy +nothing.” To relieve the apparent Epicureanism of this passage, +an editor has inserted reminders of the vanity of youthful +pleasures, and admonitions to remember God and His judgment. +The author, however, does not recommend dissipation, and does +not mean to introduce a religious motive—he offers simply a +counsel of prudence. The exhortation to remember the Creator +in the days of youth, though it is to be retained in the margin +as a pious editorial addition, here interrupts the line of thought. +In xii. 1a some critics propose to substitute for “remember thy +Creator” the expression of xi. 9, “let thy heart cheer thee”; +but the repetition is improbable. Others would read: “remember +thy cistern” (Bickell), or “thy well” (Haupt), that +is, thy wife. The wife is so called in Prov. v. 15-19 in an elaborate +poetical figure (the wife as a source of bodily pleasure), in which +the reference is clear from the context; but there is no authority, +in the Old Testament or in other literature of this period, for +<span class="pagenum"><a name="page851" id="page851"></a>851</span> +taking the term as a simple prose designation of a wife. Nor +would this reference to the wife be appropriate in the connexion, +since the writer’s purpose is simply to urge men to enjoy life +while they can. The paragraph (and the original book) concludes +with a sustained and impressive figure, in which the failing body +of the old man is compared to a house falling into decay: first, +the bodily organs (xii. 3, 4<i>a</i>): the keepers of the house (the arms +and hands) tremble, the strong men (the legs and perhaps the +backbone) are bent, the grinding women (the teeth) cease to +work, those that look out of the windows (the eyes) are darkened, +the street-doors are shut, the sound of the mill being low (apparently +a summary statement of the preceding details: communication +with the outer world through the senses is cut off, +the performance of bodily functions being feeble); the rest of +v. 4 may refer to the old man’s inability to make or hear music: +in the house there is no sound of birds<a name="fa5g" id="fa5g" href="#ft5g"><span class="sp">5</span></a> or of singers, there are +none of the artistic delights of a well-to-do household; further +(v. 5<i>a</i>) the inmates of the house fear dangers from all powerful +things and persons (the old man is afraid of everything), the +almond tree blossoms (perhaps the hair turns white). The two +next clauses are obscure.<a name="fa6g" id="fa6g" href="#ft6g"><span class="sp">6</span></a> Then comes the end: man goes to his +everlasting home; the dust (the body) returns to the earth +whence it came (Gen. ii. 7), and the breath of life, breathed by +God into the body, returns to him who gave it. This last clause +does not affirm the immortality of the soul; it is simply an +explanation of what becomes of the vital principle (the “breath +of life” of Gen. ii. 7); its positive assertion is not in accord +with the doubt expressed in iii. 21 (“who knows whether the +spirit of man goes upward?”), and it seems to be from another +hand than that of the author of the original book.</p> + +<p>There are other sayings in the book that appear to be at +variance with its fundamental thought. Wisdom is praised in a +number of passages (iv. 13, vii. 5, 11, 12, 19, viii. 1, ix. 16, 17, +x. 2, 3), though it is elsewhere denounced as worthless. It may +be said that the author, while denying that wisdom (practical +sagacity and level-headedness) can give permanent satisfaction, +yet admits its practical value in the conduct of life. This may +be so; but it would be strange if a writer who could say, “in +much wisdom is much grief,” should deliberately laud wisdom. +The question is not of great importance and may be left undecided. +It may be added that there are in the book a number +of aphorisms about fools (v. 3[4], vii. 5, 6, x. 1-3, 12-15) quite +in the style of the book of Proverbs, some of them contrasting +the wise man and the fool; these appear to be the insertions of +an editor. Further, it may be concluded with reasonable certainty +that the passages that affirm a moral government of the world are +additions by pious editors who wished to bring the book into +harmony with the orthodox thought of the time. Such assertions +as those of ii. 26 (God gives joy to him who pleases him, +<span class="correction" title="amended from amd">and</span> makes the sinner toil to lay up for the latter), viii. 12 (it +shall be well with those that fear God, but not with the wicked), +xii. 13 f. (man’s duty is simply to obey the commands of God, +for God will bring everything into judgment) are irreconcilable +with the oft-repeated statement that there is no difference in +the earthly lots of the righteous and the wicked, and no ethical +life after death.</p> + +<p>Many practical admonitions and homely aphorisms are +scattered through the book: iv. 5, quiet is a blessing; iv. 9-12, +two are better than one; iv. 17 (Eng. v. 1), be reverent in visiting +the house of God (the temple and the connected buildings)—to +listen (to the service of song or the reading of Scripture) +is better than to offer a foolish (thoughtless) sacrifice; v. 1 +(2), be sparing of words in addressing God; v. 1-5 (2-6), pay +your vows—do not say to the priest’s messenger that you made +a mistake; vii. 2-4, sorrow is better than mirth; vii. 16-18, +be not over-righteous (over-attentive to details of ritual and +convention) or over-wicked (flagrantly neglectful of established +beliefs and customs); here “righteous” and “wicked” appear +to be technical terms designating two parties in the Jewish +world of the 2nd and 1st centuries <span class="scs">B.C.</span>, the observers and the +non-observers of the Jewish ritual law; these parties represent +in a general way the Pharisees and the Sadducees; viii. 2-4, +x. 20, it is well to obey kings and to be cautious in speaking +about them, for there are talebearers everywhere; vii. 20, no +man is free from sin; vii. 21, do not listen to all that you may +overhear, lest you hear yourself ill spoken of; ix. 4, a living +dog is better than a dead lion; xi. 1-6, show prudence and +decision in business; do not set all your goods on one venture; +act promptly and hope for the best. At the close of the book +(xii. 9-12) there are two observations that appear to be editorial +recommendations and cautions. First, Koheleth is endorsed +as an industrious, discriminating and instructive writer. +Possibly this is in reply to objections that had been made to +what he had written. There follows an obscure passage (<i>v.</i> 11) +which seems to be meant as a commendation of the teaching +of the sages in general: their words are said to be like goads +(inciting to action) and like nails driven in a building (giving +firmness to character); they issue from masters of assemblies,<a name="fa7g" id="fa7g" href="#ft7g"><span class="sp">7</span></a> +heads of academies (but not of the Sanhedrin). The succeeding +clause “they are given from one shepherd” may refer to a +collection or revision by one authoritative person, but its relevancy +is not obvious. The “shepherd” cannot be God (Gen. +xlix. 24; Ps. xxiii. 1); the poetical use of the word would not be +appropriate here. The clause is possibly a gloss, a comment +on the preceding expression. A caution against certain books +is added (<i>v.</i> 12), probably works then considered harmful +(perhaps philosophic treatises), of which, however, nothing +further is known.</p> + +<p><i>Composition of the Book.</i>—If the analysis given above is +correct, the book is not a unit; it contains passages mutually +contradictory and not harmonizable. Various attempts have +been made to establish its unity. The hypothesis of “two +voices” is now generally abandoned; there is no indication of +a debate, of affirmations and responses. A more plausible +theory is that the author is an honest thinker, a keen observer +and critic of life, who sees that the world is full of miseries and +unsolved problems, regards as futile the attempts of his time +to demonstrate an ethically active future life, and, recognizing +a divine author of all, holds that the only wise course for men +is to abandon the attempt to get full satisfaction out of the +struggle for pleasure, riches and wisdom, and to content themselves +with making the best of what they have. This conception +of him is largely true, as is pointed out above, but it does not +harmonize the contradictions of the book, the discrepancies +between the piety of some passages and the emotional indifference +toward God shown in others. Other of the Biblical Wisdom +books (Job, Proverbs) are compilations—why not this? It is +not necessary to multiply authors, as is done, for example, by +Siegfried, who supposes four principal writers (a pessimistic +philosopher, an Epicurean glossator, a sage who upholds the +value of wisdom, and an orthodox editor) besides a number of +annotators; it is sufficient to assume that several conservative +scribes have made short additions to the original work. Nor is +it worth while to attempt a logical or symmetrical arrangement +of the material. It has been surmised (by Bickell) that the sheets +of the original codex became disarranged and were rearranged +incorrectly;<a name="fa8g" id="fa8g" href="#ft8g"><span class="sp">8</span></a> by other critics portions of the book are transferred +<span class="pagenum"><a name="page852" id="page852"></a>852</span> +hither and thither; in all cases the critic is guided in these +changes by what he conceives to have been the original form of +the book. But it is more probable that we have it in the form +in which it grew up—a series of observations by the original +author with interspersed editorial remarks; and it is better to +preserve the existing form as giving a record of the process +of growth.</p> + +<p><i>Date.</i>—As to the date of the book, though there are still +differences of opinion among scholars, there is a gradual approach +to a consensus. The Solomonic authorship has long since been +given up: the historical setting of the work and its atmosphere—the +silent assumption of monotheism and monogamy, the non-national +tone, the attitude towards kings and people, the picture +of a complicated social life, the strain of philosophic reflection—are +wholly at variance with what is known of the 10th century +<span class="scs">B.C.</span> and with the Hebrew literature down to the 5th or 4th +century <span class="scs">B.C.</span> The introduction of Solomon, the ideal of wisdom, +is a literary device of the later time, and probably deceived +nobody. The decisive considerations for the determination of +the date are the language, the historical background and the +thought. The language belongs to the post-classical period of +Hebrew. The numerous Aramaisms point to a time certainly +not earlier than the 4th century <span class="scs">B.C.</span>, and probably (though the +history of the penetration of Aramaic into Hebrew speech is +not definitely known) not earlier than the 3rd century. More +than this, there are many resemblances between the dialect of +Koheleth and that of Mishna. Not only are new words employed, +and old words in new significations, but the grammatical +structure has a modern stamp—some phrases have the appearance +of having been translated out of Aramaic into Hebrew. +By about the beginning of our era the Jews had given up Hebrew +and wrote in Aramaic; the process of expulsion had been going +on, doubtless, for some time; but comparison with the later +extant literature (<i>Chronicles</i>, the Hebrew <i>Ecclesiasticus</i> or +<i>Ben-Sira</i>, <i>Esther</i>) makes it improbable that such Hebrew as +that of Koheleth would have been written earlier than the +2nd century <span class="scs">B.C.</span> (for details see Driver’s <i>Introduction</i>). The +general historical situation, also, presupposed or referred to, is +that of the period from the year 200 <span class="scs">B.C.</span> to the beginning of our +era; in particular, the familiar references to kings as a part of +the social system, and to social dislocations (servants and princes +changing places, x. 7), suggest the troublous time of the later +Greek and the Maccabean rulers, of which the history of Josephus +gives a good picture.</p> + +<p>The conception of the world and of human life as controlled +by natural law, a naturalistic cosmos, is alien not only to the +prophetic and liturgical Hebrew literature but also to Hebrew +thought in general. Whether borrowed or not, it must be late; +and its resemblance to Greek ideas suggests Greek influence. +The supposition of such influence is favoured by some critics +(Tyler, Plumptre, Palm, Siegfried, Cheyne in his <i>Jewish Religious +Life after the Exile</i>, and others), rejected by some (Zeller, Renan, +Kleinert and others). This disagreement comes largely from +the attempts made to find definitely expressed Greek philosophical +dogmas in the book; such formulas it has not, but +the general air of Greek reflection seems unmistakable. <span class="correction" title="'the' originally repeated twice">The</span> +scepticism of Koheleth differs from that of Job in quality and +scope: it is deliberate and calm, not wrung out by personal +suffering; and it relates to the whole course and constitution +of nature, not merely to the injustices of fortune. Such a conception +has a Greek tinge, and would be found in Jewish circles, +probably, not before the 2nd century <span class="scs">B.C.</span></p> + +<p>A precise indication of date has been sought in certain supposed +references or allusions to historical facts. The mention of persons +who do not sacrifice or take oaths (ix. 2) is held by some to point +to the Essenes; if this be so, it is not chronologically precise, +since we have not the means of determining the beginning of +the movement of thought that issued in Essenism. So also the +coincidences of thought with <i>Ben-Sira</i> (<i>Ecclesiasticus</i>) are not +decisive: cf. iii. 14 with <i>B.S.</i> xviii. 6; v. 2-6 (3-7) with <i>B.S.</i> +xxxiv. 1-7; vii. 19 with <i>B.S.</i> xxxvii. 14; x. 8 with <i>B.S.</i> xxvii. +26a; xi. 10 with <i>B.S.</i> xxx. 21; xii. 10, 11 with <i>B.S.</i> xxxix. 2 ff., +xii. 13 with <i>B.S.</i> xliii. 27; if there be borrowing in these passages, +it is not clear on which side it lies; and it is not certain that there +is borrowing—the thoughts may have been taken independently +by the two authors from the same source. In any case, since +<i>Ben-Sira</i> belongs to about 180 <span class="scs">B.C.</span>, the date of Koheleth, so +far as these coincidences indicate it, would not be far from +200 <span class="scs">B.C.</span> The contrast made in x. 16 f. between a king who is +a boy and one who is of noble birth may allude to historical +persons. The antithesis is not exact; we expect either “boy +and mature man” or “low-born and high-born.” The “child” +might be Antiochus V. (164 <span class="scs">B.C.</span>), or Ptolemy V., Epiphanes +(204 <span class="scs">B.C.</span>), but the reference is too general to be decisive. The +text of the obscure passage iv. 13-16 is in bad condition, and +it is only by considerable changes that a clear meaning can be +got from it. The two personages—the “old and foolish king” +and the “poor and wise youth”—have been supposed (by Winckler) +to be Antiochus Epiphanes (175-164 <span class="scs">B.C.</span>) and +Demetrius (162-150 <span class="scs">B.C.</span>), or (by Haupt) Antiochus and the +impostor Alexander Balas (150-146 <span class="scs">B.C.</span>), or (by others) +Demetrius and Alexander; in favour of Alexander as the +“youth” it may be said that he was of obscure origin, was at +first popular, and was later abandoned by his friends. Such +identifications, however, do not fix the date of the book precisely; +the author may have referred to events that happened +before his time. The reign of Herod, a period of despotism and +terror, and of strife between Jewish religious parties, is preferred +by some scholars (Grätz, Cheyne and others) as best answering +to the social situation depicted in the book, while still others +(as Renan) decide for the reign of Alexander Jannaeus (104-78 +<span class="scs">B.C.</span>). The data are not numerous and distinct enough to +settle the question beyond determining general limits: for +reasons given above the book can hardly have been composed +before about 200 <span class="scs">B.C.</span>, and if, as is probable, a Septuagint translation +of it was made (though the present Septuagint text +shows the influence of Aquila), it is to be put earlier than 50 <span class="scs">B.C.</span> +Probably also, its different parts are of different dates.</p> + +<p>Of the author nothing is known beyond the obvious fact that +he was a man of wide observation and philosophic thought, of +the Sadducean type in religion, but non-Jewish in his attitude +toward life. He was, doubtless, a man of high standing, but +neither a king nor a high-priest, certainly not the apostate priest +Alcimus (1 Macc. vii. ix.); nor was he necessarily a physician—there +are no details in ch. xii. or elsewhere that any man of good +intelligence might not know. The book is written in prose, some +of which is rhythmical, with bits of verse here and there: thus +i. 2-11 is balanced prose, 12-14 plain prose, 15 a couplet, i. 16-ii. +25 simple prose, vii. contains a number of poetical aphorisms, +and so on. Some of the verses are apparently from the author, +some from editors.</p> + +<p>The fortunes of the book are not known in detail, but it is clear +that its merciless criticism of life and its literary charm made it +popular, while its scepticism excited the apprehensions of pious +conservatives. Possibly the <i>Wisdom of Solomon</i> (<i>c.</i> 50 <span class="scs">B.C.</span>) was +written partly as a reply to it. The claim of sacredness made for +it was warmly contested by some Jewish scholars. In spite of +the relief afforded by orthodox additions, it was urged that +its Epicurean sentiments contradicted the Torah and favoured +heresy. Finally, by some process of reasoning not fully recorded, +the difficulties were set aside and the book was received into the +sacred canon; Jerome (on Eccl. xii. 13, 14) declares that the +decisive fact was the orthodox statement at the end of the +book: the one important thing is to fear God and keep His +commandments. The probability is that the book had received +the stamp of popular approbation before the end of the 1st +century of our era, and the leading men did not dare to reject it. +It is not certain that it is quoted in the New Testament, but it +appears to be included in Josephus’ list of sacred books.</p> + +<div class="condensed"> +<p><span class="sc">Literature.</span>—For the older works see Zöckler (in Lange’s <i>Comm.</i>); +for Jewish commentaries see Zedner, <i>Cat. of Heb. books in Libry. of +Brit. Mus.</i> (1867), and for the history of the interpretations, C.D. +Ginsburg, <i>Coheleth</i> (1861). <i>Introductions</i> of A. Kuenen, S.R. Driver, +Cornhill, König. Articles in Herzog-Hauck, <i>Realencykl.</i> (by P. +Kleinert); Hastings, <i>Dict. Bible</i> (by A.S. Peake); T.K. Cheyne, +<span class="pagenum"><a name="page853" id="page853"></a>853</span> +<i>Encycl. Bibl.</i> (by A.B. Davidson); <i>Jew. Encycl.</i> (by D.S. Margoliouth). +Commentaries: F. Hitzig (1847); C.D. Ginsburg (1861); H. Grätz +(1871); Tyler (1874); Delitzsch (1875); E.H. Plumptre (1881); +C.H.H. Wright (1883); Nowack, revision of Hitzig (1883); Volck +(in Strack u. Zöckler’s <i>Kurzgef. Komm.</i>, 1889); Wildeboer (in +Marti’s <i>Kurzer Hand-Comm.</i>, 1898); C. Siegfried (in W. Nowack’s +<i>Handkomm.</i>, 1898); Oort (in <i>De Oude Test.</i>, 1899). Other works: +C. Taylor, <i>Dirge of Koh.</i> (1874); Wünsche, <i>Midrash</i> on Koh. (in +his <i>Biblioth. rabbin.</i>, 1880); E. Renan, <i>L’Ecclésiaste</i> (1882); Bickell, +<i>Der Prediger</i> (1884) and <i>Kohel.-Untersuchungen</i> (1886; Engl. by +E.J. Dillon, <i>Sceptics of Old Test.</i>, 1895); Schiffer, <i>Das Buch Koh. +nach d. Auffass. d. Weisen d. Talmuds</i>, &c. (1884); A. Palm, <i>Qoh. u. +d. nach-aristotel. Philosophie</i> (1885) and <i>Die Qoh.-Lit.</i> (1886); +E. Pfleiderer, <i>Die Phil. d. Heraklit</i>, &c. (1886); Cheyne, <i>Job and +Solomon</i> (1887) and <i>Jew. Relig. Life</i>, &c. (1898); W. Euringer, +<i>Der Masorahtext d. Koh.</i> (1890); W.T. Davison, <i>Wisdom-Lit. of Old +Test.</i> (1894); H. Winckler, in his <i>Altorient. Forschungen</i> (1898); +J.F. Genung, <i>Words of Koh.</i> (Boston, Mass., 1904); P. Haupt, +<i>Ecclesiastes</i> (Baltimore, 1905). The rabbinical discussions of the +book are mentioned in <i>Shabbath</i>, 30b; <i>Megilla</i>, 7a; <i>Eduyoth</i>, v. 3; +<i>Mishna Yadaim</i>, iii. 5, iv. 6; <i>Midrash Koheleth</i> (on xi. 9), <i>Aboth +d’ Rab. Nathan</i>, i.</p> +</div> +<div class="author">(C. H. T.*)</div> + +<hr class="foot" /> <div class="note"> + +<p><a name="ft1g" id="ft1g" href="#fa1g"><span class="fn">1</span></a> The Hebrew has the definite article, “the whole,” <span class="grk" title="to pan">τὸ πᾶν</span>.</p> + +<p><a name="ft2g" id="ft2g" href="#fa2g"><span class="fn">2</span></a> In fact, he suggests, a curse, as in Gen. iii. 17-19, though with +a wider sweep than that passage has in mind.</p> + +<p><a name="ft3g" id="ft3g" href="#fa3g"><span class="fn">3</span></a> The text has “folly,” but the parallelism and v. 7 point to social, +not intellectual, conditions, and a slight change (<span title="misken">מסכן</span> for <span title="haskel">הסכל</span>) gives +the sense “poor.”</p> + +<p><a name="ft4g" id="ft4g" href="#fa4g"><span class="fn">4</span></a> The Septuagint has less well: “They (the wicked) are praised +in the city.”</p> + +<p><a name="ft5g" id="ft5g" href="#fa5g"><span class="fn">5</span></a> The clause is obscure; literally “he (or, one) rises at (?) the +voice of the bird,” usually understood to refer to the old man’s +inability to sleep in the morning; but this is not a universal trait +of old age, and besides, a reference to affairs in the house is to be +expected; the Hebrew construction also is of doubtful correctness. +A change of the Hebrew text seems necessary; possibly we should +read <span title="ishpal kol">ישפל קול</span>, “low is the voice,” instead of <span title="yakum lekol">יקום לקול</span> “he rises up at +the voice.”</p> + +<p><a name="ft6g" id="ft6g" href="#fa6g"><span class="fn">6</span></a> The second is perhaps to be read: “the caper-berry blooms” +(white hair); usually “the caper-berry loses its appetizing +power”; Eng. Auth. Vers. “desire shall fail.” For the meaning +of the word <i>abyona</i> (“caper-berry,” not “desire” or “poverty”), +see art. by G.F. Moore in <i>Journ. of Bibl. Lit.</i> x. 1 (Boston, Mass., +1891).</p> + +<p><a name="ft7g" id="ft7g" href="#fa7g"><span class="fn">7</span></a> This is the Talmudic understanding of the Hebrew expression +(Jerus. Sanhed. 10, 28a, cf. Sanhed. 12a; see Ecclus. xxxix. 2). +There is no good authority for the renderings “collectors of maxims,” +“collections of maxims.”</p> + +<p><a name="ft8g" id="ft8g" href="#fa8g"><span class="fn">8</span></a> It is not certain that the codex form was in use in Palestine +or in Egypt as early as the 2nd or the 1st century <span class="scs">B.C.</span></p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECCLESIASTICAL COMMISSIONERS,<a name="ar117" id="ar117"></a></span> in England, a body +corporate, whose full title is “Ecclesiastical and Church Estates +Commissioners for England,” invested with very important +powers, under the operation of which extensive changes have been +made in the distribution of the revenues of the Established +Church. Their appointment was one of the results of the vigorous +movements for the reform of public institutions which followed +the Reform Act of 1832. In 1835 two commissions were appointed +“to consider the state of the several dioceses of England and +Wales, with reference to the amount of their revenues and the +more equal distribution of episcopal duties, and the prevention +of the necessity of attaching by commendam to bishoprics +certain benefices with cure of souls; and to consider also the +state of the several cathedral and collegiate churches in England +and Wales, with a view to the suggestion of such measures as +might render them conducive to the efficiency of the established +church, and to provide for the best mode of providing for the cure +of souls, with special reference to the residence of the clergy on +their respective benefices.” And it was enacted by an act of +1835 that during the existence of the commission the profits of +dignities and benefices without cure of souls becoming vacant +should be paid over to the treasurer of Queen Anne’s Bounty. +In consequence of the recommendation of these commissioners, +a permanent commission was appointed by the Ecclesiastical +Commissioners Act 1836 for the purpose of preparing and laying +before the king in council such schemes as should appear to them +to be best adapted for carrying into effect the alterations suggested +in the report of the original commission and recited in the act. +The new commission was constituted a corporation with power +to purchase and hold lands for the purposes of the act, notwithstanding +the statutes of mortmain. The first members of the +commission were the two archbishops and three bishops, the lord +chancellor and the principal officers of state, and three laymen +named in the act.</p> + +<p>The constitution of the commission was amended by the +Ecclesiastical Commissioners Act 1840 and subsequent acts, and +now consists of the two archbishops, all the bishops, the deans of +Canterbury, St Paul’s and Westminster, the lord chancellor, the +lord president of the council, the first lord of the treasury, the +chancellor of the exchequer, the home secretary, the lord chief +justice, the master of the rolls, two judges of the admiralty +division, and certain laymen appointed by the crown and by the +archbishop of Canterbury. The lay commissioners are required +to be “members of the Church of England, and to subscribe a +declaration to that effect.” The crown also appoints two laymen +as church estates commissioners, and the archbishop of Canterbury +one. These three are the joint treasurers of the commission, +and constitute, along with two members appointed by the commission, +the church estates committee, charged with all business +relating to the sale, purchase, exchange, letting or management +of any lands, tithes or hereditaments. The commission has +power to make inquiries and examine witnesses on oath. Five +commissioners are a quorum for the transaction of business, +provided two of them are church estates commissioners; two +ecclesiastical commissioners at least must be present at any +proceeding under the common seal, and if only two are present +they can demand its postponement to a subsequent meeting. +The schemes of the commission having, after due notice to +persons affected thereby, been laid before the king in council, may +be ratified by orders, specifying the times when they shall take +effect, and such orders when published in the <i>London Gazette</i> +have the same force and effect as acts of parliament.</p> + +<div class="condensed"> +<p>The recommendations of the commission recited in the act of +1836 are too numerous to be given here. They include an extensive +rearrangement of the dioceses, equalization of episcopal income, +providing residences, &c. By the act of 1840 the fourth report of the +original commissioners, dealing chiefly with cathedral and collegiate +churches, was carried into effect, a large number of canonries being +suspended, and sinecure benefices and dignities suppressed.</p> + +<p>The emoluments of these suppressed or suspended offices, and the +surplus income of the episcopal sees, constitute the fund at the +disposal of the commissioners. By an act of 1860, on the avoidance +of any bishopric or archbishopric, all the land and emoluments of +the see, except the patronage and lands attached to houses of +residence, become, by order in council, vested in the commissioners, +who may, however, reassign to the see so much of the land as may +be sufficient to secure the net annual income named for it by statute or +order. All the profits and emoluments of the suspended canonries, &c., +pass over to the commissioners, as well as the separate estates of those +deaneries and canonries which are not suspended. Out of this fund +the expenses of the commission are to be paid, and the residue is to +be devoted to increasing the efficiency of the church by the augmentation +of the smaller bishoprics and of poor livings, the endowment +of new churches, and employment of additional ministers.</p> + +<p>The substitution of one central corporation for the many local and +independent corporations of the church, so far at least as the management +of property is concerned, was a constitutional change of great +importance, and the effect of it undoubtedly was to correct the +anomalous distribution of ecclesiastical revenues by equalizing +incomes and abolishing sinecures. At the same time it was regarded +as having made a serious breach in the legal theory of ecclesiastical +property. “The important principle,” says Cripps, “on which the +inviolability of the church establishment depends, that the church +generally possesses no property as a corporation, or which is applicable +to general purposes, but that such particular ecclesiastical +corporation, whether aggregate or sole, has its property separate, +distinct and inalienable, according to the intention of the original +endowment, was given up without an effort to defend it” (<i>Law +Relating to the Church and Clergy</i>, p. 46).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECCLESIASTICAL JURISDICTION.<a name="ar118" id="ar118"></a></span> This phrase in its primary +sense imports not jurisdiction over ecclesiastics, but jurisdiction +exercised by ecclesiastics over other ecclesiastics and over +the laity. “Jurisdiction” is a word borrowed from the jurists +which has acquired a wide extension in theology, wherein, for +example, it is frequently used in contradistinction to “order,” +to express the right to administer sacraments as something +superadded to the <i>power</i> to celebrate them. So it is used to +express the territorial or other limits of ecclesiastical, executive +or legislative authority. Here it is used, in the limited sense +defined by an American Court, as “the authority by which +judicial officers take cognizance of and decide causes.”</p> + +<p>Such authority in the minds of lay Roman lawyers who first +used this word “jurisdiction” was essentially temporal in its +origin and in its sphere. The Christian Church transferred +the notion to the spiritual domain as part of +<span class="sidenote">Origin of ecclesiastical jurisdiction.</span> +the general idea of a Kingdom of God correlative, on +the spiritual side of man upon earth, to the powers, +also ordained of God, who had dominion over his temporal +estate (see <span class="sc"><a href="#artlinks">Canon Law</a></span>). As the Church in the earliest +ages had executive and legislative power in its own spiritual +sphere, so also it had “judicial officers,” “taking cognizance of +and deciding causes.” Only before its union with the State, its +power in this direction, as in others, was merely over the spirits +of men. Coercive temporal authority over their bodies or estates +could only be given by concession from the temporal prince. +Moreover, even spiritual authority over members of the Church, +<i>i.e.</i> baptized persons, could not be exclusively claimed as <i>of right</i> +by the Church tribunals, if the subject matter of the cause were +purely temporal. On the other hand, it is clear that <i>all</i> the +faithful were subject to these courts (when acting within their +own sphere), and that, in the earliest times, no distinction was +made in this respect between clergy and laity.</p> + +<p>The fundamental principle of ecclesiastical jurisdiction with its +<span class="pagenum"><a name="page854" id="page854"></a>854</span> +“sanction” of excommunication will be found in Christ’s words +in Matt. xviii. 15-18. A very early example of criminal spiritual +jurisdiction exercised by St Paul is found in the case of the incestuous +Corinthian (1 Cor. v.). We find later the same apostle +exercising like jurisdiction in the cause of Hymenaeus and +Alexander (1 Tim. i. 20). After the time of the Apostles, we +find this criminal jurisdiction exercised by the bishops individually +over their respective “subjects”—doubtless with the advice +of their presbyters according to the precept of St Ignatius +(<i>c.</i> 110). As neighbouring dioceses coalesced into “provinces” +and provinces into larger districts (corresponding to the civil +“dioceses” of the later Roman Empire), the provincial synods of +bishops and the synods of the larger districts acquired a criminal +jurisdiction, still purely spiritual, of their own. At first this was +“original” and mainly (although not exclusively) over bishops +(of the province or larger district). The beginnings of an +appellate jurisdiction in the cases of clerics and laymen may be +traced before the conversion of the Empire. The bishop over +whom the synod of neighbouring bishops had exercised jurisdiction +had no formal right of appeal; but sometimes bishops in +other parts of the Church would refuse to acknowledge the local +synodical sentence and would communicate with a bishop whom +they deemed unjustly deposed. The theory, as expressed in +legal phrase by St Cyprian in the 3rd century, was that the +apostolic power of delegated sovereignty from the Lord, alike +legislative and judicial, was held in joint-tenancy by the whole +body of Catholic bishops. In both capacities, however, a certain +undefined pre-eminence was conceded to the occupants of +“Apostolic” sees, <i>i.e.</i> sees traditionally founded by Apostles, or +of sees with a special secular position.</p> + +<p>Even before the edict of Milan, at least as early as the latter +half of the 3rd century, the spiritual sentences of deposition +from office had sometimes indirect temporal consequences +recognized by the secular courts. The classical example is the +case of Paul of Samosata, bishop of Antioch. It would seem +that, in the intervals of persecution, some rights of property +were recognized in the Christian Church and its officers; although +the Church was an illegal society. After some previous abortive +trials, Paul of Samosata was deposed and excommunicated, in +269, by a great synod of the Antiochene district. Paul, notwithstanding +his deposition, kept possession of the episcopal residence. +The local church sought recovery of it before the tribunals of +the Empire. The judicial authorities requested a rescript from +the emperor Aurelian for the decision of the cause. Aurelian +referred the matter to the bishop of Rome and the bishops of +Italy, who gave their award in favour of the Antiochene Church.</p> + +<p>Side by side with this which we may call criminal jurisdiction—none +the less real or coercive because its sanctions were purely +spiritual—there grew up a quasi-jurisdiction in causes +entirely temporal, based upon the free consent of the +<span class="sidenote">Temporal Jurisdiction of the Church.</span> +parties to accept the arbitration of the bishop. This +system had also its roots in the New Testament (see +Matt, xviii. 15-17 and 1 Cor. vi. 1-8). In the matter of +criminal jurisdiction we paused for a moment at the edict of +Milan; but we may at once trace this second or civil branch of +episcopal judicature or quasi-judicature down as far as the reign +of Charlemagne, when it underwent a fundamental change, and +became, if <i>either</i> litigant once chose, no longer a matter of +consent but of right.</p> + +<p>Constantine decreed that judgment in causes might be passed +by bishops when litigants preferred their adjudication to that +of the secular courts (see his epistle to the Numidian bishops and +<i>Cod. Theodos. Tit. de Episcopis</i>). The episcopal judgment was +to be equivalent to that of the emperor and irreversible, and the +civil authorities were to see to its execution. Saints Ambrose +and Augustine both spent days in deciding temporal causes. +Honorius, in the West, at the end of the 4th century, made a +constitution providing that if any desired to litigate before the +bishops they should not be forbidden, but that in civil matters +the prelates should render judgment in the manner of arbitrators +by consent (<i>Cod.</i> 1, <i>Tit.</i> iv.). Where the faithful had had recourse +to the bishop, no appeal was to be allowed, and the judges were +to command execution of the episcopal decree. A quarter of a +century later, however, Valentinian III. in the West expressly +provided that bishops were not to be permitted to be judges +(that is, of course, in temporal causes), save by the consent of the +parties. This legislation was, substantially, adopted by Justinian.</p> + +<p>On the revival of the Western Empire, however, Charlemagne, +in the beginning of the 9th century, under the mistaken belief +that he was following the authority of Constantine I. and +Theodosius I., took a great step forward, by which the bishop +ceased to be a mere legally indicated arbitrator by consent in +secular causes, and became a real judge. By a capitulary he +provided that either litigant, without the consent of the other +party, and not only at the beginning of a suit but at any time +during its continuance, might take the cause from lay cognizance +and transfer it to the bishop’s tribunal. He re-enacted the +prohibition of appeal.</p> + +<p>It should be remembered that, from the latter part of the +3rd century, the leading bishops had generally been trained in +secular learning. St Cyprian, St Ambrose and St Augustine, St +Paulinus of Nola and St John Chrysostom had practised law +as teachers or advocates. St Ambrose and St Paulinus had even +held high administrative and judicial offices.</p> + +<p>To return to the evolution of ecclesiastical jurisdiction from +the time of Constantine. With the “Nicene period” came a +great development on the criminal side. A system +begins to be formed, and the secular arm supports +<span class="sidenote">Roman empire from Constantine.</span> +the decrees of the Church. The first trace of system +is in the limited right of appeal given by the first +oecumenical council of Nicaea and its provision that episcopal +sentences or those of provincial synods on appeal were to be +recognized throughout the world. The fifth canon provides +that those, whether clerics or laymen, who are cut off from communion +in any particular province are not to be admitted +thereto elsewhere. Still examination must be had whether +persons have been expelled from the congregation by any +episcopal small-mindedness (<span class="grk" title="mikropsychia">μικροψυχία</span>), or contentious spirit, +or such-like harshness (<span class="grk" title="aêdia">ἀηδία</span>). That this may be conveniently +inquired into, synods are to be held, three in every year, in each +province, and questions of this kind examined. There is to be no +“stay of execution”; the episcopal sentence is to prevail until +the provincial synod otherwise decide. It will be noticed that +as yet no provision is made for appeals by <i>bishops</i> from provincial +synods sitting in first instance.</p> + +<p>The edicts of Milan had only admitted the Christian Church +among the number of lawful religions; but the tendency (except +in the time of Julian) was towards making it the only lawful +religion. Hence the practice, immediately after Nicaea I., of +superadding banishment by the emperor to synodical condemnation. +The dogmatic decrees of Nicaea I. were at once enforced +in this temporal manner. On the other hand, the Arian reaction +at court worked its objects (see Pusey, <i>Councils of the Church</i>) +by using the criminal spiritual jurisdiction of synods against the +Catholics—often packing the synods for the purpose. The acts +of councils of this age are full of the trials of bishops not only for +heresy but for immorality and common law crimes. The accusations +are frequently unfounded; but the trials are already +conducted in a certain regular forensic form. The secular +authorities follow the precedent of Nicaea I. and intervene to +supplement the spiritual sentence by administrative penalties. +Sometimes an imperial officer of high rank (as, <i>e.g.</i> a “count”) +is present at the synod, as an assessor to maintain order and +advise upon points of procedure. Leading examples may be +found in the various prosecutions of St Athanasius, in whose +case also there is the germ of an appeal, <i>tanquam ab abusu</i>. It +has been contended that, according to later and more formulated +jurisprudence, such an appeal would have lain, since the trial +at Tyre was not concerned with purely spiritual matters (see +the case in Hefele, <i>Councils</i>, in loc.).</p> + +<p>The trial of St Athanasius led to extensions of the right of +appeal. This was favoured by the development of the greater +sees into positions of great administrative dignity, shortly to +be called “patriarchal.” A synod was held at Rome, attended +<span class="pagenum"><a name="page855" id="page855"></a>855</span> +by bishops from various regions, which reversed the original +judgment of the synod of Tyre which had condemned Athanasius. +A much larger synod at Antioch, gathered only from the East, +on the other hand, confirmed that judgment. This last synod +did something to systematize the criminal procedure of the +Church, and its legislation has been always received.</p> + +<p>This legislation marks another step forward. Deposition of +a bishop by a synod, or of a priest or deacon by his bishop, is to +take effect even pending an appeal, and a cleric continuing his +functions after sentence in first instance is to lose all right of +appeal. The appeal given by Nicaea I. to clerics and laymen +from episcopal excommunications is extended. The synod may +restore them if convinced of the justice of their cause (and not +merely in cases of <span class="grk" title="aêdia">ἀηδία</span>). A bishop may appeal to a great +assembly of bishops. Any bishop, priest or deacon “importuning” +the emperor, instead of exerting his right of appeal to +synods, is to lose all right of appeal and never to be restored or +pardoned. If a provincial synod be divided as to the guilt of a +bishop, the metropolitan is to convene bishops from the neighbouring +provinces to decide the cause jointly with the bishops of +the original province.</p> + +<p>A few years later, in 347, the council of Sardica, a council of +practically the whole West save Africa, reversed Tyre and +acquitted St Athanasius after a full judicial inquiry. This +council endeavoured to set up a system of appeals in the case of +bishops, in which the see of Rome was made to play a great part. +“Out of honour to the memory of St Peter,” a condemned +bishop may ask the intervention of Rome. If this be done, the +synod of first instance is to send letters to Julius, bishop of +Rome. If that prelate think the cause should be heard again, +he is to appoint judges; if otherwise, the original judgment +is to be confirmed. Pending appeal, the appellant’s see is not +to be filled up. The judges appointed by the bishop of Rome +to hear the appeal are to be from the neighbouring provinces. +The appellant may, however, request that bishop to send priests +from his side to sit with the synod of appeal. If such priests are +sent, they are to preside in the court of appeal. These canons +were always repudiated in the East, and when, sixty years +afterwards, they were, for the first time, heard of in Africa, they +were repudiated there also.</p> + +<p>A rescript of Gratian in 378 empowered the bishop of Rome +to judge bishops with the assistance of six or seven other bishops +or, in the case of a metropolitan, of fifteen comprovincial bishops. +A bishop refusing to come to Rome was to be brought there by +the civil power. The rescript, however, was not incorporated in +the Codes and perhaps was only a temporary measure.</p> + +<p>The tendency to give pre-eminence to Rome appears again +in an imperial letter to St Flavian, who, in the judgment of the +East, was bishop of Antioch, but who was rejected by the West +and Egypt, summoning him to Rome to be there judged by the +bishops of the imperial city—a summons which St Flavian did +not obey (Tillemont, <i>Mém. Ecc.</i>). In Africa in the beginning of +the 5th century Apiarius, a priest who had been deposed by the +bishop of Sicca for immorality, and whose deposition had been +affirmed by the “provincial synod,” instead of further appealing +to a general synod of Africa, carried his appeal to Pope Zosimus. +The pope received the appeal, absolved him and restored him to +the rank of priest, and sent a bishop and two priests as legates +to Africa with instructions to them to hear the cause of Apiarius +anew and for execution of their sentence to crave the prefect’s +aid; moreover, they were to summon the bishop of Sicca to +Rome and to excommunicate him, unless he should amend +those things which the legates deemed wrong. The upshot of a +long conflict was that the papal claim to entertain appeals from +Africa by priests and deacons was rejected by the African +bishops, who in their final synodical epistle also repudiate in +terms any right of appeal by African <i>bishops</i> to “parts beyond +the seas” (see Hefele, <i>Councils</i>, bk. viii.).</p> + +<p>The story of the administrative development of the Church in +the 5th century is mainly the story of the final emergence and +constitution of the great “patriarchates,” as authorities superior +to metropolitans and provincial synods. In consequence of the +occupants of the thrones of Constantinople and Alexandria +falling successively into opposite heresies, the question arose how +“patriarchs” were to be judged. In both cases, as it seems, an +attempt was made by the bishop of Rome to depose the erring +patriarch by his authority as primate of Christendom, acting in +concert with a Western synod. In both cases, apparently, an +oecumenical synod ignored the Roman deposition and judged the +alleged offences of the respective patriarchs in first and last +instance. The third and fourth oecumenical synods (Ephesus, +431; Chalcedon, 451) were primarily tribunals for the trials of +Nestorius and Dioscorus; it was secondarily that they became +organs of the universal episcopate for the definition of the faith, +or legislative assemblies for the enactment of canons. Nothing +is more remarkable than their minute care as to observance of +rules of procedure. In both cases, imperial assessors were +appointed. At Ephesus the Count Candidian was commissioned +to maintain order, but took little part in the proceedings. At +Chalcedon, on the other hand, the imperial commissioners decided +points of order, kept the synod to the question, took the votes +and adjourned the court. But the synod alone judged and +pronounced sentence. No oecumenical synod has tried a +patriarch of Old Rome while yet in the flesh. The fifth oecumenical +council came nearest to so doing, in the case of Vigilius. +That pope, although in Constantinople, refused to attend the +sittings of the council. He was cited three times, in the canonical +manner, and upon not appearing was threatened in the third +session with anathema (Hefele, <i>Councils</i>, sect. 268 <i>ad fin.</i>). He +was not, however, charged with direct heresy, as were Nestorius +and Dioscorus, and the synod seems to have hesitated to deal +stringently with the primate of Christendom. In the seventh +session it accepted the suggestion of Justinian, merely to order +the name of Vigilius to be removed from the liturgical prayers, +at the same time expressing its desire to maintain unity with the +see of Old Rome (Hefele, sect. 273). After the council, Justinian +banished the pope to Egypt, and afterwards to an island, until +he accepted the council, which he ultimately did (<i>ib.</i> 276). The +sixth oecumenical synod decreed that the dead pope Honorius +should be “cast out from the holy Catholic Church of God” +and anathematized, a sentence approved by the reigning pope +Leo II. and affirmed by the seventh oecumenical synod in 787.</p> + +<p>The constitution of the patriarchal system resulted in the +recognition of a certain right of appeal to Rome from the larger +part of the West. Britain remained outside that jurisdiction, +the Celtic churches of the British islands, after those islands +were abandoned by the Empire, pursuing a course of their own. +In the East, Constantinople, from its principality, acquired +special administrative pre-eminence, naturally followed, as in +the case of “old Rome,” by judicial pre-eminence. An example +of this is found in the ninth canon of Chalcedon, which also +illustrates the enforcement upon a clerical plaintiff in dispute +with a brother cleric of that recourse to the arbitration of their +ecclesiastical superior already mentioned. The canon provides +that any clerk having a complaint against another clerk must +not pass by his own bishop and turn to secular tribunals, but +first lay bare his cause before him, so that by the sentence of the +bishop himself the dispute may be settled by arbitrators acceptable +to both parties. Any one acting against these provisions +shall be subject to canonical penalties. If any clerk have a +complaint against his own bishop, he shall have his cause adjudicated +upon by the synod of the province. But if a bishop +or clerk have a difference with the metropolitan of his province +let him bring it before the exarch of the “diocese” (<i>i.e.</i> the +larger district answering to the civil “diocese”), or before the +royal see of Constantinople, who shall do justice upon it. An +“exarch” means properly a superior metropolitan having several +provinces under him. In the next century Justinian (<i>Nov.</i> 123, +c. 22) put the other patriarchates on the same footing as Constantinople. +In c. 21 he gives either plaintiff or defendant an +appeal within ten days to the secular judge of the locality from +the bishop’s judgment. If there be no appeal, that judge is to +give execution to the episcopal award. The growth of a special +“original” jurisdiction at Constantinople, which perhaps +<span class="pagenum"><a name="page856" id="page856"></a>856</span> +developed earlier than the corresponding institution at Rome, +may be traced to the fact that bishops from all parts were +constantly in Constantinople. The bishop of Constantinople, +even before he became properly “patriarch,” would often +assemble a synod from these visiting bishops, which acquired +the technical name of <span class="grk" title="synodos endêmousa">σύνοδος ἐνδημοῦσα</span>, the synod of sojourners. +This synod frequently decided questions belonging to other +patriarchates.</p> + +<p>The criminal jurisdiction thus exercised was generally speaking +unlimited. It must be remembered that the <i>forum externum</i> of +the ecclesiastical jurisdiction, in the sense in which we now use +the phrase, of a judge deciding causes, was not then clearly +marked off from the <i>forum internum</i>, or what afterwards came +to be called the “tribunal of penance” (see Van Espen, <i>Jus ecc. +univ.</i> pars iii. tit. iv. c. 1). Ecclesiastical proceedings by way +of prosecution are called “criminal,” but they are primarily +<i>pro salute animae</i>; whereas temporal criminal proceedings are +primarily for the protection of the state and its citizens. Hence +a Christian might be first punished in the civil courts and then +put to public penance by the ecclesiastical jurisdiction, or vice +versa: an apparently double system of punishment which the +medieval Church, when the <i>forum externum</i> had become quite +separated from the <i>forum internum</i>, sometimes repudiated (see +Maitland, <i>English Canon Law</i>, 138, 139, 144).</p> + +<p>Theodosius began the system of giving secular authority to +Church tribunals. Thus, in 376, L. 23 <i>Cod. Theodos. de. Episcopis</i>, +&c., subjected clerics for small offences pertaining to the observances +of religion to bishops and synods. In 399, L. 1 <i>Cod. de +Religione</i> provides that, when it is a matter of religion, it beseems +the bishop to judge. A rescript of Constantius, in 355, inserted +in <i>Cod. Theod.</i> lxii. <i>de Epis. Ecc. et Cler.</i>, excluded bishops +from accusations before secular judges and commanded such +accusations to be speedily brought before the tribunal of other +bishops. This law was probably only intended to be of a +temporary character. Then comes the law of Gratian already +noticed. Then, in 399, a law of Honorius (<i>Cod. Theod.</i> L. 1 <i>de +Religione</i>): “As often as it concerns religion, it is meet that the +bishops should judge, but other causes which belong to ordinary +jurisdiction or to public law are to be heard in the ordinary courts +(<i>legibus oportet audiri</i>).” L. 3 <i>de Epis. Jud.</i>, at the end of the +Theodosian Code, seems spurious (see the comment of Gothofredus +in loco). But a constitution of Honorius in 412 (<i>Cod. +Theod.</i> L. xli. <i>de Epis. Ecc. et Cler.</i>) provides that clerks are not +to be accused except before the bishop. Bishops, priests, +deacons, and every other “minister of the Christian law” of +inferior degree, are taken from secular jurisdiction in criminal +cases. The words are quite general; but it has been contended +that they apply only to crimes of an ecclesiastical character (see +Gothofredus in loc.; Van Espen, pars iii. tit. iii. c. 1, 10). In +425 a constitution of Theodosius II. provides that a recent +decree of the usurper John should be disregarded and that clerks +whom he had brought before secular judges should be reserved +for the episcopal jurisdictions, “since it is not lawful to subject +the ministers of the divine office to the arbitrament of temporal +powers.” Justinian has a clearer perception of the demarcation +between the spheres of spiritual and temporal law. The 83rd +Novell provides that if the offence be ecclesiastical, needing +ecclesiastical correction, the bishop shall take cognizance of it. +The 123rd Novell (<i>c.</i> 21) provides that if a clerk be accused of +a secular crime he shall be accused before his bishop, who may +depose him from his office and order, and then the competent +judge may take him and deal with him according to the laws. +If the prosecutor have first brought him before the civil judge, +the evidence is to be sent to the bishop, and the latter, if he thinks +the crime has been committed, may deprive him of his office +and order, and the judge shall apply to him the proper legal +punishment. But if the bishop think the evidence insufficient, +the affair shall be referred to the emperor, by way of appeal both +from bishop and judge. If the cause be ecclesiastical, the civil +judges are to take no part in the inquiry. The law includes with +clerics, monks, deaconesses, nuns, ascetics; and the word +“clerics” covered persons in minor orders, down to doorkeepers. +It will be noticed that Justinian supposes that the prosecutor +may begin the proceedings before the civil judge. A constitution +of Alexius Comnenus I. seems to send him to the special forum of +the accused.</p> + +<p>Certain enactments of later Saxon times in England have been +sometimes spoken of as though they united together the temporal +and spiritual jurisdictions into one mixed tribunal +deriving its authority from the State. In the latter +<span class="sidenote">Anglo-Saxon courts.</span> +part of the 10th century, laws of Edgar provided that +the bishop should be at the county court and also the +alderman, and that there each of them should put in use both +God’s laws and the world’s law (Johnson’s <i>English Canons</i>, i. +411). This probably was, as Johnson suggests, that the bishop +might enforce secular laws by ecclesiastical censure and the +alderman ecclesiastical laws with secular punishment. But the +two jurisdictions were kept separate; for by another law of +Edgar (<i>Leges Edg.</i> c. v.) it was provided that “in the most +august assembly the bishop and alderman should be present, and +the one should interpret to the people the law of God, the other +the laws of men.” Edgar, in a speech to St Dunstan and the +bishops in synod (in 969), said, “I hold in my hands the sword of +Constantine, you that of Peter. Let us join right hands and +unite sword to sword” (Hardouin, <i>Conc.</i> tom. vi. p. 1, col. 675). +The juxtaposition of the judicatures may, however, have led to +some confusion between them.</p> + +<p>As to appeals the mixed council of Cliff at Hoo (747) +said they should go to the synod of the province. The only +appeal to Rome in Saxon times was that of St Wilfrid, +bishop of York, who appealed from the division of his see and +his deposition for refusing to consent to it, and was heard +in a Roman synod under the presidency of Pope Agatho. The +synod found him unlawfully deposed and ordered his restoration. +Upon his return to England, the Roman judgment was refused +recognition and he was for a time imprisoned. Ten years later he +was recalled to York, but refusing to consent to the division of his +see was again deposed and again appealed to Rome. The appeal +was heard at great length, in a synod of 703 under John VI., +deputies from the archbishop of Canterbury being present. +St Wilfrid was justified and was sent back to his see, with papal +letters to the kings of Northumbria and Mercia. The Roman +decree was again disregarded. At the council of “Nid” he was +reconciled to the other bishops of the province, but not restored. +In the end he was brought back to York, but not to the undivided +see. The details of the case will be found in Wilkins, <i>Concilia</i>, +in Mansi, <i>Concilia</i>, under the various councils named, and in +Haddan & Stubbs, <i>Councils and Eccl. Documents</i>, vol. iii.</p> + +<p>The penalties which the spiritual court could inflict, in the +period between the edict of Milan and c. 854, were properly +excommunication whether generally or as exclusion +from the sacraments for a term of months or years or +<span class="sidenote">Penalties inflicted by ecclesiastical courts.</span> +till the day of death and (in the case of clerics) suspension +or deposition. Gradually, however, doubtless by +way of commutation of excommunication and of +penance, temporal penalties were added, as scourging, banishment, +seclusion in a monastery, fines. It is difficult to say how +far some of these temporal penalties were penitential only or how +far they could be inflicted <i>in invitos</i>. But the secular arm, from +the time of Nicaea I., was in the habit of aiding spiritual decrees, +as by banishing deposed bishops, and gradually by other ways, +even with laymen. Scourging (although it had been a well-known +punishment of the synagogue) was at first forbidden. Can. 28 +(26) of the Apostolic Canons imposes deposition on any bishop, +priest or deacon striking the delinquent faithful. In Africa, +however, a contrary practice early sprang up (see St Augustine, +<i>Epist.</i> clix. <i>ad Marcellum al.</i> cxxxiii.). The small council of +Vannes in Brittany in 465 made it an alternative punishment for +clerks convicted of drunkenness (Can. 13). Canon 13 of the first +council of Orleans, which has been cited in this matter, seems to +have no application. St Gregory the Great seems to assume that +scourging and seclusion in a monastery are in the discretion of +episcopal tribunals (see <i>Epistles</i>, lib. ii. ep. 11, 40, 42, 44, 45; lib. +vii. ep. 11, 67; lib. xii. ep. 31, c. 4). The 16th council of Toledo +<span class="pagenum"><a name="page857" id="page857"></a>857</span> +(in 693) has been cited as if it visited certain very great sinners +with scourging as an ecclesiastical punishment. In fact, it only +approves the punishment as ordered by the Visigothic laws. +An alleged decree of a council of Autun in 670 is part of a code +of discipline for monasteries (see authorities cited by Hefele, +<i>Councils</i>, sect. 290, towards the end). Banishment does not +seem to have been inflicted by the spiritual court <i>in invitum</i>. +Seclusion in a monastery seems first to have been used by the +civil power in aid of the spiritual. The fifth canon of the council +of Macon, in 584, forbids clergy to dress like laymen and imposes +a penalty of thirty days’ imprisonment on bread and water; but +this may be merely penitential. There is little evidence of the +imposition of fines as ecclesiastical penalties; but there are +references to the practice in the epistles of St Gregory the Great, +notably in his instructions to St Augustine. Gregory III. copies +from St Gregory I. Probably these also were by way of penance. +Isolated examples in the early middle ages of metropolitans dealing +with their suffragan bishops by imprisonment in chains were +extra-canonical abuses, connected with the perversion of Church +law which treated the metropolitan (who originally was merely +convener of the provincial synod and its representative during the +intervals of sessions) as the feudal “lord” of his comprovincials.</p> + +<p>With the later 9th century we enter upon a new epoch, and by +the time of Gregory VII., in the 11th century, the tribunals have +fallen into the hands of a regular class of canonists who are in fact +professional church-lawyers in orders. The changes due to the +adoption of the False Decretals by Nicholas I. and the application +of their principles by Hildebrand (afterwards Gregory VII.) +are discussed in the article <span class="sc"><a href="#artlinks">Canon Law</a></span>. The later medieval +system, thus inaugurated, may be considered (1) in its hierarchy, +(2) in the subject matter of its jurisdiction, (3) in its penalties.</p> + +<p>1. (<i>a</i>) It is a system of courts. Much that had been done by +bishops, <i>sine strepitu forensi et figura judicii</i>, is now done in the +course of regular judicial procedure. Again, the court +takes the place of the synod. The diocesan synod +<span class="sidenote">Later medieval system.</span> +ceases to have judicial work. The court of the metropolitan +takes the place of the provincial synod, except +possibly for the trial of bishops, and even this becomes doubtful.</p> + +<p>(<i>b</i>) At first the bishop was the only judge in the diocesan court +and he always remains a judge. But just as the king appoints +judges to hear <i>placita coram rege ipso</i>, and the feudal lord appoints +his seneschal or steward, so the bishop appoints his official.</p> + +<p>(<i>c</i>) The archdeacon acquires a concurrent ordinary jurisdiction +with the bishop (see <span class="sc"><a href="#artlinks">Archdeacon</a></span>). For some time it was considered +that he was a mere office-holder dependent on the will of +the bishop with a jurisdiction merely “vicarial”; but by the +13th century it was settled that he held a “benefice” and that +his jurisdiction over causes was ordinary and independent of the +bishop (Van Espen, pars i. tit. xii. c. 1; Fournier, <i>Les Officialités +au moyen âge</i>, p. 134). It was partly in order to counterpoise the +power of archdeacons that bishops created officials (Fournier, +p. 8). Archdeacons in course of time created officials who presided +in court in their stead. The extent of jurisdiction of +archdeacons depended much upon local customs. In England the +custom was generally in their favour. Ordinarily, the appeal +from an archdeacon or his official lay to the court of the bishop; +but by custom the appeal might be to the court of the metropolitan: +The Constitutions of Clarendon, in 1164, made the appeal +from the court of the archdeacon lie to the court of the bishop.</p> + +<p>(<i>d</i>) The official of the bishop might be his official principal, +who was his <i>alter ego</i>, or a special officer for a particular locality +(<i>officialis foraneus</i>). The latter was treated as a mere delegate, +from whom an appeal could be made to the bishop. The former +had one consistory with the bishop, so that appeals from him +had to be made to the court of the metropolitan. How far the +official principal had jurisdiction in criminal matters by virtue +of his office, how far it was usual to add this jurisdiction by +special commission, and what were the respective limits of his +office and that of the vicar-general, are questions of some nicety. +The emphasis in Italy was on the vicar-general (<i>Sext. de officio +Vicarii</i>). In the Low Countries, France and England the +jurisdiction of the official principal was wider (Van Espen, +pars i. tit. xii. cc. 4, 5; Fournier, p. 21). But he could not try +criminal matters unless specially committed to him (Lyndwood, +<i>Provinciale</i>, lib. ii. tit. 1). Later in England it became usual +to appoint one man to the two offices and to call him chancellor, +a word perhaps borrowed from cathedral chapters, and not in use +for a diocesan officer till the time of Henry VIII. or later (see +<span class="sc"><a href="#artlinks">Chancellor</a></span>). In Ireland the title, till the church was disestablished, +was vicar-general.</p> + +<p>The importance of distinguishing the normal functions of an +official principal and a vicar-general lies in this: that it was +gradually established that as a king should not hear causes but +commit them to his judges, so a bishop should not hear causes +but appoint an official to hear them (see Ridley, <i>View of the +Civil and Eccl. Law</i>; Ayliffe, <i>Parergon juris ecclesiastici</i>, +p. 161; Godolphin, <i>Abridgement of the Laws Ecclesiastical</i>, p. 8). +The “parlements” of France were constantly insisting on the +independence and irremovability of the official (Fournier, p. 219). +But jurisdiction which was not necessarily incident to the office +of the official principal, that is to say voluntary jurisdiction, +such as the granting of licences and institution to benefices, +and criminal jurisdiction over clerks (and probably over laymen), +the bishop could reserve to himself. Reservations of this nature +are made in many English patents of chancellors and were held +good in <i>R.</i> v. <i>Tristram</i>, 1902, 1 K.B. 816.</p> + +<p>(<i>e</i>) The ecclesiastical and temporal courts are kept distinct. +The charter of William the Conqueror abrogated the laws of +Edgar. No bishop or archdeacon “shall any longer hold pleas +in the Hundred concerning episcopal law nor draw a cause +which concerns the rule of such to the judgment of men of the +world” (Stubbs, <i>Select Charters</i>, part iii.). In France, where +the bishop was a temporal baron, his feudal and his spiritual +courts were kept by distinct officers (Fournier, p. 2).</p> + +<p>(<i>f</i>) From the bishop, or his official, appeal lay to the metropolitan, +who again could hear causes by his official. The Constitutions +of Clarendon recognize this appeal (<i>c.</i> viii.).</p> + +<p>(<i>g</i>) An appeal lay from the court of the metropolitan to that +of the primate. There were many disputes as to the existence +of these primates (see Maitland, <i>Canon Law in the Church of +England</i>, p. 121). In England the dispute between Canterbury +and York was settled by making them both primates, giving +Canterbury the further honour of being primate of all England. +In France the primatial sees and the course of appeals to them +were well established (Fournier, p. 219).</p> + +<p>(<i>h</i>) Several attempts were made by metropolitans and their +officials to take causes arising in the dioceses of their comprovincials +in the first instance and not by way of appeal. The +officials of primates in their turn made similar attempts. After +long struggles this was hindered, in France by the bull <i>Romana</i> +(Fournier, p. 218), in England by the Bill of Citations, 23 Henry +VIII. c. 9, and Canon 94 of the Canons of 1603. The preamble +of the “Bill of Citations” is eloquent as to the mischief which +it is framed to prevent. There are, however, a few cases in which +the metropolitan is still allowed to cite in the first instance. +One of them was in cases of “perplexity.” “Perplexity” arose +where the suffragans “could not owing to the geographical +limitations of their competence do full justice” (Maitland, +pp. 118-119). Such was the case of probate where notable goods +of the deceased lay in more than one diocese. Hence the origin +of the “prerogative court” of Canterbury (cf. Van Espen, pars i. +tit. xix.; and for Spain, Covarruvias, <i>Pract. Quaest.</i> c. 9).</p> + +<p>(<i>i</i>) Gradually there grew up a mass of peculiar and exempt +jurisdictions (Ayliffe, pp. 417, 418; Phillimore, Eccl. Law, pp. +214, 927; de Maillane, <i>Dict. du droit canonique</i>, s.v. “Exemptions”). +Exempt jurisdictions began with the monasteries and +were matter of vehement discussion in the later middle ages. +There were no true exemptions before the 11th century (Van +Espen, pars iii. tit. xii.). Peculiar or special jurisdiction, equal +to that of the bishop, was given to deans and chapters over the +cathedral precincts and in places where they had corporate +property (see <i>Parham</i> v. <i>Templer</i>, 3 Phil. Ecc. R. 22). Sometimes +it was given to deans alone or to prebendaries in the parishes +whence they derived their prebends. Where the archdeacon +<span class="pagenum"><a name="page858" id="page858"></a>858</span> +had a jurisdiction co-ordinate with the bishop, it was called +a peculiar. The metropolitans had peculiars within the dioceses +of their comprovincials wherever they had residences or manors, +and some whose origin is uncertain, <i>e.g.</i> that of the fifteen parishes +in the deanery of the Arches. The official administering justice +for the metropolitan was usually called a dean. From a peculiar +jurisdiction ranking as episcopal the appeal lay to the court +of the metropolitan. As to metropolitan peculiars, the metropolitan +might give an appeal from the dean to his regular official +principal. Thus, in Canterbury there was an appeal from the +dean of Arches to the official principal of the Arches court. +When peculiars were abolished (<i>vide infra</i>) the dean of Arches +disappeared, and his title, in the 19th century, was erroneously +given to the official principal. On peculiars in Spain cf. Covarruvias, +<i>Works</i>, tit. i. p. 410. The French parlements, after the +middle ages, discouraged them. In exempt convents the head +of the monastery or priory exercised jurisdiction subject to +an appeal to the pope.</p> + +<p>(<i>j</i>) It is said that originally a metropolitan had only one +official principal, who, like the metropolitan himself, acted both +for the diocese and province. Fournier (p. 219) says that in +France it was not till the 17th century that there grew up a custom +of having different officials for the metropolitan, one for him as +bishop, a second as metropolitan, and even a third as primate, +with an appeal from one to the other, and that it was an abuse +due to the parlements which strove to make the official independent +of the bishop. In England there has been, for a long time, +a separate diocesan court of Canterbury held before the “commissary.” +The word is significant as showing that there was +something special and restricted about the position. In York +there are two courts, one called the consistory for the diocese, +the other called the chancery for the province. But the same +person was often official of both courts.</p> + +<p>(<i>k</i>) In England the Constitutions of Clarendon added a provision +for appeal to the king, “and if the archbishop shall have +failed in doing justice recourse is to be had in the last resort +(<i>postremo</i>) to our lord the king, that by his writ the controversy +may be ended in the court of the archbishop; because there +must be no further process without the assent of our lord the +king.” The last words were an attempt to limit further appeal +to Rome. It will be observed that the king does not hear the +cause or adjudicate upon it. He merely corrects slackness or +lack of doing justice (<i>Si archiepiscopus defecerit in justitia +exhibenda</i>) and by his writ (<i>precepto</i>) directs the controversy +to be determined in the metropolitan’s court. As bishop +Stubbs says (<i>Report of Eccl. Comm.</i> vol. i. <i>Hist. App.</i> i.): “The +appeal to the king is merely a provision for a rehearing before +the archbishop, such failure to do justice being not so much +applicable to an unfair decision as to the delays or refusal to +proceed common at that time” (cf. Joyce, <i>The Sword and the +Keys</i>, 2nd ed. pp. 19-20). The <i>recursus ad principem</i>, in some +form or other of appeal or application to the sovereign or his lay +judges, was at the end of the middle ages well known over +western Europe. This recourse in England sometimes took the +form of the appeal to the king given by the Constitutions of +Clarendon, just mentioned, and later by the acts of Henry VIII.; +sometimes that of suing for writs of <i>prohibition</i> or <i>mandamus</i>, +which were granted by the king’s judges, either to restrain excess +of jurisdiction, or to compel the spiritual judge to exercise +jurisdiction in cases where it seemed to the temporal court that +he was failing in his duty. The <i>appellatio tanquam ab abusu</i> +(<i>appel comme d’abus</i>) in France was an application of a like +nature. Such an appeal lay even in cases where there was a +refusal to exercise voluntary jurisdiction (de Maillane, <i>Dictionnaire +du droit canonique</i>, tit. “Abus,” cf. tit. “Appel”). This writer +traces their origin to the 14th century; but the procedure does +not seem to have become regularized or common till the reigns +of Louis XII. or Francis I. (cf. <i>Dict. eccl.</i>, Paris, 1765, titt. “Abus” +and “Appel comme d’abus”). On the <i>recursus ad principem</i> and +the practice of “cassation” in Belgium, Germany and Spain, +cf. Van Espen’s treatise under this title (<i>Works</i>, vol. iv.) and +<i>Jus eccles. univ.</i> pars iii. tit. x. c. 4. Louis XIV. forbad +the parlements to give judgment themselves in causes upon an +<i>appel comme d’abus</i>. They had to declare the proceedings null +and abusive and command the court Christian to render right +judgment (Edict of 1695, arts. 34, 36, cited in Gaudry, <i>Traité +de la législation des cultes</i>, Paris, 1854, tom. i. pp. 368, 369).</p> + +<p>In Catalonia “Pragmatics,” letters from the prince, issued +to restrain jurisdiction assumed by ecclesiastical judges contrary +to the customs of the principality. Thus in 1368 Peter III. +evoked to the royal court a prosecution for abduction pending +before the archbishop of Tarragona, declaring that the archbishop +and the official were incompetent to judge noblemen. +See this and other instances collected in <i>Usages y demas derechos +de Cataluña</i>, by Vives y Cebriá (Barcelona, 1835), tom. iv. p. 137 +et seq.</p> + +<p>(<i>l</i>) Lastly there was the appeal to the patriarchs, <i>i.e.</i> in the +West to Rome. The distinguishing feature of this appeal was +that the rule of the other appeals did not apply to it. In the +regular course of those appeals an appellant could not leap the +intermediate stages; but he could at any stage go to this final +appeal, <i>omisso medio</i>, as it was technically called (see <i>de appell. +c. Dilect.</i> iii. for general rule, and c. 3 <i>de appell.</i> in 6 for different +rule in case of the pope, and authorities cited in Van Espen, +pars iii, tit. x. c. 2, 5). Van Espen says: “The whole right of +appeal to the Roman pontiff <i>omisso medio</i> had undoubtedly +its origin in this principle, that the Roman pontiff is ordinary of +ordinaries, or, in other words, has immediate episcopal authority +in all particular churches, and this principle had its own beginning +from the False Decretals.”</p> + +<p>Appeals to Rome lay from interlocutory as well as final +judgments. Causes could even be evoked to Rome before any +judgment and there heard in first instance (Van Espen, pars iii. +tit. x. c. 1, 8).</p> + +<p>There was an alleged original jurisdiction of the pope, which +he exercised sometimes by permanent legates, whom Gregory +VII. and his successors established in the chief countries of +Europe, and to whom were committed the legislative executive +and judicial powers of the spiritual “prince” in the districts +assigned to them. These Clement IV. likened to “pro-consuls” +and declared to have “ordinary” jurisdiction; because they +had jurisdiction over every kind of cause, without any special +delegation, in a certain defined area or province (c. ii. <i>de +Officio Legati</i> in 6). They were expressed to have not merely +appellate but original jurisdiction over causes (iii. c. i. <i>de Officio +Legati</i>). The occupants of certain sees by a kind of prescription +became legates without special appointment, <i>legati nati</i>, as in +the case of Canterbury. In the 13th century Archbishop Peckham, +says Maitland (p. 117), as archbishop “asserted for himself +and his official (1) a general right to entertain in the first instance +complaints made against his suffragans’ subjects, and (2) a +general right to hear appeals <i>omisso medio</i>.” It was, for the +time, determined that the archbishop might himself, in virtue +of his legatine authority, entertain complaints from other +dioceses in first instance, but that this legatine jurisdiction was +not included in the ordinary jurisdiction of his official principal, +even if the archbishop had so willed it in his commission. In +fact, however, the official did before the end of the later medieval +period get the same power as the archbishop (Maitland, pp. 118-120; +cf. Lyndwood, lib. v. tit. 1), till it was taken from him +by the Bill of Citations.</p> + +<p>After legates came special delegates appointed by the pope +to hear a particular cause. It was the general practice to appoint +two or three to sit together (Van Espen, pars iii. tit. v. c. 2, 37). +These might sub-delegate the whole cause or any part of it as +they pleased, <i>ibid.</i> 9-18. Dr Maitland (essay on “The Universal +Ordinary”) thinks, but without very much foundation, that great +numbers especially of the more important causes were tried +before these delegates; although the records have largely perished, +since they were the records of courts which were dissolved as soon +as their single cause had been decided. These courts were convenient, +since it was the custom to appoint delegates resident +in the neighbourhood, and the power of sub-delegation, general +or limited, simplified questions of distance. In Belgium causes +<span class="pagenum"><a name="page859" id="page859"></a>859</span> +appealed to Rome had to be committed to local delegates (Van +Espen, pars iii. tit. v. c. 3, tit. x. c. 2).</p> + +<p>There could be an appeal from these delegates to the pope and +from the pope himself to the pope “better informed” (Van +Espen, pars iii. tit. x. c. 2, 12, 13). So personal had the +system of jurisdiction become that even the trials of bishops +ceased to be necessarily conciliar. Generally they were reserved +to the pope (Van Espen, pars iii. tit. iii. c. 5, 17-19); but in +England the archbishop, either in synod, or with some of his +comprovincial bishops concurring, tried and deposed bishops +(see case of Bishop Peacock and the other cases cited in <i>Read</i> +v. <i>Bishop of Lincoln</i>, 14 P.D. 148, and Phillimore, <i>Eccl. Law</i>, +pp. 66 et seq.).</p> + +<p>(<i>m</i>) The jurisdiction of a bishop <i>sede vacante</i> passed, by general +law, to the dean and chapter; but in England the metropolitans +became “guardians” of the spiritualities and exercised original +jurisdiction through the vacant diocese (Phillimore, pp. 62-63), +except in the case of Durham, and with a peculiar arrangement +as to Lincoln.</p> + +<p>If the metropolitan see were vacant the jurisdiction was +exercised by the dean and chapter through an official (Rothery, +<i>Return of Cases before Delegates</i>, Nos. 4, 5). As to France see +Fournier, p. 294.</p> + +<p>(<i>n</i>) Officials, even of bishops and metropolitans, need not be +in holy orders, though Bishop Stubbs in his paper in the <i>Report +of the Commission on Ecclesiastical Courts</i> seems to say so. +They had to be clerics, that is, to have received the tonsure. +Even papal delegates might be simple clerks (Van Espen, pars +iii. tit. v. c. 2, 20).</p> + +<p>It came, however, to be the practice to impose some restrictions, +as on clerks twice married. Thus Archbishop Chichele provided +that no clerk married or bigamous (that is, having had two wives +in succession) should exercise spiritual jurisdiction (see Lyndwood, +lib. iii. tit. 3). Abroad unsuccessful attempts were made by +local councils to enact that officials and vicars-general should +be in holy orders (Hefele on Councils of Tortosa in 1429 and +Sixth of Milan in 1582). These councils, as will be seen, are late.</p> + +<p>(<i>o</i>) With or without the concurrence and goodwill of the +national Church, restrictions were imposed by the State on the +papal jurisdiction, whether original or appellate. In England +the Constitutions of Clarendon (by chap. viii.) prohibited appeals +to the pope; but after the murder of St Thomas of Canterbury +Henry II. had to promise not to enforce them. The statutes 38 +Edw. III. st. 2, 13 Rich. II. st. 2, c. 2, and 16 Rich. II. c. 5 forbid +such appeals; but it is suggested that notwithstanding the +generality of their language they refer only to cases of temporal +cognizance. Cases upon the execution of these statutes are +collected in Stillingfleet, <i>On Ecclesiastical Jurisdiction</i>, p. 189; +Gibson, <i>Codex</i>, 83. Obstacles were placed in the way of appeals +to the pope <i>omisso medio</i>. Thus when a writ of <i>significavit</i> +issued on the mandate of a bishop, an appeal to Rome availed +not to stay execution; but if there were an appeal to the archbishop +it was otherwise. It therefore became the custom to +lodge a double appeal: one to the archbishop “for defence,” +and the other to the pope as the real appeal (“Hostiensis,” +<i>Super Decret.</i> ii. fol. 169; cf. Owen, <i>Institutes of Canon Law</i>, +1884, pt. i. c. 19, 5).</p> + +<p>There seems to have been no machinery for assisting the +original or appellate jurisdiction of the pope by secular process,—by +<i>significavit</i> or otherwise.</p> + +<p>The matrimonial cause between Henry VIII. and Catharine of +Aragon was the most famous English cause tried by delegates +under the “original” jurisdiction of the pope, and was ultimately +“evoked” to Rome. The foreseen adverse termination of this +long-drawn cause led to Henry’s legislation.</p> + +<p>When the temporal courts interfered to prevent excess of +jurisdiction, they did so by prohibiting the ecclesiastical court +from trying and the suitor from suing in that court. The pope +could not be effectively prohibited, and no instance is recorded +of a prohibition to papal delegates. But suitors have been +prohibited from appealing to the pope (see per Willes, J., in <i>Mayor +of London</i> v. <i>Cox</i>, L.R. 2 H.L. 280). Whatever may have been +the law, it is certain that, notwithstanding the statutes of Edw. +III. and Rich. II., appeals to Rome and original trials by papal +delegates did go on, perhaps with the king’s licence; for the +statute 24 Hen. VIII. c. 12 recites that the hearing of appeals was +an usurpation by the pope and a grievous abuse, and proceeds +to take away the appeal in matrimonial, testamentary and tithe +causes, and to hinder by forbidding citation and process from +Rome, all original hearings also. The statute 25 Hen. VIII. c. 19 +follows this up by taking away appeals in all other subjects of +ecclesiastical jurisdiction.</p> + +<p>In 1438 the council of Basel took away all papal original +jurisdiction (save in certain reserved cases—of which <i>infra</i>), +evocation of causes to Rome, appeals to Rome <i>omisso medio</i>, and +appeals to Rome altogether in many causes. Such appeals when +permissible, except the “greater,” were to be tried by delegates +on the spot (31st Session; Mansi, <i>Concilia, in loco</i>). These +proceedings at Basel were regarded at Rome as of no effect. +Nevertheless this decree and others were adopted by a French +national council at Bourges and promulgated by the king as a +“Pragmatic Sanction” (Migne, <i>Dict. du droit canonique</i>, +“Pragmatique Sanction”). The parlements registered the +Sanction and the effect was permanent in France. Louis XI. +and Charles VIII. sought to revoke it; but both parlements +and states-general refused to recognize the revoking decrees. +In 1499 Louis XII. ordered the Pragmatic to be inviolably +observed. The parlements thereupon condemned several private +persons for obtaining bulls from Rome. In 1516 a Concordat +between Leo X. and Francis I. settled all these questions in the +sense of the Pragmatic, substantially according to the Basel +canon. All causes, except the “greater,” were to be terminated +in the country where the proper cognizance would lie (Migne, +<i>op. cit.</i> “Concordat”). By this Concordat, by an ordinance of +Francis I. in 1539, by two or three other royal edicts, and (above +all) by the practice of the parlements, explanatory of this legislation, +and their <i>arrêts</i>, the conflict of secular and ecclesiastical +jurisdictions was settled until the Revolution (Migne, <i>ubi sup.</i>). +“Greater causes” came in France to be restricted to criminal +prosecutions of bishops. Even in these the original jurisdiction +of the pope was taken away. In first instance they were tried +by the provincial synod. Thence there was appeal to the pope +(de Maillane, <i>op. cit.</i> <i>s.v.</i> “Causes majeures”; <i>Dict. eccl.</i>, Paris, +1765, <i>s.v.</i> “Cause”). The only original jurisdiction left to the +pope was in the case of the matrimonial causes of princes. But +they could only be heard on the spot by judges delegate. +Examples are the causes of Louis XII. and Jeanne of France in +1498, and of Henry IV. and Marguerite of Valois in 1599 (Migne, +<i>op. cit.</i> <i>s.v.</i> “Causes”). The prohibition of papal interference +was enforced if necessary by the <i>appel comme d’abus</i> (<i>vide supra</i>). +Out of respect for the pope this appeal was not brought against +his decrees but against their execution (<i>Dict. eccl.</i>, Paris, 1765, +<i>s.v.</i> “Abus”).</p> + +<p>Spain appears to have permitted and recognized appeals to +the pope. A royal writ of the 16th century cited by Covarruvias +(c. xxxv.) prohibits execution of the sentence of a Spanish court +Christian pending an appeal to the pope.</p> + +<p>2. The subject matter over which the ecclesiastical courts had +jurisdiction was no longer purely “criminal” with a civil quasi-jurisdiction +by way of arbitration. In the later middle +ages these courts had jurisdiction over most questions, +<span class="sidenote">Civil jurisdiction.</span> +except indeed the then most important ones, those +relating to real property. This civil jurisdiction was +sometimes concurrent with that of the secular courts, sometimes +exclusive. For England it may be thus classified:—</p> + +<p>(<i>a</i>) <i>Matrimonial.</i>—This arose naturally from the sacred +character of Christian marriage. This jurisdiction was exclusive. +From it followed the right of the courts Christian to pronounce +upon questions of legitimacy. Upon this right an inroad was +early made, in consequence of the question of legitimation by +subsequent marriage. In the 12th century the Church’s rule, +that subsequent marriage did legitimize previous issue, was +settled (c. 6, x. 4, 17). The king’s judges then began to ask the +ordinary the specific question whether A. B. was born before +<span class="pagenum"><a name="page860" id="page860"></a>860</span> +or after his parents’ marriage. After the inconclusive proceedings +at the realm-council of Merton (1236), when spiritual and +temporal lords took opposite views, the king’s judges went a step +further and thenceforward submitted this particular question +to a jury. All other questions of legitimacy arising in the +king’s courts were still sent for trial to the bishop and concluded +by his certificate (see Pollock and Maitland, <i>Hist. Eng. Law +before Edward I.</i> vol. i. 105-106; Maitland, <i>ubi supra</i>, pp. +53-56).</p> + +<p>(<i>b</i>) <i>Testamentary and in regard to succession from intestates.</i>—Real +property was not the subject of will or testament in the +medieval period. But as to personal property, the jurisdiction +of the courts Christian became exclusive in England. The +Church, East and West, had long asserted a right to supervise +those legacies which were devoted to pious uses, a right recognized +by Justinian (<i>Cod.</i> i. 3. 46). The bishop or, failing him, the +metropolitan, was to see such legacies properly paid and applied +and might appoint persons to administer the funds (Pollock and +Maitland, <i>op. cit.</i> ii. 330). This right and duty became a jurisdiction +in all testamentary causes. Intestacy was regarded with +the greatest horror, because of the danger to the intestate’s soul +from a death without a fitting part given to pious uses (Maine, +<i>Ancient Law</i>, ed. 1906, note by Pollock, p. 230; cf. Pollock and +Maitland, <i>op. cit.</i> ii. 354). Hence came the jurisdiction of the +ordinary in intestacy, for the peace of the soul of the departed. +This head of ecclesiastical jurisdiction was in England not +transferred to the secular court till 1857.</p> + +<p>(<i>c</i>) <i>Church Lands.</i>—If undoubtedly held in <i>frankalmoign</i> or +“free alms,” by a “spiritual” tenure only, the claim of jurisdiction +for the ecclesiastical <i>forum</i> seems to have been at first +conceded. But the Constitutions of Clarendon (c. 9) reserved +the preliminary question, of “frankalmoign” or not, for a jury +in the king’s court. Then, if the tenure were found free alms, +the plea was to be heard in the court Christian. From the 13th +century, however, inclusive, the king’s courts insisted on their +exclusive jurisdiction in regard to all realty, temporal or +“spiritual” (Pollock and Maitland, <i>op. cit.</i> i. 106).</p> + +<p>(<i>d</i>) <i>Title to present to and possession of benefices.</i>—As to the +title to present to benefices, the courts Christian at one time had +concurrent jurisdiction with the temporal courts. “Advowsons” +were, however, looked upon as a species of “real” property in +England, and therefore the king’s court early claimed exclusive +jurisdiction in disputes where the title to present was involved. +The Constitutions of Clarendon provided that these causes should +be heard only in the king’s court (c. 1). This rule was applied +even where both litigants were “spiritual.” In the 13th century +abbots sue each other in the royal court for advowsons (Selden +Soc. <i>Select Civil Pleas</i>, i. pl. 245). In 1231, in such a suit, the +bishop of London accepts wager of battle (Pollock and Maitland, +<i>op. cit.</i> i. 105). In cases, however, where the title to present was +not in question, but the fitness of the clerk presented, or, in +cases of election to benefices, the validity of the election, there +was jurisdiction in the courts Christian.</p> + +<p>(<i>e</i>) <i>The recovery of tithes and church dues,</i> including in +England church rates levied to repair or improve churches and +churchyards.</p> + +<p>(<i>f</i>) Questions concerning <i>fabrics, ornaments, ritual and ceremonial</i> +of churches.</p> + +<p>(<i>g</i>) <i>Administration of pious gifts and revenues given to prelates +or convents.</i>—Their right application could be effectively enforced +only in the courts Christian; until the rise in England of the +equitable jurisdiction of the court of chancery and the development +of the doctrine of “uses” at the end of the middle +ages.</p> + +<p>(<i>h</i>) <i>Enforcement of contractual promises made by oath or pledge +of faith.</i>—The breaking of such a promissory oath was called +“perjury” (as in classical Latin and in Shakespeare), contrary +to modern usage which confines the word to false evidence +before a court of justice. In regard to the execution of these +promises, the jurisdiction of the ecclesiastical courts was possibly +traversed by c. 15 of the Constitutions of Clarendon; but +allowed by the statute 13 Edw. I. st. 4. As just intimated, +besides the enforcement of the promise, the “perjury” was +treated as an ecclesiastical crime.</p> + +<p>The <i>criminal jurisdiction of courts Christian over laymen</i> +included, besides these “perjuries,” (<i>a</i>) all <i>sexual offences</i> not +punishable on indictment; (<i>b</i>) <i>Defamation of character</i> (the +king’s courts came in time to limit this to such defamation as +could not be made the subject of a temporal action); (<i>c</i>) <i>Offences +by laymen against clerks</i> (<i>i.e.</i> against all “tonsured” persons, +supra); (<i>d</i>) <i>Offences in regard to holy places</i>—“brawling” and +such like; (<i>e</i>) <i>Heresy, schism, apostasy, witchcraft</i>.</p> + +<p>In regard to “clerks,” there was (1) all the criminal jurisdiction +which existed over laymen, and (2) criminal jurisdiction +in regard to professional misconduct. Concerning “felonious” +clerks the great questions discussed were whether the courts +Christian had exclusive jurisdiction or the king’s court, or +whether there was a concurrent jurisdiction. The subject was +dealt with in the Constitutions of Clarendon, formally revoked +after the murder of St Thomas of Canterbury. In the 13th +century it was recognized that a “clerk” for felony was subject +only to ecclesiastical trial and punishment; punishment which +might involve lifelong imprisonment. For “misdemeanours,” +as yet unimportant, he had no exemption from secular jurisdiction +(Pollock and Maitland, <i>op. cit.</i> ch. iv.). At some indeterminate +later period, the “clerk” was tried for felony by a jury +in the king’s court and then “pleaded his clergy,” after conviction +there, and was remitted to the ordinary for ecclesiastical punishment. +“Clerks” for the purpose of “benefit of clergy” included +not only persons in minor orders, but all “religious” persons, +<i>i.e.</i> monks, friars, nuns, &c. Later the custom arose of taking +“clerk” to include any “literate,” even if not in orders or +“religious” (cf. Stephen, <i>Hist. Crim. Law</i>, i. 461). The statute +4 Hen. VII. c. 13 took away benefit of clergy, if claimed a +second time, from persons not “within orders,” in certain bad +cases. 4 Hen. VIII. c. 2 (a temporary act) took away “clergy,” +in certain heinous crimes, from all persons not in “holy” +orders. This statute was partly renewed by 22 Hen. VIII. +c. 13. Other changes were introduced by 23 Hen. VIII. c. 1 +and later acts. In time, “benefit of clergy” became entirely +diverted from its original objects.</p> + +<p>In <i>France</i>, till 1329, there seems to have been no clear line of +demarcation between secular and ecclesiastical jurisdictions. +Beaumanoir (<i>Coutume de Baulvoisis</i>, ch. xi., cited Gaudry, +<i>op. cit.</i> i. 22) had laid down the principle that spiritual justice +should meddle only with spiritual things. In the year named +the secular courts complained to the king, Philip of Valois, of +the encroachments of the courts Christian. The “cause” was +solemnly argued before that monarch, who decided to leave +things as they were (Migne, <i>Dict. du droit canon.</i>, <i>s.v.</i> “Officialités”). +In 1371 Charles V. forbade spiritual courts to take +cognizance of “real” and “possessory” actions even in regard +to clerks (Migne, <i>loc. cit.</i>; cf. Gaudry, <i>ubi sup.</i>). From this +period the parlements began the procedure which, after the +Pragmatic Sanction of Charles VII., in 1438 took regular shape +as the <i>appel comme d’ abus</i> (<i>supra</i>; Migne, <i>loc. cit.</i>). Testamentary +causes at first were subject to the concurrent jurisdiction of the +spiritual and secular courts. After the 14th century, the latter +had exclusive jurisdiction (Van Espen, <i>op. cit.</i> lib. iii. tit. ii. +cc. 2, 15, 16). In regard to <i>marriage</i> the secular jurists distinguished +between the civil contract and the sacrament, for +purposes of separating the jurisdiction (<i>Dict. eccl.</i>, Paris, 1765, +<i>s.v.</i> “Mariage”). The voluntary jurisdiction as regards dispensations +was kept for the Church. The contentious jurisdiction +of the courts Christian was confined to promises of marriage, +nullity of marriage caused by “diriment” impediments only, +validity or invalidity of the sacrament, divorce <i>a thoro</i> (<i>ibid.</i>). +Questions in regard to the <i>property in a benefice</i> were for the +courts Christian; in regard to its <i>possession</i>, for the king’s +courts. But if a “possessory” action had been brought in the +latter, a subsequent suit in the courts spiritual for the property +was deemed “abusive” and restrained (<i>ib., s.v.</i> “Pétitoire”) +<i>Breach of faith or of promise confirmed by oath</i> was matter for +the court Christian (Fournier, pp. 95, 99, 109, 125). This +<span class="pagenum"><a name="page861" id="page861"></a>861</span> +branch of jurisdiction was larger and more freely used than in +England (cf. Pollock and Maitland, <i>op. cit.</i>, as to Normandy). +The only other remaining civil jurisdiction of the ecclesiastical +courts was in <i>personal actions where clerks were defendants</i> (Migne, +<i>op. cit.</i>, <i>s.v.</i> “Officialités,” Fournier, pp. 65-125); or, after +the 14th century, where both parties were clerks. In regard to +crimes delicts (<i>délits</i>) were divided into classes for purposes of +jurisdiction. Clerks were punishable only in the court Christian, +except in cases of grave crimes such as murder, mutilation +(Fournier, p. 72), and cases called “royal cases” (<i>vide infra</i>). +Laymen were punishable in the court Christian for the <i>délits</i> +following: injury to sacred or religious places, sacrilege, heresy +(except where it was a “royal case”), sorcery, magic, blasphemy +(also punishable in the secular court), adultery, simony, usury +and infractions of the truce of God (Fournier, pp. 90-93). What +were called “privileged delicts” were judged in the case of the +clergy conjointly by the spiritual judge and the king’s judge. +Bishops had no exemption (<i>Dict. ecc.</i>, <i>s.v.</i> “Délits,” “Cas +privilégié,” “Causes majeures”). “Royal cases” included +such crimes as touched the prince, as all forms of treason; or +the dignity of his officers; or the public safety. In this class +were also included such heresies as troubled the state, as by +forbidden assemblies, or by teaching prohibited doctrine. +Among these heresies were reckoned idolatry, atheism, Protestantism, +relapse (<i>ib. et</i> “Cas royaux,” “Hérésie”). These +were of exclusive royal jurisdiction as against both spiritual +courts and the courts of feudal lords. A similar claim was made +by Pombal for Portugal (<i>vide infra</i>).</p> + +<p>The parlements, in order to have a ready means of enforcing +all these restrictions by <i>appel comme d’abus</i>, compelled the +bishops to appoint officials, Frenchmen, graduates, and (as it +seems) “seculars” (<i>Dict. eccl.</i>, Paris, 1765, <i>s.v.</i> “Official”). +This last qualification was disputed (see Fevret, <i>Traité de l’abus</i>).</p> + +<p>3. <i>Punishments.</i>—Ecclesiastical sanctions were divided into +<i>punishments</i> (<i>poenae</i>), either purely temporal in character or else +of a mixed spiritual and temporal character, and <i>censures</i> (<i>censurae</i>), +purely spiritual and remedial (see Van Espen, pars iii. +tit. xl. cc. 1, 3; Phillimore, <i>Ecclesiastical Law</i>, p. 1064). In the +book last cited <i>censurae</i> and <i>poenae</i> are classed together as +“censures” (which is the modern use).</p> + +<p><i>Poenae.</i>—(<i>a</i>) Fines sprang from the older custom of directing +alms by way of penance in the internal forum (Van Espen, +<i>ubi sup.</i> c. 1, 5-10). They were to be applied to pious uses. +(<i>b</i>) <i>Reclusion in a monastery</i> continued from former period, +and might be either temporary or perpetual (<i>loc. cit.</i> 17-19). +(<i>c</i>) <i>Imprisonment</i>, in the bishop’s prison, might be in chains, or +on bread and water, and temporary or perpetual. In its severer +forms it was only inflicted for more atrocious crimes which the +secular law would have punished with death (<i>loc. cit.</i> 21-27). +The act 23 Henry VIII. c. 11 made special provision for convicted +clerks who broke out of the prisons of the ordinary. (<i>d</i>) <i>Fustigation</i>, +as in former period, was hardly an ecclesiastical punishment. +If given, it was to be of a paternal character (<i>loc. cit.</i> 39-45). +Punishments of a mixed nature were: (<i>e</i>) <i>Suspension</i> either +from office alone or from office and benefice; (<i>f</i>) <i>Deprivation</i> of +benefice; (<i>g</i>) <i>Deposition</i> or <i>Degradation</i> (a more solemn and +ceremonial form) from the ministry; (<i>h</i>) <i>Irregularity</i>—not always +a punishment—a state of incapacity to be ordained, or, being +ordained, to execute the ministry; this might result from some +defect of mind and body, but was also incurred by some grave +offences.</p> + +<p><i>Censures</i> were as follows: (<i>i</i>) <i>Suspension</i> from attending +divine offices or <i>ab ingressu ecclesiae</i>, more appropriate for a +layman. A clerk in like case might be suspended from office. +(<i>j</i>) <i>Interdict</i> was another form of partial or total suspension from +the benefit of the rites and sacraments of the Church. An interdict +might be personal or local (see <span class="sc"><a href="#artlinks">Interdict</a></span>). (<i>k</i>) <i>Excommunication</i> +was either greater or less. The greater separated +entirely from the Church. It might be pronounced under +anathema. The less deprived of participation in the sacraments, +and made a clerk incapable of taking a benefice.</p> + +<p>On the European continent the courts Christian often carried +out their decrees by their own apparitors who could levy pecuniary +penalties on a defendant’s goods (Van Espen, pars iii. tit. ix. +c. 4). They could arrest and imprison. In England, except in +the peculiar case of imprisonment pending trial for heresy, or in +the case of a clerk convicted of crime, these things could not be. +The sentence of the court Christian had in all other cases to be +enforced by the secular arm. Early in Henry II.’s time it had +become the custom of England for the court Christian to “signify” +its sentence of excommunication to the king and to demand from +him a writ of <i>significavit</i> to the sheriff, to imprison the person +excommunicated. The writ apparently issued for no court +inferior to the bishop’s, unless upon the bishop’s request. In +some sense the king’s writ of <i>significavit</i> was discretionary; but +its issue could be enforced by excommunication or interdict.</p> + +<p>In the cases of heresy, apostasy and sorcery, the spiritual +courts sought the aid of the secular jurisdiction to superadd the +punishment of death. Incorrigible offenders on these matters +were “left” to the secular power, to be corrected with due +“animadversion.” This provision of the fourth Lateran Council +in 1215 was always interpreted to mean death (see Van Espen, +<i>Observ. in Conc. Lat. IV. Canones</i>, and the decree in the <i>Sext. ut +inquisitionis negotium</i>; and, as to English law and practice, +Maitland, <i>op. cit.</i>, Essay vi., and pp. 161, 176; 2 Hen. IV. c. 15; +Fitzherbert, <i>Natura brevium</i>, 269; 2 Hen. V. st. 1, c. 7). The +“capital” punishment was generally (always in England) by +burning. Burning was an English punishment for some secular +offences.</p> + +<p>The Concordat with Francis I. by which the pope gave up the +right of hearing appeals from France was not many years before +the legislation of Henry VIII. in England. Both monarchs +proceeded on the same lines; but Francis I. got the pope’s consent: +Henry VIII. acted <i>in invitum</i>, and in time went rather +further.</p> + +<p>The Statute of Appeals (24 Hen. VIII. c. 12) takes away +appeals to Rome in causes testamentary and matrimonial and in +regard to right of tithes, oblations and obventions. +A final appeal is given to the archbishop of the particular +<span class="sidenote">Ecclesiastical jurisdiction in England.</span> +province; but in causes touching the king +a final appeal is given to the Upper House of Convocation +of the province. The statute is aimed at appeals; +but the words used in it concerning “citations and all other +processes” are wide enough to take away also the “original” +jurisdiction of the pope. No appeal was yet given to the crown. +Canterbury, York, Armagh, Dublin, Cashel and Tuam are put +in the place of Rome. The English and Irish provinces are +treated as self-contained. All ends there.</p> + +<p>The “Act of Submission of the Clergy” (25 Hen. VIII. c. 19) +took away <i>all</i> appeals to Rome and gave a further appeal, “for +lack of justice,” from the several courts of the archbishops to the +king in chancery. Thence a commission was to issue to persons +named therein to determine the appeal definitely. This was +copied from the then existent practice in admiralty appeals and +was the origin of the so-called court of delegates. It is a moot +question whether this statute took away the appeal to the Upper +Houses of the various convocations in causes wherein the king +was concerned (see <i>Gorham</i> v. <i>Bishop of Exeter</i>, 15 Q.B. 52; <i>Ex +parte Bishop of Exeter</i>, 10 C.B. 102; <i>Re Gorham</i> v. <i>Bishop of +Exeter</i>, 5 Exch. 630). 37 Hen. VIII. c. 17 provided that married +laymen might be judges of the courts Christian if they were +doctors of civil law, created in any university. This qualification +even was considered unnecessary in Charles I.’s time (<i>Cro. +Car.</i> 258). Canon 127 of 1603 provided that the judges must be +learned in the civil and ecclesiastical laws and at least masters +of arts or bachelors of laws. Canon Law as a study had been +practically prohibited at the universities since 1536 (Merriman, +<i>Thomas Cromwell</i>, i. 142-143; <i>Cal. State Papers</i>, vol. ix. p. xxix. +117; Owen, <i>Institutes of Canon Law</i>, viii.). The substitution +of “civilians,” rather than common lawyers, for canonists +(civilians, hitherto, not an important body in England) had +important consequences (see Maitland, <i>op. cit.</i> 92 et seq.).</p> + +<p>Henry VIII. had exercised his jurisdiction as Supreme +Head through a vicar-general. Edward VI. exercised original +<span class="pagenum"><a name="page862" id="page862"></a>862</span> +jurisdiction in spiritual causes by delegated commissions (see +Archdeacon Hale, <i>Precedents in Criminal Cases</i>, p. xlviii.). Unless +the king was to be regarded as an ecclesiastical person, they were +not properly ecclesiastical courts; although spiritual persons +might sit in them, for they sat only as royal commissioners. The +same point has been taken by large bodies of clergy and laity in +regard to the court of final appeal created by 25 Hen. VIII. c. 19 +and its present successor the judicial committee of Privy Council +(<i>infra: Rep. Com. Ecc. Discipline</i>, pp. 9, 94 et seq.). At any rate +the “original” jurisdiction claimed for the monarch personally +and his delegates, under Henry VIII. and Edward VI., has not +permanently remained. In theory, Hooker’s contentions have +been conceded that “kings cannot in their own proper persons +decide questions about matters of faith and Christian religion” +and that “they have not ordinary spiritual power” (<i>Ecc. Pol.</i> +vii. 8, 1, 6; cf. <i>XXXIX. Articles</i>, Art. 37).</p> + +<p>Under Henry VIII. a system began of making certain crimes, +which previously had been only of spiritual cognizance, felonies +(25 Hen. VIII. c. 6), excluding thereby spiritual jurisdiction +(Stephen, <i>Hist. Crim. Law</i>, ii. 429). Bigamy (in its modern +sense) was thus made felony (1 Jac. I. c. 11). In this reign and +the next, temporal courts were sometimes given jurisdiction +over purely spiritual offences. A trace of this remains in 1 Edw. +VI. c. 1 (still on the statute book; Stephen, <i>Hist. Crim. Law</i>, +ii. 439). Other traces occur in the Acts of Uniformity, which +make offences of depraving the Book of Common Prayer triable +at Assizes (between 23 Eliz. c. 1 and 7 & 8 Vict. c. 102—also at +Sessions) as well as in the courts Christian.</p> + +<p>During Edward VI.’s time the courts Christian seem practically +to have ceased to exercise criminal jurisdiction (Hale, <i>Precedents +in Criminal Cases</i>, p. xlix.). But they sat again for this purpose +under Mary and Elizabeth and (save between 1640 and 1661) +continued regular criminal sessions till towards the end of the +17th century as continuously and constantly as the king’s courts +(<i>op. cit.</i>).</p> + +<p>The “ordinary” ecclesiastical tribunals of the later middle +ages still subsist in England, at least as regards the laity. This +is hardly the case elsewhere in the Western Church, though some +exceptions are noted below. Nevertheless, their exercise of +criminal jurisdiction over the laity is now in practice suspended; +although in law it subsists (see Stephen, <i>Hist. Crim. Law</i>; <i>Ray</i> v. +<i>Sherwood</i>, 1 Curt. R. 193; 1 Moore P.C.R. 363; the observations +of Kelly, C.B., in <i>Mordaunt</i> v. <i>Moncrieffe</i>, L.R. 2 Sc. & Div. 381, +and of Lord Coleridge in <i>Martin</i> v. <i>Mackonochie</i>, L.R. 4 Q.B.D. +770, and, on the other hand, of Lord Penzance in <i>Phillimore</i> v. +<i>Machon</i>, L.R. 1 P.D. 480). Theoretically still, in cases of sexual +immorality, penance may be imposed. Monitions to amend +may be decreed and be enforced by <i>significavit</i> and writ <i>de contumace +capiendo</i>, or by excommunication with imprisonment not +to exceed six months (53 Geo. III. c. 127). The tribunals thus +subsisting are the courts of the bishop and archbishop, the latter +sometimes called the court of appeal of the province. Peculiar +jurisdictions have been gradually taken away under the operation +of the acts establishing the ecclesiastical commissioners. The +appeal given to delegates appointed by the crown has been +transferred, first by 2 & 3 Will. IV. c. 92 to the privy council, +and then by 3 & 4 Will. IV. c. 41 to the judicial committee of +the privy council. Bishops may now be summoned as assessors +by 39 & 40 Vict. c. 59.</p> + +<p>There was in the time of Elizabeth, James I. and Charles I. +a “Court of High Commission” with jurisdiction over laity +and clergy, based on 1 Eliz. c. i. s. 15, which was reckoned as an +ecclesiastical judicature (5 R. 1, <i>Cawdrey’s case</i>) concurrent with +the ordinary court Christian. It was created by virtue of the +royal supremacy, and was taken away by 16 Car. I. c. 11. As +to its history see Stephen, <i>Hist. Crim. Law</i>, ii. 414-428.</p> + +<p>In regard to clerical offences, 3 & 4 Vict. c. 86 (the “Church +Discipline Act”) creates new tribunals; and first a commission +of inquiry appointed by the bishop of five persons, of whom the +vicar-general, or an archdeacon, or a rural dean of the diocese +must be one. If they report a <i>prima facie</i> case, the bishop may +(with the consent of parties) proceed to sentence. In the absence +of such consent, the bishop may hear the cause with three +assessors, of whom one shall be a barrister of seven years’ +standing and another the dean of the cathedral, or one of the +archdeacons, or the chancellor. This court is called the “consistory” +court, but is not the old consistory. Both these +tribunals are new. But the bishop may instead send the cause, in +first instance, to the old provincial court, to which appeal lies, +if it be not so sent.</p> + +<p>The Public Worship Regulation Act (37 & 38 Vict. c. 85) gave +criminal jurisdiction over beneficed clerks (concurrent with +that of the tribunal under 3 & 4 Vict. c. 86) to the judge under +the act in matters of the fabric, ornaments, furniture and decorations +of churches, and the conduct of divine service, rites and +ceremonies. The “judge” under the act is to be a barrister of +ten years’ standing, or an ex-judge of a superior secular court, +appointed by the archbishops of Canterbury and York, with the +approval of the crown, or, if they fail to appoint, by the crown. +Proceedings under this act are to be deemed to be taken in the +appropriate ancient ecclesiastical courts (<i>Green</i> v. <i>Lord Penzance</i>, +6 A. C. 657). The judge under this act became (upon vacancies +occurring) <i>ex officio</i> official principal of the arches court of +Canterbury and of the chancery court of York. This provision +caused grave doubts to be entertained as to the canonical +position of this statutory official principal.</p> + +<p>Finally, the Clergy Discipline Act 1892 (55 & 56 Vict. c. 32) +creates yet a new court of first instance for the trial of clerical +offences against morality in the shape of a consistory court, +which is not the old court of that name, but is to comprehend +the chancellor and five assessors (three clergymen and two +laymen chosen from a prescribed list), with equal power with the +chancellor on questions of fact. In many instances the conviction +of a temporal court is made conclusive on the bishop without +further trial. In regard to moral offences, jurisdiction under this +act is exclusive. But it only applies to clerks holding preferment. +Under all these three acts there is a final appeal to the +judicial committee of the privy council.</p> + +<p>None of these acts applies to the trial of bishops, who are left +to the old jurisdictions, or whatever may be held to be the old +jurisdictions (with that of the Roman See eliminated). As to +suffragan bishops in the province of Canterbury, see <i>Read</i> v. +<i>Bishop of Lincoln</i>, 13 P.D. 221, 14 P.D. 88. (On general questions +see Phillimore, <i>Ecc. Law</i>, 65, 73.) Despite the bishop of +Lincoln’s case, the law is in some uncertainty.</p> + +<p>Dilapidations are now not made matters of suit before the +court, but of administrative action by the bishop.</p> + +<p>The subject matter of ecclesiastical jurisdiction has been +gradually reduced in England, &c., by various causes. (1) The +taking away of all matrimonial, testamentary and <i>ab intestate</i> +jurisdiction by 20 & 21 Vict. c. 77 (testamentary, &c., England), +c. 79 (testamentary, &c., Ireland), c. 85 (matrimonial, England); +33 & 34 Vict. c. 110 (matrimonial, Ireland). Matrimonial jurisdiction +was taken from the bishop of Sodor and Man in 1884. (2) +Since 6 & 7 Will. IV. c. 71, tithe has become, except in a few +rare cases, tithe rent charge, and its recovery has been entirely +an operation of secular law. Most kinds of offerings are now +recoverable in secular courts. (3) Administration of pious gifts +has passed to the court of chancery. (4) The enforcement of +contractual promises has long been abandoned by the courts +Christian themselves. (5) Church rates can no longer be enforced +by suit (31 & 32 Vict. c. 109). (6) <i>Defamation</i> was taken away +in England by 18 & 19 Vict. c. 41, and in Ireland by 23 & 24 +Vict. c. 32. (7) Laymen can no longer be tried in the spiritual +courts for offences against clerks. (8) The jurisdiction for +“brawling” in church, &c., is taken away by 23 & 24 Vict. c. 32 +in the case of the laity. In the case of persons in holy orders there +is a concurrent jurisdiction of the two tribunals (<i>Valancy</i> v. +<i>Fletcher</i>, 1897, 1 Q.B. 265). This was an offence very frequently +prosecuted in the courts Christian (see A.J. Stephens, <i>Ecclesiastical +Statutes</i>, i. 336).</p> + +<p>The existing ecclesiastical jurisdiction in England is therefore +now confined to the following points. (1) Discipline of the +clergy. (2) Discipline of the laity in respect of sexual offences +<span class="pagenum"><a name="page863" id="page863"></a>863</span> +as already stated. (3) Control of lay office-bearers, church-wardens, +sidesmen, organists, parish clerks, sextons. (4) Protection +of the fabrics of churches, of churchyards, ornaments, +fittings, &c., sanctioning by licence or faculty any additions or +alterations, and preventing or punishing unauthorized dealings by +proceedings on the criminal side of the courts. (5) Claims by +individuals to particular seats in church or special places of +sepulture. (6) Rare cases of personal or special tithes, offerings +or pensions claimed by incumbents of benefices. In the Isle of +Man and the Channel Islands courts Christian have now jurisdiction +substantially as in England. In Jersey and in Guernsey +there are courts of first instance with appeal to the bishop of +Winchester. Ecclesiastical jurisdiction in Ireland was as in +England till the Irish Church was disestablished in 1869 by +32 & 33 Vict. c. 42.</p> + +<p>The position of a disestablished or an unestablished Church +is comparatively modern, and has given rise to new jural conceptions. +These Churches are <i>collegia licita</i> and come +within the liberty of association so freely conceded in +<span class="sidenote">Ecclesiastical jurisdiction in non-established churches.</span> +modern times. The relations of their bishops, priests +or other ministers and lay office-bearers <i>inter se</i> and +to their lay folk depend upon contract; and these +contracts will be enforced by the ordinary courts of +law. A consensual ecclesiastical jurisdiction is thus created, +which has to this extent temporal sanction. <i>In foro conscientiae</i> +spiritual censures canonically imposed are as binding +and ecclesiastical jurisdiction is as powerful as ever.</p> + +<p>Into the British-settled colonies no bishops were sent till 1787; +and consequently there were no regular courts Christian. The +bishop of London was treated as the diocesan bishop of the +colonists in North America; and in order to provide for testamentary +and matrimonial jurisdiction it was usual in the letters +patent appointing the governor of a colony to name him ordinary. +In New York state there is still a court called the surrogates +court, surrogate being the regular name for a deputy ecclesiastical +judge. In Lower Canada, by treaty, the Roman Catholic +Church remained established.</p> + +<p>Throughout the United States, whatever may have been the +position in some of them before their independence, the Church +has now no position recognized by the State, but is just a body +of believers whose relations are governed by contract and with +whom ecclesiastical jurisdiction is consensual.</p> + +<p>The position is the same now through all the British colonies +(except, as already mentioned, Lower Canada or Quebec). From +1787 onwards, colonial bishops and metropolitans were appointed +by letters patent which purported to give them jurisdiction for +disciplinary purposes. But a series of cases, of which the most +remarkable was that <i>Re the Bishop of Natal</i> (3 Moore P.C. +N.S. <span class="scs">A.D.</span> 1864), decided that in colonies possessing self-governing +legislatures such letters patent were of no value; +and soon after the crown ceased to issue them, even for crown +colonies.</p> + +<p>In India the metropolitan of Calcutta and the bishops of +Madras and Bombay have some very limited jurisdiction which +is conferred by letters patent under the authority of the statutes +53 Geo. III. c. 155 and 3 & 4 Will. IV. c. 85. But the other +Indian bishops have no position recognized by the State and no +jurisdiction, except consensual.</p> + +<p>The Church had the same jurisdiction in Scotland, and +exercised it through similar courts to those which she had in +England and France, till about 1570. As late as 1566 +Archbishop Hamilton of Glasgow, upon his appointment, +<span class="sidenote">Ecclesiastical jurisdiction in Scotland.</span> +had restitution of his jurisdiction in the probate +of testaments and other matters (Keith, <i>History of +the Scottish Bishops</i>, Edinburgh, 1824, p. 38). There was an +interval of uncertainty, with at any rate titular bishops, +till 1592. Then parliament enacted a new system of Church +courts which, though to some extent in its turn superseded by +the revival of episcopacy under James VI., was revived or ratified +by the act of 1690, c. 7, and stands to this day. It is a Presbyterian +system, and the Scottish Episcopal Church is a disestablished +and voluntary body since 1690.</p> + +<p>The Presbyterian courts thus created are arranged in ascending +order:—</p> + +<p>(<i>a</i>) <i>Kirk Session</i> consists of the minister of the parish and the +“ruling elders” (who are elected by the session). It has cognizance +of scandalous offences by laymen and punishes them +by deprivation of religious privileges. It does not judge ministers +(Brodie-Innes, <i>Comparative Principles of the Laws of England +and Scotland</i>, 1903, p. 144).</p> + +<p>(<i>b</i>) The <i>Presbytery</i> has jurisdiction, partly appellate and +partly original, over a number of parishes. There are now eighty-four +presbyteries. These courts consist of every parochial +minister or professor of divinity of any university within the +limits, and of an elder commissioned from every kirk session. +A minister is elected to preside as moderator. These courts +judge ministers in first instance for scandalous conduct. As +civil courts they judge in first instance all questions connected +with glebes and the erection and repair of churches and manses. +They regulate matters concerning public worship and ordinances, +and have appellate jurisdiction from the kirk session.</p> + +<p>(<i>c</i>) The <i>Provincial Synod</i> consists of a union of three or more +presbyteries with the same members. There are now sixteen. +They meet twice a year to hear appeals from presbyteries. No +appeal can go direct to the General Assembly, <i>omisso medio</i>, +unless the presbytery have so expressly directed, or unless there +be no meeting of synod after the decision of the presbytery +before the meeting of General Assembly.</p> + +<p>(<i>d</i>) The <i>General Assembly</i> is the supreme ecclesiastical court +of this system. It meets annually. The king’s “lord high +commissioner” attends the sittings; but does not intervene +or take part in the court’s decisions. The court consists of +ministers and elders, elected from the presbyteries in specified +proportions, and of commissioners from the four universities, +the city of Edinburgh and the royal burghs. The Presbyterian +Church in India sends one minister and one elder. The whole +Assembly consists of 371 ministers and 333 elders. The jurisdiction +is entirely appellate. The Assembly appoints a commission +to exercise some of its functions during the intervals of +its session. To this commission may be referred the cognizance +of particular matters.</p> + +<p>Questions of <i>patronage</i> now (by 37 & 38 Vict. c. 82) belong to +the Church courts; but not questions of <i>lapse</i> or <i>stipend</i>. Seats, +seat rents, pews, the union and disjunction of parishes and +formation of district parishes are of secular jurisdiction. Questions +of tithes (or “teinds”) and ministers’ stipends were referred +to commissioners by acts of the Scots parliaments beginning in +1607. The commissioners of teinds became a species of ecclesiastical +court. By Scots act of 1707, c. 9, their powers were +transferred to the judges of the court of session, who now constitute +a “teind court” (Brodie-Innes, <i>op. cit.</i> pp. 138, 139). +Matrimonial matters and those relating to wills and succession +(called in Scotland “consistorial” causes) were in 1563 taken +from the old bishops’ courts and given to “commissaries” +appointed by the crown with an appeal to the court of session, +which by act 1609, c. 6, was declared the king’s great consistory. +They have remained matters of secular jurisdiction.</p> + +<p>The Scots ecclesiastical courts are entitled to the assistance of +the secular courts to carry out their jurisdiction by “due assistance.” +Within the limits of their jurisdiction they are supreme. +But if a court go outside its jurisdiction, or refuse to exercise +powers conferred on it by law, the civil court may “reduce” +(<i>i.e.</i> set aside) the sentence and award damages to the party +aggrieved.</p> + +<p>With the Reformation in the 16th century, Church courts +properly speaking disappeared from the non-episcopal +religious communities which were established in +<span class="sidenote">Protestant continental European states.</span> +Holland, in the Protestant states of Switzerland and +of Germany, and in the then non-episcopal countries +of Denmark and Norway.</p> + +<p>Discipline over ministers and other office-bearers was exercised +by administrative methods in the form of trials before consistories +or synods. To this extent ecclesiastical jurisdiction is +still exercised in these countries. Consistories and synods have +<span class="pagenum"><a name="page864" id="page864"></a>864</span> +exercised discipline of a penitential kind over their lay members; +but in later times their censures have generally ceased to carry +temporal consequences. Ecclesiastical jurisdiction on the civil +side for the trial of causes soon disappeared. Heresy has been +treated as a crime to be tried in and punished by the ordinary +courts of the country, as in the cases of Servetus (<i>q.v.</i>) and +Grotius (<i>q.v.</i>).</p> + +<p>For the episcopal churches of Sweden and Finland the first +constitution or “Church order” was formed in 1571. It provided +for the visitation of the clergy by the bishop, and for the +power of the clergy to exclude their lay folk from the Holy +Communion, subject to appeal to the bishop. Both minor and +major excommunication had been in use, and for a long time +public penance was required. The procedure underwent great +modification in 1686; but public penance was not taken away +till 1855, and then confession to and absolution by the priest in +the presence of witnesses was still required. Civil jurisdiction in +causes appears to have been given up early (Cornelius, <i>Svenska +Kirkaus Historia</i>, Upsala, 1875, pp. 146, 186, 189, 285).</p> + +<p>Over the rest of western continental Europe and in the colonies +of Spain, Portugal and France, ecclesiastical jurisdiction remained +generally in the state which we have already described +till near the end of the 18th century. The council of +<span class="sidenote">Roman Catholic countries.</span> +Trent took away the jurisdiction of archdeacons in +marriage questions. The testamentary jurisdiction +disappeared (as already stated) in France. Disputed cases of +contract were more often tried in the secular courts. Recourse +to the secular prince by way of <i>appel comme d’abus</i>, or otherwise, +became more frequent and met with greater encouragement. +Kings began to insist upon trying ecclesiastics for treason or +other political crimes in secular courts. So under the advice of +his minister (the marquis of Pombal), King Joseph of Portugal in +1759-1760 claimed that the pope should give him permission to +try in all cases clerics accused of treason, and was not content +with the limited permission given to try and execute, if guilty, +the Jesuits then accused of conspiring his death (<i>Life of Pombal</i>, +by Count da Carnota, 1871, pp. 128, 141). But there was no +sudden change in the position of the courts Christian till the +French Revolution.</p> + +<p>In France a law of the Revolution (September 1790) purported +to suppress all ecclesiastical jurisdictions. On the re-establishing +of the Catholic religion on the basis of the new Concordat, +promulgated 18 Germinal, year X. (April 8, 1802), no express +provision was made for ecclesiastical jurisdictions; but several +bishops did create new ecclesiastical tribunals, “officialities” +(Migne, <i>Dict. de droit canon.</i>, <i>s.v.</i>). The government in some +cases recognized these tribunals as capable of judging ecclesiastical +causes (Migne, <i>ubi sup.</i>). In 1810 the diocesan official of +Paris entertained the cause between Napoleon and Josephine, +and pronounced a decree of nullity (Migne, <i>ubi sup.</i> <i>s.v.</i> +“Causes”). Such litigation as still continued before the spiritual +forum was, however, confined (save in the case of the matrimonial +questions of princes) to the professional conduct of the clergy.</p> + +<p>Such neighbouring countries as were conquered by France or +revolutionized after her pattern took the same course of suppressing +their ecclesiastical jurisdictions. After 1814, some of +these jurisdictions were revived. But the matter is now determined +for all countries which have adopted codes, whether after +the pattern of the Code Napoléon or otherwise. These countries +have created a hierarchy of temporal courts competent to deal +with every matter of which law takes cognizance, and a penal +code which embraces and deals with all crimes or delicts which +the state recognizes as offences. Hence, even in countries where +the Roman Church is established, such as Belgium, Italy, the +Catholic states of Germany and cantons of Switzerland, most +of the Latin republics of America, and the province of Quebec, +and <i>a fortiori</i> where this Church is not established, there is +now no discipline over the laity, except penitential, and no jurisdiction +exercised in civil suits, except possibly the matrimonial +questions of princes (of which there was an example in the +case of the reigning prince of Monaco). In Spain causes of +nullity and divorce <i>a thoro</i>, in Portugal causes of nullity between +Catholics, are still for the court Christian. In Peru, the old +ecclesiastical matrimonial jurisdiction substantially remains +(Lehr, <i>Le Mariage dans les principaux pays</i>, 1899, arts. 362, 797, +772, 781). Otherwise these three countries are Code countries. +In Austria, the ancient ecclesiastical jurisdiction was taken away +by various acts of legislation from 1781 to 1856; even voluntary +jurisdiction as to dispensations. The Concordat of 1856 and +consequent legislation restored matrimonial jurisdiction to the +courts Christian over marriages between Roman Catholics. In +1868 this was taken away. The Austrian bishops, however, +maintain their tribunals for spiritual purposes, and insist that +such things as divorce <i>a vinculo</i> must be granted by their authority +(Aichner, <i>Compendium juris ecclesiastici</i>, pp. 551-553).</p> + +<p>By consent and submission of her members, the Roman Church +decides <i>in foro conscientiae</i> questions of marriage, betrothal and +legitimacy everywhere; but no temporal consequences follow +except in Spain, Portugal and Peru.</p> + +<p>The position in France was the same as that in Belgium, Italy, +&c., till 1906, when the Church ceased to be established. The +only Latin countries in which conflict has not arisen appear to +be the principality of Andorra and the republic of San Marino +(Giron y Areas, <i>Situación jurídica de la Iglesia Católica</i>, Madrid, +1905, p. 173 et seq.).</p> + +<p>Even as to the discipline of the Roman clergy it is only in +certain limited cases that one can speak of ecclesiastical jurisdiction. +Bishops and beneficed incumbents (<i>curés</i>) must be regularly +tried; and where the Church is established the canonical courts +are recognized. But the majority of parishes are served by mere +<i>desservants</i> or <i>vicaires</i>, who have no rights and can be recalled +and dismissed by mere administrative order without trial (Migne, +<i>ubi sup.</i> <i>s.v.</i> “Inamovibilité,” “Desservants”).</p> + +<p>The Napoleonic legislation re-established the <i>appel comme +d’abus</i> (“<i>Articles organiques</i>,” art. 6). The recourse was now to +the council of state (see Migne, <i>ubi supra</i>, “Officialité”). But +the revocation of a <i>desservant</i>, and the forbidding him the execution +of his ministry in the diocese, was not a case in which the +council of state would interfere (Migne, <i>ubi sup.</i> “Appel comme +d’abus,” “Conseil d’état”).</p> + +<p>In those provinces of the Anglican communion where the +Church is not established by the state, the tendency is +<span class="sidenote">Jurisdiction in Anglican communion.</span> +not to attempt any external discipline over the laity; +but on the other hand to exercise consensual jurisdiction +over the clergy and office-bearers through courts +nearly modelled on the old canonical patterns.</p> + +<p>In the Roman communion, on the other hand, both where +the Church is established and where it is not, the tendency is +to reduce the status of <i>curé</i> to that of <i>desservant</i>, and to +deal with all members of the priestly or lower orders +<span class="sidenote">Modern jurisdiction of Church of Rome.</span> +by administrative methods. This practice obtains in +all missionary countries, <i>e.g.</i> Ireland and also in +Belgium (S.B. Smith, <i>Elements of Ecclesiastical Law</i>, +New York, i. 197 et seq.; p. 403 et seq.; Tauber, <i>Manuale +juris canonici</i>, Sabariae, 1904, p. 277). In the United States, +the 3rd plenary council of Baltimore in 1884 provided that one +rector out of ten should be irremovable (Smith, <i>op. cit.</i> i. 197, +419). In England there are few Roman “benefices” (E. +Taunton, <i>Law of the Church</i>, London, 1906, <i>s.v.</i> “Benefice”). +A <i>desservant</i> has an informal appeal, by way of recourse, to the +metropolitan and ultimately to the pope (Smith, <i>op. cit.</i> p. 201). +The bishop’s “official” is now universally called his vicar-general +(except in France, where sometimes an <i>official</i> is appointed +<i>eo nomine</i>), and generally exercises both voluntary and contentious +jurisdiction (<i>op. cit.</i> i. 377). As of old, he must be at +least tonsured and without a wife living. At the Vatican +Council, a desire was expressed that he should be a priest (<i>ib.</i>). +He should be a doctor in theology or a licentiate in canon law +(<i>ib.</i> p. 378). Whether a bishop is bound to appoint a vicar-general +is still disputed (<i>ib.</i> p. 380; cf. <i>supra</i>; <i>contra</i>, Bouix, <i>Inst. Juris +Canon. De Judic.</i> i. 405). In 1831 the pope enacted that in +all the dioceses of the then Pontifical States, the court of first +instance for the criminal causes of ecclesiastics should consist of +the ordinary and four other judges. In the diocese of Rome, +<span class="pagenum"><a name="page865" id="page865"></a>865</span> +the court of the cardinal vicar-general consists of such vicar-general +and four other prelates (Smith, <i>ubi supra</i>). In the +Roman communion in England and the United States, there +are commissions of investigation appointed to hear in first +instance the criminal causes of clerks. They consist of five, or at +least three, priests nominated by the bishop in and with the +advice of the diocesan synod. In the United States, since 1884, +the bishop presides on these commissions. They report their +opinions to the bishop, who passes final sentence (<i>ib.</i> ii. 129-131).</p> + +<p>“Exemptions” now include all the regular religious orders, +<i>i.e.</i> those orders which have solemn vows. Over the members of +these orders their superiors have jurisdiction and not the bishop. +Otherwise if they live out of their monastery, or even within that +enclosure so notoriously offend as to cause scandal. In the first +case, they may be punished by the ordinary of the place, acting as +delegate of the pope without <span class="correction" title="amended from speical">special</span> appointment (<i>Conc. Trid. +Sess.</i> vi. c. 3). In the second case, the bishop may require the +superior to punish within a certain time and to certify the +punishment to him; in default he himself may punish (<i>Conc. +Trid. Sess.</i> xxv. c. 14, cf. Smith, <i>op. cit.</i> i. 204-206). So, +regulars having cure of souls are subject to the jurisdiction of the +bishop in matters pertaining thereto (<i>ib.</i> p. 206). The exemption +of regular religious orders may be extended to religious +societies without solemn vows by special concession of the pope, +as in the case of the Passionists and Redemptorists (<i>ib.</i> p. 205; +Sanguineti, <i>Juris ecc. inst.</i>, Rome, 1800, pp. 393, 394).</p> + +<p>Appeal lies, in nearly all cases, to the metropolitan (Smith, +<i>op. cit.</i> pp. 219-223). Metropolitans usually now have a metropolitan +tribunal distinct from their diocesan court (<i>ib.</i> ii. 141), +but constructed on the same lines, with the metropolitan as judge +and his vicar-general as vice-judge. In some “missionary” +dioceses, the metropolitan, <i>qua</i> metropolitan, has a separate +commission of investigation, to try the criminal causes of +clerks, sentence being passed by himself or his vicar-general (<i>ib.</i> +p. 142).</p> + +<p>The next step in the hierarchy, that of “primates” (<i>supra</i>), +has “in the present state of the Church” ceased to exist for our +purpose (Sanguineti, <i>op. cit.</i> p. 334), as a result of Tridentine legislation. +The only appellate jurisdiction from the metropolitans is +the Roman See. To it also lies a direct appeal from the court of +first instance, <i>omisso medio</i> (Smith, <i>op. cit.</i> i. 224). The pope’s +immediate and original jurisdiction in every diocese is now +expressly affirmed by the Vatican Council (<i>ib.</i> p. 239). That +original jurisdiction he reserves exclusively to himself in <i>causis +majoribus</i> (<i>ib.</i> pp. 249-250). These are (1) causes relating to +elections, translations and deprivations of, and criminal prosecutions +against, bishops, and (2) the matrimonial cases of princes +(Taunton, <i>op. cit. s.v.</i> “Cause”).</p> + +<p>In the Eastern Church, the early system of ecclesiastical +judicature long continued. But a sacred character was ascribed +to the emperors. They are “anointed lords like the +bishops” (Balsamon, in <i>Conc. Ancyr. Can.</i> xii., representing +<span class="sidenote">Eastern Church.</span> +the view of the 12th and 13th centuries). +Bishops were often deposed by administrative order of the +emperor; synods being expected afterwards to confirm, or rather +accept, such order. The germ of this dealing with a <i>major causa</i> +may be found in the practice of the Arian emperors in the 4th +century. The cause of Ignatius and Photius was dealt with in +the 9th century by various synods; those in the East agreeing +with the emperor’s view for the time being, while those in the +West acted with the pope. (The details are in Mansi, <i>Conc. in +locis</i>, and in Hefele, <i>Conc. in locis</i>, more briefly. They are summarized +in Landon, <i>Manual of Councils</i>, <i>s.v.</i> “Constantinople,” +“Rome,” and in E.S. Foulkes, <i>Manual of Ecclesiastical History</i>, +<i>s.v.</i> “Century IX.”) Since these transactions patriarchs have been +deposed by the Byzantine emperors; and the Turkish sultans +since the 15th century have assumed to exercise the same +prerogative.</p> + +<p>The spiritual courts in the East have permanently acquired +jurisdiction in the matrimonial causes of baptized persons; +the Mahommedan governments allowing to Christians a personal +law of their own. The patriarch of Constantinople is enabled +to exercise an extensive criminal jurisdiction over Christians +(Neale, <i>Hist. of the Eastern Church</i>, i. 30, 31).</p> + +<p>The empire of Russia has in the matter of ecclesiastical jurisdiction +partly developed into other forms, partly systematized +4th century and later Byzantine rules. The provincial system +does not exist; or it may be said that all Russia is one province. +An exception should be made in the case of Georgia, which is +governed by an “exarch,” with three suffragans under him. +In the remainder of the empire the titles of metropolitan, save +in the case of the metropolitan of all Russia, and of archbishop, +were and are purely honorary, and their holders have merely +a diocesan jurisdiction (see Mouravieff, <i>History of the Russian +Church</i>, translated Blackmore, 1842, translator’s notes at pp. 370, +390, 416 et seq.). So in Egypt the bishop or “pope” (afterwards +patriarch) of Alexandria was the only true metropolitan (Neale, +<i>History of the Eastern Church</i>, Gen. Introd. vol. i. p. 111). The +metropolitan of Russia from the time of the conversion (<span class="scs">A.D.</span> 988) +settled at Kiev, and his province was part of the patriarchate of +Constantinople, and appeals lay to Constantinople. Many such +appeals were taken, notably in the case of Leon, bishop of Rostov +(Mouravieff, <i>op. cit.</i> p. 38). The metropolitical see was for a +short time transferred to Vladimir and then finally to Moscow +(Mouravieff, chs. iv., v.). After the taking of Constantinople in +1452, the Russian metropolitans were always chosen and consecrated +in Russia, appeals ceased, and Moscow became <i>de facto</i> +autocephalous (Joyce, ubi sup. p. 379; Mouravieff, <i>op. cit.</i> +p. 126). The tsar Theodore in 1587 exercised the power of the +Byzantine emperors by deposing the metropolitan, Dionysius +Grammaticus (Mouravieff, p. 125). In 1587 the see of Moscow +was raised to patriarchal rank with the consent of Constantinople, +and the subsequent concurrence of Alexandria, Antioch and +Jerusalem (<i>ib.</i> c. vi.). Moscow became the final court, in theory, +as it had long been in practice. Certain religious houses, however, +had their own final tribunals and were “peculiars,” exempt from +any diocesan or patriarchal jurisdiction for at least all causes +relating to Church property (<i>ib.</i> p. 131).</p> + +<p>The subject matter of ecclesiastical jurisdiction in Russia +during the whole patriarchal period included matrimonial and +testamentary causes, inheritance and sacrilege, and many questions +concerning the Church domains and Church property, as well as +spiritual offences of clergy and laity (<i>ib.</i>). The bishops had +consistorial courts; the patriarchs, chanceries and consistories +(<i>ib.</i>). Bishops were judged in synod (see, <i>e.g.</i> the case of the +archbishop of Polotsk in 1622, <i>ib.</i> p. 179) and only lawfully +judged in synod (<i>ib.</i> p. 215).</p> + +<p>Clerks and the dependants of the metropolitan (afterwards +the patriarch) appear to have been immune from secular jurisdiction, +except in the case of crimes against life, from the time of +Ivan the Terrible (<i>ib.</i> pp. 180-181). The tsar Michael, in the +earlier 17th century, confirmed these immunities in the case of +the clergy of the patriarch’s own diocese, but provided that in +country places belonging to his diocese, monasteries, churches and +lands should be judged in secular matters by the Court of the +Great Palace, theoretically held before the tsar himself (<i>ib.</i> p. 181). +This tsar limited the “peculiar” monasteries to three, and gave +the patriarch jurisdiction over them (<i>ib.</i>). The next tsar, Alexis, +however, by his code instituted a “Monastery Court,” which was +a secular tribunal composed of laymen, to judge in civil suits +against spiritual persons, and in matters arising out of their +manors and properties (<i>ib.</i> p. 193). This court was not in operation +during the time when the patriarch Nikon was also in effect +first minister; but upon his decline exercised its full jurisdiction +(<i>ib.</i> p. 216). Nikon was himself tried for abdicating his see, causing +disorder in the realm, oppression and violence, first before a synod +of Moscow composed of his suffragans and some Greek bishops, +and afterwards before another synod in which sat the patriarchs +of Alexandria and Antioch, the metropolitans of Servia and +Georgia, the archbishops of Sinai and Wallachia, and the metropolitans +of Nice, Amasis, Iconium, Trebizond, Varna and Scio, +besides the Russian bishops. This synod in 1667 deposed Nikon, +degraded him from holy orders, and sentenced him to perpetual +penance in a monastery (<i>ib.</i> pp. 220-232). The next tsar, Theodore, +<span class="pagenum"><a name="page866" id="page866"></a>866</span> +suppressed the secular “monastery court,” and directed that all +suits against spiritual persons should proceed only in the patriarchal +“court of requests” (<i>ib.</i> p. 264). There was, however, +a species of <i>appel comme d’abus</i>. Causes could be evoked to the +tsar himself, “when any partiality of the judges in any affair in +which they themselves were interested was discovered” (<i>ib.</i>).</p> + +<p>The old system was swept away by Peter the Great, who +settled ecclesiastical jurisdiction substantially on its present +basis. The patriarchate was abolished and its jurisdiction +transferred by a council at St Petersburg in 1721 to a Holy +Governing Synod. The change was approved by the four +patriarchs of the East in 1723 (<i>ib.</i> chs. xv.-xvii.). Peter permanently +transferred to the secular <i>forum</i> the testamentary +jurisdiction and that concerning inheritance, as also questions of +“sacrilege” (<i>ib.</i> p. 264). As the result of a long series of legislation, +beginning with him and ending with Catherine II., all church +property of every kind was transferred to secular administration, +allowances, according to fixed scales, being made for ministers, +monks and fabrics (<i>op. cit.</i> translator’s appendix i. p. 413 et seq.). +There remain to the spiritual courts in Russia the purely ecclesiastical +discipline of clerks and laity and matrimonial causes.</p> + +<p>The court of first instance is the “consistorial court” of the +bishop. This consists of a small body of ecclesiastics. Its +decisions must be confirmed by the bishop (<i>op. cit.</i> translator’s +appendix ii. pp. 422-423). In the more important causes, as +divorce (<i>i.e.</i> <i>a vinculo</i>), it only gives a provisional decision, +which is reported by the bishop, with his own opinion, for final +judgment, to the Most Holy Governing Synod.</p> + +<p>The governing synod is the final court of appeal. It consists +of a small number of bishops and priests nominated by the tsar, +and is assisted by a “procurator,” who is a layman, who explains +to it the limits of its jurisdiction and serves as the medium of +communication between it and the autocrat and secular +authorities. It deals with the secular crimes of spiritual persons, +if of importance and if not capital (these last being reserved +for the secular forum), and with heresy and schism. It is the +only court which can try bishops or decree divorce. The tsar +formally confirms its judgments; but sometimes reduces +penalties in the exercise of the prerogative of mercy (see Mouravieff, +<i>op. cit.</i> ch. xvii. translator’s app. ii.).</p> + +<p>The governing synod now sits at St Petersburg, but appoints +delegated commissions, with a portion of its jurisdiction, in +Moscow and Georgia. The latter commission is presided over +by the “exarch” (<i>supra</i>).</p> + +<p>Since the War of Independence, the kingdom of Greece has +been ecclesiastically organized after the model of Russia, as one +autocephalous “province,” separated from its old patriarchate +of Constantinople, with an honorary metropolitan and honorary +archbishops (Neale, <i>op. cit.</i> Gen. Introd. vol. i.). The Holy +Synod possesses the metropolitical jurisdiction. It sits at +Athens. The metropolitan of Athens is president, and there are +four other members appointed by the government in annual +rotation from the senior bishops. There is attached to it a government +commissioner, with no vote, but affixing his signature to +the synodical judgments (Joyce, <i>op. cit.</i> p. 35).</p> + +<p>The subject matter of the jurisdiction of Hellenic courts +Christian seems to be confined to strictly spiritual discipline, +mainly in regard to the professional misconduct of the clergy. +Imprisonment may be inflicted in these last cases (<i>ib.</i>). All +matrimonial causes are heard by the secular tribunals (Lehr, +<i>op. cit.</i> sec. 587).</p> + +<p>The bishop’s consistorial court, consisting of himself and four +priests, has a limited jurisdiction in first instance. Such a court +can only suspend for seven days unless with the sanction of the +Holy Synod (Joyce, <i>op. cit.</i>).</p> + +<p>The Holy Synod can only inflict temporary suspension, or +imprisonment for fifteen days, unless with the sanction of the +King’s ministry. Deprivation, or imprisonment for more than +two months, requires the approval of the king (<i>ib.</i>). The king +or the ministry do not, however, rehear the cause by way of +appeal, but merely restrain severity of sentence (<i>ib.</i>).</p> + +<p>The Church of Cyprus has been autocephalous since at any rate +the oecumenical synod of Ephesus in 431. The episcopate now +consists of an archbishop and three suffragans (Hackett, <i>Orthodox +Church in Cyprus</i>, 1901, ch. v. <i>et passim</i>). The final court is +the island synod, which consists of the archbishop, his suffragans +and four dignified priests. It has original and exclusive cognizance +of causes of deposition of bishops (<i>op. cit.</i> pp. 260, 262).</p> + +<p>Each bishop is assisted by at least two officers with judicial +or quasi-judicial powers, the “archimandrite” who adjudicates +upon causes of revenue and the archdeacon who adjudicates on +questions between deacons (<i>op. cit.</i> pp. 272-273). The “exarch” +of the archbishop, who is a dignitary but not a bishop, has a seat +in the provincial synod.</p> + +<p>In the Balkan States, the system—inherited from Byzantine +and Turkish times—of ecclesiastical jurisdictions prevails, except +that they are now autocephalous, and independent of the patriarch +of Constantinople. Matrimonial causes in Servia are of ecclesiastical +cognizance (Lehr, <i>op. cit.</i> sect. 901).</p> + +<div class="condensed"> +<p><span class="sc">Authorities.</span>—St Augustine, <i>Epistles</i>; <i>Codex Theodosianus</i>, +edited by Th. Mommsen and P.M. Meyer (1905); <i>Code and Novells +of Emperor Justinian</i>, ed. J. Gothofredus (1665); T. Balsamon, +“In Conc. Ancyr.” in the <i>Corpus juris canonici</i> (1879-1881); +“<i>Hostiensis</i>” <i>Super Decretum</i>; W. Lyndwood, <i>Provinciale</i> (Oxford, +1679); Sir A. Fitzherbert, <i>Natura brevium</i> (1534); Sir T. Ridley, +<i>View of the Civile and Ecclesiastical Law</i> (1607); J. Ayliffe, <i>Parergon +juris ecclesiastici</i> (1726); J. Godolphin, <i>Abridgement of the Laws +Ecclesiastical</i> (London, 1687); E. Gibson, <i>Codex juris ecclesiastici</i> +(Oxford, 1761); D. Covarruvias, <i>Opera omnia</i> (Antwerp, 1638); +Jean Hardouin, <i>Concilia</i> (1715); J.D. Mansi, <i>Concilia</i> (1759-1798); +E. Stillingfleet, <i>Ecclesiastical Jurisdiction</i> (1704); L.S. le Nain de +Tillemont, <i>Mémoires pour servir à l’histoire ecclésiastique</i> (1701-1712); +P.T. Durand de Maillane, <i>Dictionnaire du droit canonique</i> (1761); +<i>Dictionnaire ecclésiastique et canonique</i>, par une société de religieux +(Paris, 1765); Z.B. van Espen, <i>Jus ecclesiasticum universum</i> +(Louvain, 1720), <i>De recursu ad Principem, observationes in Concilium +Lateranense iv.</i>; L. Thomassin, <i>Vetus et nova disciplina +ecc.</i> (1705-1706); W. Beveridge, <i>Synodicon</i> (Oxford, 1672); +J.A.S. da Carnota, <i>Life of Pombal</i> (1843); J.P. Migne, <i>Dictionnaire +de droit canon.</i> (Paris, 1844); R. Keith, <i>History of the Scottish +Bishops</i> (Edinburgh, 1824); P.N. Vives y Cebriá, <i>Usages y demas +derechos de Cataluña</i> (1832); C.A. Cornelius, <i>Svenska Kyrkaus +Historia</i> (Upsala, 1875); Mouravieff, <i>History of the Russian Church</i> +(trans. Blackmore, 1842); Ffoulkes, <i>Manual of Ecclesiastical History</i> +(1851); E.H. Landon, <i>Manual of Councils of the Church</i> (1893); +W.H. Hale, <i>Precedents in Criminal Cases</i> (London, 1847); E.B. +Pusey, <i>Councils of the Church</i> (Oxford, 1857); C.J. von Hefele, +<i>Conciliengeschichte</i> (Freiburg, 1855-1890); M. Gaudry, <i>Traité de +la législation des cultes</i> (Paris, 1854); W. Stubbs, <i>Select Charters</i> +(Oxford, 1895); A.W. Haddan and W. Stubbs, <i>Councils and +Ecclesiastical Documents</i> (Oxford, 1869); A.J. Stephens, <i>Ecclesiastical +Statutes</i> (1845); H.C. Rothery, <i>Return of Cases before Delegates</i> +(1864); J.W. Joyce, <i>The Sword and the Keys</i> (2nd ed., 1881); +<i>Report of Ecclesiastical Courts Commission</i> (1888); P. Fournier, <i>Les +Officialités au moyen âge</i> (1880); S.B. Smith, <i>Elements of Ecclesiastical +Law</i> (New York, 1889-1890); S. Sanguineti, <i>Juris ecc. inst.</i> (Rome, +1890); J.F. Stephen, <i>History of the Criminal Law of England</i> +(London, 1883); Pollock and Maitland, <i>History of English Law +before Edward I.</i> (1898); F.W. Maitland, <i>Roman Canon Law in +the Church of England</i> (1898); R. Owen, <i>Canon Law</i> (1884); Sir +R.J. Phillimore, <i>Ecclesiastical Law</i> (2nd ed., 1895); J.W. Brodie-Innes, +<i>Comparative Principles of the Laws of England and Scotland</i> +(1903); R.B. Merriman, <i>Life and Letters of Thomas Cromwell</i> (1902); +S. Aichner, <i>Compendium juris ecclesiast.</i> (8th ed., Brixen, 1905, +especially in regard to Austro-Hungarian Empire); J. Hackett, +<i>History of the Orthodox Church in Cyprus</i> (1901); Tauber, <i>Manuale +juris canonici</i> (1906); E.L. Taunton, <i>Law of the Church</i> (London, +1906); <i>Report of Royal Commission on Ecclesiastical Discipline</i> +(1906).</p> +</div> +<div class="author">(W. G. F. P.)</div> + + +<hr class="art" /> +<p><span class="bold">ECCLESIASTICAL LAW,<a name="ar119" id="ar119"></a></span> in its broadest sense, the sum of +the authoritative rules governing the Christian Church, whether +in its internal polity or in its relations with the secular power. +Since there are various churches, widely differing alike in their +principles and practice, it follows that a like difference exists +in their ecclesiastical law, which is the outcome of their corporate +consciousness as modified by their several relations to the +secular authority. At the outset a distinction must be made +between churches which are “established” and those that are +“free.” The ecclesiastical laws of the latter are, like the rules +of a private society or club, the concern of the members of the +church only, and come under the purview of the state only in +so far as they come in conflict with the secular law (<i>e.g.</i> polygamy +among the Mormons, or violation of the trust-deeds under which +<span class="pagenum"><a name="page867" id="page867"></a>867</span> +the property of a church is held). In the case of “established” +Churches, on the other hand, whatever the varying principle +on which the system is based, or the difference in its practical +application, the essential conditions are that the ecclesiastical +law is also the law of the land, the decisions of the church courts +being enforced by the civil power. This holds good both of the +Roman Catholic Church, wherever this is recognized as the +“state religion,” of the Oriental Churches, whether closely +identified with the state itself (as in Russia), or endowed with +powers over particular nationalities within the state (as in the +Ottoman empire), and of the various Protestant Churches +established in Great Britain and on the continent of Europe.</p> + +<p>Writers on the theory of ecclesiastical law, moreover, draw +a fundamental distinction between that of the Church of Rome +and that of the Protestant national or territorial Churches. +This distinction is due to the claim of the Roman Catholic Church +to be the <i>only</i> Church, her laws being thus of universal obligation; +whereas the laws of the various established Protestant Churches +are valid—at least so far as legal obligation is concerned—only +within the limits of the countries in which they are established. +The practical effects of this distinction have been, and still are, +of enormous importance. The Roman Catholic Church, even +when recognized as the state religion, is nowhere “established” +in the sense of being identified with the state, but is rather an +<i>imperium in imperio</i> which negotiates on equal terms with the +state, the results being embodied in concordats (<i>q.v.</i>) between +the state and the pope as head of the Church. The concordats +are of the nature of truces in the perennial conflict between the +spiritual and secular powers, and imply in principle no surrender +of the claims of the one to those of the other. Where the Roman +Catholic Church is not recognized as a state religion, as in the +United States or in the British Islands, she is in the position of +a “free Church,” her jurisdiction is only <i>in foro conscientiae</i>, +and her ecclesiastical laws have no validity from the point of +view of the state. On the other hand, the root principle of the +ecclesiastical law of the established Protestant Churches is the +rejection of alien jurisdiction and the assertion of the supremacy +of the state. The theory underlying this may vary. The +sovereign may be regarded, as in the case of the Russian emperor +or of the English kings from the Reformation to the Revolution, +as the vicar of God in all causes spiritual as well as temporal +within his realm. As the first fervent belief in the divine right +of kings faded, however, a new basis had to be discovered for +a relation between the spiritual and temporal powers against +which Rome had never ceased to protest. This was found in +the so-called “collegial” theory of Church government (<i>Kollegialsystem</i>), +which assumed a sort of tacit concordat between the state +and the religious community, by which the latter vests in the +former the right to exercise a certain part of the <i>jus in sacra</i> +properly inherent in the Church (see <span class="sc"><a href="#artlinks">Pufendorf, Samuel</a></span>). +This had great and lasting effects on the development of the +theory of Protestant ecclesiastical law on the continent of +Europe. In England, on the other hand, owing to the peculiar +character of the Reformation there and of the Church that was +its outcome, no theory of the ecclesiastical law is conceivable +that would be satisfactory at once to lawyers and to all schools +of opinion within the Church. This has been abundantly proved +by the attitude of increasing opposition assumed by the clergy, +under the influence of the Tractarian movement, towards the +civil power in matters ecclesiastical, an attitude impossible to +justify on any accepted theory of the Establishment (see below).</p> + +<p>Protestant ecclesiastical law, then, is distinguished from that +of the Roman Catholic Church (1) by being more limited in its +scope, (2) by having for its authoritative source, not the Church +only or even mainly, but the Church in more or less complete +union with or subordination to the State, the latter being considered, +equally with the Church, as an organ of the will of God. +The ecclesiastical law of the Church of Rome, on the other hand, +whatever its origin, is now valid only in so far as it has the +sanction of the authority of the Holy See. And here it must +be noted that the “canon law” is not identical with the “ecclesiastical +law” of the Roman Catholic Church. By the canon law +is meant, substantially, the contents of the <i>Corpus juris canonici</i>, +which have been largely superseded or added to by, <i>e.g.</i> the +canons of the council of Trent and the Vatican decrees. The +long projected codification of the whole of the ecclesiastical +law of the Church of Rome, a work of gigantic labour, was not +taken in hand until the pontificate of Pius X. (See also <span class="sc"><a href="#artlinks">Canon +Law</a></span> and <span class="sc"><a href="#artlinks">Ecclesiastical Jurisdiction</a></span>.)</p> + +<p>The ecclesiastical law of England is in complete dependence +upon the authority of the state. The Church of England cannot +be said, from a legal point of view, to have a corporate existence +or even a representative assembly. The Convocation of York and +the Convocation of Canterbury are provincial assemblies possessing +no legislative or judicial authority; even such purely +ecclesiastical questions as may be formally commended to their +attention by “letters of business” from the crown can only be +finally settled by act of parliament. The ecclesiastical courts are +for the most part officered by laymen, whose subordination to +the archbishops and bishops is purely formal, and the final court +of appeal is the Judicial Committee of the Privy Council. In +like manner changes in the ecclesiastical law are made directly +by parliament in the ordinary course of legislation, and in point +of fact a very large portion of the existing ecclesiastical law +consists of acts of parliament.</p> + +<p>The sources of the ecclesiastical law of England are thus +described by Dr. Richard Burn (<i>The Ecclesiastical Law</i>, 9th ed., +1842):—“The ecclesiastical law of England is compounded +of these four main ingredients—the civil law, the canon law, the +common law, and the statute law. And from these, digested in +their proper rank and subordination, to draw out one uniform +law of the church is the purport of this book. When these laws +do interfere and cross each other, the order of preference is this:—’The +civil law submitteth to the canon law; both of these to +the common law; and all three to the statute law. So that +from any one or more of these, without all of them together, +or from all of them together without attending to their comparative +obligation, it is not possible to exhibit any distinct +prospect of the English ecclesiastical constitution.’ Under the +head of statute law Burn includes ‘the Thirty-nine Articles of +Religion, agreed upon in Convocation in the year 1562; and in +like manner the Rubric of the Book of Common Prayer, which, +being both of them established by Acts of Parliament, are to be +esteemed as part of the statute law.’”</p> + +<p>The first principle of the ecclesiastical law in England is the +assertion of the supremacy of the crown, which in the present +state of the constitution means the same thing as the supremacy +of parliament. This principle has been maintained ever since +the Reformation. Before the Reformation the ecclesiastical +supremacy of the pope was recognized, with certain limitations, +in England, and the Church itself had some pretensions to +ecclesiastical freedom. The freedom of the Church is, in fact, +one of the standing provisions of those charters on which the +English constitution was based. The first provision of Magna +Carta is <i>quod ecclesia Anglicana libera sit</i>. By the various enactments +of the period of the Reformation the whole constitutional +position of the Church, not merely with reference to the pope +but with reference to the state, was definitely fixed. The legislative +power of convocation was held to extend to the clergy +only, and even to that extent required the sanction and assent +of the crown. The common law courts controlled the jurisdiction +of the ecclesiastical courts, claiming to have “the exposition of +such statutes or acts of parliament as concern either the extent +of the jurisdiction of these courts or the matters depending +before them. And therefore if these courts either refuse to allow +these acts of parliament, or expound them in any other sense +than is truly and properly the exposition of them, the king’s +great courts of common law may prohibit and control them.”</p> + +<p>The design of constructing a code of ecclesiastical laws was +entertained during the period of the Reformation, but never +carried into effect. It is alluded to in various statutes of the +reign of Henry VIII., who obtained power to appoint a commission +to examine the old ecclesiastical laws, with a view of +deciding which ought to be kept and which ought to be abolished; +<span class="pagenum"><a name="page868" id="page868"></a>868</span> +and in the meantime it was enacted that “such canons, +institutions, ordinances, synodal or provincial or other ecclesiastical +laws or jurisdictions spiritual as be yet accustomed and +used here in the Church of England, which necessarily and conveniently +are requisite to be put in ure and execution for the +time, not being repugnant, contrarient, or derogatory to the laws +or statutes of the realm, nor to the prerogatives of the royal +crown of the same, or any of them, shall be occupied, exercised, +and put in ure for the time with this realm” (35 Henry VIII. +c. 16, 25 c. 19, 27 c. 8).</p> + +<p>The work was actually undertaken and finished in the reign +of Edward VI. by a sub-committee of eight persons, under the +name of the <i>Reformatio legum ecclesiasticarum</i>, which, however, +never obtained the royal assent. Although the powers of the +25 Henry VIII. c. 1 were revived by the 1 Elizabeth c. 1, the +scheme was never executed, and the ecclesiastical laws remained +on the footing assigned to them in that statute—so much of the +old ecclesiastical laws might be used as had been actually in use, +and was not repugnant to the laws of the realm.</p> + +<p>The statement is, indeed, made by Sir R. Phillimore (<i>Ecclesiastical +Law</i>, 2nd ed., 1895) that the “Church of England has at +all times, before and since the Reformation, claimed the right +of an independent Church in an independent kingdom, to be +governed by the laws which she has deemed it expedient to +adopt.” This position can only be accepted if it is confined, as the +authorities cited for it are confined, to the resistance of interference +from abroad. If it mean that the Church, as distinguished +from the kingdom, has claimed to be governed by laws of her +own making, all that can be said is that the claim has been +singularly unsuccessful. From the time of the Reformation no +change has been made in the law of the Church which has not +been made by the king and parliament, sometimes indirectly, as +by confirming the resolutions of convocation, but for the most +part by statute. The list of statutes cited in Sir R. Phillimore’s +<i>Ecclesiastical Law</i> fills eleven pages. It is only by a kind of legal +fiction akin to the “collegial” theory mentioned above, that the +Church can be said to have deemed it expedient to adopt these +laws.</p> + +<p>The terms on which the Church Establishment of Ireland +was abolished, by the Irish Council Act of 1869, may be mentioned. +By sect. 20 the present ecclesiastical law was made binding on +the members for the time being of the Church, “as if they had +mutually contracted and agreed to abide by and observe the +same”; and by section 21 it was enacted that the ecclesiastical +courts should cease after the 1st of January 1871, and that the +ecclesiastical laws of Ireland, except so far as relates to matrimonial +causes and matters, should cease to exist as law. (See also +<span class="sc"><a href="#artlinks">England, Church of</a></span>; <span class="sc"><a href="#artlinks">Establishment</a></span>; &c.)</p> + +<div class="condensed"> +<p><span class="sc">Authorities.</span>—The number of works on ecclesiastical law is very +great, and it must suffice here to mention a few of the more conspicuous +modern ones: Ferdinand Walter, <i>Lehrbuch des Kirchenrechts +aller christlichen Konfessionen</i> (14th ed., Bonn, 1871); G. Phillips, +<i>Kirchenrecht</i>, Bde. i.-vii. (Regensburg, 1845-1872) incomplete; the +text-book by Cardinal Hergenröther (<i>q.v.</i>); P. Hinschius, <i>Kirchenrecht +der Katholiken und Protestanten in Deutschland</i>, 6 Bde. (Berlin, +1869 sqq.), only the Catholic part, a masterly and detailed survey +of the ecclesiastical law, finished; Sir Robert Phillimore, <i>Eccl. Law +of the Church of England</i> (2nd ed., edited by Sir Walter Phillimore, +2 vols., London, 1895). For further references see <span class="sc"><a href="#artlinks">Canon Law</a></span>, and +the article “Kirchenrecht” in Herzog-Hauck, <i>Realencyklopädie</i> +(ed. Leipzig, 1901).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECCLESIASTICUS<a name="ar120" id="ar120"></a></span> (abbreviated to <i>Ecclus.</i>), the alternative +title given in the English Bible to the apocryphal book otherwise +called “The Wisdom of Jesus the son of Sirach.” The Latin +word <i>ecclesiasticus</i> is, properly speaking, not a name, but an +epithet meaning “churchly,” so that it would serve as a designation +of any book which was read in church or received ecclesiastical +sanction, but in practice Ecclesiasticus has become a +by-name for the Wisdom of Sirach. The true name of the book +appears in the authorities in a variety of forms, the variation +affecting both the author’s name and the description of his book. +The writer’s full name is given in l. 27 (Heb. text) as “Simeon the +son of Jeshua (<i>i.e.</i> Jesus) the son of Eleazar the son of Sira.” +In the Greek text this name appears as “Jesus son of Sirach +Eleazar” (probably a corruption of the Hebrew reading), and the +epithet “of Jerusalem” is added, the translator himself being +resident in Egypt. The whole name is shortened sometimes to +“Son of Sira,” <i>Ben Sira</i> in Hebrew, <i>Bar Sira</i> in Aramaic, and +sometimes (as in the title prefixed in the Greek cod. B) to <i>Sirach</i>. +The work is variously described as the <i>Words</i> (Heb. text), the +<i>Book</i> (Talmud), the <i>Proverbs</i> (Jerome), or the <i>Wisdom</i> of the son +of Sira (or Sirach).</p> + +<p>Of the date of the book we have only one certain indication. +It was translated by a person who says that he “came into Egypt +in the 38th year of Euergetes the king” (Ptolemy VII.), <i>i.e.</i> in +132 <span class="scs">B.C.</span>, and that he executed the work some time later. The +translator believed that the writer of the original was his own +grandfather (or ancestor, <span class="grk" title="pappos">πάππος</span>). It is therefore reasonable to +suppose that the book was composed not later than the first half +of the 2nd century <span class="scs">B.C.</span>, or (if we give the looser meaning to <span class="grk" title="pappos">πάππος</span>) +even before the beginning of the century. Arguments for a pre-Maccabean +date may be derived (<i>a</i>) from the fact that the book +contains apparently no reference to the Maccabean struggles, +(<i>b</i>) from the eulogy of the priestly house of Zadok which fell into +disrepute during these wars for independence.</p> + +<p>In the Jewish Church Ecclesiasticus hovered on the border of +the canon; in the Christian Church it crossed and recrossed the +border. The book contains much which attracted and also +much which repelled Jewish feeling, and it appears that it was +necessary to pronounce against its canonicity. In the Talmud +(Sanhedrin 100 b) Rabbi Joseph says that it is forbidden to read +(<i>i.e.</i> in the synagogue) the book of ben Sira, and further that +“if our masters had not hidden the book (<i>i.e.</i> declared it uncanonical), +we might interpret the good things which are in it” +(Schechter, <i>J. Q. Review</i>, iii. 691-692). In the Christian Church it +was largely used by Clement of Alexandria (<i>c.</i> <span class="scs">A.D.</span> 200) and by +St Augustine. The lists of the Hebrew canon, however, given by +Melito (<i>c.</i> <span class="scs">A.D.</span> 180) and by Origen (<i>c.</i> <span class="scs">A.D.</span> 230) rightly exclude +Ecclesiasticus, and Jerome (<i>c.</i> <span class="scs">A.D.</span> 390-400) writes: “Let the Church +read these two volumes (Wisdom of Solomon and Ecclesiasticus) +for the instruction of the people, not for establishing the authority +of the dogmas of the Church” (<i>Praefatio in libros Salomonis</i>). +In the chief MS. of the Septuagint, cod. B, Ecclesiasticus comes +between Wisdom and Esther, no distinction being drawn between +canonical and uncanonical. In the Vulgate it immediately +precedes Isaiah. The council of Trent declared this book and +the rest of the books reckoned in the Thirty-nine Articles as +apocryphal to be canonical.</p> + +<p>The text of the book raises intricate problems which are still +far from solution. The original Hebrew (rediscovered in fragments +and published between 1896 and 1900) has come down +to us in a mutilated and corrupt form. The beginning as far as +iii. 7 is lost. There is a gap from xvi. 26 to xxx. 11. There are +marginal readings which show that two different recensions +existed once in Hebrew. The Greek version exists in two forms—(<i>a</i>) +that preserved in cod. B and in the other uncial MSS., (<i>b</i>) +that preserved in the cursive codex 248 (Holmes and Parsons). +The former has a somewhat briefer text, the latter agrees more +closely with the Hebrew text. The majority of Greek cursives +agree generally with the Latin Vulgate, and offer the fuller text +in a corrupt form. The Syriac (Peshitta) version is paraphrastic, +but on the whole it follows the Hebrew text. Owing to the +mutilation of the Hebrew by the accidents of time the Greek +version retains its place as the chief authority for the text, and +references by chapter and verse are usually made to it.</p> + +<p>Bickell and D.S. Margoliouth have supposed that the Hebrew +text preserved in the fragments is not original, but a retranslation +from the Greek or the Syriac or both. This view has not commended +itself to the majority of scholars, but there is at least a +residuum of truth in it. The Hebrew text, as we have it, has a +history of progressive corruption behind it, and its readings +can often be emended from the Septuagint, <i>e.g.</i> xxxvii. 11 (read +<span title="umira al">ומירא על</span> for the meaningless <span title="umerer el">ומרר אל</span>). The Hebrew marginal +readings occasionally seem to be translations from the Greek +or Syriac, <i>e.g.</i> xxxviii. 4 (<span title="bara shamaym">ברא שמים</span> for <span class="grk" title="ektisen pharmaka">ἒκτισεν φάρμακα</span>). More +frequently, however, strange readings of the Greek and Syriac +<span class="pagenum"><a name="page869" id="page869"></a>869</span> +are to be explained as corruptions of our present Hebrew. +Substantially our Hebrew must be pronounced original.</p> + +<p>The restoration of a satisfactory text is beyond our hopes. +Even before the Christian era the book existed in two recensions, +for we cannot doubt, after reading the Greek translator’s preface, +that the translator amplified and paraphrased the text before +him. It is probable that at least one considerable omission must +be laid to his charge, for the hymn preserved in the Hebrew +text after ch. li. 12 is almost certainly original. Ancient translators +allowed themselves much liberty in their work, and Ecclesiasticus +possessed no reputation for canonicity in the 2nd century <span class="scs">B.C.</span> +to serve as a protection for its text. Much, however, may be +done towards improving two of the recensions which now lie +before us. The incomplete Hebrew text exists in four different +MSS., and the study of the peculiarities of these had already +proved fruitful. The Syriac text, made without doubt from the +Hebrew, though often paraphrastic is often suggestive. The +Greek translation, made within a century or half-century of the +writing of the book, must possess great value for the criticism +of the Hebrew text. The work of restoring true Hebrew readings +may proceed with more confidence now that we have considerable +portions of the Hebrew text to serve as a model. For the +restoration of the Greek text we have, besides many Greek MSS., +uncial and cursive, the old Latin, the Syro-Hexaplar, the +Armenian, Sahidic and Ethiopic versions, as well as a considerable +number of quotations in the Greek and Latin Fathers. Each +of the two recensions of the Greek must, however, be separately +studied, before any restoration of the original Greek text can be +attempted.</p> + +<p>The uncertainty of the text has affected both English versions +unfavourably. The Authorized Version, following the corrupt +cursives, is often wrong. The Revised Version, on the other +hand, in following the uncial MSS. sometimes departs from the +Hebrew, while the Authorized Version with the cursives agrees +with it. Thus the Revised Version (with codd. <span title="alef">א</span>*, A, B, C) omits +the whole of iii. 19, which the Authorized Version retains, but for +the clause, “Mysteries are revealed unto the meek,” the Authorized +Version has the support of the Hebrew, Syriac and cod. 248. +Sometimes both versions go astray in places in which the Hebrew +text recommends itself as original by its vigour; <i>e.g.</i> in vii. 26, +where the Hebrew is,</p> + +<table class="reg f90" summary="poem"><tr><td> <div class="poemr"> +<p>Hast thou a wife? abominate her not.</p> +<p>Hast thou a hated wife? trust not in her.</p> +</div> </td></tr></table> + +<p class="noind">Again in ch. xxxviii. the Hebrew text in at least two interesting +passages shows its superiority over the text which underlies both +English versions.</p> + +<table class="pic f90" summary="Contents"> + +<tr><td class="tcc" colspan="2"><i>Hebrew.</i></td> <td class="tcc"><i>Revised Version</i> (<i>similarly<br />Authorized Version</i>).</td></tr> + +<tr><td class="tcl">ver. 1.</td> + +<td class="tcl" style="width: 40%; vertical-align: top;">Acquaint thyself with a +physician before thou have +need of him.</td> + +<td class="tcl" style="width: 40%; vertical-align: top;">Honour a physician according +to thy need of him with the +honours due unto him.</td></tr> + +<tr><td class="tcl">ver. 15.</td> + +<td class="tcl" style="width: 40%; vertical-align: top;">He that sinneth against his +Maker will behave himself +proudly against a physician.</td> + +<td class="tcl" style="width: 40%; vertical-align: top;">He that sinneth before his +Maker, let him fall into the +hands of the physician.</td></tr> +</table> + +<p class="noind">In the second instance, while the Hebrew says that the man who +rebels against his Heavenly Benefactor will <i>a fortiori</i> rebel +against a human benefactor, the Greek text gives a cynical +turn to the verse, “Let the man who rebels against his true +benefactor be punished through the tender mercies of a quack.” +The Hebrew text is probably superior also in xliv. 1, the opening +words of the eulogy of the Fathers: “Let me now praise favoured +men,” <i>i.e.</i> men in whom God’s grace was shown. The Hebrew +phrase is “men of grace,” as in v. 10. The Greek text of <i>v.</i> 1, +“famous men,” seems to be nothing but a loose paraphrase, +suggested by <i>v.</i> 2, “The Lord manifested in them great +glory.”</p> + +<p>In character and contents Ecclesiasticus resembles the book of +Proverbs. It consists mainly of maxims which may be described +in turn as moral, utilitarian and secular. Occasionally the +author attacks prevalent religious opinions, <i>e.g.</i> the denial of +free-will (xv. 11-20), or the assertion of God’s indifference towards +men’s actions (xxxv. 12-19). Occasionally, again, Ben Sira +touches the highest themes, and speaks of the nature of God: +“He is All” (xliii. 27); “He is One from everlasting” (xlii. 21, +Heb. text); “The mercy of the Lord is upon all flesh” (xviii. 13). +Though the book is imitative and secondary in character it +contains several passages of force and beauty, <i>e.g.</i> ch. ii. (how to +fear the Lord); xv. 11-20 (on free-will); xxiv. 1-22 (the song of +wisdom); xlii. 15-25 (praise of the works of the Lord); xliv. +1-15 (the well-known praise of famous men). Many detached +sayings scattered throughout the book show a depth of insight, +or a practical shrewdness, or again a power of concise speech, +which stamps them on the memory. A few examples out of +many may be cited. “Call no man blessed before his death” +(xi. 28); “He that toucheth pitch shall be defiled” (xiii. 1); +“He hath not given any man licence to sin” (xv. 20); “Man +cherisheth anger against man; and doth he seek healing from +the Lord?” (xxviii. 3); “Mercy is seasonable ... as clouds of +rain” (xxxv. 20); “All things are double one against another: +and he hath made nothing imperfect” (xlii. 24, the motto of +Butler’s <i>Analogy</i>); “Work your work before the time cometh, +and in his time he will give you your reward” (li. 30). In spite, +however, of the words just quoted it cannot be said that Ben +Sira preaches a hopeful religion. Though he prays, “Renew +thy signs, and repeat thy wonders ... Fill Sion with thy +majesty and thy Temple with thy glory” (xxxvi. 6, 14 [19], +Heb. text), he does not look for a Messiah. Of the resurrection +of the dead or of the immortality of the soul there is no word, +not even in xli. 1-4, where the author exhorts men not to fear +death. Like the Psalmist (Ps. lxxxviii. 10, 11) he asks, “Who +shall give praise to the Most High in the grave?” In his +maxims of life he shows a somewhat frigid and narrow mind. +He is a pessimist as regards women; “From a woman was the +beginning of sin; and because of her we all die” (xxv. 24). He +does not believe in home-spun wisdom; “How shall he become +wise that holdeth the plough?” (xxxviii. 25). Artificers are not +expected to pray like the wise man; “In the handywork of +their craft is their prayer” (<i>v.</i> 34). Merchants are expected +to cheat; “Sin will thrust itself in between buying and selling” +(xxvii. 2).</p> + +<div class="condensed"> +<p><span class="sc">Bibliography.</span>—The literature of Ecclesiaticus has grown very +considerably since the discovery of the first Hebrew fragment in +1896. A useful summary of it is found at the end of Israel Levi’s +article, “Sirach,” in the <i>Jewish Encyclopedia</i>. Eberhard Nestle’s +article in Hastings’s <i>Dictionary of the Bible</i> is important for its +bibliographical information as well as in other respects. A complete +edition of the Hebrew fragments in collotype facsimile was published +jointly by the Oxford and Cambridge Presses in 1901. +J.H.A. Hart’s edition of cod. 248 throws much light on some of +the problems of this book. It contains a fresh collation of all the chief +authorities (Heb., Syr., Syr.-Hex., Lat. and Gr.) for the text, together +with a complete textual commentary.</p> + +<p>The account given in the <i>Synopsis</i> attributed to Athanasius +(Migne, <i>P.G.</i>, iv. 375-384) has an interest of its own. The beginning +is given in the Authorized Version as “A prologue made by an +uncertain author.”</p> +</div> +<div class="author">(W. E. B.)</div> + + +<hr class="art" /> +<p><span class="bold">ECGBERT,<a name="ar121" id="ar121"></a></span> or <span class="sc">Ecgberht</span> (d. 839), king of the West Saxons, +succeeded to the throne in 802 on the death of Beorhtric. It +is said that at an earlier period in his life he had been driven out +for three years by Offa and Beorhtric. The accession of Ecgbert +seems to have brought about an invasion by Æthelmund, earl +of the Hwicce, who was defeated by Weoxtan, earl of Wiltshire. +In 815 Ecgbert ravaged the whole of the territories of the West +Welsh, which probably at this time did not include much more +than Cornwall. The next important occurrence in the reign +was the defeat of Beornwulf of Mercia at a place called Ellandun +in 825. After this victory Kent, Surrey, Sussex and Essex submitted +to Wessex; while the East Anglians, who slew Beornwulf +shortly afterwards, acknowledged Ecgbert as overlord. In +829 the king conquered Mercia, and Northumbria accepted +him as overlord. In 830 he led a successful expedition against +the Welsh. In 836 he was defeated by the Danes, but in 838 +he won a battle against them and their allies the West Welsh +at Hingston Down in Cornwall. Ecgbert died in 839, after a +reign of thirty-seven years, and was succeeded by his son Æthelwulf. +A somewhat difficult question has arisen as to the +parentage of Ecgbert. Under the year 825 the Chronicle states +<span class="pagenum"><a name="page870" id="page870"></a>870</span> +that in his eastern conquests Ecgbert recovered what had been +the rightful property of his kin. The father of Ecgbert was +called Ealhmund, and we find an Ealhmund, king in Kent, +mentioned in a charter dated 784, who is identified with Ecgbert’s +father in a late addition to the Chronicle under the date 784. +It is possible, however, that the Chronicle in 825 refers to some +claim through Ine of Wessex from whose brother Ingeld Ecgbert +was descended.</p> + +<div class="condensed"> +<p>See <i>Anglo-Saxon Chronicle</i>, edited by Earle and Plummer (Oxford, +1899); W. de G. Birch, <i>Cartularium Saxonicum</i> (London, 1885-1893). +Also a paper by Sir H.H. Howorth in <i>Numismatic Chronicle</i>, +third series, vol. xx. pp. 66-87 (reprinted separately, London, 1900), +where attention is called to the peculiar dating of several of Ecgbert’s +charters, and the view is put forward that he remained abroad considerably +later than the date given by the Chronicle for his accession. +On the other hand a charter in Birch, <i>Cart. Sax.</i>, purporting to date +from 799, contains the curious statement that peace was made +between Cœnwulf and Ecgbert in that year.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECGBERT,<a name="ar122" id="ar122"></a></span> or <span class="sc">Ecgberht</span> (d. 766), archbishop of York, was +made bishop of that see in 734 by Ceolwulf, king of Northumbria, +succeeding Wilfrid II. on the latter’s resignation. The pall was +sent him in 735 and he became the first northern archbishop +after Paulinus. He was the brother of Eadberht, who ruled +Northumbria 737-758. He was the recipient of the famous +letter of Bede, dealing with the evils arising from spurious +monasteries. Ecgberht himself wrote a <i>Dialogus Ecclesiasticae +Institutionis</i>, a <i>Penitentiale</i> and a <i>Pontificale</i>. He was a correspondent +of St Boniface, who asks him to support his censure +of Æthelbald of Mercia.</p> + +<div class="condensed"> +<p>See Bede, <i>Continuatio</i>, sub. ann. 732, 735, 766, and <i>Epistola ad +Ecgberctum</i> (Plummer, Oxford, 1896); <i>Chronicle</i>, sub ann. 734, 735, +738, 766 (Earle and Plummer, Oxford, 1899); Haddan and Stubbs, +<i>Councils and Ecclesiastical Documents</i> (Oxford, 1869-1878), iii. +403-431; <i>Proceedings of Surtees Society</i> (Durham, 1853).</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECGFRITH<a name="ar123" id="ar123"></a></span> (d. 685), king of Northumbria, succeeded his +father Oswio in 671. He was married to Æthelthryth, daughter +of Anna of East Anglia, who, however, took the veil shortly after +Ecgfrith’s accession, a step which possibly led to his long quarrel +with Wilfrid archbishop of York. Ecgfrith married a second wife, +Eormenburg, before 678, the year in which he expelled Wilfrid +from his kingdom. Early in his reign he defeated the Picts who +had risen in revolt. Between 671 and 675 Ecgfrith defeated +Wulfhere of Mercia and seized Lindsey. In 679, however, he +was defeated by Æthelred of Mercia, who had married his sister +Osthryth, on the river Trent. Ecgfrith’s brother Ælfwine was +killed in the battle, and the province of Lindsey was given up +when peace was restored at the intervention of Theodore of +Canterbury. In 684 Ecgfrith sent an expedition to Ireland +under his general Berht, which seems to have been unsuccessful. +In 685, against the advice of Cuthbert, he led a force against +the Picts under his cousin Burde, son of Bile, was lured by +a feigned flight into their mountain fastnesses, and slain at +Nechtanesmere (now Dunnichen) in Forfarshire. Bede dates +the beginning of the decline of Northumbria from his death. +He was succeeded by his brother Aldfrith.</p> + +<div class="condensed"> +<p>See Eddius, <i>Vita Wilfridi</i> (Raine, <i>Historians of Church of York</i>, +Rolls, Series, London, 1879-1894), 19, 20, 24, 34, 39, 44; Bede, <i>Hist. +Eccl.</i> (Plummer, Oxford, 1896), iii. 24, iv. 5, 12, 13, 18, 19, 21, 26.</p> +</div> + + +<hr class="art" /> +<p><span class="bold">ECGONINE,<a name="ar124" id="ar124"></a></span> in chemistry, C<span class="su">9</span>H<span class="su">15</span>NO<span class="su">3</span>, a cycloheptane derivative +with a nitrogen bridge. It is obtained by hydrolysing cocaine +with acids or alkalis, and crystallizes with one molecule of water, +the crystals melting at 198° to 199° C. It is laevo-rotatory, and on +warming with alkalis gives iso-ecgonine, which is dextro-rotatory. +It is a tertiary base, and has also the properties of an acid and +an alcohol. When boiled with caustic baryta it gives methylamine. +It is the carboxylic acid corresponding to tropine, for it +yields the same products on oxidation, and by treatment with +phosphorus pentachloride is converted into anhydroecgonine, +C<span class="su">9</span>H<span class="su">13</span>NO<span class="su">2</span>, which, when heated to 280° C. with hydrochloric +acid, splits out carbon dioxide and yields tropidine, C<span class="su">8</span>H<span class="su">13</span>N. +Anhydroecgonine melts at 235° C., and has an acid and a basic +character. It is an unsaturated compound, and on oxidation +with potassium permanganate gives succinic acid. It is apparently +a tropidine monocarboxylic acid, for on exhaustive +methylation it yields cycloheptatriene-1·3·5-carboxylic acid-7. +Sodium in amyl alcohol solution reduces it to hydroecgonidine +C<span class="su">9</span>H<span class="su">15</span>NO<span class="su">2</span>, while moderate oxidation by potassium permanganate +converts it into <i>norecgonine</i>. The presence of the heptamethylene +ring in these compounds is shown by the production +of suberone by the exhaustive methylation, &c., of hydroecgonidine +ethyl ester (see <span class="sc"><a href="#artlinks">Polymethylenes</a></span> and <span class="sc"><a href="#artlinks">Tropine</a></span>). The +above compounds may be represented as:</p> + +<div class="center pt2"><img style="width:502px; height:93px" src="images/img870.jpg" alt="" /></div> + + +<hr class="art" /> +<p><span class="bold">ECHEGARAY Y EIZAGUIRRE, JOSÉ<a name="ar125" id="ar125"></a></span> (1833-  ), Spanish +mathematician, statesman and dramatist, was born at Madrid +in March 1833, and was educated at the grammar school of +Murcia, whence he proceeded to the Escuela de Caminos at the +capital. His exemplary diligence and unusual mathematical +capacity were soon noticed. In 1853 he passed out at the head +of the list of engineers, and, after a brief practical experience at +Almería and Granada, was appointed professor of pure and +applied mathematics in the school where he had lately been a +pupil. His <i>Problemas de geometría analítica</i> (1865) and <i>Teorías +modernas de la física unidad de las fuerzas materiales</i> (1867) are +said to be esteemed by competent judges. He became a member +of the Society of Political Economy, helped to found <i>La Revista</i>, +and took a prominent part in propagating Free Trade doctrines +in the press and on the platform. He was clearly marked out +for office, and when the popular movement of 1868 overthrew the +monarchy, he resigned his post for a place in the revolutionary +cabinet. Between 1867 and 1874 he acted as minister of education +and of finance; upon the restoration of the Bourbon +dynasty he withdrew from politics, and won a new reputation as +a dramatist.</p> + +<p>As early as 1867 he wrote <i>La Hija natural</i>, which was rejected, +and remained unknown till 1877, when it appeared with the title +of <i>Para tal culpa tal pena</i>. Another play, <i>La Última Noche</i>, also +written in 1867, was produced in 1875; but in the latter year +Echegaray was already accepted as the successful author of <i>El +Libro talonario</i>, played at the Teatro de Apolo on the 18th of +February 1874, under the transparent pseudonym of Jorge +Hayaseca. Later in the same year Echegaray won a popular +triumph with <i>La Esposa del vengador</i>, in which the good and bad +qualities—the clever stagecraft and unbridled extravagance—of +his later work are clearly noticeable. From 1874 onwards +he wrote, with varying success, a prodigious number of plays. +Among the most favourable specimens of his talent may be +mentioned <i>En el puño de la espada</i> (1875); <i>O locura ó santidad</i> +(1877), which has been translated into Swedish and Italian; +<i>En el seno de la muerte</i> (1879), of which there exists an admirable +German version by Fastenrath. <i>El gran Galeoto</i> (1881), perhaps +the best of Echegaray’s plays in conception and execution, has +been translated into several languages, and still holds the stage. +The humorous proverb, <i>¿Piensa mal y acertarás?</i> exemplifies the +author’s limitations, but the attempt is interesting as an instance +of ambitious versatility. His susceptibility to new ideas is +illustrated in such pieces as <i>Mariana</i> (1892), <i>Mancha que limpia</i> +(1895), <i>El Hijo de Don Juan</i> (1892), and <i>El Loco Dios</i> (1900): +these indicate a close study of Ibsen, and <i>El Loco Dios</i> more +especially might be taken for an unintentional parody of +Ibsen’s symbolism.</p> + +<p>Echegaray succeeded to the literary inheritance of López de +Ayala and of Tamayo y Baus; and though he possesses neither +the poetic imagination of the first nor the instinctive tact of the +second, it is impossible to deny that he has reached a larger +audience than either. Not merely in Spain, but in every land +where Spanish is spoken, and in cities as remote from Madrid as +Munich and Stockholm, he has met with an appreciation incomparably +beyond that accorded to any other Spanish dramatist +of recent years. But it would be more than usually rash to +prophesy that this exceptional popularity will endure. There +have been signs of a reaction in Spain itself, and Echegaray’s +return to politics in 1905 was significant enough. He applies +<span class="pagenum"><a name="page871" id="page871"></a>871</span> +his mathematics to the drama; no writer excels him in artful +construction, in the arrangement of dramatic scenes, in mere +theatrical technique, in the focusing of attention on his chief +personages. These are valuable gifts in their way, and Echegaray +has, moreover, a powerful, gloomy imagination, which is momentarily +impressive. In the drawing of character, in the invention +of felicitous phrase, in the contrivance of verbal music, he is +deficient. He alternates between the use of verse and prose; +and his hesitancy in choosing a medium of expression is amply +justified, for the writer’s prose is not more distinguished than his +verse. These serious shortcomings may explain the diminution +of his vogue in Spain; they will certainly tell against him in the +estimate of posterity.</p> +<div class="author">(J. F.-K.)</div> + + +<hr class="art" /> +<p><span class="bold">ÉCHELON<a name="ar126" id="ar126"></a></span> (Fr. from <i>échelle</i>, ladder), in military tactics, a +formation of troops in which each body of troops is retired on, +but not behind, the flank of the next in front, the position of +the whole thus resembling the steps of a staircase. To form +échelon from line, the parts of the line move off, each direct to +its front, in succession, so that when the formation is completed +the rightmost body, for example, is farthest advanced, the one +originally next on its left is to the left rear, a third is to the left +rear of the second, and so on. The word is also used more loosely +to express successive lines, irrespective of distances and relative +positions, <i>e.g.</i> the “second échelon of ammunition supply,” +which is fully a day’s march behind the first.</p> + + +<hr class="art" /> +<p><span class="bold">ECHIDNA,<a name="ar127" id="ar127"></a></span> or <span class="sc">Porcupine Ant-Eater</span> (<i>Echidna aculeata</i>), +one of the few species of Monotremata, the lowest subclass of +Mammalia, forming the family Echidnidae. It is a native of +Australia, where it chiefly abounds in New South Wales, inhabiting +rocky and mountainous districts, where it burrows among the +loose sand, or hides itself in crevices of rocks. In size and +appearance it bears a considerable resemblance to the hedgehog, +its upper surface being covered over with strong spines directed +backwards, and on the back inwards, so as to cross each other +on the middle line. The spines in the neighbourhood of the tail +form a tuft sufficient to hide that almost rudimentary organ. +The head is produced into a long tubular snout, covered with +skin for the greater part of its length. The opening of the mouth +is small, and from it the echidna puts forth its long slender +tongue, lubricated with a viscous secretion, by means of which it +seizes the ants and other insects on which it feeds. It has no +teeth. Its legs are short and strong, and form, with its broad +feet and large solid nails, powerful burrowing organs. In +common with the other monotremes, the male echidna has its +heel provided with a sharp hollow spur, connected with a secreting +gland, and with muscles capable of pressing the secretion from +the gland into the spur. It is a nocturnal or crepuscular animal, +generally sleeping during the day, but showing considerable +activity by night. When attacked it seeks to escape either by +rolling itself into a ball, its erect spines proving a formidable +barrier to its capture, or by burrowing into the sand, which its +powerful limbs enable it to do with great celerity. “The only +mode of carrying the creature,” writes G. Bennett (<i>Gatherings +of a Naturalist in Australasia</i>), “is by one of the hind legs; its +powerful resistance and the sharpness of the spines will soon +oblige the captor, attempting to seize it by any other part of the +body, to relinquish his hold.” In a younger stage of their +development, however, the young are carried in a temporary +abdominal pouch, to which they are transferred after hatching, +and into which open the mammary glands. The echidnas are +exceedingly restless in confinement, and constantly endeavour by +burrowing to effect their escape. From the quantity of sand and +mud always found in the alimentary canal of these animals, +it is supposed that these ingredients must be necessary to the +proper digestion of their insect food.</p> + +<p>There are two varieties of this species, the Port Moresby +echidna and the hairy echidna. The last-mentioned is found in +south-eastern New Guinea, Australia and Tasmania. In all the +spines are mixed with hair; in the Tasmanian race they are +nearly hidden by the long harsh fur. Of the three-clawed +echidnas (<i>Proechidna</i>) confined to New Guinea there are two +species, Bruijn’s echidna (<i>P. bruijnii</i>), discovered in 1877 in the +mountains on the north-east coast at an elevation of 3500 ft., and +the black-spined echidna (<i>P. nigroaculeata</i>) of larger size—the +type specimen measuring 31 in., as against 24 in.—with shorter +claws.</p> + +<hr class="art" /> + + + + + + + + + +<pre> + + + + + +End of the Project Gutenberg EBook of Encyclopaedia Britannica, 11th +Edition, Volume 8, Slice 9, by Various + +*** END OF THIS PROJECT GUTENBERG EBOOK ENCYCLOPAEDIA BRITANNICA *** + +***** This file should be named 34878-h.htm or 34878-h.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/3/4/8/7/34878/ + +Produced by Marius Masi, Don Kretz and the Online +Distributed Proofreading Team at http://www.pgdp.net + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +http://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need, are critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at http://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +http://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at http://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit http://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including checks, online payments and credit card donations. +To donate, please visit: http://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart is the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + http://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. + + +</pre> + +</body> +</html> + diff --git a/34878-h/images/img764.jpg b/34878-h/images/img764.jpg Binary files differnew file mode 100644 index 0000000..e37670a --- /dev/null +++ b/34878-h/images/img764.jpg diff --git a/34878-h/images/img765.jpg b/34878-h/images/img765.jpg Binary files differnew file mode 100644 index 0000000..887772f --- /dev/null +++ b/34878-h/images/img765.jpg diff --git a/34878-h/images/img766a.jpg b/34878-h/images/img766a.jpg Binary files differnew file mode 100644 index 0000000..aa8326e --- /dev/null +++ b/34878-h/images/img766a.jpg diff --git a/34878-h/images/img766b.jpg b/34878-h/images/img766b.jpg Binary files differnew file mode 100644 index 0000000..8d2663b --- /dev/null +++ b/34878-h/images/img766b.jpg diff --git a/34878-h/images/img766c.jpg b/34878-h/images/img766c.jpg Binary files differnew file mode 100644 index 0000000..57a44d2 --- /dev/null +++ b/34878-h/images/img766c.jpg diff --git a/34878-h/images/img766d.jpg b/34878-h/images/img766d.jpg Binary files differnew file mode 100644 index 0000000..09dfd66 --- /dev/null +++ b/34878-h/images/img766d.jpg diff --git a/34878-h/images/img766e.jpg b/34878-h/images/img766e.jpg Binary files differnew file mode 100644 index 0000000..0605cdd --- /dev/null +++ b/34878-h/images/img766e.jpg diff --git a/34878-h/images/img767.jpg b/34878-h/images/img767.jpg Binary files differnew file mode 100644 index 0000000..fd3cede --- /dev/null +++ b/34878-h/images/img767.jpg diff --git a/34878-h/images/img768a.jpg b/34878-h/images/img768a.jpg Binary files differnew file mode 100644 index 0000000..f81e64c --- /dev/null +++ b/34878-h/images/img768a.jpg diff --git a/34878-h/images/img768b.jpg b/34878-h/images/img768b.jpg Binary files differnew file mode 100644 index 0000000..8aacadc --- /dev/null +++ b/34878-h/images/img768b.jpg diff --git a/34878-h/images/img769a.jpg b/34878-h/images/img769a.jpg Binary files differnew file mode 100644 index 0000000..3cc4a08 --- /dev/null +++ b/34878-h/images/img769a.jpg diff --git a/34878-h/images/img769b.jpg b/34878-h/images/img769b.jpg Binary files differnew file mode 100644 index 0000000..a13da93 --- /dev/null +++ b/34878-h/images/img769b.jpg diff --git a/34878-h/images/img769c.jpg b/34878-h/images/img769c.jpg Binary files differnew file mode 100644 index 0000000..993c44b --- /dev/null +++ b/34878-h/images/img769c.jpg diff --git a/34878-h/images/img769d.jpg b/34878-h/images/img769d.jpg Binary files differnew file mode 100644 index 0000000..7e50ede --- /dev/null +++ b/34878-h/images/img769d.jpg diff --git a/34878-h/images/img770a.jpg b/34878-h/images/img770a.jpg Binary files differnew file mode 100644 index 0000000..7129333 --- /dev/null +++ b/34878-h/images/img770a.jpg diff --git a/34878-h/images/img770b.jpg b/34878-h/images/img770b.jpg Binary files differnew file mode 100644 index 0000000..13ddff8 --- /dev/null +++ b/34878-h/images/img770b.jpg diff --git a/34878-h/images/img771a.jpg b/34878-h/images/img771a.jpg Binary files differnew file mode 100644 index 0000000..638fda7 --- /dev/null +++ b/34878-h/images/img771a.jpg diff --git a/34878-h/images/img771b.jpg b/34878-h/images/img771b.jpg Binary files differnew file mode 100644 index 0000000..d2cf335 --- /dev/null +++ b/34878-h/images/img771b.jpg diff --git a/34878-h/images/img771c.jpg b/34878-h/images/img771c.jpg Binary files differnew file mode 100644 index 0000000..9e8e404 --- /dev/null +++ b/34878-h/images/img771c.jpg diff --git a/34878-h/images/img772a.jpg b/34878-h/images/img772a.jpg Binary files differnew file mode 100644 index 0000000..0ef7fb6 --- /dev/null +++ b/34878-h/images/img772a.jpg diff --git a/34878-h/images/img772b.jpg b/34878-h/images/img772b.jpg Binary files differnew file mode 100644 index 0000000..b3ae9cf --- /dev/null +++ b/34878-h/images/img772b.jpg diff --git a/34878-h/images/img772c.jpg b/34878-h/images/img772c.jpg Binary files differnew file mode 100644 index 0000000..7afa286 --- /dev/null +++ b/34878-h/images/img772c.jpg diff --git a/34878-h/images/img772d.jpg b/34878-h/images/img772d.jpg Binary files differnew file mode 100644 index 0000000..529b4fc --- /dev/null +++ b/34878-h/images/img772d.jpg diff --git a/34878-h/images/img773a.jpg b/34878-h/images/img773a.jpg Binary files differnew file mode 100644 index 0000000..1f7cb30 --- /dev/null +++ b/34878-h/images/img773a.jpg diff --git a/34878-h/images/img773b.jpg b/34878-h/images/img773b.jpg Binary files differnew file mode 100644 index 0000000..d0884e2 --- /dev/null +++ b/34878-h/images/img773b.jpg diff --git a/34878-h/images/img773c.jpg b/34878-h/images/img773c.jpg Binary files differnew file mode 100644 index 0000000..f22f8c4 --- /dev/null +++ b/34878-h/images/img773c.jpg diff --git a/34878-h/images/img774a.jpg b/34878-h/images/img774a.jpg Binary files differnew file mode 100644 index 0000000..aca6d71 --- /dev/null +++ b/34878-h/images/img774a.jpg diff --git a/34878-h/images/img774b.jpg b/34878-h/images/img774b.jpg Binary files differnew file mode 100644 index 0000000..18f3473 --- /dev/null +++ b/34878-h/images/img774b.jpg diff --git a/34878-h/images/img774c.jpg b/34878-h/images/img774c.jpg Binary files differnew file mode 100644 index 0000000..acbccd6 --- /dev/null +++ b/34878-h/images/img774c.jpg diff --git a/34878-h/images/img775a.jpg b/34878-h/images/img775a.jpg Binary files differnew file mode 100644 index 0000000..5e41b8f --- /dev/null +++ b/34878-h/images/img775a.jpg diff --git a/34878-h/images/img775b.jpg b/34878-h/images/img775b.jpg Binary files differnew file mode 100644 index 0000000..7a38929 --- /dev/null +++ b/34878-h/images/img775b.jpg diff --git a/34878-h/images/img776a.jpg b/34878-h/images/img776a.jpg Binary files differnew file mode 100644 index 0000000..835788c --- /dev/null +++ b/34878-h/images/img776a.jpg diff --git a/34878-h/images/img776b.jpg b/34878-h/images/img776b.jpg Binary files differnew file mode 100644 index 0000000..c32aed5 --- /dev/null +++ b/34878-h/images/img776b.jpg diff --git a/34878-h/images/img776c.jpg b/34878-h/images/img776c.jpg Binary files differnew file mode 100644 index 0000000..1f9a6af --- /dev/null +++ b/34878-h/images/img776c.jpg diff --git a/34878-h/images/img778.jpg b/34878-h/images/img778.jpg Binary files differnew file mode 100644 index 0000000..998f3ec --- /dev/null +++ b/34878-h/images/img778.jpg diff --git a/34878-h/images/img779.jpg b/34878-h/images/img779.jpg Binary files differnew file mode 100644 index 0000000..fc5cad6 --- /dev/null +++ b/34878-h/images/img779.jpg diff --git a/34878-h/images/img779a.jpg b/34878-h/images/img779a.jpg Binary files differnew file mode 100644 index 0000000..3f87fd7 --- /dev/null +++ b/34878-h/images/img779a.jpg diff --git a/34878-h/images/img780a.jpg b/34878-h/images/img780a.jpg Binary files differnew file mode 100644 index 0000000..3ca5a21 --- /dev/null +++ b/34878-h/images/img780a.jpg diff --git a/34878-h/images/img780b.jpg b/34878-h/images/img780b.jpg Binary files differnew file mode 100644 index 0000000..06b53cc --- /dev/null +++ b/34878-h/images/img780b.jpg diff --git a/34878-h/images/img780c.jpg b/34878-h/images/img780c.jpg Binary files differnew file mode 100644 index 0000000..0638efa --- /dev/null +++ b/34878-h/images/img780c.jpg diff --git a/34878-h/images/img781.jpg b/34878-h/images/img781.jpg Binary files differnew file mode 100644 index 0000000..7c7a7dc --- /dev/null +++ b/34878-h/images/img781.jpg diff --git a/34878-h/images/img782a.jpg b/34878-h/images/img782a.jpg Binary files differnew file mode 100644 index 0000000..b2f66d7 --- /dev/null +++ b/34878-h/images/img782a.jpg diff --git a/34878-h/images/img782b.jpg b/34878-h/images/img782b.jpg Binary files differnew file mode 100644 index 0000000..389059a --- /dev/null +++ b/34878-h/images/img782b.jpg diff --git a/34878-h/images/img783a.jpg b/34878-h/images/img783a.jpg Binary files differnew file mode 100644 index 0000000..787fb7e --- /dev/null +++ b/34878-h/images/img783a.jpg diff --git a/34878-h/images/img783b.jpg b/34878-h/images/img783b.jpg Binary files differnew file mode 100644 index 0000000..0cb5674 --- /dev/null +++ b/34878-h/images/img783b.jpg diff --git a/34878-h/images/img783c.jpg b/34878-h/images/img783c.jpg Binary files differnew file mode 100644 index 0000000..c2eeaaf --- /dev/null +++ b/34878-h/images/img783c.jpg diff --git a/34878-h/images/img783d.jpg b/34878-h/images/img783d.jpg Binary files differnew file mode 100644 index 0000000..0b7e22b --- /dev/null +++ b/34878-h/images/img783d.jpg diff --git a/34878-h/images/img784a.jpg b/34878-h/images/img784a.jpg Binary files differnew file mode 100644 index 0000000..f217bdf --- /dev/null +++ b/34878-h/images/img784a.jpg diff --git a/34878-h/images/img784b.jpg b/34878-h/images/img784b.jpg Binary files differnew file mode 100644 index 0000000..6aa359f --- /dev/null +++ b/34878-h/images/img784b.jpg diff --git a/34878-h/images/img784c.jpg b/34878-h/images/img784c.jpg Binary files differnew file mode 100644 index 0000000..0108b45 --- /dev/null +++ b/34878-h/images/img784c.jpg diff --git a/34878-h/images/img788a.jpg b/34878-h/images/img788a.jpg Binary files differnew file mode 100644 index 0000000..fe74992 --- /dev/null +++ b/34878-h/images/img788a.jpg diff --git a/34878-h/images/img788b.jpg b/34878-h/images/img788b.jpg Binary files differnew file mode 100644 index 0000000..4a2ca48 --- /dev/null +++ b/34878-h/images/img788b.jpg diff --git a/34878-h/images/img788c.jpg b/34878-h/images/img788c.jpg Binary files differnew file mode 100644 index 0000000..36caffa --- /dev/null +++ b/34878-h/images/img788c.jpg diff --git a/34878-h/images/img788d.jpg b/34878-h/images/img788d.jpg Binary files differnew file mode 100644 index 0000000..1bef0b1 --- /dev/null +++ b/34878-h/images/img788d.jpg diff --git a/34878-h/images/img788e.jpg b/34878-h/images/img788e.jpg Binary files differnew file mode 100644 index 0000000..dc51f98 --- /dev/null +++ b/34878-h/images/img788e.jpg diff --git a/34878-h/images/img788f.jpg b/34878-h/images/img788f.jpg Binary files differnew file mode 100644 index 0000000..9b1174f --- /dev/null +++ b/34878-h/images/img788f.jpg diff --git a/34878-h/images/img788g.jpg b/34878-h/images/img788g.jpg Binary files differnew file mode 100644 index 0000000..57cc1c4 --- /dev/null +++ b/34878-h/images/img788g.jpg diff --git a/34878-h/images/img788h.jpg b/34878-h/images/img788h.jpg Binary files differnew file mode 100644 index 0000000..d062b6a --- /dev/null +++ b/34878-h/images/img788h.jpg diff --git a/34878-h/images/img788i.jpg b/34878-h/images/img788i.jpg Binary files differnew file mode 100644 index 0000000..fa58bee --- /dev/null +++ b/34878-h/images/img788i.jpg diff --git a/34878-h/images/img790a.jpg b/34878-h/images/img790a.jpg Binary files differnew file mode 100644 index 0000000..b335e85 --- /dev/null +++ b/34878-h/images/img790a.jpg diff --git a/34878-h/images/img790b.jpg b/34878-h/images/img790b.jpg Binary files differnew file mode 100644 index 0000000..f47bf8c --- /dev/null +++ b/34878-h/images/img790b.jpg diff --git a/34878-h/images/img791.jpg b/34878-h/images/img791.jpg Binary files differnew file mode 100644 index 0000000..d2c4a70 --- /dev/null +++ b/34878-h/images/img791.jpg diff --git a/34878-h/images/img792a.jpg b/34878-h/images/img792a.jpg Binary files differnew file mode 100644 index 0000000..dfc42c7 --- /dev/null +++ b/34878-h/images/img792a.jpg diff --git a/34878-h/images/img792b.jpg b/34878-h/images/img792b.jpg Binary files differnew file mode 100644 index 0000000..6c5fefa --- /dev/null +++ b/34878-h/images/img792b.jpg diff --git a/34878-h/images/img793a.jpg b/34878-h/images/img793a.jpg Binary files differnew file mode 100644 index 0000000..15658ce --- /dev/null +++ b/34878-h/images/img793a.jpg diff --git a/34878-h/images/img793b.jpg b/34878-h/images/img793b.jpg Binary files differnew file mode 100644 index 0000000..1f15e8c --- /dev/null +++ b/34878-h/images/img793b.jpg diff --git a/34878-h/images/img799a.jpg b/34878-h/images/img799a.jpg Binary files differnew file mode 100644 index 0000000..bce5eec --- /dev/null +++ b/34878-h/images/img799a.jpg diff --git a/34878-h/images/img799b.jpg b/34878-h/images/img799b.jpg Binary files differnew file mode 100644 index 0000000..13f5102 --- /dev/null +++ b/34878-h/images/img799b.jpg diff --git a/34878-h/images/img811.jpg b/34878-h/images/img811.jpg Binary files differnew file mode 100644 index 0000000..fada829 --- /dev/null +++ b/34878-h/images/img811.jpg diff --git a/34878-h/images/img825.jpg b/34878-h/images/img825.jpg Binary files differnew file mode 100644 index 0000000..def173f --- /dev/null +++ b/34878-h/images/img825.jpg diff --git a/34878-h/images/img870.jpg b/34878-h/images/img870.jpg Binary files differnew file mode 100644 index 0000000..1288394 --- /dev/null +++ b/34878-h/images/img870.jpg |
