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diff --git a/17167-h/17167-h.htm b/17167-h/17167-h.htm new file mode 100644 index 0000000..2401ad9 --- /dev/null +++ b/17167-h/17167-h.htm @@ -0,0 +1,4647 @@ +<!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"> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" /> + +<title> +The Project Gutenberg eBook of Scientific American Supplement, February 18, 1888 +</title> + +<style type="text/css"> +<!-- + body {margin-left: 15%; margin-right: 15%; background-color: white} + img {border: 0;} + p { text-align: justify;} + h1,h2,h3 {text-align: center;} + + hr {text-align: center; width: 50%;} + hr.short {width: 25%;} + hr.long {width: 75%;} + hr.full {width: 100%;} + + table {margin-left: auto; margin-right: auto;} + sub {font-size: 0.7em;} + sup {font-size: 0.7em;} + + .note {margin-left: 2em; margin-right: 2em; margin-bottom: 1em;} + + .caption {font-weight: bold;} + .longcaption {margin-left: 10%; + margin-right: 10%; + text-align: left; } + + .center {text-align: center; + margin-left: auto; + margin-right: auto; } + .center table { + margin-left: auto; + margin-right: auto; } + + .signature {font-variant: small-caps; + text-align: right;} + .smcap {font-variant: small-caps;} + + .figcenter {margin: auto; text-align: center;} + + .figleft {float: left; clear: left; margin-left: 0; margin-bottom: 1em; + margin-top: 1em; margin-right: 1em; padding: 0; text-align: center;} + + .figright {float: right; clear: right; margin-left: 1em; margin-bottom: 1em; + margin-top: 1em; margin-right: 0; padding: 0; text-align: center;} + + .toc1 {vertical-align: top; text-align: left;} + .toc2, toc3 {text-align: left; } + .poem {margin-left: 10%; + text-align: left; + text-indent: 10em; } + .poem span.i2 {display: block; margin-left: 1em;} + .u {text-decoration: underline;} + .ov {text-decoration: overline;} + +--> +</style> +</head> + +<body> + + +<pre> + +The Project Gutenberg EBook of Scientific American Supplement, No. 633, +February 18, 1888, 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: Scientific American Supplement, No. 633, February 18, 1888 + +Author: Various + +Release Date: November 27, 2005 [EBook #17167] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Juliet Sutherland and the Online Distributed +Proofreading Team at www.pgdp.net + + + + + + +</pre> + +<div class="center" style="margin-left: -10%; margin-right: -10%;"><a href="./images/title.png"> +<img src="./images/title_th.png" alt="Issue Title" /></a> +</div> +<h1>SCIENTIFIC AMERICAN SUPPLEMENT NO. 633</h1> +<h2>NEW YORK, FEBRUARY 18, 1888</h2> +<h4>Scientific American Supplement. Vol. XXV., No. .</h4> +<h4>Scientific American established 1845</h4> +<h4>Scientific American Supplement, $5 a year.</h4> +<h4>Scientific American and Supplement, $7 a year.</h4> +<hr /> + +<table summary="Contents" border="0" cellspacing="5"> +<tr> +<th colspan="2" align="center">TABLE OF CONTENTS.</th> +</tr> +<tr><td colspan="2"> </td><td>PAGE.</td> +</tr> +<tr> +<td class="toc1">I.</td> +<td class="toc2"><a href="#art01"> +ARCHITECTURE.—Elements of Architectural Design.—By <span class="smcap">H.H. + Statham.</span>—The commencement of a series of lectures delivered + before the London Society of Arts, giving the line of development + of the different styles and the aspirations of their originators. + 34 illustrations.</a></td> +<td class="toc3">10106</td> +</tr> +<tr> +<td class="toc1">II.</td> +<td class="toc2"><a href="#art02">ASTRONOMY.—A Fivefold Comet.—A curious astronomical deduction; + the probable division of one comet into five by the disturbing + effects of the sun. 1 illustration.</a></td><td class="toc3">10116</td> +</tr> + + +<tr> +<td class="toc1">III.</td> +<td class="toc2"><a href="#art03">BIOGRAPHY.—Linnæus.—By <span class="smcap">C.S. Hallberg.</span>—The life and + work of the great botanist, his portrait and birthplace. + 2 illustrations.</a></td><td class="toc3">10114</td> +</tr> + +<tr> +<td class="toc1">IV.</td> +<td class="toc2"><a href="#art04">CHEMISTRY.—An Apparatus for Preparing Sulphurous, Carbonic, + and Phosphoric Anhydrides.—By <span class="smcap">H.N. Warren.</span>—A simple + apparatus for this purpose described and illustrated. + 1 illustration.</a></td><td class="toc3">10117</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art05">The Arrangement of Atoms in Space in Organic Molecules.—A + review of Prof. <span class="smcap">Johannes Wislicenus'</span> recent theories + on this abstract subject.</a></td><td class="toc3">10117</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art06">The Isolation of Fluorine.—Note on this last isolation of an + element, with the properties of the gas. 1 illustration.</a></td><td class="toc3">10117</td> +</tr> + +<tr> +<td class="toc1">V.</td> +<td class="toc2"><a href="#art07">ELECTRICITY.—Observations on Atmospheric Electricity.—By + Prof. <span class="smcap">L. Weber.</span>—Abstract of a British Association paper on + this important subject.</a></td><td class="toc3">10114</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art08">The Menges Thermo-Magnetic Generator and Motor.—The direct + conversion of electricity into heat; the generator fully + described. 5 illustrations.</a></td><td class="toc3">10113</td> +</tr> + +<tr> +<td class="toc1">VI.</td> +<td class="toc2"><a href="#art09">ENGINEERING.—An Investigation into the Internal Stresses + Occurring in Cast Iron and Steel.—By General <span class="smcap">Nicholas + Kalakoutzky.</span>—First installment of an elaborate paper, + giving theoretical and experimental examination of this subject. + 2 illustrations.</a></td><td class="toc3">10105</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art10">Hargreaves' Thermo-Motor.—A new caloric engine.—Its + construction, theory, and cylinder diagrams. 6 illustrations.</a></td><td class="toc3">10104</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art11">The Compound Steam Turbine.—A description and discussion + of this motor, in which a series of forty-five turbines are + acted on by the current of steam. 2 illustrations.</a></td><td class="toc3">10103</td> +</tr> + + +<tr> +<td class="toc1">VII.</td> +<td class="toc2"><a href="#art12">MISCELLANEOUS.—Cold Storage for Potatoes.—The application + of artificial cold to preserving potatoes.—Results obtained + in actual experience.—A practical paper by Mr. + <span class="smcap">Edwin Taylor.</span></a></td><td class="toc3">10115</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art16"><ins class="trans" title="Transcriber's Note: TOC Entry not in original">Great Warmth In Paper.</ins></a></td> +<td class="toc3">10118</td> +</tr> + +<tr> +<td class="toc1">VIII.</td> +<td class="toc2"><a href="#art13">PHYSICS.—On a Method of Making the Wave Length of Sodium + Light the Actual and Practical Standard of Length.—By<span class="smcap"> Albert + A. Michelson</span> and <span class="smcap">Edward W. Morley.</span>—Description of the + new standard of length and outlines of the practical method for + its determination.—The question of check determinations. + 1 illustration.</a></td><td class="toc3">10115</td> +</tr> + +<tr> +<td class="toc1">IX.</td> +<td class="toc2"><a href="#art14">TECHNOLOGY.—Progress of the Sorghum Sugar Industry.— + Elaborate report on the diffusion process as developed at the + Fort Worth, Kan., station. 2 illustrations.</a></td><td class="toc3">10110</td> +</tr> +<tr><td></td> +<td class="toc2"><a href="#art15">The Lowe Incandescent Gas Burner.—The well known advanced + type of gas burner described and illustrated. 1 illustration</a></td><td class="toc3">10110</td> +</tr> +</table> + +<hr /> + +<h2><a name="art11"></a><a name="Page_10103"></a>THE COMPOUND STEAM TURBINE. </h2> + +<p>Last year the whole of the lighting of the Newcastle Exhibition was +effected by the agency of seventeen of these motors, of which four were +spare, giving in the aggregate 280 electrical horse power. As the steam +was provided by the authorities of the exhibition, it was good proof to +the public that they had satisfied themselves that the consumption would +not be extravagant as however favorable might be the terms on which the +manufacturers would be willing to lend their engines, they could +scarcely be sufficiently tempting to compensate for an outrageous +consumption of coal, even in Newcastle. At the time we gave an account +of the result of the test, showing that the steam used was 65 lb. per +electrical horse power, a very satisfactory result, and equal to 43 lb. +per indicated horse power if compared with an ordinary engine driving a +generator through a belt. Recently Mr. Parsons has given an account of +the theory and construction of his motor before the Northeast Coast +Institution, and has quoted 52 lb. of steam per electric horse power as +the best result hitherto attained with a steam pressure of 90 lb. As now +made there are forty-five turbines through which the steam passes in +succession, expanding in each, until it is finally exhausted.</p> + +<div class="figcenter" style="width: 600px"> +<a href="./images/1b.png"><img src="./images/1b_th.png" alt="THE COMPOUND STEAM TURBINE." /></a> +<span class="caption">THE COMPOUND STEAM TURBINE.</span></div> + +<p>The theoretical efficiency of a motor of this kind is arrived at by Mr. +Parsons in the following manner:</p> + +<p>The efflux of steam flowing from a vessel at 15.6 lb. per square inch +absolute pressure through an orifice into another vessel at 15 lb. +pressure absolute is 366 ft. per second, the drop of pressure of 0.6 lb. +corresponding to a diminution of volume of 4 per cent. in the opposite +direction. The whole 45 turbines are so proportioned that each one, +starting from the steam inlet, has 4 per cent. more blade area or +capacity than that preceding it. Taking the pressure at the exhaust end +to be 15 lb. absolute, that at the inlet end will be 69 lb. above the +atmosphere. The steam enters from the steam pipe at 69 lb. pressure, and +in passing through the first turbine it falls 2.65 lb. in pressure, its +velocity due to the fall being 386 ft. per second, and its increase of +volume 3.85 per cent. of its original volume. It then passes through the +second turbine, losing 2.55 lb. in pressure, and gaining 3.85 per cent. +in volume, and so on until it reaches the last turbine, when its +pressure is 15.6 lb. before entering, and 15 lb. on leaving. The +velocity due to the last drop is 366 ft. per second. The velocity of the +wheels at 9,200 revolutions per minute is 150 ft. per second, or 39.9 +per cent. of the mean velocity due to the head throughout the turbines. +Comparing this velocity with the results of a series of experiments made +by Mr. James B. Francis on a Tremont turbine at Lowell, Mass., it +appears that there should be an efficiency of 72 per cent. if the +blades be equally well shaped in the steam as in the water turbine, and +that the clearances be kept small and the steam dry. Further, as each +turbine discharges without check into the next, the residual energy +after leaving the blades is not lost as it is in the case of the water +turbine, but continues into the next guide blades, and is wholly +utilized there. This gain should be equal to 3 to 5 per cent.</p> + +<p>As each turbine of the set is assumed to give 72.5 per cent. efficiency, +the total number may be assumed to give the same result, or, in other +words, over 72 per cent. of the power derived from using the steam in a +perfect engine, without losses due to condensation, clearances, +friction, and such like. A perfect engine working with 90 lb. boiler +pressure, and exhausting into the atmosphere, would consume 20.5 lb. of +steam per hour for each horse power. A motor giving 70 per cent. +efficiency would, therefore, require 29.29 lb. of steam per horse power +per hour. The best results hitherto attained have been 52 lb. of steam +per hour per electrical horse power, as stated above, but it is +anticipated that higher results will be attained shortly. Whether that +be so or not, the motor has many advantages to recommend it, and among +these is the increased life of the lamps due to the uniform rotation of +the dynamo. At the Phœnix Mills, Newcastle, an installation of 159 +Edison-Swan lamps has been running, on an average, eleven hours a day +for two years past, yet in that time only 94 lamps have failed, the +remaining 65 being in good condition after 6,500 hours' service. Now, +if the lamps had only lasted 1,000 hours on the average, as is commonly +assumed, the renewals would have amounted to double the year's cost of +fuel, as at present consumed.</p> + +<p>The present construction of the motor and dynamo is shown in the +figures.</p> + +<div class="figcenter" style="width: 570px"> +<a href="./images/1a.png"><img src="./images/1a_th.png" alt="Fig. 1 though 6" /></a> +<span class="caption"><span class="smcap">Figs.</span> 1 though 6</span></div> + +<p>Fig. 2 shows the arrangement of 90 complete turbines, 45 lying on each +side of the central steam inlet. The guide blades, R, are cut on the +internal periphery of brass rings, which are afterward cut in halves and +held in the top and bottom halves of the cylinder by feathers. The +moving blades, S, are cut on the periphery of brass rings, which are +afterward threaded and feathered on to the steel shaft, and retained +there by the end rings, which form nuts screwed on to the spindle. The +whole of this spindle with its rings rotate together in bearings, shown +in enlarged section, Fig. 3. Steam entering at the pipe, O, flows all +round the spindle and passes along right and left, first through the +guide blades, R, by which it is thrown on to the moving blades, S, then +back on to the next guide blades, and so on through the whole series on +each hand, and escapes by the passages, P, at each end of the cylinder +connected to the exhaust pipe at the back of cylinder. The bearings, +Fig. 3, consist of a brass bush, on which is threaded an arrangement of +washers, each successive washer alternately fitting to the bush and the +block, while being alternately 1/32 smaller than the block outside and +1/32 larger than the bush in the hole. One broad washer at the end holds +the bearings central. These washers are pressed together by a spiral +spring, N, and nut, and, by friction against each other, steady or damp +any vibration in the spindle that may be set up by want of balance or +other cause at the high rate of speed that is necessary for economical +working.</p> + +<p>The bearings are oiled by a small screw propeller, I, attached to the +shaft. The oil in the drain pipes, D and F, and the oil tank, D, lies at +a lower level than the screw, but the suction of the fan, K, raises it +up into the stand pipe, H, over and around the screw, which gripes it +and circulates it along the pipes to the bearings. The course of the oil +is as follows: The oil is forced by the propeller, I, and oils the +bearing, A. The greater part passes along the pipe, E, to the end +bearing, C; some after oiling the bearing, C, drains back by the pipe, +F, to the reservoir, D; the remaining oil passes along through the +armature spindle, oils the bearings, B, and drains into the reservoir, +D, from which the oil is again drawn along the pipe, G, into the stand +pipe, H, by the suction of the fan, K. The suction of the fan is also +connected to the diaphragm, L, and forms, with it and the spring, M, the +principal <a name="Page_10104"></a>part of the governor which actuates the throttle valve, V. +Fig. 4 is the electrical control governor, which will be further +described in connection with the dynamo. It acts directly upon the +controlling diaphragm, L, by admitting or closing a large access of air +to it, and thus exercises a controlling influence upon it.</p> + +<p>The dynamo which forms the other portion of the electric generator, Fig. +1, is coupled to the motor spindle by a square tube coupling fitted on +to the square spindle ends. The armature is of the drum type. The body +is built up of thin iron disks threaded on to the spindle and insulated +from each other by tracing paper. This iron body is turned up and +grooves milled out to receive the conducting wires. For pressures of 60 +to 80 volts there are fifteen convolutions of wire, or 30 grooves. The +wire starting at <i>b</i>, Fig. 6, is led a quarter of a turn spirally, <i>c</i>, +round the cylindrical portion, a, then passing along a groove +longitudinally is again led a quarter turn spirally, <i>d</i>, round the +cylindrical portion, <i>a</i>, then through the end washer, and back +similarly a quarter turn, <i>e</i>, then led along the diametrically opposite +groove, and lastly a little over a quarter turn, <i>f</i>, back to <i>g</i>, where +it is coupled to the next convolution. The commutator is formed of rings +of sections. Each section is formed of short lengths. Each length is +dovetailed and interlocked between conical steel rings. The whole is +insulated with asbestos, and, when screwed up by the end nut, forms, +with the steel bush, a compact whole. There are fifteen sections in the +commutator, and each coupling is connected to a section. The whole +armature is bound externally from end to end with brass or pianoforte +steel wire. The magnets are of soft cast iron and of the horseshoe type. +They are shunt-wound only.</p> + +<p>On the top of the magnet yoke is the electrical control governor, Fig. +4. It consists of one moving spindle on which are keyed a small soft +iron bar, and also a double finger, T. There is also a spiral spring, X, +attached at one end to the spindle, and at the other to an adjustable +top head and clamping nut, Y. The double finger, T, covers or opens a +small hole in the face, U, communicating by the pipe, W, to the +diaphragm, L. The action of the magnet yoke is to attract the needle +toward the poles of the magnet, while by turning the head the spiral +spring, X, is brought into tension to resist and balance this force, and +can be set and adjusted to any degree of tension. The double finger, T, +turns with the needle, and, by more or less covering the small air inlet +hole, U, it regulates the access of air to the regulating diaphragm, L. +The second finger is for safety in case the brushes get thrown off, or +the magnet circuit be broken, in which case the machine would otherwise +gain a considerable increase of speed before the diaphragm would act. In +these cases, however, the needle ceases to be attracted, falls back, and +the safety finger closes the air inlet hole.</p> + +<p>There is no resistance to the free movement of this regulator. A +fraction of a volt increase or decrease of potential produces a +considerable movement of the finger, sufficient to govern the steam +pressure, and in ordinary work it is found possible to maintain the +potential within one volt of the standard at all loads within the +capacity of the machine, excepting only a slight momentary variation +when a large portion of the load is switched on or off.</p> + +<p>The resistance of the armature from brush to brush is only 0.0032 ohm, +the resistance of the field magnets is only 17.7 ohms, while the normal +output of the dynamo is 200 amperes at 80 volts. This, excluding other +losses, gives an efficiency of 97 per cent. The other losses are due to +eddy currents throughout the armature, magnetic retardation, and bearing +friction. They have been carefully measured. By separately exciting the +field magnets from another dynamo, and observing the increased steam +pressure required to maintain the speed constant, the corresponding +power was afterward calculated in watts.</p> + +<p>The commercial efficiency of this dynamo, after allowing for all losses, +is a little over 90 per cent. In the larger sizes it rises to 94 per +cent. Assuming the compound steam turbine to give a return of 70 per +cent. of the total mechanical energy of the steam, and the dynamos to +convert 90 per cent of this into electrical output, gives a resulting +efficiency of 63 per cent. As steam at 90 lb. pressure above the +atmosphere will with a perfect non-condensing engine give a horse power +for every 20.5 lb. of steam consumed per hour, it follows that an +electrical generator of 63 per cent. efficiency will consume 32.5 lb. of +steam for every electrical horse power per hour.</p> + +<p>Again, with steam at 150 lb. pressure above the atmosphere, a generator +of the same efficiency would consume only 22.2 lb. of steam per +electrical horse power per hour.</p> + +<p>The results so far actually obtained are a consumption of 52 lb. per +hour of steam for each electrical horse power with a steam pressure of +90 lb. above the atmosphere.—<i>Engineering.</i></p> + +<hr /> + +<h2><a name="art10"></a>HARGREAVES' THERMO-MOTOR.</h2> + +<p>From the researches and investigations of Carnot, Joule, Rankine, +Clausius, and Sir William Thomson, the science of thermo-dynamics has +not only been brought into existence, but fully matured. We learn from +it that whereas in the steam engine, on account of the limited range of +temperature in the working cylinder and the rapid conduction of steam +during condensation, no combination of cylinders can materially affect +its present efficiency, internally fired engines, such as gas and +caloric engines—being, as it were, less fettered—can have their +already high efficiency increased by simply overcoming mechanical +difficulties. To this fact is no doubt due the recent remarkable +development of gas and caloric engines. The first caloric or hot air +engine was invented by Sir George Cayley in 1807, and in 1827 Dr. Robert +Stirling, a Scotch minister, took out his first patent for a hot air +engine, which was the foundation of many subsequent machines, and by the +invention of the regenerator he converted what was practically a +scientific toy into an efficient machine.</p> + +<p>One of the most ardent workers in this field at the present time is Mr. +James Hargreaves, of Widnes, who, with a thorough theoretical knowledge +of the subject has, after many years of patient perseverance, over come +many of the mechanical difficulties, and designed the engine of which +the above is an illustration.</p> + +<p>The sectional elevation, shown in Fig. 1, is an expanded view of the +machine, shown thus to enable the action of the machine to be more +clearly understood; the relative position of the different parts, as +actually made, is shown in the side elevation (Fig. 4). The principal +working parts of the machine are the combustion chamber, D, which is of +the form shown, lined with fire brick, and having an entrance, with the +door screwed down like a manhole lid; the working cylinder, A, +surrounded by the water casing, K; the piston, B, with a water lining, +and coupled to the end of the working beam by a parallel motion, the +beam being supported by two rocking columns, Z, as in engines of the +"grasshopper" type; the air compressor, C, coupled directly to the +piston of the working cylinder; the injection pump, F, for supplying the +fuel—creosote or coal tar—to the combustion chamber; the regenerator +E; the receiver and separator, V Y; the feed and exhaust valves, M.</p> + +<div class="figcenter" style="width: 600px"> +<a href="./images/2a.png"><img src="./images/2a_th.png" alt="Fig. 1" /></a> +<span class="caption"><span class="smcap">Fig.</span> 1—SECTIONAL ELEVATION—HARGREAVES' +THERMO-MOTOR.</span></div> + +<div class="figcenter" style="width: 500px"> +<img src="./images/2b.png" alt="Fig. 2." /> +<span class="caption"><span class="smcap">Fig.</span> 2.</span></div> + +<p>The action of the machine is as follows: Assuming the engine to be in +condition for starting, the sides of the combustion chamber, D, are red +hot, the chamber charged with air, and the spray of creosote, injected +by the pump, F, is ignited; the expansion of the gases produced by the +combustion acts upon the bottom of the piston, B, forcing it to the top +of the cylinder, and thus, by intermediate mechanism, causing the crank +shaft to revolve. By the same stroke a charge of air is forced by the +compressor, C, into the receiver <a name="Page_10105"></a>through the pipe, R. The cylinder is, +of course, single acting, and on the down stroke of the piston, B—which +falls by its own weight and the momentum of the fly wheel—the exhaust +gases are forced through the regenerator, E, which absorbs most of their +heat; they then pass through the exhaust valve, placed immediately under +the feed valve, M, along the pipe, Q, up through the pipes, T, fitted +into the receiver, V, down the pipes, T, fitted into the saturator, Y, +and out of the funnel fixed to the bottom of Y.</p> + +<div class="figcenter" style="width: 560px"> +<img src="./images/2c.png" alt="Fig 3." /> +<span class="caption"><span class="smcap">Fig.</span> 3.</span></div> + +<div class="figcenter" style="width: 460px"> +<a href="./images/2d.png"><img src="./images/2d_th.png" alt="Fig. 4." /></a> +<span class="caption"><span class="smcap">Fig.</span> 4.</span></div> + +<p>The charge of air for supplying the combustion chamber is forced by the +compressor, C, through the pipe, R, <i>outside</i> the tubes, T, in the +chambers, V and Y, along the pipe, P, through the feed valve, M, and the +regenerator, E, into the combustion chamber. In its passage from the +compressor, it first picks up the residual heat of the exhaust gases in +the tubes, T, and finally the heat absorbed by the regenerator, E, thus +entering the combustion chamber in a highly heated state. Having +described generally the passage of the air from the compressor to the +working cylinder, and back again to the funnel, we will now describe the +details. The working cylinder, A, is fitted into the casting which forms +the water casing, K, a space being left between the bottom of the +cylinder and the casing, which is filled with a non-conducting mixture +of asbestos to protect it from the heat of combustion; the bottom of the +piston, B, has a similar protection, and the regenerator has a lining +of the same mixture, to prevent any heat from escaping through the +casting which holds it. The water in the casing, K, and in the piston, +B, is supplied by a small pump, G, which forces the water through the +pipe, P<sub>4</sub>, into the telescopic pipe, L either into the piston, B, or +through the pipe, P<sub>6</sub>, into the casing, K—the bottom of the casing +being connected by the pipe, P<sub>10</sub>, with the auxiliary boiler, W. The +steam generated in the casing, K, is carried to the boiler, W, by the +pipe, P<sub>3</sub>, and from the boiler it passes along the pipe, P<sub>2</sub>, +through the valve, A<sub>2</sub>, into the chamber, V, thus giving up its heat +to the incoming air, with which it mixes. The vapor gradually condenses +at the bottom of the vessel, Y, and the water so formed is drawn by the +pump, J, along the suction pipe, P<sub>9</sub>, and forced through the pipe, +P<sub>8</sub>, back to the chamber, Y, through the valve, A<sub>1</sub>, and in the form +of spray plays on the tubes, T, and absorbing any residual heat. The +heat generated by compression in the cylinder, C, is absorbed by a spray +of water from the pump, H, the vapor being carried along with the air +through the pipe, R, to the chamber, Y, where it is separated, and +falling to the bottom is circulated, as just described, by the pump, J. +X is a small auxiliary air compressor, to obtain the necessary +compression to start the engine, and is worked from the boiler, W. In +future engines this compressor will be superseded by a specially +designed injector, which will produce the necessary pressure at a +considerable reduction in cost. When once the engine is started, the +fire of the auxiliary boiler can, of course, be drawn, as the main +engine afterward makes its own steam. The regenerator, E, has circular +ends of fire clay perforated, the body being filled with fire clay +spirals of the shape clearly shown in elevation in Fig. 2. The injector +valve for the creosote is shown to a larger scale in Fig. 3. This valve +has, however, been since considerably modified and improved. The feed +and exhaust valves, M, are actuated by cams keyed to a countershaft +driven by bevel wheels from the main shaft. The creosote pump, F, is +also worked by a cam on the same shaft, but the pumps, G H J, are worked +by eccentrics. A stop valve, N, is fixed to the supply pipe, P, under +which is place a back pressure valve to retain the pressure in the +combustion chamber. The engine is regulated by an ordinary Porter +governor actuating the throttle valve, O. An engine, as described, has +been constructed by Messrs. Adair & Co., engineers, Waterloo Road, +Liverpool, and has been running most satisfactorily for several weeks, +the results being clearly shown by the indicator diagrams (Figs. 5 and +6). The results obtained by this motor are very remarkable, and are a +long way in advance of any previous performance, as only a little over ½ +lb. of fuel is used per i.h.p. per hour. It may be mentioned that the +temperature of the combustion chamber is calculated to be about +2,500°F., and that of the exhaust gases does not exceed +180°F.—<i>Industries.</i></p> + +<div class="figcenter" style="width: 500px" > + +<img src="./images/2e.png" alt="Fig 5." /> +<div class="caption"> +<p>Diagram from cylinder—25 in. diam, 18 in. stroke. +I.H.P., 63. Scale, 1/30 in. Mean pressure, 28.2 lb..</p> +<p class="center"><span class="smcap">Fig.</span> 5.</p> + +<img src="./images/2f.png" alt="Fig 6." /> +<p>Diagram from air pump—15 in. diam., 18 in. stroke. +I.H.P., 23. Scale, 1/30 in—Mean pressure, 28.5 lb.</p> +<p class="center"><span class="smcap">Fig.</span> 6.</p> +<p class="center">DIAGRAMS FROM CYLINDER AND AIR PUMP.</p> + +<p>Net indicated horse power, 40; revolutions per minute, 100; coal tar +consumed per hour, 20.5 lb.; coal tar per I.H.P. per hour, 0.512 lb.</p> +</div> +</div> + +<hr /> + +<h2><a name="art09"></a>AN INVESTIGATION INTO THE INTERNAL STRESSES OCCURRING IN CAST IRON +AND STEEL.</h2> + +<h3>By General <span class="smcap">Nicholas Kalakoutzky.</span></h3> + +<h3>NO. I.</h3> + +<p><i>Determination of the Influence of Internal Stresses on the Strength of +Materials.</i>—We call internal stresses those which exist within the mass +of any hollow cylinder or other body, when it appears to be in a state +of repose, or not under the influence of external forces. When pressure +is applied to a hollow cylinder, either externally or internally, the +interior layers into which its walls may be conceived to be divided are +subjected to a new series of stresses, the magnitude of which is +independent of those already existing. These additional stresses combine +with the former in such a manner that at every point of the thickness of +the cylinder they have common resultants acting in various directions. +Thus, if we call <i>t</i> the internal stress existing at a distance <i>r<sub>x</sub></i> +from the axis of the cylinder, and in a direction tangential to its +cross section, and T the additional stress due to pressure inside the +cylinder acting at the same point and in the same direction, then the +newly developed stress will be <i>t</i> + T.</p> + +<p>If R and <i>r<sub>0</sub></i> be the external and internal radii of the cylinder, and +if we suppose the external pressure <i>nil</i>, then, if the pressure inside +the bore be P<sub>0</sub>, the stress on the radius <i>r<sub>x</sub></i> is determined by the +following expression deduced from the well-known fundamental formulæ of +Lame:<a name="FNanchor_1"></a><a href="#Footnote_1"><sup>1</sup></a></p> + +<div class="center"> +<table summary="equation"> +<tr><td>T =</td><td>P<sub>0</sub></td> +<td><i>r<sub>0</sub></i><sup>2</sup><br/>————<br />R<sup>2</sup>-<i>r<sub>0</sub></i><sup>2</sup></td> +<td> · </td> +<td>R<sup>2</sup> + <i>r<sub>x</sub></i><sup>2</sup><br />————<br /><i>r<sub>x</sub></i><sup>2</sup></td> +</tr> +</table> +</div> + +<p>From which we see that T is a maximum when <i>r<sub>x</sub></i> = <i>r<sub>0</sub></i>, <i>i.e.</i>, for +the layer immediately next to the bore of the cylinder. Calling <i>t<sub>0</sub></i> +the internal stress in this layer, and T<sub>0</sub> the stress resulting from +the action inside the bore of the pressure P<sub>0</sub>, and allowing that the +sum of both these quantities must not exceed the elastic limit U of the +material, we have—T<sub>0</sub> = U - <i>t<sub>0</sub></i>. And for this value of T<sub>0</sub>, the +corresponding pressure inside the bore will be</p> + +<div class="center"> +<table summary="equation"> +<tr><td>P = (U - <i>t<sub>0</sub></i>)</td><td>P<sub>0</sub></td> +<td>R<sup>2</sup> - <i>r<sub>0</sub></i><sup>2</sup> +<br/>————<br /> +R<sup>2</sup> + <i>r<sub>0</sub></i><sup>2</sup></td> +</tr> +</table> +</div> + +<p>This pressure increases with the term (U-<i>t<sub>0</sub></i>). With <i>t<sub>0</sub></i> +positive, <i>i.e.</i>, when the internal stresses in the thickness of the +hollow cylinder are such that the metal of the layers nearest to the +bore is in a state of tension and that of the outer layers in a state of +compression, then the cylinder will have the least strength when <i>t<sub>0</sub></i> +has the greatest numerical value. Such stresses are termed injurious or +detrimental stresses. With <i>t<sub>0</sub></i> negative, the strength of the +cylinder increases with the numerical value of <i>t<sub>0</sub></i>, and those +stresses which cause compression in the layers nearest to the bore of +the cylinder and tension in the outer layers are termed beneficial or +useful stresses.</p> + +<p>For these reasons, and in order to increase the power of resistance of a +cylinder, it is necessary to obtain on the inner layer a state of +initial compression approaching as nearly as possible to the elastic +limit of the metal. This proposition is in reality no novelty, since it +forms the basis of the theory of hooped guns, by means of which the +useful initial stresses which should be imparted to the metal throughout +the gun can be calculated, and the extent to which the gun is thereby +strengthened determined. The stresses which arise in a hollow cylinder +when it is formed of several layers forced on one upon another, with a +definite amount of shrinkage, we call the stress of built-up cylinders, +in order to distinguish them from natural stresses developed in +homogeneous masses, and which vary in character according to the +conditions of treatment which the metal has undergone. If we conceive a +hollow cylinder made up of a great number of very thin layers—for +instance, of wire wound on with a definite tension—in which case the +inner layer would represent the bore of the gun, then the distribution +of the internal stresses and their magnitude would very nearly approach +the ideally perfect useful stresses which should exist in a homogeneous +cylinder; but in hollow cylinders built up of two, three, and four +layers of great thickness, there would be a considerable deviation from +the conditions which should be aimed at.</p> + +<p>The magnitude of the stresses in built-up cylinders is determined by +calculation, on the presumption that initial stresses do not exist in +the respective layers of the tube and of the hoops which make up the +walls of the cylinder. Nevertheless, Rodman, as early as the year 1857, +first drew attention to the fact that when metal is cast and then +cooled, under certain conditions, internal stresses are necessarily +developed; and these considerations led him, in the manufacture of cast +iron guns, to cool the bore with water and to heat the outside of the +moulds after casting. Although Rodman's method was adopted everywhere, +yet up to the present time no experiments of importance have been made +with the view of investigating the internal stresses which he had drawn +attention to, and in the transition from cast iron to steel guns the +question has been persistently shelved, and has only very lately +attracted serious attention. With the aid of the accepted theory +relating to the internal stresses in the metal of hooped guns, we can +form a clear idea of the most advantageous character for them to assume +both in homogeneous and in built-up hollow cylinders. In proof of this, +we can adduce the labors of Colonels Pashkevitch and Duchene, the former +of whom published an account of his investigations in the <i>Artillery +Journal</i> for 1884—St. Petersburg—and the latter in a work entitled +"Basis of the Theory of Hooped Guns," from which we borrow some of the +following information.</p> + +<p>The maximum resistance of a tube or hollow cylinder to external stresses +will be attained when all the layers are expanded simultaneously to the +elastic limit of the material employed. In that case, observing the same +notation as that already adopted, we have—</p> + +<div class="center"> +<table summary="equation"> +<tr><td>P<sub>0</sub> = T</td> +<td>R - <i>r<sub>0</sub></i> +<br/>———<br /> +<i>r<sub>0</sub></i></td> +<td align="right" > (1) </td> +</tr> +</table> +</div> + +<p>But since the initial internal stresses before firing, that is previous +to the action of the pressure inside the bore, should not exceed the +elastic limit,<a name="FNanchor_2"></a><a href="#Footnote_2"><sup>2</sup></a> the value of R will depend upon this condition.</p> + +<p>In a hollow cylinder which in a state of rest is free from initial +stresses, the fiber of which, under fire, will undergo the maximum +extension, will be that nearest to the internal surface, and the amount +of extension of all the remaining layers will decrease with the increase +of the radius. This extension is thus represented—</p> + +<div class="center"> +<table summary="equation"> +<tr><td><i>t<sub>x</sub></i><sup>1</sup> = P<sub>0</sub></td> +<td><i>r<sub>0</sub></i><sup>2</sup> +<br />————<br /> +R<sup>2</sup> - <i>r<sub>0</sub></i><sup>2</sup></td> +<td><big> · </big></td> +<td><i>r<sub>x</sub></i><sup>2</sup> + R<sup>2</sup> +<br />————<br /> +<i>r<sub>x</sub></i><sup>2</sup></td> +</tr> +</table> +</div> + +<p>Therefore, to obtain the maximum resistance in the cylinder, the value +<i>t<sub>x</sub></i> of the initial stress will be determined by the difference T - +t'<sub>x</sub>, and since P<sub>0</sub> is given by Equation (1), then</p> + +<div class="center"> +<table summary="equation"> +<tr><td><i>t<sub>x</sub></i> = T </td><td><big>(</big></td> +<td> 1 - </td> +<td><i>r<sub>0</sub></i><br />———<br />R<sub>0</sub> + <i>r<sub>0</sub></i></td> +<td><big> · </big></td> +<td><i>r<sub>x</sub></i><sup>2</sup> + R<sup>2</sup><br />————<br /><i>r<sub>x</sub></i><sup>2</sup></td> +<td><big>)</big></td> +<td align="right"> (2) </td> +</tr> +</table> +</div> + +<p>The greatest value <i>t<sub>x</sub></i> = <i>t<sub>0</sub></i> corresponds to the surface of the +bore and must be <i>t<sub>0</sub></i> =-T, therefore</p> + +<div class="center"> +<table summary="equation"> +<tr><td><i>r<sub>0</sub></i><sup>2</sup> + R<sup>2</sup><br />———— +<br /><i>r<sub>0</sub></i> (R + <i>r<sub>0</sub></i>)</td> +<td> = 2</td> +</tr> +</table> +</div> + +<p>whence P<sub>0</sub> = T √<span class="ov">2</span> = 1.41 T.</p> + +<p>From the whole of the preceding, it follows that in a homogeneous +cylinder under fire we can only attain simultaneous expansion of all the +layers when certain relations between the radii obtain, and on the +assumption that the maximum pressure admissible in the bore does not +exceed 1.41 U.</p> + +<p>Equation (2) may be written thus—</p> + +<div class="center"> +<table summary="equation"> +<tr><td><i>t<sub>x</sub></i> = T</td> +<td>R<br />———<br />R + <i>r<sub>0</sub></i></td> +<td><big> · </big></td> +<td><i>r<sub>x</sub></i> - R<i>r</i><br />————<br /><i>r<sub>x</sub></i><sup>2</sup></td> +<td align="right"> (3) </td> +</tr> +</table> +</div> + +<p>Substituting successively <i>r<sub>x</sub></i> = <i>r<sub>0</sub></i> and <i>r<sub>x</sub></i> = R, we obtain +expressions for the stresses on the external and internal radii—</p> + +<div class="center"> +<table summary="equation"> +<tr><td>t<sub>R</sub> = T</td> +<td>R - <i>r<sub>0</sub></i><br />———<br />R + <i>r<sub>0</sub></i></td> +<td> and </td> +<td>t<sub><i>r<sub>0</sub></i></sub> = - T</td> +<td>R<br />—<br /><i>r<sub>0</sub></i></td> +<td> </td> +<td>R - <i>r<sub>0</sub></i><br />——<br />R + <i>r<sub>0</sub></i></td> +</tr> +</table> +</div> + +<p>Therefore, in a homogeneous hollow cylinder, in which the internal +stresses are theoretically most advantageous, the layer situated next to +the bore must be in a state of compression, and the amount of +compression relative to the tension in the external layer is measured by +the inverse ratio of the radii of these layers. It is further evident +that the internal stresses will obey a definite but very simple law, +namely, there will be in the hollow cylinder a layer whose radius is +√<span class="ov">R <i>r</i></span><i><sub>0</sub></i>, in which the stress is <i>nil</i>; from this layer the +stresses increase toward the external and the internal radii of the +cylinder, where they attain a maximum, being in compression in the +internal layers and in tension in the external ones.</p> + +<p>The internal pressures corresponding to these stresses may be found by +means of very simple calculations. The expression for this purpose, +reduced to its most convenient form, is as follows:</p> + +<div class="center"> +<table summary="equation"> +<tr><td><i>p<sub>x</sub></i> = T </td> +<td>R<br />———<br />R + <i>r<sub>0</sub></i></td> +<td><big>(</big></td> +<td>R<br />—<br /><i>r<sub>x</sub></i></td><td> - 1</td> +<td><big>)</big></td> +<td><big>(</big></td> +<td>1 - </td><td><i>r<sub>0</sub></i><br />—<br /> <i>r<sub>x</sub></i></td> +<td><big>)</big></td> +<td align="right"> (4)</td> +</tr> +</table> +</div> + + +<p>In order to represent more clearly the distribution of stresses and +pressures in the metal of a homogeneous ideally perfect hollow cylinder, +let us take, as an example, the barrel of a 6 in. gun—153 mm. Let us +suppose T = 3,000 atmospheres; therefore, under the most favorable +conditions, P<sub>0</sub> = 1.41 T, or 4,230 atmospheres. From Equation (1) we +determine R = 184.36 mm. With these data were calculated the internal +stresses and the pressures from which the curve represented in Fig. 1 is +constructed. The stresses developed under fire with a pressure in the +bore of 4,230 atmospheres are represented by a line parallel to the axis +of the abscissæ, since their value is the same throughout all the layers +of metal and equal to the elastic limit, 3,000 atmospheres. If, previous +to firing, the metal of the tube were free from any internal stresses, +then the resistance of the tube would be</p> + +<div class="center"> +<table summary="equation"> +<tr><td>P<sub>0</sub> = U </td> +<td>R<sup>2</sup> - <i>r<sup>2</sup></i><sub>0</sub><br /> +————<br /> +R<sup>2</sup> + <i>r<sup>2</sup></i><sub>0</sub></td> +</tr> +</table> +</div> + +<p>or 2,115 atmospheres—that is, one-half that in the ideally perfect +cylinder. From this we perceive the great advantage of developing useful +initial stresses in the metal and of regulating the conditions of +manufacture accordingly. Unless due attention be paid to such +precautions, and injurious stresses be permitted to develop themselves +in the metal, then the resistance of the cylinder will always be less +than 2,115 atmospheres; besides which, when the initial stresses exceed +a certain intensity, the elastic limit will be exceeded, even without +the action of external pressures, so that the bore of the gun will not +be in a condition to withstand any pressure because the tensile stress +due to such pressure, and which <a name="Page_10106"></a>acts tangentially to the circumference, +will increase the stress, already excessive, in the layers of the +cylinder; and this will occur, notwithstanding the circumstance that the +metal, according to the indications of test pieces taken from the bore, +possessed the high elastic limit of 3,000 atmospheres.</p> + +<div class="figcenter" style="width: 510px"> +<a href="./images/3a.png"><img src="./images/3a_th.png" alt="Fig. 1" /></a> +<span class="caption"><span class="smcap">Fig.</span> 1</span></div> + +<p>In order to understand more thoroughly the difference of the law of +distribution of useful internal stresses as applied to homogeneous or to +built-up cylinders, let us imagine the latter having the external and +internal radii of the same length as in the first case, but as being +composed of two layers—that is to say, made up of a tube with one hoop +shrunk on under the most favorable conditions—when the internal radius +of the hoop = √<span class="ov">R <i>v</i></span><i><sub>0</sub></i> or 118.7 mm., Fig. 2, has been traced, +after calculating, by means of the usual well known formulæ, the amount +of pressure exerted by the hoop on the tube, as well as the stresses and +pressures inside the tube and the hoop, before and after firing. A +comparison of these curves with those on Fig. 1 will show the difference +between the internal stresses in a homogeneous and in a built-up +cylinder. In the case of the hooped gun, the stresses in the layers +before firing, both in the tube and in the hoop, diminish in intensity +from the inside of the bore outward; but this decrease is comparatively +small. In the first place, the layer in which the stresses are = 0 when +the gun is in a state of rest does not exist. Secondly, under the +pressure produced by the discharge, all the layers do not acquire +simultaneously a strain equal to the elastic limit. Only two of them, +situated on the internal radii of the tube and hoop, reach such a +stress; whence it follows that a cylinder so constructed possesses less +resistance than one which is homogeneous and at the same time endowed +with ideally perfect useful initial stresses. The work done by the +forces acting on a homogeneous cylinder is represented by the area <i>a b +c d</i>, and in a built-up cylinder by the two areas <i>a' b' c' d'</i> and <i>a" +b" c" d"</i>. Calculation shows also that the resistance of the built-up +cylinder is only 3,262 atmospheres, or 72 per cent. of the resistance of +a homogeneous cylinder. By increasing the number of layers or rows of +hoops shrunk on, while the total thickness of metal and the caliber of +the gun remains the same, we also increase the number of layers +participating equally in the total resistance to the pressure in the +bore, and taking up strains which are not only equal throughout, but are +also the greatest possible. We see an endeavor to realize this idea in +the systems advocated by Longridge, Schultz, and others, either by +enveloping the inner tubes in numerous coils of wire, or, as in the +later imitations of this system, by constructing guns with a greater +number of thin hoops shrunk on in the customary manner. But in wire +guns, as well as in those with a larger number of hoops—from four to +six rows and more—the increase in strength anticipated is acknowledged +to be obtained in spite of a departure from one of the fundamental +principles of the theory of hooping, since in the majority of guns of +this type the initial compression of the metal at the surface of the +bore exceeds its elastic limit.<a name="FNanchor_3"></a><a href="#Footnote_3"><sup>3</sup></a> We have these examples of departure +from first principles, coupled with the assumption that initial stresses +do not exist in any form in the metal of the inner tube previous to the +hoops having been shrunk on; but if the tube happen to be under the +influence of the most advantageous initial stresses, and we proceed +either to hoop it or to envelope it with wire, according to the +principles at present in vogue, then, without doubt, we shall injure the +metal of the tube; its powers of resistance will be diminished instead +of increased, because the metal at the surface of the bore would be +compressed to an amount exceeding twice its elastic limit. An example of +injury inflicted in this way is to be found in the method adopted for +hooping cast iron tubes cast by Rodman's process. If we take into +consideration the undoubted fact of the existence to a considerable +extent of useful initial stresses in these tubes, then the hoops should +be put on them either with very little shrinkage or none at all, whereas +ordnance authorities everywhere have applied to this case methods which +are only correct for tubes which are free from initial stresses.</p> + + +<div class="figcenter" style="width: 500px"> +<a href="./images/3b.png"><img src="./images/3b_th.png" alt="Fig. 2" /></a> +<span class="caption"><span class="smcap">Fig.</span> 2</span></div> + +<p>During the process of hooping guns it is very important to know how to +take into account the value and mode of distribution of the prejudicial +stresses in the inner tube, should such exist. Knowing these stresses, +it is possible, by regulating the tension of the hoops, to reduce the +compression of the metal at the surface of the bore to the proper +extent, thus doing away with the previously existing tension, and by +that means removing a source of weakness in the tube. In precisely the +same way in the shrinkage of gun hoops attention must be paid to the +character and value of the stresses which arise in the course of their +manufacture; otherwise it will be impossible to hoop the barrel +throughout in a proper manner. If prejudicial stresses exist in the +metal of a hoop before it is put in its place, then, when the gun is +fired, if it had been shrunk on with the degree of tension usually +allowed, the layer situated in the internal radius will be extended +beyond admissible limits, thereby causing the resistance of the gun to +be less than that prescribed.<a name="FNanchor_4"></a><a href="#Footnote_4"><sup>4</sup></a></p> + +<p>It is evident, from what has been said, that in order to determine +precisely the resistance of hollow cylinders to internal pressures, and +to make the correct calculations for hooping tubes, it is absolutely +necessary to know whether internal initial stresses exist in the tube +and in the hoops, and to ascertain what their nature and intensity may +be—that is to say, whether they are useful or detrimental; yet it is +incontestable that in the construction of modern ordnance no attention +has been paid to the investigations indicated. If it be possible to +ignore these considerations in the manufacture of guns of small caliber, +and where the thickness of metal is not sufficiently great to admit of +strongly developed internal stresses, such is by no means the case with +the colossal and costly weapons of the present day. In these the +thickness of metal in the tube and hoops is very great; hence the +extreme probability of very considerable internal stresses developing +themselves. That the strength of large guns is often far below that +anticipated is demonstrated, year by year, by the repeated cases of +failure. Consciousness as to the want of strength in such guns is made +evident by the precautionary measures as to their use everywhere +adopted. The heavy artillery produced in the gun factories of Europe is +constructed with all the skill, science, and experience which engineers +and artillerists can command, and therefore it would seem that instances +of defective strength should not arise. Such cases, however, do occur +everywhere, and irresistibly give rise to the suspicion that not only is +the system of construction of guns of large caliber faulty, but also +that the conditions of their manufacture must be considered as +defective. Bearing in mind the enormous sums of money expended by every +nation in order to secure an armament of completely trustworthy guns, +this question demands speedy and searching investigation. The first step +in this direction is the study of the internal stresses inherent in the +metal; because, if such exist, and are capable of attaining, under +certain conditions, considerable magnitudes, then it is absolutely +necessary to take advantage of them in order to increase the resistance +of the metal, instead of allowing them to act to its detriment.</p> + +<p>The study of natural internal stresses is of importance, not only with +reference to gun making, but also in respect of other structures where +great resistance is required. All have heard of the sudden failure of +crank shafts and piston rods, of the bursting of boiler shells and +tubes, of the breaking of tires, etc. In the majority of cases the +investigations into the causes of such sudden failures have not led to +any definite results. It has usually been found that the metal possessed +a satisfactory elastic resistance, and satisfied all the conditions set +down in the specifications. Had attention been paid during these +investigations to the state of the internal stresses in the metal, the +cause of unlooked-for accidents might have been explained, and steps +would consequently have been taken to avoid them in future.</p> + +<p>We are also familiar with the development of considerable internal +stresses in various kinds of steel articles which are subjected to +hardening and tempering; for example, as dies, tools of various +description, sword blades, and thin plates rolled at a low temperature +or subjected to cold hammering. In the foundry the appearance of +internal stresses is of still more frequent occurrence. The neglect of +certain practical rules in casting, and during the subsequent cooling, +leads to the spontaneous breakage of castings after a few hours or days, +although taken out of the sand apparently perfectly sound. Projectiles +for penetrating armor plate, and made of cast steel, as well as shells +which have been forged and hardened, and in which the metal possessed an +ultimate resistance of over twelve thousand (12,000) atmospheres, with +an elastic limit of more than six or seven thousand atmospheres, will +crack to a serious extent, and even break up in the lathe, while the +recess for the copper ring is being turned out. In shell of this nature, +as well as in chilled cast iron shell, the heads are apt to fly off +spontaneously either while they are lying in store or during transport. +Such phenomena, it seems to me, demonstrate the existence of internal +stresses of considerable magnitude in the metal of the projectiles, and +it is highly probable that the manufacture of many articles would have +approached nearer to perfection had more attention been bestowed upon +the study of the internal stresses which they were liable to. Having +thus explained the nature and importance of the subject, I will proceed +to describe the experiments which I have made with a view to its +illustration.—<i>London Engineer.</i></p> + +<p><a name="Footnote_1"></a><a href="#FNanchor_1">[1]</a></p> +<div class="note"> +<p>Lame holds that in a homogeneous tube subjected to the +action of two pressures, external and internal, the difference between +the tension and the compression developed at any point of the thickness +of the tube is a constant quantity, and that the sum of these two +stresses is inversely proportional to the square of the radius of the +layer under consideration. Let <i>r<sub>0</sub></i>, R, and <i>r<sub>x</sub></i> be the respective +radii, <i>p<sub>0</sub></i>, <i>p<sup>1</sup></i>, and <i>p<sub>x</sub></i> the corresponding pressures, and +T<sub>0</sub>, T<sup>1</sup>, and T<sub>x</sub>, the tensions, then we have:</p> + +<div class="center"> +<table summary="equations"> +<tr><td>T<sub>0</sub> - <i>p<sub>0</sub></i> = T<sub>x</sub> - <i>p<sub>x</sub></i></td> +<td> (1) </td> </tr> +<tr><td>(T<sub>0</sub> + <i>p<sub>0</sub></i>)<i>r<sub>0</sub></i><sup>2</sup> = (T<sub>x</sub> + <i>p<sub>x</sub></i>)<i>r<sub>x</sub></i><sup>2</sup></td> +<td> (2) </td> </tr> +<tr><td> T<sub>x</sub> - <i>p<sub>x</sub></i> = T<sup>1</sup> - <i>p<sup>1</sup></i></td> +<td> (3) </td> </tr> +<tr><td>(T<sub>x</sub> + <i>p<sub>x</sub></i>)<i>r<sub>x</sub></i><sup>2</sup> = (T<sup>1</sup> + P<sup>1</sup>)R<sup>2</sup></td> +<td> (4) </td> </tr> +</table> +</div> + +<p>if the radii are known and p and <i>p<sup>1</sup></i> be given, then deducing from +the above equations the values T<sub>0</sub> and T<sup>1</sup>, and also the variable +pressure <i>p<sub>x</sub></i>, we determine—</p> + +<div class="center"> +<table summary="equation"> +<tr><td>T<sub>x</sub> = </td> +<td><i>p<sub>0</sub></i> <i>r<sub>0</sub></i><sup>2</sup>(R<sup>2</sup> + <i>r<sub>x</sub></i><sup>2</sup>) - <i>p<sup>1</sup></i> R<sup>2</sup>(<i>r<sub>x</sub></i><sup>2</sup>+<i>r<sub>0</sub></i><sup>2</sup>) +<br />—————————————— +<br />(R<sup>2</sup> + <i>r<sub>0</sub></i><sup>2</sup>)<i>r<sub>x</sub></i><sup>2</sup></td> +</tr> +</table> +</div> + +<p>This is the formula of Lame, from which, making <i>p<sup>1</sup></i>=0, we obtain the +expression in the text.</p> +</div> + +<p><a name="Footnote_2"></a><a href="#FNanchor_2">[2]</a></p> +<div class="note"><p>We must, however, remark that in a built-up hollow cylinder +the compression of the metal at the surface of the bore may exceed the +elastic limit. This cannot occur in the case of natural stresses.</p> +</div> + +<p><a name="Footnote_3"></a><a href="#FNanchor_3">[3]</a></p> +<div class="note"><p>In certain cases this, of course, may be an advantage, as, +for instance, when the inner tube is under injurious initial stresses; +but then, in order to be able to apply the necessary shrinkage, we must +know the magnitude of these stresses.</p></div> + +<p><a name="Footnote_4"></a><a href="#FNanchor_4">[4]</a></p> +<div class="note"><p>When the inner tube is strengthened by means of wire, the +initial or natural stresses in the latter may be neglected on account of +its thinness; but when the thickness of the hoops is reduced, and the +number of layers thereby increased, then the value of the initial +stresses in these hoops is a very important factor with respect to the +decrease or increase Of the powers of resistance of the gun.</p></div> + + +<hr /> + +<h2><a name="art01"></a>ELEMENTS OF ARCHITECTURAL DESIGN.<a name="FNanchor_5"></a><a href="#Footnote_5"><sup>1</sup></a></h2> + +<h3>By <span class="smcap">H.H. Statham.</span></h3> + +<h3>LECTURE I.</h3> + +<p>Judging from the nature of the correspondence on architecture and the +duty of architects which is frequently seen in the columns of the daily +papers, the <i>Times</i> especially, it would seem that the popular notion of +architecture now is that it is a study mainly of things connected with +sanitary engineering—of the best forms of drain pipes and intercepting +traps. This is indeed a very important part of sound building, and it is +one that has been very much neglected, and has been, in fact, in a +comparatively primitive state until very recent times; and therefore it +is not surprising that there should be a reaction in regard to it, and +that newspapers which follow every movement of public opinion, and try +to keep pace with it, should speak as if the drain pipe were the true +foundation of architecture. I have a great respect for the drain pipe, +and wish to see it as well laid and "intercepted" as possible; but I +think, for all that, that there is something in architecture higher than +sanitary engineering. I wish to consider it in these lectures as what I +think it essentially is, what it has evidently been in the eyes of all +those of past days who have produced what we now regard as great +architectural monuments, namely, as an intellectual art, the object of +which is to so treat the buildings which we are obliged to raise for +shelter and convenience as to render them objects of interest and +beauty, and not mere utilitarian floors, walls, and roofs to shelter a +race who care nothing for beauty, and who only want to have their +physical comfort provided for.</p> + +<p>Architecture, then, from the point of view from which I am asking you to +regard it—and the only point of view in which it is worth the serious +regard of thoughtful people—is the art of erecting expressive and +beautiful buildings. I say expressive <i>and</i> beautiful, and I put +expressive first, because it is the characteristic which we can at least +realize even when we cannot realize what can fairly be called beauty, +and it is the characteristic which comes first in the order of things. A +building may be expressive and thereby have interest, without rising +into beauty; but it can never be, architecturally speaking, beautiful +unless it has expression. And what do we mean by expression in a +building? That brings us to the very pith of the matter.</p> + +<p>We know pretty well what we mean when we say that a painted or +sculptured figure is expressive. We mean that, while correctly +representing the structure of the human figure, it also conveys to our +minds a distinct idea of a special emotion or sentiment, such as human +beings are capable of feeling and expressing by looks and actions. +Expression in this sense a building cannot be said to have. It is +incapable of emotion, and it has no mobility of surface or feature. Yet +I think we shall see that it is capable of expression in more senses +than one. It may, in the first place, express or reflect the emotion of +those who designed it, or it may express the facts of its own internal +structure and arrangement. The former, however, can only, I think, be +said to be realized in the case of architecture of the highest class, +and when taken collectively as a typical style. For instance, we can all +pretty well agree that the mediæval cathedral expresses an emotion of +aspiration on the part of its builders. The age that built the +cathedrals longed to soar in some way, and this was the way then open to +it, and it sent up its soul in spreading vaults, and in pinnacles and +spires. So also we can never look at Greek architecture without seeing +in it the reflection of a nature refined, precise, and critical; loving +grace and finish, but content to live with the graces and the muses +without any aspirations that spurned this earth. We can hardly go +further than this in attributing emotional expression to architecture. +But in a more restricted sense of the word <i>expression</i>, a building may +express very definitely its main constructive facts, its plan and +arrangement, to a certain extent even its purpose, so far at least that +we may be able to identify the class of structure to which it belongs. +It not only may, but it ought to do this, unless the architecture is to +be a mere ornamental screen for concealing the prosaic facts of the +structure. There is a good deal of architecture in the world which is in +fact of this kind—an ornamental screen unconnected with the +constructional arrangement of the building. Nor is such architecture to +be entirely scouted. It may be a very charming piece of scenery in +itself, and you may even make a very good theoretical defense for it, +from a certain point of view. But on the whole, architecture on that +principle becomes uninteresting. You very soon tire of it. It is a mask +rather than a countenance, and tends to the production of a dull +uniformity of conventional design.</p> + +<p>For we must remember that architecture, although a form of artistic +expression, is not, like painting and sculpture, unfettered by practical +considerations. It is an art inextricably bound up with structural +conditions and practical requirements. A building is erected first for +convenience and shelter; secondly only for appearance, except in the +case of such works as monuments, triumphal arches, etc., which represent +architectural effect pure and simple, uncontrolled by practical +requirements. With such exceptions, therefore, a building ought to +express in its external design its internal planning and arrangement; in +other words, the architectural design should arise out of the plan and +disposition of the interior, or be carried on concurrently with it, not +designed as a separate problem. Then a design is dependent on structural +conditions also, and if these are not observed, the building does not +stand, and hence it is obvious that the architectural design must +express these structural conditions. It must not appear to stand or be +constructed in a way in which it could not stand (like the modern shops +which are supposed to stand on sheets of plate glass), and its whole +exterior appearance ought to be in accordance with, and convey the idea +of, the manner and principle on which it is constructed. The most +important portions of the interior must be shown as such externally by +the greater elaboration and emphasis of their architectural treatment. +If the general arrangement of the plan is symmetrical, on either side of +a center (which, however, it cannot often be except in the largest type +of monumental or public buildings), the architectural treatment must be +symmetrical. If the building is necessarily arranged, in accordance with +the requirements of the plan, unsymmetrically, the architectural +treatment must follow suit, and the same principle must be carried out +through all the details.</p> + +<p>Now this dependence of architectural design upon plan and construction +is one of the conditions which is often overlooked by amateurs in +forming a judgment upon architectural design; and the overlooking of +this is one reason of the uncertainty of opinion about architecture as +compared with such arts as sculpture and painting. Few people know or +care much about the structure and planning of buildings except those +whose business it is to care about this; and consequently they do not +realize what it is which they should look for in the architectural +design. They like it or do not like it, and they regard this as what is +called a mere question of taste, which, according to the proverb, is not +to be disputed about. In fact, however, the good or bad taste of an +architectural design, say, if you like, its correctness or +incorrectness, is to a considerable extent a matter of logical +reasoning, of which you must accurately know the premises before you can +form a just conclusion. But there is another reason for this prevalent +uncertainty and vagueness of opinion, arising out of the very nature of +architectural art itself, as compared with the imitative arts. A +painting of a figure on a landscape is primarily a direct imitation of +the physical facts of nature. I do not for a moment say it is only that, +for there is far more involved in painting than the imitation of nature; +but the immediate reference to nature does give a standard of comparison +which to a certain extent every eye can appreciate. But architecture is +not an art which imitates natural forms at all, except as minor +decorations, and it then does so, or should do so, only in a +conventionalized manner, for reasons which we shall consider later on. +Architecture is, like music, a metaphysical art. It deals with the +abstract qualities of proportion, balance of form, and direction of +line, but without any imitation of the concrete facts of nature. The +comparison between architecture and music is an exercise of the fancy +which may indeed be pushed too far, but there is really a definite +similarity between them which it is useful to notice. For instance, the +regular rhythm, or succession of accentuated points in equal times, +which plays so important a part in musical form, is discernible in +architecture as a rhythm in space. We may treat a cottage type of +design, no doubt, with a playful irregularity, especially if this +follows and is suggested by an irregularity, of plan. But in +architecture on a grand scale, whether it be in a Greek colonnade or a +Gothic arcade, we cannot tolerate irregularity of spacing except where +some constructive necessity affords an obvious and higher reason for it. +Then, <a name="Page_10107"></a>again, we find the unwritten law running throughout all +architecture that a progress of line in one direction requires to be +stopped in a marked and distinct manner when it has run its course, and +we find a similarly felt necessity in regard to musical form. The +repetition so common at the close of a piece of music of the same chord +several times in succession is exactly analogous to the repetition of +cross lines at the necking of a Doric column to stop the vertical lines +of the fluting, or to the strongly marked horizontal lines of a cornice +which form the termination of the height or upward progress of an +architectural design. The analogy is here very close. A less close +analogy may also be felt between an architectural and a musical +composition regarded as a whole. A fugue of Bach's is really a built-up +structure of tones (as Browning has so finely put it in his poem, "Abt +Vogler"), in accordance with certain ideas of relation and proportion, +just as a temple or a cathedral is a built-up structure of lines and +spaces in accordance with ideas of relation and proportion. Both appeal +to the same sense of proportion and construction in the brain; the one +through the ear, the other through the eye. Then, in regard to +architecture again, we have further limiting conditions arising not only +out of the principle of construction employed, but out of the physical +properties of the very material we employ. A treatment that is suitable +and expressive for a stone construction is quite unsuitable for a timber +construction. Details which are effective and permanent in marble are +ineffective and perishable in stone, and so; on and the outcome of all +this is that all architectural design has to be judged, not by any easy +and ready reference to exterior physical nature, with which it has +nothing to do, but by a process of logical reasoning as to the relation +of the design to the practical conditions, first, which are its basis, +and as to the relation of the parts to each other. Of course beyond all +this there is in architecture, as in music, something which defies +analysis, which appeals to our sense of delight we know not how or why, +and probably we do not want to know; the charm might be dissolved if we +did. But up to this point architectural design and expression are based +on reasoning from certain premises. The design is good or bad as it +recognizes or ignores the logic of the case, and the criticism of it +must rest on a similar basis. It is a matter of thought in both cases, +and without thought it can neither be designed nor appreciated to any +purpose, and this is the leading idea which I wish to urge and to +illustrate in these lectures.</p> + +<p>You may say: May not a design satisfy all these logical conditions, and +yet be cold and uninteresting, and give one no pleasure? Certainly it +may. Indeed, we referred just now to that last element of beauty which +is beyond analysis. But, if we cannot analyze the result, I rather think +we can express what it is which the designer must evince, beyond clear +reasoning, to give the highest interest to his architecture. He must +have taken an interest in it himself. That seems a little thing to say, +but much lies in it. As Matthew Arnold has said of poetry:</p> + +<div class="poem"> +<p>"What poets feel not, when they make<br /> +<span class="i2">A pleasure in creating,</span> +The world, in its turn, will not take<br /> +<span class="i2">Pleasure in contemplating."</span> +</p> +</div> + +<p>The truth runs through all art. There are, alas, so many people who do +not seem to have the faculty of taking pleasure, and there is so much +architecture about our streets which it is impossible to suppose any one +took "pleasure in creating." When a feature is put into a design, not +because the designer liked it, but because it is the usual thing and it +saves trouble, it always proclaims that melancholy truth. But where +something is designed because the designer liked doing it, and was +trying to please his own fancy instead of copying what a hundred other +men have done before, it will go hard but he will give some pleasure to +the spectator. It is from this blessed faculty that a design becomes +inspired with what is best described as "character." It is not the same +thing as style. I have something to say in my next lecture as to what I +think <i>style</i> means, but it is certain that a building may have <i>style</i> +and yet want <i>character</i>, and it may have a good deal of <i>character</i> and +yet be faulty or contradictory in <i>style</i>. We cannot define "character," +but when we feel that it is present we may rely upon it that it is +because the designer took interest and pleasure in his work, was not +doing it merely scholastically—in short, he put something of his own +character into it, which means that he had some to put.</p> + +<div class="figcenter" style="width: 600px"> +<a href="./images/5a.png"><img src="./images/5a_th.png" alt="Figs. 1 through 3" /></a> +<span class="caption"><span class="smcap">Figs.</span> 1 through 3</span></div> + +<p>Now, coming back to the axiom before mentioned, that architectural +design should express and emphasize the practical requirements and +physical conditions of the building, let us look a little more in detail +into the manner in which this may be done. We will take, to begin with, +the very simplest structure we can possibly build—a plain wall (Fig. +1).<a name="FNanchor_6"></a><a href="#Footnote_6"><sup>2</sup></a> Here there is no expression at all; only stones piled one on +another, with sufficient care in coursing and jointing to give stability +to the structure. It is better for the wall, constructively, however, +that it should have a wider base, to give it more solidity of +foundation, and that the coping should project beyond the face of the +wall, in order to throw the rain off, and these two requirements may be +treated so as to give architectural expression to our work (Fig. 2). It +now consists of three distinct portions—a plinth, or base, a +superficies of wall, and a coping. We will mark the thickening at the +base by a moulding, which will give a few horizontal lines (at B), and +the coping in the same way. The moulding of the coping must also be so +designed as to have a hollow throating, which will act as a drip, to +keep the rain from running round the under side of the coping and down +the wall. We may then break up the superficies by inserting a band of +single ornament in one course of this portion of the wall—not half way, +for to divide any portion of a building into mere "halves" has usually a +weak and monotonous effect, but about two thirds of the distance from +the base line; and this band of ornament not only breaks up the plain +surface a little, but also, by carrying another horizontal line along +the wall, emphasizes its horizontality. Always emphasize that which is +the essential characteristic of your structure. A wall of this kind is +essentially a long horizontal boundary. Emphasize its length and +horizontality.</p> + + +<p>If we are millionaires, and can afford to spend a great deal on a wall, +we may not only (Fig. 3) carry further the treatment of the coping and +base, by giving them ornamental adjuncts as well as mouldings, but we +might treat the whole wall superficies as a space for surface carving, +not mechanically repeated, but with continual variation of every +portion, so as to render our wall a matter of interest and beauty while +retaining all its usefulness as a boundary, observing that such surface +ornament should be designed so as to fulfill a double object: 1, to give +general relief to the surface of the wall; 2, to afford matter of +interest to the eye on close inspection and in detail.</p> + +<p>That is the double function of nearly all architectural ornament. It is, +in the first place, to aid the general expression and balance of the +building, and give point and emphasis where needed; and, in the second +place, to furnish something to the eye for study on its own account when +viewed more closely.</p> + + +<div class="figcenter" style="width: 600px"> +<img src="./images/5b.png" alt="Figs. 4 through 9" /> +<span class="caption"><span class="smcap">Figs.</span> 4 through 9</span></div> + +<p>We will take another typical and simple erection, a stone pillar to +support the ends of two lintels or beams. This may be simply a long +squared piece set on end (Fig. 4), and will perform its constructive +functions perfectly well in that form; but it is not only absolutely +expressionless, but is in one sense clumsy and inconvenient, as taking +up more space than need be, presenting an unwieldy-looking mass when +viewed at an angle, and shutting out a good deal of light (if that +happen to be a matter of practical consequence in the case). Cutting off +the angles (Fig. 5) does not weaken it much, and renders it much less +unwieldy-looking, besides giving it a certain degree of verticality of +expression, and rendering it more convenient as taking up less room and +obstructing less light. But though the column is quite strong enough, +the octagonal top does not make so good a seat or bearing for the ends +of the lintels. We will therefore put a flat square stone on the top of +it (Fig. 6), which will serve as a bed for the lintels to rest on +securely. But the angles of this bed plate, where they project beyond +the face of the column, appear rather weak, and are so actually to some +extent—a double defect, for it is not enough in architecture that a +thing should be strong enough, it is necessary that it should appear so, +architecture having to do with expression as well as with fact. We will, +therefore, strengthen this projecting angle, and correct the abruptness +of transition between the column and the bed plate, by brackets (Fig. 7) +projecting from the alternate faces of the column to the angles of the +bed plates. As this rather emphasizes four planes of the octagon column +at the expense of the other four, we will bind the whole together just +under the brackets by a thin band of ornament constituting a necking, +and thus we have something like a capital developed, a definitely +designed finish to our column, expressive of its purpose. This treatment +of the upper end, however, would make the lower end rising abruptly from +the ground seem very bare. We will accordingly emphasize the base of the +column, just as we emphasized the base of the wall, by a projecting +moulding, not only giving expression to this connection of the column +with the ground, but also giving it the appearance, and to some extent +the reality, of greater stability, by giving it a wider and more +spreading base to rest on. We have here still left the lines of one +column vertically parallel, and there is no constructive reason why they +should not remain so. There is, however, a general impression to the eye +both of greater stability and more grace arising from a slight +diminution upward. It is difficult to account for this on any +metaphysical principle, but the fact has been felt by most nations which +have used a columnar architecture, and we will accept it and diminute +(so to speak) our column (Fig. 8). We have here taken a further step by +treating the shaft of the column in two heights, keeping the lower +portion octagonal and reducing the upper portion to a circle, and we now +find it easier to treat the capital so as to have a direct and complete +connection with the column, the capital being here merely a spreading +out of the column into a bracket form all round, running it into the +square of the bed plate.<a name="FNanchor_7"></a><a href="#Footnote_7"><sup>3</sup></a> The spreading portion is emphasized by +surface ornament, and the necking is again emphasized, this time more +decisively, by a moulding, forming a series of parallel rings round the +column. If we wish to give our column an expression of more grace and +elegance, we can further reduce the thickness of it (Fig. 9), and give +more spread to the capital, always taking care to be sure that the +strength of the column is not reduced below what the weight which it has +to carry requires. In this case a bracket is shown above the capital, +projecting longitudinally only (in the direction of the lintel bearing), +a method of giving a larger bearing surface for the ends of the lintels, +shortening their actual bearing<a name="FNanchor_8"></a><a href="#Footnote_8"><sup>4</sup></a> (in other <a name="Page_10108"></a>words, widening the space +which can be bridged between column and column) and giving a workmanlike +appearance of stability to the construction at this point. The idea of +the division of the column into two sections, suggested in Fig. 8, is +kept up in Fig. 9 by treating the lower portion up to the same height +with incised decorative carving. The dotted lines on each side in Fig. 9 +give the outline of the original square column as shown in Fig. 4. The +finished column was within that block; it is the business of the +architectural designer to get it out.<a name="FNanchor_9"></a><a href="#Footnote_9"><sup>5</sup></a></p> + +<div class="figcenter" style="width: 550px"> +<img src="./images/5c.png" alt="Figs. 10" /> +<span class="caption"><span class="smcap">Fig.</span> 10</span></div> + +<p>Let us see if we can apply the same kind of process of evolving +expression in regard to a building. We will take again the very simplest +form of building (Fig. 10), a square house with a door in the center and +uniform rows of windows. There cannot be said to be any architectural +expression in this. There is no base or plinth at all, no treatment of +the wall. The slight projection at the eaves is only what is necessary +to keep the rain from running down the walls, and facilitate the +emptying of the gutters, and the even spacing of the windows is +essential for constructive reasons, to keep the masses of wall over each +other, and keep the whole in a state of equally balanced pressure. The +first thing we should do in endeavoring to give some expression to the +building would be to give it a base or plinth (Fig. 11), and to mark +that and the cornice a little more decidedly by mouldings and a line of +paneling at the plinth.</p> + +<div class="figcenter" style="width: 540px"> +<img src="./images/5d.png" alt="Figs. 11" /> +<span class="caption"><span class="smcap">Fig.</span> 11</span></div> + +<p>The house being obviously in three stories, we should give it some echo +externally of this division into horizontal stages by horizontal +mouldings, or what are called in architectural phraseology "string +courses," not necessarily exactly at the floor levels, but so as to +convey the idea of horizontal division; observing here, as in the case +of the wall and column, that we should take care not to divide the +height into equal parts, which is very expressionless. In this case we +will keep the lower string close down on the ground floor windows, and +keep these rather low, thus showing that the ground floor apartments are +not the most important; while the fact that the first floor ones are so +is conversely made apparent by keeping these windows rather higher, +putting a double string course over them, and a slight extra depth of +moulding, forming a kind of cornice over each.</p> + +<p>The space left between these and the roof, in which the attic windows +are placed, is treated with a series of mullions and panelings, into +which the attic windows are worked, as part of the series of openings; +this gives a little richness of effect to the top story, and a +continuity of treatment, which binds the whole series of windows +together. To have treated the whole of the walls and windows in this way +would have been merely throwing away labor; what little effect it has +consists in the "character" given by the contrast of this top story +treatment with the plain wall surfaces below.</p> + +<p>The last thing is to emphasize the door, as the principal opening in the +walls, and quite distinct in use and meaning from the other openings, by +giving it a little architectural frame or setting, which may be done in +many ways, but in this case is done by the old fashioned device (not +very logical certainly) of putting a little entablature over it, and a +column on either side; there is, however, this to be said for it, that +the projecting tablature forms a semi-porch, protecting those at the +door somewhat from rain; it must be carried in some way, and columns are +the readiest and most seemly manner of doing it, and they also form, +practically, something of a weather screen; the bases on which they +stand also form a framework or inclosing wall for the steps, which are +thus made part of the architectural design, instead of standing out as +an eyesore, as on Fig. 10. We have now given the house a little general +expression, but it still is vague in its design as far as regards the +distribution of the interior; we do not know whether the first floor, +for instance, is one large room, or two or more rooms, or how they are +divided; and the little house is very square and prim in effect.</p> + +<p>Let us try grouping the windows a little, and at the same time breaking +up the flat surface of the front wall (Fig. 12). Here, as before, we +have divided the building by a horizontal string, but only by one main +one on the first floor level, keeping the same contrast, however, +between a richer portion above and a plainer portion below; we have +divided the building vertically, also, by two projecting bays finishing +in gables, thus breaking also the skyline of the roof, and giving it a +little picturesqueness, and we have grouped the windows, instead of +leaving them as so many holes in the wall at equal distances. The +contrast between the ground and first floor windows is more emphatic; +and it is now the more evident that the upper floor rooms are the best +apartments, from their ample windows; it is also pretty evident that the +first floor is divided into two main rooms with large bay windows, and a +smaller room or a staircase window, between them; the second floor +windows are also shifted up higher, the two principal ones going in to +the gables, showing that the rooms below them have been raised in +height. Windows carried up the full height of these rooms, however, +might be too large either for repose internally or for appearance +externally, so the wall intervening between the top of these and the +sill of the gables is a good field for some decorative treatment, +confined to the bays, so as to assist in separating them from the +straight wall which forms the background to them.</p> + +<div class="figcenter" style="width: 560px"> +<img src="./images/5e.png" alt="Fig. 12" /> +<span class="caption"><span class="smcap">Fig.</span> 12</span></div> + +<p>So far we have treated our building only as a private house. Without +altering its general scale and shape we may suggest something entirely +different from a private house. On Fig. 13, we have tried to give a +municipal appearance to it, as if it were the guild hall of a small +country town. The plain basement and the wide principal doorway, and the +row of three very large equal-spaced windows above, render it +unquestionable that this is a building with a low ground story, and one +large room above. A certain "public building" effect is given to it by +the large and enriched cornice with balustrade above and paneling below, +and by the accentuation of the angles by projecting piers, and by the +turrets over them, which give it quite a different character from that +of a private house.</p> + +<div class="figcenter" style="width: 550px"> +<img src="./images/5f.png" alt="Fig. 13" /> +<span class="caption"><span class="smcap">Fig.</span> 13</span></div> + +<p>If, on the other hand, the building were the free library and reading +room of the same small country town, we should have little doubt of this +if we saw it as in Fig. 14, with the walls all blank (showing that they +are wanted for ranging something against, and cannot be pierced for +windows), and windows only in the upper portion. Similarly, if we want +to build it as the country bank, we should have to put the large windows +on the ground floor, bank clerks wanting plenty of light, and the ground +story being always the principal one; and we might indulge the humor of +giving it a grim fortress-like strength by a rusticated plinth (<i>i.e.</i>, +stones left or worked rough and rock-like) and by very massive piers +between the windows, and a heavy cornice over them; the residential +upper floor forming a low story subordinate to the bank story. It is +true this would not satisfy a banker, who always wants classic pilasters +stuck against the walls, that being his hereditary idea of bank +expression in architecture.</p> + + +<div class="figcenter" style="width: 540px"> +<img src="./images/6a.png" alt="Fig. 14" /> +<span class="caption"><span class="smcap">Fig.</span> 14</span></div> + +<div class="figcenter" style="width: 560px"> +<img src="./images/6b.png" alt="Fig. 15" /> +<span class="caption"><span class="smcap">Fig.</span> 15</span></div> + +<p>Now if we proceed to take to pieces the idea of architectural design, +and consider wherein the problem of it consists, we shall find that it +falls into a fourfold shape. It consists first in arranging the plan; +secondly, in carrying up the boundary lines of this plan vertically in +the shape of walls; thirdly, in the method of covering in the space +which we have thus defined and inclosed; and, fourthly, in the details +of ornamentation which give to it the last and concluding grace and +finish. All building, when it gets beyond the mere wall with which we +began, is really a method of covering in a space, or, if we may put it +so, a collection of spaces, marked out and arranged for certain +purposes. The first thing that the architect has to do is to arrange +these spaces on the ground so that they may conveniently meet the +necessary requirements of the building. Convenience and practical +usefulness come first; but in any building which is worth the name of +architecture something more than mere convenience has to be kept in +mind, even in the arrangement of the plan upon the site. It is to be a +combination of convenience with effectiveness of arrangement. We shall +probably find that some one compartment of the plan is of paramount +importance. We have to arrange the interior so that this most important +compartment shall be the climax of the plan.</p> + +<p>The entrance and the other subsidiary compartments must be kept +subordinate to it, and must lead up to it in such a manner that the +spectator shall be led by a natural gradation from the subsidiary +compartments up to the main one, which is the center and <i>raison +d'etre</i> of the whole—everything in the lines of the plan should point +to that. This is the great <i>crux</i> in the planning of complicated public +buildings. A visitor to such a building, unacquainted with it +previously, ought to have no difficulty in finding out from the +disposition of the interior which are the main lines of route, and when +he is on the line leading him up to the central feature of the plan. +There are public buildings to be found arranged on what may be called +the rabbit warren system, in which perhaps a great number of apartments +are got upon the ground, but which the visitor is obliged laboriously to +learn before he can find his way about them. That is not only +inconvenient but inartistic planning, and shows a want of logic and +consideration, and, in addition to this, a want of feeling for artistic +effect. I saw not long ago, for instance, in a set of competitive +designs for an important public building, a design exhibiting a great +deal of grace and elegance in the exterior architectural embellishment, +but in which the principal entrance led right up to a blank wall facing +the entrance, and the spectator had to turn aside to the left and then +to the right before finding himself on the principal axis of the plan. +That is what I should call inartistic or unarchitectural planning. The +building may be just as convenient when you once know its dodges, but it +does not appear so, and it loses the great effect of direct vista and +climax.</p> + +<p>An able architect, who had given much thought to a plan of a large +building of this kind, said to me, in showing me his plan, with a +justifiable gratification in it, "It has cost me endless trouble, but it +is a satisfaction to feel that you have got a plan with backbone in it." +That is a very good expression of what is required in planning a +complicated building, but few outsiders have any notion of the amount of +thought and contrivance which goes to the production of a plan "with +backbone;" a plan in which all the subordinate and merely practical +departments shall be in the most convenient position in regard to each +other, and yet shall all appear as if symmetrically and naturally +subordinate to the central and leading feature; and if the public had a +little more idea what is the difficulty of producing such a plan, they +would perhaps do a little more justice to the labors of the man who +contrives the plan, which they think such an easy business; and no doubt +it may appear an easy business, because the very characteristic of a +really good plan is that it should appear as if it were quite a natural +and almost inevitable arrangement.</p> + +<p> <a name="Page_10109"></a>Just as it is said in regard to literature that easy writing is hard +reading, so, in regard to planning, it is the complicated and rabbit +warren plans that are the easiest to make, because it is just doing what +you please; it is the apparently perfectly simple and natural plan which +springs from thought and contrivance. Then there is the next step of +raising the walls on the plan, and giving them architectural expression. +This must not be thought of as an entirely separate problem, for no +truly architectural intellect will ever arrange a plan without seeing +generally, in his mind's eye, the superstructure which he intends to +rear upon it; but the detailed treatment of this forms a separate branch +of the design. Then comes the third and very important problem—the +covering in of the space. Next to the plan, this is the most important. +All building is the covering over of a space, and the method of covering +it over must be foreseen and provided for from the outset. It largely +influences the arrangement of the plan. If there were no roofing, you +could arrange the walls and carry them up pretty much as you chose, but +the roofing of a large space is another matter. It requires extra +strength at certain points, where the weight of the roof is +concentrated, and it has to be determined whether you will employ a +method of roofing which exercises only a vertical pressure on the walls, +like the lid of a box, or one which, like an arch, or a vault, or a +dome, is abutting against the walls, and requires counterforts to resist +the outward thrust of the roof. We shall come upon this subject of the +influence of the roof on the design of the substructure more in detail +later on. Then, if the plan is convenient and effective, the walls +carried up with the architectural expression arising from the placing +and grouping of the openings, and the proper emphasizing of the base and +the cornice, and the horizontal stages (if any) of the structure, and +the roof firmly and scientifically seated on the walls; after all these +main portions of the structure are designed logically and in accordance +with one another and with the leading idea of the building, then the +finishing touches of expression and interest are given by well designed +and effective ornamental detail. Here the designer may indulge his fancy +as he pleases, as far as the nature of the design is concerned, but not, +if you please, as far as its position and distribution are concerned. +There the logic of architecture still pursues us.</p> + +<p>We may not place ornament anywhere at haphazard on a building simply +because it looks pretty. At least, to do so is to throw away great part +of its value. For everything in architectural design is relative; it is +to be considered in relation to the expression and design of the whole, +and ornament is to be placed where it will emphasize certain points or +certain features of the building. It must form a part of the grouping of +the whole, and be all referable to a central and predominating idea. A +building so planned, built, and decorated becomes, in fact, what all +architecture—what every artistic design in fact should be—an organized +whole, of which every part has its relation to the rest, and from which +no feature can be removed without impairing the unity and consistency of +the design. You may have a very good, even an expressive, building with +no ornament at all if you like, but you may not have misplaced ornament. +That is only an excrescence on the design, not an organic portion of it.</p> + +<p>I have thought that it would be of use to those who are unacquainted +with architectural procedure in delineating architecture by geometrical +drawings if I took the opportunity of illustrating very briefly the +philosophy of elevations, plans, and sections, which many +non-professional people certainly do not understand.</p> + +<div class="figright" style="width: 380px"> +<a href="./images/6c.png"><img src="./images/6c_th.png" alt="Figs. 16 through 25" /></a> +<span class="caption"><span class="smcap">Figs.</span> 16 through 25</span></div> + +<p>A simple model of a building, like that in Fig. 16, will serve the +purpose, as the principle is the same in the most complicated as in the +simplest building. It must be remembered that the object of +architectural drawings on the geometrical system is not to show a +picture of the building, but to enable the designer to put together his +design accurately in all its parts, according to scale, and to convey +intelligible and precise information to those who have to erect the +building. A perspective drawing like Fig. 16 is of no use for this +purpose. It shows generally what the design is, but it is impossible to +ascertain the size of any part by scale from it, except that if the +length of one line were given it would be possible, by a long process of +projection and calculation, to ascertain the other sizes. The +<i>rationale</i> of the architect's geometrical drawings is that on them each +plane of the building (the front, the side, the plan, etc.) is shown +separately and without any distortion by perspective, and in such a +manner that every portion is supposed to be opposite to the eye at once. +Only the width of any object on one side can be shown in this way at one +view; for the width of the return side you have to look to another +drawing; you must compare the drawings in order to find out those +relative proportions which the perspective view indicates to the eye at +a glance; but each portion of each side can be measured by reference to +a scale, and its precise size obtained, which can only be guessed at +roughly from the perspective drawing. Thus the side of the model is +shown in Fig. 19, the end in Fig. 17; the two together give the precise +size and proportions of everything outside to scale, except the +projection of the pilasters. This has to be got at from the plan and +section. Everything being drawn on one plane, of course surfaces which +are sloping on one elevation are represented as flat in the other. For +instance, on No. 17 the raking line of the sloping roof is shown at N. +So we know the slope of the roof, but we do not know to what length it +extends the other way. This is shown on Fig. 19, where the portion +showing the roof is also marked N, and it will be seen that the surface +which is sloping in Fig. 17 is seen in the side elevation only as a +space between a top and bottom line. We see the length of the roof here, +and its height, but for its slope we go to the end elevation. Neither +elevation tells us, however, what is inside the building; but the +section (Fig. 18) shows us that it has an arched ceiling, and two +stories, a lower and a higher one. The section is the building cut in +half, showing the end of the walls, the height and depth of the window +openings, the thickness of the floor, etc., and as all parts which are +opposite the eye are shown in the drawing, the inside of the cross wall +at the end of the building is shown as a part of the section drawing, +between the sectional walls. In Fig. 23 the section is sketched in +perspective, to show more clearly what it means. Another section is made +lengthwise of the building (Fig. 20). It is customary to indicate on +the plan by dotted lines the portion through which the section is +supposed to be made. Thus on the plans the lines A B and C D are drawn, +and the corresponding sections are labeled with the same lines. As with +the elevation, one section must be compared with another to get the full +information from them. Thus in Fig. 18, the ceiling, M, is shown as a +semicircle; in Fig. 20, it is only a space between the top and bottom +lines. It is, certainly, shaded here to give the effect of rotundity, +but that is quite a superfluity. On Fig. 18 the height of the side +windows is shown at F, and the thickness of the wall in which they are +made. In Fig. 20 (F) their width and spacing are shown. In Fig. 18 some +lines drawn across, one over the other, are shown at H. These are the +stairs, of which in this section we see only the fronts, or risers, so +that they appear merely as lines (showing the edge of each step) drawn +one over the other. At H on the plan, Fig. 21, we again see them +represented as a series of lines, but here we are looking down on the +top of them, and see only the upper surfaces, or "treads," the edges +again appearing as a series of lines. At H on the longitudinal section, +we see the same steps in section, and consequently their actual slope, +which, however, could have been calculated from Figs. 18 and 21, by +putting the heights shown in section with the width shown in plan. The +plan, Fig. 21, shows the thickness and position on the floor of the +pillars, G G. Their height is shown in the sections. The plan of a +building is merely a horizontal section, cutting off the top, and +looking down on the sectional top of the walls, so as to see all their +thicknesses. I have drawn (Fig. 24) a perspective sketch of one end of +the plan (Fig. 22) of the building, on the same principle as was done +with the section (Fig. 23), in order to show more intelligibly exactly +what it is that a plan represents—the building with the upper part +lifted off.</p> + +<p>Returning for a moment to the subject of the relation between the plan +and the exterior design, it should be noted that the plan of a building +being practically the first consideration, and the basis of the whole +design, the latter should be in accordance with the principle of +disposition of the plan. For example, if we have an elevation (shown in +diagram) showing two wings of similar design on either side of a center, +designed so as to convey the idea of a grand gallery, with a suite of +apartments on either side of similar importance—if the one side only of +the plan contains such a suite, and the opposite side is in reality +divided up into small and inferior rooms, filled in as well as may be +behind the architectural design—the whole design is in that case only +a blind or screen, giving a false exterior symmetry to a building which +is not so planned. This is an extreme case (or might be called so if it +were not actually of pretty frequent occurrence); but it illustrates in +a broad sense a principle which must be carried out in all cases, if the +architecture is to be a real expression of the facts of the building.</p> + +<p>In this lecture, which is concerned with general principles, a word may +fittingly be said as to the subject of <i>proportion</i>, concerning which +there are many misapprehensions. The word may be, and is, used in two +senses, first in regard to the general idea suggested in the words "a +well proportioned building." This expression, often vaguely used, seems +to signify a building in which the balance of parts is such as to +produce an agreeable impression of completeness and repose. There is a +curious kind of popular fallacy in regard to this subject, illustrated +in the remark which used to be often made about St. Peter's, that it is +so well proportioned that you are not aware of its great size, etc.—a +criticism which has been slain over and over again, but continues to +come to life again. The fact that this building does not show its size +is true. But the inference drawn is the very reverse of the truth. One +object in architectural design is to give full value to the size of a +building, even to magnify its apparent size; and St. Peter's does not +show its size, because it is <i>ill</i> proportioned, being merely like a +smaller building, with all its parts magnified. Hence the deception to +the eye, which sees details which it is accustomed to see on a smaller +scale, and underrates their actual size, which is only to be ascertained +by deliberate investigation. This confusion as to scale is a weakness +inherent in the classical forms of columnar architecture, in which the +scale of all the parts is always in the same proportion to each other +and to the total size of the building so that a large Doric temple is in +most respects only a small one magnified. In Gothic architecture the +scale is the human figure, and a larger building is treated, not by +magnifying its parts, but by multiplying them. Had this procedure been +adopted in the case of St. Peter's, instead of merely treating it with a +columnar order of vast size, with all its details magnified in +proportion, we should not have the fault to find with it that it does +not produce the effect of its real size. In another sense, the word +"proportion" in architecture refers to the system of designing buildings +on some definite geometrical system of regulating the sizes of the +different parts. The Greeks certainly employed such a <a name="Page_10110"></a>system, though +there are not sufficient data for us to judge exactly on what principle +it was worked out. In regard to the Parthenon, and some other Greek +buildings, Mr. Watkiss Lloyd has worked out a very probable theory, +which will be found stated in a paper in the "Transactions of the +Institute of Architects."</p> + +<p>Vitruvius gives elaborate directions for the proportioning of the size +of all the details in the various orders; and though we may doubt +whether his system is really a correct representation of the Greek one, +we can have no doubt that some such system was employed by them. Various +theorists have endeavored to show that the system has prevailed of +proportioning the principal heights and widths of buildings in +accordance with geometrical figures, triangles of various angles +especially; and very probably this system has from time to time been +applied, in Gothic as well as in classical buildings. This idea is open +to two criticisms, however. First, the facts and measurements which have +been adduced in support of it, especially in regard to Gothic buildings, +are commonly found on investigation to be only approximately true. The +diagram of the section of the building has nearly always, according to +my experience, to be "coaxed" a little in order to fit the theory; or it +is found that though the geometrical figure suggested corresponds +exactly with some points on the plan or section, these are really of no +more importance than other points which might just as well have been +taken. The theorist draws our attention to those points in the building +which correspond with his geometry, and leaves on one side those which +do not. Now it may certainly be assumed that any builders intending to +lay out a building on the basis of a geometrical figure would have done +so with precise exactitude, and that they would have selected the most +obviously important points of the plan or section for the geometrical +spacing. In illustration of this point, I have given (Fig. 25) a +skeleton diagram of a Roman arch, supposed to be set out on a +geometrical figure. The center of the circle is on the intersection of +lines connecting the outer projection of the main cornice with the +perpendiculars from those points on the ground line. This point at the +intersection is also the center of the circle of the archway itself. But +the upper part of the imaginary circle beyond cuts the middle of the +attic cornice. If the arch were to be regarded as set out in reference +to this circle, it should certainly have given the most important +line—the top line, of the upper cornice, not an inferior and less +important line; and that is pretty much the case with all these +proportion theories (except in regard to Greek Doric temples); they are +right as to one or two points of the building, but break down when you +attempt to apply them further. It is exceedingly probable that many of +these apparent geometric coincidences really arise, quite naturally, +from the employment of some fixed measure of division in setting out +buildings. Thus, if an apartment of somewhere about 30 feet by 25 feet +is to be set out, the builder employing a foot measure naturally sets +out exactly 30 feet one way and 25 feet the other way. It is easier and +simpler to do so than to take chance fractional measurements. Then comes +your geometrical theorist, and observes that "the apartment is planned +precisely in the proportion of six to five." So it is, but it is only +the philosophy of the measuring-tape, after all. Secondly, it is a +question whether the value of this geometrical basis is so great as has +sometimes been argued, seeing that the results of it in most cases +cannot be judged by the eye. If, for instance, the room we are in were +nearly in the proportion of seven in length to five in width, I doubt +whether any of us here could tell by looking at it whether it were truly +so or not, or even, if it were a foot out one way or the other, in which +direction the excess lay; and if this be the case, the advantage of such +a geometrical basis must be rather imaginary than real.</p> + +<div class="figcenter" style="width: 510px"> +<a href="./images/7a.png"><img src="./images/7a_th.png" alt="Figs. 26 through 28" /></a> +<span class="caption"><span class="smcap">Figs.</span> 26 through 28</span></div> + +<p>Having spoken of plan as the basis of design, I should wish to conclude +this lecture by suggesting also, what has never to my knowledge been +prominently brought forward, that the plan itself, apart from any +consideration of what we may build up upon it, is actually a form of +artistic thought, of architectural poetry, so to speak. If we take three +such plans as those shown in Figs. 26, 27, and 28, typical forms +respectively of the Egyptian, Greek, and Gothic plans, we certainly can +distinguish a special imaginative feeling or tendency in each of them. +In the Egyptian, which I have called the type of "mystery," the plan +continually diminishes as we proceed inward. In the third great +compartment the columns are planted thick and close, so as to leave no +possibility of seeing through the building except along a single avenue +of columns at a time. The gloom and mystery of a deep forest are in it, +and the plan finally ends, still lessening as it goes, in the small and +presumably sacred compartment to which all this series of colonnaded +halls leads up. In the Greek plan there is neither climax nor +anti-climax, only the picturesque feature of an exterior colonnade +encircling the building and surrounding a single oblong compartment. It +is a rationalistic plan, aiming neither at mystery nor aspiration. In +the plan of Rheims (Fig. 28) we have the plan of climax or aspiration; +as in the Egyptian, we approach the sacred portion through a long avenue +of piers; but instead of narrowing, the plan extends as we approach the +shrine. I think it will be recognized, putting aside all considerations +of the style of the superstructure on these plans, that each of them in +itself represents a distinct artistic conception. So in the plan of the +Pantheon (Fig. 29), this entrance through a colonnaded porch into a vast +circular compartment is in itself a great architectural idea, +independently of the manner in which it is built up.</p> + +<div class="figcenter" style="width: 530px"> +<a href="./images/7b.png"><img src="./images/7b_th.png" alt="Figs. 29 through 34" /></a> +<span class="caption"><span class="smcap">Figs.</span> 29 through 34</span></div> + +<p>We may carry out this a little further by imagining a varied treatment +on plan of a marked-out space of a certain size and proportion, on which +a church of some kind, for instance, is to be placed. The simplest idea +is to inclose it round with four walls as a parallelogram (Fig. 30), +only thickening the walls where the weight of the roof principals comes. +But this is a plan without an idea in it. The central or sacred space at +the end is not expressed in the plan, but is merely a railed-off portion +of the floor. The entrance is utterly without effect as well as without +shelter. If we lay out our plan as in Fig. 31, we see that there is now +an idea in it. The two towers, as they must evidently be, form an +advanced guard of the plan, the recessed central part connecting them +gives an effective entrance to the interior; the arrangement in three +aisles gives length, the apse at the end incloses and expresses the +<i>sacrarium</i>, which is the climax and object of the plan. The shape of +the ground, however, is not favorable to the employment of a long or +avenue type of plan, it is too short and square; let us rather try a +plan of the open area order, such as Fig 32. This is based on the +short-armed Greek cross, with an open center area; again there is an +"advanced guard" in the shape of an entrance block with a porch; and the +three apses at the end give architectural emphasis to the <i>sacrarium</i>. +Fig. 35 is another idea, the special object of which is to give an +effect of contrast between the entrance, approached first through a +colonnaded portico, then through an internal vestibule, lighted from +above, and flanked by rows of small coupled columns; then through these +colonnaded entrances, the inner one kept purposely rather dark, we come +into an interior expanding in every direction; an effect of strong +contrast and climax. If our plot of ground again be so situated that one +angle of it is opposite the vista of two or more large streets, there +and nowhere else will be the salient angle, so to speak, of the plan, +and we can place there a circular porch—which may, it is evident, rise +into a tower—and enter the interior at the angle instead of in the +center; not an effective manner of entering as a rule, but quite +legitimate when there is an obvious motive for it in the nature and +position of the site. A new feature is here introduced in the circular +colonnade dividing the interior into a central area and an aisle. Each +of these plans might be susceptible of many different styles of +architectural treatment; but quite independently of that, it will be +recognized that each of them represents in itself a distinct idea or +invention, a form of artistic arrangement of spaces, which is what +"plan," in an architectural sense, really means.</p> + +<p><a name="Footnote_5"></a><a href="#FNanchor_5">[1]</a></p> +<div class="note"><p>Delivered before the Society of Arts, London, November 28, +1887. From the <i>Journal</i> of the Society.</p></div> + +<p><a name="Footnote_6"></a><a href="#FNanchor_6">[2]</a></p> +<div class="note"><p>The dark shaded portion in this and the next two diagrams +show the "section" of the wall as seen if we cut it through and look at +it endwise.</p></div> + +<p><a name="Footnote_7"></a><a href="#FNanchor_7">[3]</a></p> +<div class="note"><p>This is the feature called "abacus" (<i>i.e.</i>, "tile") in +Greek architecture, but I am here considering it apart from any special +style or nomenclature.</p></div> + +<p><a name="Footnote_8"></a><a href="#FNanchor_8">[4]</a></p> +<div class="note"><p>"Bearing," in building language, is used in a double sense, +for the distance between the points of support, and the extent to which +the beam rests on the walls. Thus a beam which extends 20 feet between +the points of support is a beam of 20 feet bearing. If the beam is 22 +feet long, so that 1 foot rests on the walls at each end, it has "1 foot +bearing on the wall."</p></div> + +<p><a name="Footnote_9"></a><a href="#FNanchor_9">[5]</a></p> +<div class="note"><p>None of the forms of column sketched here have any +existence in reality. They are purposely kept apart from imitation of +accepted forms to get rid of the idea that architecture consists in the +acceptance of any particular form sanctioned by precedent.</p></div> + +<hr /> + +<h2><a name="art15"></a>THE LOWE INCANDESCENT GAS BURNER.</h2> + +<p>This burner is in the form of a cylinder made of a composition in which +magnesium predominates, and gives a light of 210 candle power with a +consumption of three and one-half cubic feet of gas per hour.</p> + +<div class="figright" style="width: 230px"> +<a href="./images/8.png"><img src="./images/8_th.png" alt="Figs. 29 through 34" /></a> +</div> + +<p>The cylinder to be heated to incandescence is firmly held in place on a +metal spindle, which is slowly revolved by means of an ingenious +clock-work in the base of the fixture. The arrangement is such that by +turning off the gas the clock-work is stopped, and by the turning on of +the gas, it is again set in motion. The movement of the spindle is so +slow that a casual observer would not notice it, there being only one +revolution made in twenty-four hours. The object of this movement is to +continually present new surface to be heated, as that which is exposed +to the high temperature wears away, similarly to the carbons used in +electric lighting, though much more slowly.</p> + +<p>These burners can be made of 2,000 candle power, down to fifty candle +power.</p> + +<p>Pure oxygen can now be obtained from the atmosphere at a cost of about +twenty-five cents per 1,000 cubic feet, and the small amount required to +supplement the fuel water gas in producing this light can be supplied +under proper pressure from a very small pipe, which can be laid in the +same trench with the fuel gas pipe, at much less cost than is required +to carry an electric wire to produce an equal amount of light.</p> + +<p>The oxygen pipe necessary to carry the gas under pressure need not +exceed an inch and a half in diameter to supply 5,000 lamps of 2,000 +candle power each. The only reason why this burner has not been further +perfected and placed upon the market is because of the continual +preoccupation of Prof. Lowe in other lines of invention, and the amount +of attention required by his large business interests. Besides, the +field for its usefulness has been limited, as cheap fuel gas has only +just begun to be generally introduced. Now, however, that extensive +preparations are being made for the rapid introduction of the Lowe fuel +gas system into various cities, this burner will receive sufficient +attention to shortly complete it for general use in large quantities. It +is a more powerful and at the same time a softer light than is the +electric incandescent or the arc light. The light-giving property of a +burner of 1,000 candle power would not cost more than one cent for ten +hours' lighting, and the cylinder would only require to be changed once +a week; whereas the carbons of arc lights are changed daily. The cost of +the gas required to maintain such a lamp ten hours would be six cents, +allowing the same profit on the gas as when it is sold for other heating +purposes. The lamps complete will cost much less than the present +electric lamps, and after allowing a large profit to companies supplying +them, will not cost consumers more than one-fourth as much as arc lamps, +and will give a much clearer and steadier light.</p> + +<p>Since Prof. Lowe perfected his first incandescent burner great progress +has been made in this line of invention, and it is no wonder that the +attention of the whole gas fraternity of the country has been drawn to +the subject of cheap fuel water gas, which is so admirably adapted to +all purposes of heat, light, and power.</p> + +<p>While there is no doubt that light can be more cheaply produced by +incandescence obtained by the use of fuel water gas than by any other +means, still a large amount of electric lighting will continue to hold +its position, and the electric system will gain ground for many uses. +But the electric light also can be more economically produced when fuel +water gas is used as power to revolve the dynamos. Therefore, we believe +it to be for the best interests of every gas company that would move in +the line of progress to commence without delay to make preparations for +the introduction of fuel water gas, if, at first, only as supplementary +to their present illuminating gas business.-<i>Progressive Age.</i></p> + +<hr /> + +<h2><a name="art14"></a>PROGRESS OF THE SORGHUM SUGAR INDUSTRY. </h2> + +<p>We are indebted to Prof. E.B. Cowgill, of Kansas, for a copy of his +recent report to the Kansas State Board of Agriculture concerning the +operations of the Parkinson Sugar Works, at Fort Scott, Kansas. The +report contains an interesting historical sketch of the various efforts +heretofore made to produce sugar from sorghum, none of which proved +remunerative until 1887, when the persevering efforts of a few energetic +individuals, encouraged and assisted by a small pecuniary aid from +government, were crowned with success, and gave birth, it may justly be +said, to a new industry which seems destined shortly to assume gigantic +proportions and increase the wealth of the country.</p> + +<p>We make the following abstracts from the report:</p> + +<p>The sorghum plant was introduced into the United States in 1853-54, by +the Patent Office, which then embraced all there was of the United +States Department of Agriculture. Its juice was known to be sweetish, +and chemists were not long in discovering that it contained a +considerable percentage of some substance giving the reactions of cane +sugar. The opinion that the reactions were due to cane sugar received +repeated confirmations in the formation of true cane sugar crystals in +sirups made from sorghum. Yet the small amounts that were crystallized, +compared with the amounts present in the juices as shown by the +analyses, led many to believe that the reactions were largely due to +some other substance than cane sugar.</p> + +<p>During the years 1878 to 1882, inclusive, while Dr. Peter Collier was +chief chemist of the Department of Agriculture, much attention was given +to the study of sorghum juices from canes cultivated in the gardens of +the department at Washington. Dr. Collier became an enthusiastic +believer in the future greatness of sorghum as a sugar producing plant, +and the extensive series of analyses published by him attracted much +attention.</p> + +<p>As a result large sugar factories were erected and provided with costly +appliances. Hon. John Bennyworth erected one of these at Larned, in +Kansas. S.A. Liebold & Co. subsequently erected one at Great Bend.</p> + +<p>Sterling and Hutchinson followed with factories which made considerable +amounts of merchantable sugar at no profit.</p> + +<p>The factory at Sterling was erected by R.M. Sandy & Co., of New Orleans, +and while the sirup produced paid the expenses of the factory, not a +crystal of sugar was made. The factory then, in 1883, changed hands, and +passed under the superintendency of Prof. M.A. Scovell, then of +Champaign, Illinois, who, with Prof. Webber, had worked out, in the +laboratories of the Illinois Industrial University, a practical method +for obtaining sugar from sorghum in quantities which at prices then +prevalent would pay a profit on the business. But prices declined, and +after making sugar for two years in succession, the Sterling factory +succumbed.</p> + +<p>The Hutchinson factory at first made no sugar, but subsequently passed +under the management of Prof. M. Swenson, who had successfully made +sugar in the laboratory of the University of Wisconsin. Large amounts of +sugar were made at a loss, and the Hutchinson factory closed its doors. +In 1884, Hon. W.L. Parkinson fitted up a complete sugar factory at +Ottawa, and for two years made sugar at a loss. Mr. Parkinson was +assisted during the first year by Dr. Wilcox, and during the second year +by Prof. Swenson.</p> + +<p>Much valuable information was developed by the experience in those +several factories, but the most important of all was the fact that, with +the best crushers, the average extraction did not exceed half of the +sugar contained in the cane. It was known to scientists and well +informed sugar makers in this country that the process of diffusion was +theoretically efficient for the extraction of sugar from plant cells, +and that it had been successfully applied by the beet sugar makers of +Europe for this purpose.</p> + +<p>In 1883, Prof. H.W. Wiley, chief chemist of the Department of +Agriculture, made an exhaustive series of practical experiments in the +laboratories of the department on the extraction of the sugars from +sorghum by the diffusion process, by which the extraction of at least 85 +per cent. of the total sugars present was secured.</p> + +<p>The Kansas delegation in Congress became interested. Senator Plumb made +a thorough study of the entire subject, and, with the foresight of +statesmanship, gave his energies to the work of securing an +appropriation of $50,000 for the development of the sugar industry, +which was granted in 1884, and fifty thousand dollars more was added in +1885 to the agricultural <a name="Page_10111"></a>appropriation bill. This was expended at +Ottawa, Kansas, and in Louisiana.</p> + +<p>In that year Judge Parkinson, at Fort Scott, organized the Parkinson +Sugar Company. Taking up the work when all others had failed, this +company has taken a full share of the responsibilities and losses, until +it has at last seen the Northern sugar industry made a financial +success.</p> + +<p>The report of 1895 showed such favorable results that in 1886 the House +made an appropriation of $90,000, to be used in Louisiana, New Jersey, +and Kansas. A new battery and complete carbonatation apparatus were +erected at Fort Scott. About $60,000 of the appropriation was expended +here in experiments in diffusion and carbonatation.</p> + +<p>Last year (1887) the Fort Scott management made careful selection of +essential parts of the processes already used, omitted non-essential and +cumbrous processes, availed themselves of all the experience of the past +in this country, and secured a fresh infusion of experience from the +beet sugar factories of Germany, and attained the success which finally +places sorghum sugar making among the profitable industries of the +country.</p> + +<p>The success has been due, first, to the almost complete extraction of +the sugars from the cane by the diffusion process; second, the prompt +and proper treatment of the juice in defecating and evaporating; third, +the efficient manner in which the sugar was boiled to grain in the +strike pan.</p> + + +<div class='center'> +<table border="0" summary=""> +<tr><td align='left'>Total number tons of</td><td align='left'>cane bought</td><td align='right'>3,840</td></tr> +<tr><td align='center'>"</td><td align='left'>seed tops bought</td><td align='right'>437</td></tr> +<tr><td align='left' colspan="2"></td><td align='left'>———</td></tr> +<tr><td align='left' colspan="2">Total number tons of field cane</td><td align='right'>4,277</td></tr> +</table></div> + +<p>There was something over 500 acres planted. Some of it failed to come at +all, some "fell upon the rocky places, where they had not much earth, +and when the sun was risen they were scorched;" so that, as nearly as we +can estimate, about 450 acres of cane were actually harvested and +delivered at the works. This would make the average yield of cane 9½ +tons per acre, or $19 per acre in dollars and cents.</p> + +<p class="center">TOTAL PRODUCT OF THE SEASON, 1887.</p> + +<table summary="product table" width="75%"> +<tr><td align="left">Sugar,</td><td align="left">235,826 lb., @ 5¾c</td><td align="right">$13,559 98</td></tr> +<tr><td align="left">"</td><td align="left">State bounty, @ 2c</td><td align="right">4,716 53</td></tr> +<tr><td colspan="3" align="right">————</td><td align="right">$17,276 50</td></tr> +<tr><td align="left">Sirups,</td><td align="left"> 51,000 gals,(estimated) @ 20c.</td><td colspan="2" align="right">10,200 00</td></tr> +<tr><td colspan="2" align="left">Seed (estimated)</td><td colspan="2" align="right">7,000 00</td></tr> +<tr><td colspan="2" align="left">Value of total product </td><td colspan="2" align="right"><span class="ov">$34,476 50</span></td></tr> +</table> + +<p class="center">TOTAL COST.</p> + +<table summary="product table" width="75%"> +<tr><td align="left">Cane, 3,840 tons,@ $2</td><td align="right">$7,680</td></tr> +<tr><td align="left">Seed, 967 tons, @ $3</td><td align="right">1,934</td></tr> +<tr><td colspan="2" align="right">———</td><td align="right">$9,614 00</td></tr> +<tr><td align="left">Labor bill from August 15 to October 15,<br /> +including labor for department experiments</td><td colspan="2" align="right"> 5,737 16</td></tr> +<tr><td align="left">Coal, including all experiments</td><td colspan="2" align="right">1,395 77</td></tr> +<tr><td align="left">Salaries, etc.</td><td colspan="2" align="right">3,500 00</td></tr> +<tr><td align="left">Insurance, sundries, etc.</td><td colspan="2" align="right">1,500 00</td></tr> +<tr><td colspan="3" align="right">————</td></tr> +<tr><td align="left"><span class="note">Total</span></td><td colspan="2" align="right">$21,746 93</td></tr> +<tr><td colspan="3" align="right">==========</td></tr> +<tr><td align="left">Total value</td><td colspan="2" align="right">$34,476 50</td></tr> +<tr><td align="left">Total cost</td><td colspan="2" align="right"> 31,248 93</td></tr> +<tr><td colspan="3" align="right">————</td></tr> +<tr><td align="left"><span class="note">Net</span></td><td colspan="2" align="right">$13,329 57</td></tr> +<tr><td align="left">To be paid by the department</td><td colspan="2" align="right"> 6,534 75</td></tr> +<tr><td colspan="3" align="right">————</td></tr> +<tr><td align="left">Total profit for season's work, 1887</td><td colspan="2" align="right">$19,764 32</td></tr> +</table> + + +<h3>OUTLINE OF THE PROCESSES OF SORGHUM SUGAR MAKING.</h3> + +<p>As now developed, the processes of making sugar from sorghum are as +follows:</p> + +<div class="note"> +<p><i>First</i>, The topped cane is delivered at the factory by the farmers who +can grow it.</p> + +<p><i>Second</i>, The cane is cut by a machine into pieces about one and a +quarter inches long.</p> + +<p><i>Third</i>, The leaves and sheaths are separated from the cut cane by +fanning mills.</p> + +<p><i>Fourth</i>, The cleaned cane is cut into fine bits called chips.</p> + +<p><i>Fifth</i>, The chips are placed in iron tanks, and the sugar "diffused," +soaked out with hot water.</p> + +<p><i>Sixth</i>, The juice obtained by diffusion has its acids nearly or quite +neutralized with milk of lime, and is heated and skimmed.</p> + +<p><i>Seventh</i>, The defecated or clarified juice is boiled to a semi-sirup in +vacuum pans.</p> + +<p><i>Eighth</i>, The semi-sirup is boiled "to grain" in a high vacuum in the +"strike pan."</p> + +<p><i>Ninth</i>, The mixture of sugar and molasses from the strike pan is passed +through a mixing machine into centrifugal machines which throw out the +molasses and retain the sugar.</p> +</div> + +<p>The process of the formation of sugar in the cane is not fully +determined, but analyses of canes made at different stages of growth +show that the sap of growing cane contains a soluble substance having a +composition and giving reactions similar to starch. As maturity +approaches, grape sugar is also found in the juice. A further advance +toward maturity discloses cane sugar with the other substances, and at +full maturity perfect canes contain much cane sugar and little grape +sugar and starchy matter.</p> + +<p>In sweet fruits the change from grape sugar to cane sugar does not take +place, or takes place but sparingly. The grape sugar is very sweet, +however.</p> + +<p>Cane sugar, called also sucrose or crystallizable sugar, when in dilute +solution is changed very readily into grape sugar or glucose, a +substance which is much more difficult than cane sugar to crystallize. +This change, called inversion, takes place in over-ripe canes. It sets +in very soon after cutting in any cane during warm weather; it occurs in +cane which has been injured by blowing down, or by insects, or by frost, +and it probably occurs in cane which takes a second growth after nearly +or quite reaching maturity.</p> + +<p>To insure a successful outcome from the operations of the factory, the +cane must be so planted, cultivated and matured as to make the sugar in +its juice. It must be delivered to the factory very soon after cutting, +and it must be taken care of before the season of heavy frosts.</p> + +<h3>THE WORK AT THE FACTORY.</h3> + +<p>The operations of the factory are illustrated in the large diagram. The +first cutting is accomplished in the ensilage or feed cutter at E. This +cutter is provided with three knives fastened to the three spokes of a +cast iron wheel which makes about 250 revolutions per minute, carrying +the knives with a shearing motion past a dead knife. By a forced feed +the cane is so fed as to be cut into pieces about one and a quarter +inches long. This cutting frees the leaves and nearly the entire sheaths +from the pieces of cane. By a suitable elevator, F, the pieces of cane, +leaves and sheaths are carried to the second floor.</p> + +<p>The elevator empties into a hopper, below which a series of four or five +fans, G, is arranged one below the other. By passing down through these +fans the cane is separated from the lighter leaves, much as grain is +separated from chaff. The leaves are blown away, and finally taken from +the building by an exhaust fan. This separation of the leaves and other +refuse is essential to the success of the sugar making, for in them the +largest part of the coloring and other deleterious matters are +contained. If carried into the diffusion battery, these matters are +extracted (see reports of Chemical Division, U.S. Department of +Agriculture), and go into the juice with the sugar. As already stated, +the process of manufacturing sugar is essentially one of separation. The +mechanical elimination of these deleterious substances at the outset at +once obviates the necessity of separating them later and by more +difficult methods, and relieves the juice of their harmful influences. +From the fans the pieces of cane are delivered by a screw carrier to an +elevator which discharges into the final cutting machine on the third +floor. This machine consists of an eight inch cast iron cylinder, with +knives like those of a planing machine. It is really three cylinders +placed end to end in the same shaft, making the entire length eighteen +inches. The knives are inserted in slots and held in place with set +screws. The cylinder revolves at the rate of about twelve hundred per +minute, carrying the knives past an iron dead knife, which is set so +close that no cane can pass without being cut into fine chips. From this +cutter the chips of cane are taken by an elevator and a conveyer, K, to +cells, MM, of the diffusion battery. The conveyer passes above and at +one side of the battery, and is provided with an opening and a spout +opposite each cell of the battery. The openings are closed at pleasure +by a slide. A movable spout completes the connection with any cell which +it is desired to fill with chips.</p> + +<h3>WHAT IS DIFFUSION?</h3> + +<p>The condition in which the sugars and other soluble substances exist in +the cane is that of solution in water. The sweetish liquid is contained, +like the juices of plants generally, in cells. The walls of these cells +are porous. It has long been known that if a solution of sugar in water +be placed in a porous or membraneous sack, and the sack placed on water, +an action called osmosis, whereby the water from the outside and the +sugar solution from the inside of the sack each pass through, until the +liquids on the two sides of the membrane are equally sweet. Other +substances soluble in water behave similarly, but sugar and other +readily crystallizable substances pass through much more readily than +uncrystallizable or difficultly crystallizable. To apply this properly +to the extraction of sugar, the cane is first cut into fine chips, as +already described, and put into the diffusion cells, where water is +applied and the sugar is displaced.</p> + +<div class="figcenter" style="width: 600px"> +<a href="./images/9.png"><img src="./images/9_th.png" alt="Fig. 1" /></a><br /> +<span class="caption"> +<span class="smcap">Fig.</span> 1—APPARATUS FOR MANUFACTURE OF SORGHUM BY THE +DIFFUSION PROCESS.</span> +</div> + +<h3>THE DIFFUSION BATTERY,</h3> + +<p>as used at the Parkinson factory, consists of twelve iron tanks. (See +diagram.) They are arranged in a line, as shown in diagram, Fig. 1. Each +has a capacity of seventy-five cubic feet, and by a little packing holds +a ton of cane chips. The cells are supported by brackets near the +middle, which rest on iron joists. Each cell is provided with a heater, +through which the liquid is passed in the operation of the battery. The +cells are so connected by pipes and valves that the liquid can be passed +into the cells, and from cell to cell, at the pleasure of the operator. +The bottom of each cell consists of a door, which closes on an annular +rubber hose placed in a groove, and filled with water, under a pressure +greater than that ever given to the liquids in the cell. This makes a +water tight joint whenever the trap door bottom is drawn up firmly +against it. The upper part is of cast iron and is jug shaped, and is +covered with a lid which is held with a screw on rubber packing. In the +jug neck and near the bottom the sides are double, the inner plates +being perforated with small holes to let water in and out. The bottoms +are double, the inner <a name="Page_10112"></a>plates being perforated like the neighboring +sides, and for the same purpose. The cells, of whose appearance a fair +idea may be had from diagram, Fig. 2, are connected with a water pipe, a +juice pipe, a compressed air pipe, and the heaters, by suitable valves. +The heaters are connected with a steam pipe. This, and the compressed +air pipe, are not shown in the diagram. The water pipe is fed from an +elevated tank, which gives a pressure of twelve pounds per square inch +The valve connections enable the operator to pass water into the cells +at either the top or the bottom; to pass the liquid from any cell to the +next, or to the juice pipe through the heater; to separate any cell from +any or all others, and to turn in compressed air.</p> + +<p>Now let the reader refer to Fig. 2.</p> + +<div class="figcenter" style="width: 600px;"> +<a href="./images/10.png"><img src="./images/10_th.png" alt="Fig. 2" /></a> +<span class="caption"><span class="smcap">Fig.</span> 2—DIFFUSION PROCESS—MANUFACTURE OF SORGHUM +SUGAR.</span></div> + +<p>The cutters are started, and cell 1 is filled with chips. This done, the +chips from the cutters are turned into cell 2; cell 1 is closed, and cut +off from the others, and water is turned into it by opening valve, <i>c</i>, +of cell 1 (see Fig. 2) until it is filled with water among the chips. +When 2 is filled with chips, its valve, <i>a</i>, is raised to allow the +liquid to pass down into the juice pipe. Valve <i>a</i> of 3 is also raised. +Now the juice pipe fills, and when it is full the liquid flows through +valve, <i>a</i>, of 3, and into the heater between 2 and 3, and into the +bottom of 2, until 2 is full of water among the chips. (This may be +understood by following the course of the arrows shown in the diagrams +of 9 and 10). Valve <i>a</i> of 2 is now screwed down; <i>c</i> is down and <i>b</i> is +opened. It will be readily seen by attention to the diagram that this +changes the course of the flow so that it will no longer enter at the +bottom, but at the top of 2, as shown by the arrows at cell 2.</p> + +<p>It is to be observed that the water is continually pressing in at the +top of 1, and driving the liquid forward whenever a valve is opened to +admit it to another cell, heater, or pipe. When cell 3 is full of chips, +its valves are manipulated just as were those of 2. So as each +succeeding cell is filled, the manipulation of valves is repeated until +cell 6 is filled with liquid. After passing through six cells of fresh +chips, this liquid is very sweet, and is drawn off into the measuring +tank shown at <i>p</i> in diagram, Fig. 1, and is thence conveyed for +subsequent treatment in the factory. To draw this juice from 6, valve +<i>a</i> of 7 is raised to connect the heater between 6 and 7 with the juice +pipe. A gate valve in the juice pipe is opened into the measuring tank, +and the pressure of water into the top of 1 drives the liquid forward +through the bottom of 1, through the heater, into the top of 2, out from +the bottom of 2, through the heater into the top of 3, out from the +bottom of 3, through the heater into the top of 4, out from the bottom +of 4, through the heater, into the top of 5, out from the bottom of 5, +through the heater, into the top of 6, and now out from the bottom of 6, +through the heater, into the juice pipe, and from the juice pipe into +the measuring tank. It will be understood that the liquid which is drawn +from 6 is chiefly that which was passed into 1 when it was filled with +chips. There is doubtless a little mixing as the pressure drives the +liquid forward. But the lighter liquid is always pressed in at the top +of the cells, so that the mixing is the least possible. The amount of +liquid, now called juice, which is drawn from 6 is 1,110 liters, or 291 +gallons. When this quantity has been drawn into the measuring tank, the +gate valve is closed, and the valves connecting with 7 are manipulated +as were those of 6, a measure of juice being drawn in the same way. All +this time the water has been passed into the top of 1, and this is +continued until the juice has been drawn from 9. Valve <i>c</i> to cell 1 is +now closed, and compressed air is turned into the top of 1 to drive the +liquid forward into 10. After the water has thus been nearly all +expelled from 1, valve a of cell 2 is lowered so as to shut off +communication with the juice pipe, and <i>b</i>, of cell 2 is closed. <i>a</i> and +<i>b</i> of cell 1 have, it will be observed, been closed or down from the +beginning. Cell 1 is now isolated from all others. Its chips have been +exhausted of sugar, and are ready to be thrown out. The bottom of 1 is +opened, and the chips fall out into the car, <i>o</i> (see diagram, Fig. 1), +and are conveyed away. Immediately on closing valves <i>a</i> and <i>b</i> of cell +2, <i>c</i> is opened, and the water presses into the top of 2, as before +into the top of 1, and the circulation is precisely similar to that +already described, 2 having taken the place of 1, 3 of 2, and so on.</p> + +<p>When 2 is emptied, 3 takes the first place in the series and so on. When +12 has been filled, it takes the l3th place. (The juice pipe returns +from the termination of the series, and connects with 1, making the +circuit complete.) The process is continuous, and the best and most +economical results are obtained if there is no intermission.</p> + +<p>One cell should be filled and another emptied every eight minutes, so +that in twenty-four hours the number of cells diffused should be one +hundred and eighty.</p> + +<h3>WHAT HAS TAKEN PLACE IN THE DIFFUSION CELLS. </h3> + +<p>For the purpose of illustration, let us assume that when it has been +filled with chips just as much water is passed into the cell as there +was juice in the chips. The process of osmosis or diffusion sets in, and +in a few minutes there is as much sugar in the liquid outside of the +cane cells as in the juice in these cane cells; <i>i.e.</i>, the water and +the juice have divided the sugar between them, each taking half.</p> + +<p>Again, assume that as much liquid can be drawn from 1 as there was water +added. It is plain that if the osmotic action is complete, the liquid +drawn off will be half as sweet as cane juice. It has now reached fresh +chips in 2, and again equalization takes place. Half of the sugar from 1 +was brought into 2, so that it now contains one and a half portions of +sugar, dissolved in two portions of liquid, or the liquid has risen to +three quarters of the strength of cane juice. This liquid having three +fourths strength passes to 3, and we have in 3 one and three fourths +portions of liquid, or after the action has taken place the liquid in 3 +is seven eighths strength. One portion of this liquid passes to 4, and +we have one and seven eighths portions of sugar in two portions of +liquid, or the liquid becomes 15/16 strength. One portion of this liquid +passes to 5, and we have in 5 one and fifteen sixteenths portions of +sugar in two portions of liquid, or the liquid is 31/32 strength. It is +now called <i>juice</i>. From this time forward a cell is emptied for every +one filled.</p> + +<p>Throughout the operation, the temperature is kept as near the boiling +point as can be done conveniently without danger of filling some of the +cells with steam. Diffusion takes place more rapidly at high than at low +temperatures, and the danger of fermentation, with the consequent loss +of sugar, is avoided.</p> + +<h3>WHAT HAS HAPPENED TO THE CHIPS.</h3> + +<p>By the first action of water in 1, ½ of the sugar was left in cell 1; by +the second ¼ was left, by the third 1/8 was left, by the fourth 1/16 was +left, by the fifth 1/32 was left, by the sixth 1/64 was left, by the +seventh 1/128 was left, by the eighth 1/256 was left, by the ninth 1/512 +was left. The fractions representing the strength of the juice on the +one hand and the sugar left in each cell on the other hand, after the +battery is fully in operation, are not so readily deduced. The theory is +easily understood, however, although the computation is somewhat +intricate. Those who desire to follow the process by mathematical +formula are referred to pages 9 and 10, Bulletin No. 2, Chemical +Division U.S. Department of Agriculture, where will be found the formula +furnished by Professor Harkness, of the U.S. Naval Observatory.</p> + +<p>For the sake of simplifying the explanation, it was assumed that the +water added is equal in volume to the juice in a cellful of cane chips. +In practice more water is added, to secure more perfect exhaustion of +the chips, and with the result of yielding about thirteen volumes of +juice for every nine volumes as it exists in the cane, and of extracting +92.04 per cent. of all the sugars from the cane, as shown by the report +of Dr. C.A. Crampton, Assistant Chemist of the U.S. Department of +Agriculture.</p> + +<h3>INVERSION OF SUGAR IN THE DIFFUSION CELLS.</h3> + +<p>In the experiments at Fort Scott in 1886, much difficulty was +experienced on account of inversion of the sugar in the diffusion +battery. The report shows that this resulted from the use of soured cane +and from delays in the operation of the battery on account of the +imperfect working of the cutting and elevating machinery, much of which +was there experimental. Under the circumstances, however, it became a +matter of the gravest importance to find a method of preventing this +inversion without in any manner interfering with the other processes. On +the suggestion of Prof. Swenson, a portion of freshly precipitated +carbonate of lime was placed with the chips in each cell.<a name="FNanchor_10"></a><a href="#Footnote_10"><sup>1</sup></a> In the +case of soured cane, this took up the acid which otherwise produced +inversion. In case no harmful acids were present, this chalk was +entirely inactive. Soured canes are not desirable to work under any +circumstances, and should be rejected by the chemist, and not allowed to +enter the factory. So, also, delays on account of imperfect machinery +are disastrous to profitable manufacturing, and must be avoided. But for +those who desired to experiment with deteriorated canes and untried +cutting machines, the addition of the calcium carbonate provides against +disastrous results which would otherwise be inevitable.</p> + + +<p>Immediately after it is drawn from the diffusion battery the juice is +taken from the measuring tanks into the defecating tanks or pans. These +are large, deep vessels, provided with copper steam coils in the bottom +for the purpose of heating the juice. Sufficient milk of lime is added +here to nearly or quite neutralize the acids in the juice, the test +being made with litmus paper. The juice is brought to the boiling point, +and as much of the scum is removed as can be taken quickly. The scum is +returned to the diffusion cells, and the juice is sent by a pump to the +top of the building, where it is boiled and thoroughly skimmed. These +skimmings are also returned to the diffusion cells.</p> + +<p>This method of disposing of the skimmings was suggested by Mr. +Parkinson. It is better than the old plan of throwing them away to +decompose and create a stench about the factory. Probably a better +method would be to pass these skimmings through some sort of filter, or, +perhaps better still, to filter the juice and avoid all skimming. After +this last skimming the juice is ready to be boiled down to a thin sirup +in</p> + +<h3>THE DOUBLE EFFECT EVAPORATORS.</h3> + +<p>These consist of two large closed pans provided within with steam pipes +of copper, whereby the liquid is heated. They are also connected with +each other and with pumps in such a way as to reduce the pressure in the +first to about three fifths and in the second to about one fifth the +normal atmospheric pressure.</p> + +<p>The juice boils rapidly in the first at somewhat below the temperature +of boiling water, and in the second at a still lower temperature. The +exhaust steam from the engines is used for heating the first pan, and +the vapor from the boiling juice in the first pan is hot enough to do +all the boiling in the second, and is taken into the copper pipes of the +second for this purpose. In this way the evaporation is effected without +so great expenditure of fuel as is necessary in open pans, or in single +effect vacuum pans, and the deleterious influences of long continued +high temperature on the crystallizing powers of the sugar are avoided.</p> + +<p>From the double effects the sirup is stored in tanks ready to be taken +into the strike pan, where the sugar is crystallized.</p> + +<h3>THE FIRST CHANCE TO PAUSE.</h3> + +<p>At this point the juice has just reached a condition in which it will +keep. From the moment the cane is cut in the fields until now, every +delay is liable to entail loss of sugar by inversion. After the water is +put into the cells of the battery with the chips, the temperature is +carefully kept above that at which fermentation takes place most +readily, and the danger of inversion is thereby reduced. But with all +the precautions known to science up to this point the utmost celerity is +necessary to secure the best results. There is here, however, a natural +division in the process of sugar making, which will be further +considered under the heading of "Auxiliary Factories." Any part of the +process heretofore described may be learned in a few days by workmen of +intelligence and observation who will give careful attention to their +respective duties.</p> + +<h3>BOILING THE SIRUP TO GRAIN THE SUGAR.</h3> + +<p>This operation is the next in course, and is performed in what is known +at the sugar factory as the strike pan, a large air tight iron vessel +from which the air and vapor are almost exhausted by means of a suitable +pump and condensing apparatus. As is the case with the saccharine juices +of other plants, the sugar from sorghum crystallizes best at medium +temperature.</p> + +<p>The process of boiling to grain may be described as follows: A portion +of the sirup is taken into the pan, and boiled rapidly <i>in vacuo</i> to the +crystallizing density. If in a sirup the molecules of sugar are brought +sufficiently near to each other through concentration—the removal of +the dissolving liquid—these molecules attract each other so strongly as +to overcome the separating power of the solvent, and they unite to form +crystals. Sugar is much more soluble at high than at low temperatures, +the heat acting in this as in almost all cases as a repulsive force +among the molecules. It is therefore necessary to maintain a high vacuum +in order to boil at a low temperature, in boiling to grain. When the +proper density is reached the crystals sometimes fail to appear, and a +fresh portion of cold sirup is allowed to enter the pan. This must not +be sufficient in amount to reduce the density of the contents of the pan +below that at which crystallization may take place. This cold sirup +causes a sudden though slight reduction in temperature, which may so +reduce the repulsive forces as to allow the attraction among the +molecules to prevail, resulting in the inception of crystallization. To +discover this requires the keenest observation. When beginning to form, +the crystals are too minute to show either form or size, even when +viewed through a strong magnifying glass. There is to be seen simply a +very delicate cloud. The inexperienced observer would entirely overlook +this cloud, his attention probably being directed to some curious +globular and annular objects, which I have nowhere seen explained. Very +soon after the sample from the pan is placed upon glass for observation, +the surface becomes cooled and somewhat hardened. As the cooling +proceeds below the surface, contraction ensues, and consequently a +wrinkling of the surface, causing a shimmer of the light in a very +attractive manner. This, too, is likely to attract more attention than +the delicate, thin cloud of crystals, and may be even confounded with +the reflection and refraction of light, by which alone the minute +crystals are determined. The practical operator learns to disregard all +other attractions, and to look for the cloud and its peculiarities. When +the contents of the pan have again reached the proper density, another +portion of sirup is added. The sugar which this contains is attracted to +the crystals already formed, and goes to enlarge these rather than to +form new crystals, provided the first are sufficiently numerous to +receive the sugar as rapidly as it can crystallize.</p> + +<p>The contents of the pan are repeatedly brought to the proper density, +and fresh sirup added as above described until the desired size of grain +is obtained, or until the pan is full. Good management should bring +about these two conditions at the same time. If a sufficient number of +crystals has not been started at the beginning of the operation to +receive the sugar from the sirup added, a fresh crop of crystals will be +started at such time as the crystallization becomes too rapid to be +accommodated on the surfaces of the grain already formed. The older and +larger crystals grow more rapidly, by reason of their greater attractive +force, than the newer and smaller ones on succeeding additions of sirup, +so that the disparity in size will increase as the work proceeds. This +condition is by all means to be avoided, since it entails serious +difficulties on the process of separating the sugar from the molasses. +In case this second crop of crystals, called "false grain" or "mush +sugar" has appeared, the sugar boiler must act upon his judgment, guided +by his experience as to what is to be done. He may take enough thin +sirup into the pan to dissolve all of the crystals and begin again, or, +if very skillful, he may so force the growth of the false grain as to +bring it up to a size that can be worked.</p> + +<p>The completion of the work in the strike pan leaves the sugar mixed with +molasses. This mixture is called <i>malada</i> or <i>masscuite</i>. It may be +drawn off into iron sugar wagons and set in the hot room above +mentioned, in which case still more of the sugar which remains in the +uncrystallized state generally joins the crystals, somewhat increasing +the yield of "first sugars." At the proper time these sugar wagons are +emptied into a mixing machine, where the mass is brought to a uniform +consistency. If the sugar wagons are not used, the strike pan is emptied +directly into the mixer.</p> + +<h3>THE CENTRIFUGAL MACHINES.</h3> + +<p>From the mixer the melada is drawn into the centrifugal machines. These +consist, first, of an iron case <a name="Page_10113"></a>resembling in form the husk of mill +stones. A spout at the bottom of the husk connects with a molasses tank. +Within this husk is placed a metallic vessel with perforated sides. This +vessel is either mounted or hung on a vertical axis, and is lined with +wire cloth. Having taken a proper portion of the melada into the +centrifugal, the operator starts it to revolving, and by means of a +friction clutch makes such connection with the engine as gives it about +1,500 revolutions per minute. The centrifugal force developed drives the +liquid molasses through the meshes of the wire cloth, and out against +the husk, from which it flows off into a tank. The sugar, being solid, +is retained by the wire cloth. If there is in the melada the "false +grain" already mentioned, it passes into the meshes of the wire cloth, +and prevents the passage of the molasses. After the molasses has been +nearly all thrown out, a small quantity of water is sprayed over the +sugar while the centrifugal is in motion. This is forced through the +sugar, and carries with it much of the molasses which would otherwise +adhere to the sugar, and discolor it. If the sugar is to be refined, +this washing with water is omitted. When the sugar has been sufficiently +dried, the machine is stopped, the sugar taken out, and put into barrels +for market.</p> + +<p>Simple as the operation of the centrifugals is, the direction of the +sugar boiler as to the special treatment of each strike is necessary, +since he, better than any one else, knows what difficulties are to be +expected on account of the condition in which the melada left the strike +pan.</p> + +<h3>CAPACITY OF THE SUGAR FACTORY.</h3> + +<p>A plant having a battery like that at Fort Scott, in which the cells are +each capable of containing a ton of cane chips, should have a capacity +of 180 tons of cleaned cane, or 200 tons of cane with leaves, or 240 +tons of cane as it grows in the field, per day of twenty-four hours. +Those who have given most attention to the subject think that a battery +composed of one and a half ton cells may be operated quite as +successfully as a battery of one ton cells. Such a battery would have a +capacity of 360 tons of field cane per day.</p> + +<h3>THE CUTTING AND CLEANING APPARATUS.</h3> + +<p>This consists of modifications of appliances which have long been used. +Simple as it is, and presenting only mechanical problems, the cutting, +cleaning, and evaporating apparatus is likely to be the source of more +delays and perplexities in the operation of the sugar factory than any +other part.</p> + +<p>The diffusion battery in good hands works perfectly; the clarification +of the juice causes no delays; the concentration to the condition of +semi-sirup may be readily, rapidly, and surely effected in apparatus +which has been brought to great perfection by long experience, and in +many forms; the work at the strike pan requires only to be placed in the +hands of an expert; the mixer never fails to do its duty; there are +various forms of centrifugal machines on the market, some of which are +nearly perfect. If, then, the mechanical work of delivering, cutting, +cleaning, and elevating the cane can be accomplished with regularity and +rapidity, the operation of a well adjusted sugar factory should proceed +without interruption or delay from Monday morning to Saturday night.</p> + +<h3>THE FUTURE OF THE SORGHUM SUGAR INDUSTRY.</h3> + +<p>An acre of land cultivated in sorghum yields a greater tonnage of +valuable products than in any other crop, with the possible exception of +hay. Under ordinary methods of cultivation, ten tons of cleaned cane per +acre is somewhat above the average, but under the best cultivation the +larger varieties often exceed twelve, while the small early amber +sometimes goes below eight tons per acre. Let seven and a half tons of +cleaned cane per acre be assumed for the illustration. This corresponds +to a gross yield of ten tons for the farmer, and at two dollars per ton +gives him twenty dollars per acre for his crop. These seven and a half +tons of clean cane will yield:</p> + +<div class="note"> +<p>750 pounds of sugar.<br /> +1,000 pounds of molasses.<br /> +900 pounds of seed.<br /> +1,500 pounds of fodder (green leaves).<br /> +1,500 pounds of exhausted chips (dried). A total of 5,650 pounds.</p> +</div> + +<p>The first three items, which are as likely to be transported as wheat or +corn, aggregate 2,650 pounds per acre.</p> + +<p>Sorghum will yield seven and a half tons of cleaned cane per acre more +surely than corn will yield thirty bushels or wheat fifteen bushels per +acre.</p> + +<p>In the comparison, then, of products which bear transportation, these +crops stand as follows:</p> + +<div class="note"> +<p>Sorghum, at 7½ tons, 2,650 pounds per acre.<br /> +Corn, at 30 bushels, 1,680 pounds per acre.<br /> +Wheat, at 15 bushels, 900 pounds per acre.</p> +</div> + +<p>The sugar from the sorghum is worth say 5 cents per pound; the molasses, +1¾ cents per pound; the seed, ½ cent per pound.</p> + +<p>The sorghum products give market values as follows:</p> + +<div class="note"> +<p>750 pounds sugar at say 5 cents,<a name="FNanchor_11"></a><a href="#Footnote_11"><sup>2</sup></a> $37.50.<br /> +1,000 pounds molasses at say 1¾ cents,<a href="#Footnote_11"><sup>2</sup></a> $17.50.<br /> +900 pounds seed at say ½ cent,<a href="#Footnote_11"><sup>2</sup></a> $4.50.<br /> +Total value of sorghum, less fodder, $59.50.<br /> +The corn crop gives 1,680 pounds, at ½ cent $8.40.<br /> +The wheat crop gives 900 pounds, at 1 cent, $9.</p> +</div> + + +<p>Thus it will be seen that the sorghum yields to the farmer more than +twice as much per acre as either of the leading cereals, and as a gross +product of agriculture and manufacture on our own soil more than six +times as much per acre as is usually realized from either of these +standard crops.</p> + +<p><a name="Footnote_10"></a><a href="#FNanchor_10">[1]</a></p><div class="note"> +<p>For this improvement Prof. Swenson obtained a patent Oct. +11, 1887, the grant of which was recently made the subject of +congressional inquiry.</p></div> + +<p><a name="Footnote_11"></a><a href="#FNanchor_11">[2]</a></p> +<div class="note"><p>The sugar sold this year at 5¾ cents per pound, the +molasses at 20 cents per gallon, and the seed at —— per bushel of 56 +pounds. The seed is of about equal value with corn for feeding stock.</p></div> + +<hr /> + +<p>A new process for producing iron and steel direct from the ore has been +brought out in Russia. Under the new process iron ore, after being +submitted to the smelting processes, is taken direct from the furnace to +the rolling mill and turned into thin sheets of the finest charcoal +iron. At present the process has only been commercially applied with +charcoal fuel, but experiments are stated to have shown that equal +success can be obtained with coke. The secret of the process lies in the +construction of the furnace, which is said to be simple and inexpensive.</p> + +<hr /> + +<h2><a name="art08"></a>THE MENGES THERMO-MAGNETIC GENERATOR AND MOTOR.</h2> + +<p>We have received from M. Menges (of the Hague) a most interesting +description of an apparatus on which he has been at work for some time +past, with the object of generating electricity by the direct conversion +of heat, or, as it might be more accurately described, by a more direct +conversion than that of an ordinary dynamo. M. Menges' apparatus +depends, like that of Edison, upon the fact that the magnetic metals +lose their magnetic permeability at a certain temperature.</p> + +<p>It differs greatly, however, from its predecessor in important points, +especially in the fact that it does not require the aid of any external +source of motive power.</p> + +<p>In Edison's pyromagnetic dynamo it will be remembered that it is +necessary to provide some small amount of motive power from an +extraneous source in order to revolve the shield by which the heat is +alternately directed on one half or the other of the armature cores. M. +Menges' apparatus is, on the contrary, wholly automatic.</p> + +<p>We proceed to give a free translation of the description furnished us by +the inventor.</p> + +<p>In attempting to employ the thermo-magnetic properties of iron or nickel +in the construction of machines for the generation of electricity upon +an industrial scale, we are met with the difficulty that the heating and +cooling of large masses of metal not only involves great loss of heat, +but also requires much time. Hence, to obtain a useful effect of any +importance, it would appear necessary to employ machines of dimensions +altogether impracticable. By the device and method of construction now +to be explained this difficulty has, however, been completely overcome.</p> + +<p>The action of a magnetic pole diminishes so rapidly with the increase of +distance that it may suffice to remove the armature to a distance +relatively small compared with its own dimensions, or with those of the +magnet, in order to reduce the action to a negligible value. But if the +magnet, N S, and the armature, A, being at a certain distance, we bring +between them a piece of iron or nickel, <i>d</i>, then the magnetic force +upon A is immediately and very considerably increased. In modern +language, the resistance of the magnetic circuit has been reduced by the +introduction of a better magnetic conductor, and the number of lines of +force passing through A is proportionately increased. The mass of the +piece, <i>d</i>, may, moreover, be relatively small compared with that of N S +and A. If d be again withdrawn, the magnetic resistance is increased, +and the lines through A are again a minimum.</p> + +<p>Now, it is evident that we can also obtain the same effect by +sufficiently heating and cooling the intermediate piece, <i>d</i>; and again, +with a broad field we can alter the distribution of the lines at will by +heating or cooling one side of this piece or the other. For this reason +we will call the piece d the <i>thermo-magnetic distributor</i>, or, briefly, +the distributor.</p> + +<p>We will now describe the manner in which this principle has been +realized in the practical construction of both a thermo-magnetic +generator and motor.</p> + +<div class="figcenter" style="width: 600px"> +<img src="./images/11a.png" alt="Fig. 1." /> +<span class="caption"><span class="smcap">Fig.</span> 1.</span></div> + +<p>Fig. 1 shows an elevation and part section of one of the arrangements +employed. Fig. 2 is a plan of the same machine (in the latter the ring, +<i>a a</i>, appearing on a higher plane than it actually occupies).</p> + +<div class="figcenter" style="width: 530px"> +<img src="./images/11b.png" alt="Fig. 2." /> +<span class="caption"><span class="smcap">Fig.</span> 2.</span></div> + +<p>N S is an electro-magnet, <i>a a</i> the armature, wound as a Gramme ring, +and fixed to a frame with four arms, which can turn freely upon a pivot +midway between the poles. The cross arms of the frame are attached at 1, +2, 3, 4, Fig. 2. Between the magnets and the armature is placed the +distributor, <i>d d</i>, where it occupies an annular space open above and +below. Both the magnets and the armature are coated on the sides facing +the distributor with mica or some other non-conductor of heat and +electricity. The distributor is attached to and supported by the cross +arms, so that it turns with the armature.</p> + +<p>The distributor is composed of a ribbon of iron or nickel, bent into a +continuous zigzag. This form has the advantage of presenting, in the +cool part of the distributor, an almost direct road for the lines of +force between the poles and the armature, thus diminishing the magnetic +resistance as far as possible. At the same time the Foucault currents +are minimized. To the same end it is useful to slit the ribbon, as in +Fig. 3. This also facilitates the folding into zigzags.</p> + +<div class="figleft" style="width: 300px"> +<img src="./images/11c.png" alt="Fig. 3." /> +<span class="caption"><span class="smcap">Fig.</span> 3.</span></div> + +<p>The distributor is heated at two opposite points on a diameter by the +burners, <i>b b</i>, above which are the chimneys, <i>e e</i>. The cooling of the +alternate section is aided by the circulation of cold air, which is +effected by means of the draught in the chimneys, <i>e e</i>. At the points +of lowest temperature a jet of air or water is maintained. The cross +arms are insulated with mica or asbestos at the points where they extend +from the armature to the distributor.</p> + +<p>It will now be evident that while the distributor is entirely cool, many +of the lines of force pass from N to S without entering the armature +core; but if heat is applied at the points 1 and 2 in the figure, so as +to increase the magnetic resistance at these points, then a great +portion of the lines will leave the distributor, and pass through the +armature core. Under these conditions, so long as heat is applied at two +points equidistant from N and S, we might, if we so pleased, cause the +armature to be rotated by an external source of power, and we should +then have an E.M.F. generated in the armature coils—that is to say, the +machine would work as an ordinary dynamo, and the power expended in +driving the armature would be proportionate to the output.</p> + +<div class="figright" style="width: 300px"> +<img src="./images/11d.png" alt="Fig. 4." /> +<span class="caption"><span class="smcap">Fig.</span> 4.</span></div> + +<p>Suppose next that the points of heating, and with them the alternate +points of cooling 90 deg. apart, are shifted round about 45 deg., so +that the two hot regions are no longer symmetrically situated in respect +to each pole of the field. The distribution of the magnetization has +therefore become unsymmetrical, and the iron core is no longer in +equilibrium in the magnetic field. We have, in fact, the conditions of +Schwedoff's experiment upon a larger scale, and if the forces are +sufficient to overcome the frictional resistance, a rotation of the ring +ensues in the endeavor to restore equilibrium. The regions of heating +and cooling being fixed in space, this rotation is continuous so long as +the difference of temperature is maintained. The ring in rotating +carries with it the armature coils, and of course an E.M.F. is generated +in the same way as if the motive power came from an external source. In +this respect the machine therefore resembles a motor generator, and the +rotation is entirely automatic.</p> + +<p>The armature coils are connected with a commutator in the usual way, and +the field may, of course, be excited either in shunt or in series. M. +Menges says that the residual magnetization is sufficient in his machine +to start the rotation by itself.</p> + +<p>When the machine is to be used as a motor, it is evident that the +windings on the armature core need only be sufficient to supply current +to excite the field, or by <a name="Page_10114"></a>the use of permanent magnets they may be +dispensed with altogether.</p> + +<p>M. Menges has further designed a large number of variations on the +original type, varying the arrangement of the several parts, and +employing armatures and fields of many different types, such as are +already in use for dynamos.</p> + +<p>In Fig. 4 a machine is represented in which the field is external to the +armature.</p> + +<p>In Fig. 5 we have a thermo-magnetic generator, which corresponds to the +disk machine in dynamos. Similar parts are indicated by the same letters +in each of these figures, so that no further detailed description is +necessary.</p> + +<div class="figcenter" style="width: 470px"> +<img src="./images/11e.png" alt="Fig. 5." /> +<span class="caption"><span class="smcap">Fig.</span> 5.</span></div> + +<p>In another modification M. Menges proposes to rotate the burners and +leave the armature and distributor at rest. But in this case it is +evident that the E.M.F. produced would be much less, because the +magnetization of the core would only undergo a variation of intensity, +and would nowhere be reversed, except, perhaps, just in front of the +poles. In machines modeled on the Brush type it is evident that the +distributor need not be continuous.</p> + +<p>Enough has, however, been said to indicate the extent of the field upon +which the principle may be applied.—<i>The Electrician.</i></p> + +<hr /> + +<h2><a name="art07"></a>OBSERVATIONS ON ATMOSPHERIC ELECTRICITY.<a name="FNanchor_12"></a><a href="#Footnote_12"><sup>1</sup></a></h2> + + +<h3>By Prof. <span class="smcap">L. Weber.</span></h3> + +<p>I will try to give a short report of some experiments I have made during +the last year in regard to atmospheric electricity. It was formerly +uncertain whether the electrostatic potential would increase by rising +from the surface of the earth to more elevated region of the atmosphere +or not, and also whether the potential in a normal—that is, +cloudless—state of the atmosphere was always positive or sometimes +negative. Sir William Thomson found by exact methods of measuring that +the increase of the potential with elevation is very important, and +values about 100 volts per meter. That fact is proved by many other +observers, especially lately by Mr. F. Exner, at Vienna, who found an +increase of 60 to 600 volts per meter. The observations were made by +means of an electrometer. In respect of many inconveniences which are +connected with the use of an electrometer, I have tried the measurements +with a very sensitive galvanometer. In this case it is necessary to +apply a separating air exhaust apparatus, for example flame, or a system +of points at the upper end of the conductor, which is elevated in the +atmosphere. In order to get a constant apparatus, I have used 400 of the +finest needles inserted in a metallic ribbon. This system I have raised +in the air by means of a captive balloon, or by a kite, which was +attached to a conductor of twine or to a twisted line of the finest +steel wire. In this way I have attained a height of 100 to 300 meters. +When the lower end of the kite line was communicating with the +galvanometer whose other terminal was in contact with the earth, a +current passed through the galvanometer. For determining the strength of +this current I proposed to called a micro-ampere the 10<sup>-9</sup> part of an +ampere. At the height of about 100 meters in the average the current +begins to be regular, and increases at the height of 300 meters to 4,000 +or 5,000 of these units. The increase is very regular, and seems to be a +linear function of the height. I have, nevertheless, found the smallest +quantities of dust contained in the atmosphere or the lightest veil of +cirrus disturbed the measurement very materially, and generally made the +potential lower. In negative experiments of this nature I have made at +Breslau, at the Sohneekoppe, and at the "Reisengebirge," especially at +the last station, an increase of potential was observed, not only by +reason of the perpendicular height, but also by reaching such regions of +the atmosphere as were situated horizontally to about 200 meters from +the utmost steep of the same mountain, Sohneekoppe. Therefore it must, +according to Mr. Exner, be assumed that the surface of the air presents +a surface of equal potential, and that the falling surfaces of high +potential were stretched parallel over the plane contours of the air, +and more thinly or narrow lying over all the elevated points, as, for +example, mountains, church towers, etc. On the basis of these facts I +think it easy to explain the electricity of thunder storm clouds, in +fact every cloud, or every part of a cloud, may be considered as a +leading conductor, such clouds as have for the most part perpendicular +height. After being induced the change results by supposing the +conduction of electricity either from the upper or from the lower side, +according to greater or smaller speed of the air in the height. In the +first case the clouds will be charged positive, in the other negative. I +am inclined, therefore, to state that the electricity of thunder storm +clouds must be considered as a special but disturbed case of the normal +electric state of the atmosphere, and that all attempts to explain +thunder storm electricity must be based on the study of the normal +electric state of the atmosphere.</p> + +<p><a name="Footnote_12"></a><a href="#FNanchor_12">[1]</a></p> +<div class="note"><p>Abstract of a paper read before the British Association +meeting at Manchester, September, 1887.</p></div> + +<hr /> + +<h2><a name="art03"></a>LINNÆUS.<a name="FNanchor_13"></a><a href="#Footnote_13"><sup>1</sup></a></h2> + + +<h3>By <span class="smcap">C.S. Hallberg.</span></h3> + +<p>At intervals in the history of science, long periods of comparative +inertia have attended the death of its more distinguished workers. As +time progresses and the number of workers increases, there is a +corresponding increase in the number of men whose labors merit +distinction in the literature of every language; but as these accessions +necessitate in most cases further division of the honors, many names +conspicuously identified with modern science fail of their just relative +rank, and fade into unmerited obscurity. Thus the earlier workers in +science, like Scheele, Liebig, Humboldt, and others of that and later +periods, have won imperishable fame, to which we all delight to pay +homage, while others of more recent times, whose contributions have +perhaps been equally valuable for their respective periods, are given +stinted recognition of their services, if indeed their names are not +quite forgotten. Nothing illustrates so clearly the steps in the +evolution of science as a review of the relative status of its +representatives. As in the political history of the world an epoch like +that of the French revolution stands out like a mountain peak, so in the +history of science an epoch occurs rather by evolution than revolution, +when a hitherto chaotic, heterogeneous mass of knowledge is rapidly +given shape and systematized. Previous to the seventeenth century an +immense mass of facts had accumulated through the labors of +investigators working under the Baconian philosophy, but these facts had +been thrown together in a confused, unsystematic manner. A man of master +mind was then needed to grasp the wonders of nature and formulate the +existing knowledge of them into a scientific system with a natural +basis. Such a system was given by Linnæus, and so great were its merits +that it continues the foundation of all existing systems of +classification.</p> + +<p>Charles Linnæus was born May 13, 1707, in a country place named Roshult +in Smaland, near Skane, Sweden. He was called Charles after the well +known Swedish knight errant, King Charles XII., then at the height of +his renown.</p> + +<p>The natural beauty of his native place, with its verdure-clad hills, its +stately trees, and sparkling brooks fringed with mosses and flowers, +inspired the boy Linnæus with a love of nature and a devotion to her +teachings which tinged the current of his whole life. He was destined by +his parents for the ministry, and in accordance with their wish was sent +to the Vexio Academy ("gymnasium"). Here the dull theological studies +interfered so much with his study of nature that he would have felt lost +but for the sympathy of Dr. Rothman, one of his teachers, a graduate of +Harderwyk University, Holland, who had been a pupil of Boerhaave (the +most eminent physician and scientist of his day), and been much +impressed by his scientific teachings.</p> + +<div class="figcenter" style="width: 318px;"> +<a href="./images/12.png"><img src="images/12_th.png" alt="Portrair of Linnaeus" title="" /></a> +</div> + +<p>Dr. Rothman took a great interest in Linnæus, and assured his father +that he would prove a great success financially and otherwise as a +physician (an occupation whose duties then included a study of all +existing sciences). The father was satisfied, but dreaded the effect the +announcement of such a career would have on the mother, whose ambition +had been to see her son's name among the long list of clergymen of the +family who had been ministers to the neighboring church of Stentrohult. +She finally yielded, and the best possible use was made by Linnæus of +Dr. Rothman's tuition. Latin, then the mother tongue of all scientists +and scholars, he wrote and spoke fluently.</p> + +<p>At the age of twenty Linnæus entered the University of Lund, and +remained there a year. Here he formed the acquaintance of a medical man, +a teacher in the university, who opened his home and his library to him, +and took him on his botanical excursions and professional visits. Some +time later, on Dr. Rothman's advice, Linnæus entered the University of +Upsala, then the most celebrated university of Northern Europe. His +parents were able to spare him but one hundred silver thalers for his +expenses. At the end of a year his money was spent, his clothing and +shoes were worn out, and he was without prospects of obtaining a +scholarship. When things were at their gloomiest he accidentally entered +into a discussion with a stranger in the botanical garden, who turned +out to be a clergyman scientist named Celsius. Celsius, while staying at +Upsala, had conceived the plan of given a botanical description of +biblical plants. Having learned that Linnæus had a herbarium of 600 +plants, he took the young man under his protection, and opened up to him +his home and library.</p> + +<p>While studying in this library, his observations regarding the sexes in +plants, hitherto in a chaotic state, took form, stimulated by an +abstract published in a German journal of Vaillant's views, and before +the end of 1729 the basis of the sexual system had appeared in +manuscript. This treatise having been seen by a member of the university +faculty, Linnæus was invited to fill a temporary vacancy, and lectured +with great success therein one and a half years. Meanwhile the +foundation of the celebrated treatises afterward published on the sexual +system of classification and on plant nomenclature had been laid.</p> + +<p>As in the history of most great men, a seemingly great misfortune proved +to be a turning point in his career. The position he had temporarily +filled with such credit to himself and profit to the students was +claimed by its regular occupant, and, despite the opposition of the +faculty, Linnæus had to relinquish it. The two subsequent years were +spent in botanical investigations under the patronage of various eminent +men. During one of these he traveled through Lapland to the shores of +the Polar Sea, and the results of this expedition were embodied in his +"Lapland Flora," the first flora founded on the sexual system. He +delivered a peripatetic course of lectures, and during one of these he +formed the acquaintance of Dr. Moræus, a pupil of the great Boerhaave. +Dr. Moræus took Linnæus into partnership with him. Here again a seeming +misfortune proved to be a great advantage. Linnæus fell in love with the +eldest daughter of Dr. Moræus, but was denied her hand until he should +graduate in medicine. Linnæus, to complete his studies as a physician, +then entered the University of Harderwyk, Holland, the alma mater of his +first benefactor, Dr. Rothman, and of the great Boerhaave.</p> + +<p><a name="Page_10115"></a>After two years' study he was graduated in medicine with high honors. +His thesis, "The Cause of Chills," received special commendation. He +visited all the botanical gardens and other scientific institutions for +which Holland was then renowned. A learned and wealthy burgomaster, +Gronovius, having read his "Systema Naturæ" in manuscript, not only +defrayed the cost of its publication, but secured him the high honor of +an interview with the great Boerhaave—an honor for which even the Czar +Peter the Great had to beg.</p> + +<p>Boerhaave's interest was at once awakened, and he gave Linnæus so strong +a recommendation to Dr. Burman, of Amsterdam, that the influence of the +scientific circles of the Dutch metropolis was exerted in behalf of +Linnæus, and he was soon offered the position of physician +superintendent of a magnificent botanical garden owned by a millionaire +horticultural enthusiast, Clifford, a director of the Dutch East India +Company. Linnæus' financial and scientific future was now secure. +Publication of his works was insured, and his position afforded him +every opportunity for botanical research. After five years' residence in +Holland, during which he declined several positions of trust, he +determined to return to Sweden. His fame had become so widespread in +Western Europe that his system was already adopted by scientists and +made the basis of lectures at the Dutch universities. In the French +metropolis he was greatly esteemed, and during a visit thereto he was a +highly distinguished guest.</p> + +<div class="figcenter" style="width: 600px"> +<a href="./images/13a.png"><img src="./images/13a_th.png" alt="ROSHULT, SWEDEN, BIRTHPLACE OF LINNÆUS." /></a> +<span class="caption">ROSHULT, SWEDEN, BIRTHPLACE OF LINNÆUS.</span></div> + +<p>His reception in Sweden was rather frigid, and but for the hearty +welcome by his family and betrothed he would probably have returned to +Holland. His <i>amour propre</i> was also doubtless wounded, and he +determined to remain and fight his way into the magic circle of the +gilt-edged aristocracy which then monopolized all scientific honors in +Stockholm and the universities. He acquired a great reputation for the +treatment of lung disease, and was popularly credited with the ability +to cure consumption. This reached the ears of the queen (a sufferer from +the disease), who directed one of her councilors to send for Linnæus. He +soon recognized the name of Linnæus as one of great renown on the +Continent, and at once took him under his protection.</p> + +<p>The star of Linnæus was now in the ascendant. He was soon delegated to +various pleasant duties, among which was the delivery of lectures on +botany and mineralogy in the "auditorium illustre" at Stockholm. He at +this time founded the "Swedish Scientific Academy," and was its first +president. In 1741 he was elected professor of medicine in Upsala +University, which chair he exchanged for that of botany and the position +of director of the botanical garden. This opened up a new era for +science in Sweden. He who was regarded as the world's greatest botanist +abroad had at last been similarly acknowledged in his native land.</p> + +<p>With the indomitable courage and tact characteristic of the man, he set +on foot a gigantic scientific popular educational project. The +government, under his direction, established a system of exploring +expeditions into the fauna, flora, and mineralogy of the whole Swedish +peninsula, partly for the purpose of developing the resources of the +country, partly in the interest of science, but more especially to +interest the mass of the people in scientific research. The vast +majority of the people of Sweden, like those of other countries, were +dominated by fetichic superstitions and absurd notions about plants and +vegetables, which were indorsed to a certain extent by popular handbooks +devoted more to the dissemination of marvels than facts. A popular +clergyman, for instance, stated in a description of the maritime +provinces that "certain ducks grew upon trees." The vast stride which +was made by the populace in the knowledge of nature was due to these +efforts of Linnæus, who, in order to further popularize science, +established and edited, in conjunction with Salvius, a journal devoted +to the discussion of natural history.</p> + +<p>During this period, on the first of May, semi-weekly excursions were +made from the university, the public being invited to attend. The people +came to these excursions by hundreds, and all classes were represented +in them—physicians, apothecaries, preachers, merchants, and mechanics, +all joined the procession, which left the university at seven in the +morning, to return at eve laden with zoological, botanical, and +mineralogical specimens.</p> + +<p>A man who could thus arouse popular enthusiasm for science a century and +a half ago must have been a remarkable genius. Trusted students of +Linnæus were sent on botanical exploring expeditions throughout the +world. The high renown in which Linnæus was held was shown in the +significant title, almost universally bestowed upon him, of "The Flower +King."—<i>Western Druggist.</i></p> + +<p><a name="Footnote_13"></a><a href="#FNanchor_13">[1]</a></p> +<div class="note"><p>For the illustrations and many facts in the life of +Linnæus we are indebted to the <i>Illustrated Tidning</i>, Stockholm.</p></div> + +<hr /> + +<h2><a name="art13"></a>ON A METHOD OF MAKING THE WAVE LENGTH OF SODIUM LIGHT THE ACTUAL AND +PRACTICAL STANDARD OF LENGTH.</h2> + +<h3>By <span class="smcap">Albert A. Michelson</span> and <span class="smcap">Edward W. Morley.</span></h3> + +<p>The first actual attempt to make the wave length of sodium light a +standard of length was made by Peirce.<a name="FNanchor_14"></a><a href="#Footnote_14"><sup>1</sup></a> This method involves two +distinct measurements: first, that of the angular displacement of the +image of a slit by a diffraction grating, and, second, that of the +distance between the lines of the grating. Both of these are subject to +errors due to changes of temperature and to instrumental errors. The +results of this work have not as yet been published; but it is not +probable that the degree of accuracy attained is much greater than one +part in fifty or a hundred thousand. More recently, Mr. Bell, of the +Johns Hopkins University, using Rowland's gratings, has made a +determination of the length of the wave of sodium light which is claimed +to be accurate to one two hundred thousandth part<a name="FNanchor_15"></a><a href="#Footnote_15"><sup>2</sup></a>. If this claim is +justified, it is probably very near the limit of accuracy of which the +method admits. A short time before this, another method was proposed by +Mace de Lepinay.<a name="FNanchor_16"></a><a href="#Footnote_16"><sup>3</sup></a> This consists in the calculation of the number of +wave lengths between two surfaces of a cube of quartz. Besides the +spectroscopic observations of Talbot's fringes, the method involves the +measurement of the index of refraction and of the density of quartz, and +it is not surprising that the degree of accuracy attained was only one +in fifty thousand.</p> + +<p>Several years ago, a method suggested itself which seemed likely to +furnish results much more accurate than either of the foregoing, and +some preliminary experiments made in June have confirmed the +anticipation. The apparatus for observing the interference phenomena is +the same as that used in the experiments on the relative motion of the +earth and the luminiferous ether.</p> + +<p>Light from the source at <i>s</i> (Fig. 1), a sodium flame, falls on the +plane parallel glass, <i>a</i>, and is divided, part going to the plane +mirror, <i>c</i>, and part to the plane mirror, <i>b</i>. These two pencils are +returned along <i>cae</i> and <i>bae</i>, and the interference of the two is +observed in the telescope at <i>e</i>. If the distances, <i>ac</i> and <i>ab</i>, are +made equal, the plane, <i>c</i>, made parallel with that of the image of <i>b</i>, +and the compensating glass, <i>d</i>, interposed, the interference is at once +seen. If the adjustment be exact, the whole field will be dark, since +one pencil experiences external reflection and the other internal.</p> + +<p>If now <i>b</i> be moved parallel with itself a measured distance by means of +the micrometer screw, the number of alternations of light and darkness +is exactly twice the number of wave lengths in the measured distance. +Thus the determination consists absolutely of a measurement of a length +and the counting of a number.</p> + +<p>The degree of accuracy depends on the number of wave lengths which it is +possible to count. Fizeau was unable to observe interference when the +difference of path amounted to 50,000 wave lengths. It seemed probable +that with a smaller density of sodium vapor this number might be +increased, and the experiment was tried with metallic sodium in an +exhausted tube provided with aluminum electrodes. It was found possible +to increase this number to more than 200,000. Now it is very easy to +estimate tenths or even twentieths of a wave length, which implies that +it is possible to find the number of wave lengths in a given fixed +distance between two planes with an error less than one part in two +millions and probably one in ten millions. But the distance +corresponding to 400,000 wave lengths is roughly a decimeter, and this +cannot be determined or reproduced more accurately than say to one part +in 500,000. So it would be necessary to increase this distance. This +can be done by using the same instrument together with a comparer.</p> + +<p>The intermediate standard decimeter, <i>lm</i> (Fig. 2), is put in place of +the mirror, <i>b</i>. It consists of a prism of glass one decimeter long with +one end, <i>l</i>, plane, and the other slightly convex, so that when it +touches the plane, <i>m</i>, Newton's rings appear, and these serve to +control any change in the distance, lm, which has been previously +determined in wave lengths.</p> + +<p>The end, <i>l</i>, is now adjusted so that colored fringes appear in white +light. These can be measured to within one-twentieth of a wave length, +and probably to within one-fiftieth. The piece, <i>lm</i>, is then moved +forward till the fringes again appear at <i>m</i>. Then the refractometer is +moved in the same direction till the fringes appear again at <i>l</i>, and so +on till the whole meter has been stepped off. Supposing that in this +operation the error in the setting of the fringes is always in the same +direction, the whole error in stepping off the meter would be one part +in two millions. By repetition this could of course be reduced. A +microscope rigidly attached to the carriage holding the piece, lm, would +serve to compare, and a diamond attached to the same piece would be used +to produce copies. All measurements would be made with the apparatus +surrounded by melting ice, so that no temperature corrections would be +required.</p> + +<p>Probably there would be considerable difficulty in actually counting +400,000 wave lengths, but this can be avoided by first counting the wave +lengths and fractions in a length of one millimeter and using this to +step off a centimeter. This will give the nearest whole number of +wave-lengths, and the fractions may be observed directly. The centimeter +is then used in the same way to step off a decimeter, which again +determines the nearest whole number, the fraction being observed +directly as before.</p> + +<p>The fractions are determined as follows: The fringes observed in the +refractometer under the conditions above mentioned can readily be shown +to be concentric circles. The center has the minimum intensity when the +difference in the distances, <i>ab</i>, <i>ac</i>, is an exact number of wave +lengths. The diameters of the consecutive circles vary as the square +roots of the corresponding number of waves. Therefore, if <i>x</i> is the +fraction of a wave length to be determined, and <i>y</i> the diameter of the +first dark ring, <i>d</i> being the diameter of the ring corresponding to one +wave length, then <i>x</i> = <i>y</i><sup>2</sup>/<i>d</i><sup>2</sup>.</p> + +<div class="figcenter" style="width: 500px"> +<img src="./images/13b.png" alt="" /></div> + +<p>There is a slight difficulty to be noted in consequence of the fact that +there are two series of waves in sodium light. The result of this +superposition of these is that as the difference of path increases, the +interference becomes less distinct and finally disappears, reappears, +and has a maximum of distinctness again, when the difference of path is +an exact multiple of both wave lengths. Thus there is an alternation of +distinct interference fringes with uniform illumination. If the length +to be measured, the centimeter for instance, is such that the +interference does not fall exactly at the maximum—to one side by, say, +one-tenth the distance between two maxima, there would be an error of +one-twentieth of a wave length requiring an arithmetical correction.</p> + +<p>Among other substances tried in the preliminary experiments were +thallium, lithium, and hydrogen. All of these gave interference up to +fifty to one hundred thousand wave lengths, and could therefore all be +used as checks on the determination with sodium. It may be noted that in +case of the red hydrogen line, the interference phenomena disappeared at +about 15,000 wave lengths, and again at about 45,000 wave lengths; so +that the red hydrogen line must be a double line with the components +about one-sixtieth as distant as the sodium lines.—<i>Amer. Jour. +Science.</i></p> + +<p><a name="Footnote_14"></a><a href="#FNanchor_14">[1]</a></p><div class="note"> +<p>Nature, xx, 99, 1879; this Journal, III, xviii, 51, 1879.</p></div> + +<p><a name="Footnote_15"></a><a href="#FNanchor_15">[2]</a></p><div class="note"> +<p>On the absolute wave lengths of light, this Journal, III, xxxiii, 167, 1887.</p></div> + +<p><a name="Footnote_16"></a><a href="#FNanchor_16">[3]</a></p> +<div class="note"><p>Comptes Rendus, cii, 1153, 1886; Journal, de Phys., II, v, 411, 1886.</p></div> + +<hr /> + +<p class="center">[RURAL NEW YORKER]</p> + +<h2><a name="art12"></a>COLD STORAGE FOR POTATOES.</h2> + +<p>Upon this subject I am able to speak with the freedom habitually enjoyed +by some voluminous agricultural writers—my imagination will not be +hampered by my knowledge.</p> + +<p>In debatable climates, like Ohio, Illinois, Kansas and southward, it is +conceded that a great point would be gained by the discovery of some +plan—not too expensive—that would make it safe to put away potatoes in +the summer, as soon as ripe, so that they would go through the winter +without sprouting and preserve their eating qualities till potatoes come +again. As it is, digging must be deferred till late, for fear of rot; +the fields of early varieties grow up with weeds after they are "laid +by." In the spring a long interregnum is left between old potatoes fit +to eat and the new crop, and the seed stock of the country loses much of +its vigor through sprouting in cellars and pits. Most farmers have had +occasion to notice the difference between the yield from crisp, +unsprouted seed potatoes and that from the wilted, sprouted tubers so +often used. Some years ago Professor Beal made a test of this +difference. I speak from recollection, but think I am right in saying +that, according to the published account which I saw, he found one +sprouting of seed potatoes lowered the yield 10 per cent.; each +additional sprouting still further reduced the crop, till finally there +was no yield at all. Even a 10 per cent. shrinkage <a name="Page_10116"></a> in all that portion +of the annual potato crop grown from sprouted seed would result in an +aggregate loss of millions of bushels. The question how to store +potatoes and not have them sprout I have seen answered in the papers by +recommending a "cold" cellar, of about 40 degrees temperature. If there +are cellars that are cold in warm weather, without the use of some +artificial process, I have not seen them. The temperature of well water +is about 45 degrees only, and anybody knows how much colder a well is +than a cellar. But the greatest difficulty comes in from the fact that +potatoes are such a prolific source of heat in themselves.</p> + +<p>If a 40 degree cellar could be found and be filled with potatoes, the +temperature would at once begin to rise, and the later in the season, +the faster it would go up. I repeat that a cellar filled with potatoes +will have a much higher temperature than the same cellar would have if +empty. This I have learned as Nimbus learned tobacco growing—"by +'sposure." I hope I won't be asked "why." I don't know. The reason is +unimportant. The remedy is the thing. The only help for it that I know +of is to give the cellar plenty of ventilation, put the potatoes in as +clean as possible, and then shovel them over every month or two. This +will keep the sprouting tendency in check very largely; but it won't +make it practicable to begin storing potatoes in July or cause them to +keep in good flavor till June.</p> + +<p>Several years ago I placed some barrels of early Ohio potatoes in the +Kansas City cold storage warehouses from March till July. They were kept +in a temperature of 38 degrees, and came out crisp and very little +sprouted. The plan of this structure was very simple: a three-story +brick building so lined with matched lumber and tarred paper as to make +three air-spaces around the wall. In the top story was a great bulk of +ice, which was freely accessible to the air that, when cooled, passed +through ducts to the different "cool rooms." The results were +satisfactory, but the system seemed too expensive for potatoes. I have +wondered whether it was necessary for potatoes to be kept as cold as 38 +degrees. Would not a current of air passing through pipes showered with +well water keep them cold enough? Wine vaults, I believe, are sometimes +cooled by air currents forced through a cold water spray. If the air +blast of well water temperature would be sufficient, the apparatus for +producing it would be comparatively inexpensive—or at least much +cheaper than those plans of cold storage where ice is stored in quantity +over the cool room. However, any process that could be devised would +probably be unprofitable to the small cropper, and the larger the +business done, the less the cost per bushel. If it should be found that +individual operators could not reach such an improvement on a profitable +scale, why could not several of them pool their issues sufficiently to +build, jointly, a potato elevator? There are at least 50,000 bushels of +potatoes held in store by farmers within three miles of where I live. It +seems to me there would be many advantages and economies in having that +large stock under one roof, one insurance, one management; on a side +track where they could be loaded in any weather or state of the roads, +besides the great item that the temperature could be controlled, by +artificial means, in one large building much cheaper than in several +small ones.</p> + +<p class="signature"> EDWIN TAYLOR.</p> +<p> Edwardsville, Kans.</p> + +<hr /> + +<p class="center">[KNOWLEDGE.]</p> + +<h2><a name="art02"></a>A FIVEFOLD COMET.</h2> + +<p>The figure illustrating this article is taken from <i>L'Astronomie</i>, and +represents the remarkable southern comet of January, 1887, as drawn on +successive days by Mr. Finlay, of Cape Town.</p> + +<p>The comet was first seen by a farmer and a fisherman of Blauwberg, near +Cape Town, on the night of January 18-19. The same night it was seen at +the Cordoba Observatory by M. Thome. On the next Mr. Todd discovered it +independently at the Adelaide Observatory, and watched it till the 27th. +On the 22d Mr. Finlay detected the comet, and was able to watch it till +the 29th. At Rio de Janeiro M. Cruls observed it from the 23d to the +25th; and at Windsor, New South Wales, Mr. Tebbutt observed the comet on +the 28th and 30th. Moonlight interfered with further observations.</p> + +<p>The comet's appearance was remarkable. Its tail, long and straight, +extended over an arc of 30 degrees, but there was no appreciable +condensation which could be called the comet's head. The long train of +light, described as nearly equal in brightness to the Magellanic clouds, +seemed to be simply cut off at that end where in most comets a nucleus +and coma are shown.</p> + +<p>This comet has helped to throw light on one of the most perplexing +puzzles which those most perplexing of all the heavenly bodies, comets, +have presented to astronomers.</p> + +<p>In the year 1668 a comet was seen in the southern skies which attracted +very little notice at the time, and would probably have been little +thought of since had not attention been directed to it by the appearance +and behavior of certain comets seen during the last half century. +Visible for about three weeks, and discovered after it had already +passed the point of its nearest approach to the sun, the comet of 1668 +was not observed so satisfactorily that its orbit could be precisely +determined. In fact, two entirely different orbits would satisfy the +observations fairly, though one only could be regarded as satisfying +them well.</p> + +<p>This orbit, however, was so remarkable that astronomers were led to +prefer the other, less satisfactory though it was, in explaining the +observed motions of the comet. For the orbit which best explained the +comet's movements carried the comet so close to the sun as actually to +graze his visible surface.</p> + +<p>Moreover, there was this remarkable, and, indeed, absolutely unique +peculiarity about the orbit thus assigned: the comet (whose period of +revolution was to be measured by hundreds of years) actually passed +through the whole of that part of its course during which it was north +of our earth's orbit plane in less than two hours and a half! though +this part of its course is a half circuit around the sun, so far as +direction (not distance of travel) is concerned. That comet, when at its +nearest to the sun, was traveling at the rate of about 330 miles per +second. It passed through regions near the sun's surface commonly +supposed to be occupied by atmospheric matter.</p> + +<p>Now, had the comet been so far checked in its swift rush through those +regions as to lose one thousandth part of its velocity, it would have +returned in less than a year. But the way in which the comet retreated +showed that nothing of this sort was to be expected. I am not aware, +indeed, that any anticipations were ever suggested in regard to the +return of the comet of 1668 to our neighborhood. It was not till the +time of Halley's comet, 1682, that modern astronomy began to consider +the question of the possibly periodic character of cometic motions with +attention. (For my own part, I reject as altogether improbable the +statement of Seneca that the ancient Chaldean astronomers could +calculate the return of comets.) The comet of 1680, called Newton's, was +the very first whose orbital motions were dealt with on the principles +of Newtonian astronomy, and Halley's was the first whose periodic +character was recognized.</p> + +<p>In 1843 another comet came up from the south, and presently returned +thither. It was, indeed, only seen during its return, having, like the +comet of 1668, been only discovered a day or two after perihelion +passage. Astronomers soon began to notice a curious resemblance between +the orbits of the two comets. Remembering the comparative roughness of +the observations made in 1668, it may be said that the two comets moved +in the same orbit, so far as could be judged from observation. The comet +of 1843 came along a path inclined at apparently the same angle to the +earth's orbit plane, crossed that plane ascendingly at appreciably the +same point, swept round in about two hours and a half that part of its +angular circuit which lay north of the earth's orbit plane, and, +crossing that plane descendingly at the same point as the comet of 1668, +passed along appreciably the same course toward the southern stellar +regions! The close resemblance of two paths, each so strikingly +remarkable in itself, could not well be regarded as a mere accidental +coincidence.</p> + +<div class="figcenter" style="width: 385px;"> +<a href="./images/14.png"><img src="images/14_th.png" alt="Sky With Comets" title="" /></a> +<span class="caption">The Constellations, though unnamed, can readily be +identified, when it is noted that the Comet's course, as here +represented, began in the constellation of the Crane.</span> +</div> + +<p>However, at that time no very special attention was directed to the +resemblance between the paths of the comets of 1843 and 1668. It was not +regarded as anything very new or striking that a comet should return +after making a wide excursion round the sun; and those who noticed that +the two comets really had traversed appreciably the same path around the +immediate neighborhood of the sun, simply concluded that the comet of +1668 had come back in 1843, after 175 years, and not necessarily for the +first time.</p> + +<p>It must be noticed, however, before leaving this part of the record, +that the comet of 1843 was suspected of behaving in a rather strange way +when near the sun. For the first observation, made rather roughly, +indeed, with a sextant, by a man who had no idea of the interest his +observation might afterward have, could not be reconciled by +mathematicians (including the well-known mathematician, Benjamin Pierce) +with the movement of the comet as subsequently observed. It seemed as +though when in the sun's neighborhood the comet had undergone some +disturbance, possibly internal, which had in slight degree affected its +subsequent career.</p> + +<p>According to some calculations, the comet of 1843 seemed to have a +period of about thirty-five years, which accorded well with the idea +that it was the comet of 1668, returned after five circuits. Nor was it +deemed at all surprising that the comet, conspicuous though it is, had +not been detected in 1713, 1748, 1783, and 1818, for its path would +carry it where it would be very apt to escape notice except in the +southern hemisphere, and even there it might quite readily be missed. +The appearance of the comet of 1668 corresponded well with that of the +comet of 1843. Each was remarkable for its extremely long tail and for +the comparative insignificance of its head. In the northern skies, +indeed, the comet of 1843 showed a very straight tail, and it is usually +depicted in that way, whereas the comet of 1668 had a tail showing +curvature. But pictures of the comet of 1843, as seen in the southern +hemisphere, show it with a curved tail, and also the tail appeared +forked toward the end during that part of the comet's career.</p> + +<p>However, the best observations, and the calculations based on them, +seemed to show that the period of the comet of 1843 could not be less +than 500 years.</p> + +<p>Astronomers were rather startled, therefore, when, in 1880, a comet +appeared in the southern skies which traversed appreciably the same +course as the comets of 1668 and 1843. When I was in Australia, in 1880, +a few months after the great comet had passed out of view, I met several +persons who had seen both the comet of that year and the comet of 1843. +They all agreed in saying that the resemblance between the two comets +was very close. Like the comet of 1843, that of 1880 had a singularly +long tail, and both comets were remarkable for the smallness and dimness +of their heads. One observer told me that at times the head of the comet +of 1880 could barely be discerned.</p> + +<p>Like the comets of 1668 and 1843, the comet of 1880 grazed close past +the sun's surface. Like them, it was but about two hours and a half +north of the earth's orbit place. Had it only resembled the other two in +these remarkable characteristics, the coincidence would have been +remarkable. But of course the real evidence by which the association +between the comets was shown was of a more decisive kind. It was not in +general character only, but in details, that the path of the comet of +1880 resembled those on which the other two comets had traveled. Its +path had almost exactly the same slant to the earth's orbit plane as +theirs, crossed that plane ascendingly and descendingly at almost +exactly the same points, and made its nearest approach to the sun at +very nearly the same place. To the astronomer such evidence is decisive. +Mr. Hind, the superintendent of the "Nautical Almanac," and as sound and +cautious a student of cometic astronomy as any man living, remarked, so +soon as the resemblance of these comets' paths had been ascertained, +that if it were merely accidental, the case was most unusual; nay, it +might be described as unique. And, be it noticed, he was referring only +to the resemblance between the comets of 1880 and 1843. Had he recalled +at the time the comet of 1668, and its closely similar orbit, he would +have admitted that the double coincidence could not possibly be merely +casual.</p> + +<p>But this was by no means the end of the matter. Indeed, thus far, +although the circumstances were striking, there was nothing to prevent +astronomers from interpreting them as other cases of coincident, or +nearly coincident, cometic paths had been interpreted. Hind and others, +myself included, inferred that the comets of 1880, 1843, and 1668 were +simply one and the same comet, whose return in 1880 probably followed +the return in 1843 after a single revolution.</p> + +<p>In 1882, however, two years and a half after the appearance of the comet +of 1880, another comet came up from the south, which followed in the +sun's neighborhood almost the same course as the comets of 1668, 1843, +and 1880. The path it followed was not quite so close to those followed +by the other three as these had been to each other, but yet was far too +close to indicate possibly a mere casual resemblance; on the contrary, +the resemblance in regard to shape, slope, and those peculiarities which +render this family of comets unique <a name="Page_10117"></a>in the cometary system, was of the +closest and most striking kind.</p> + +<p>Many will remember the startling ideas which were suggested, by +Professor Piazzi Smyth respecting the portentous significance of the +comet of 1882. He regarded it as confirming the great pyramid's teaching +(according to the views of orthodox pyramidalists) respecting the +approaching end of the Christian dispensation. It was seen under very +remarkable circumstances, blazing close by the sun, within a fortnight +or three weeks of the precise date which had been announced as marking +that critical epoch in the history of the earth.</p> + +<p>Moreover, even viewing the matter from a scientific standpoint, +Professor Smyth (who, outside his pyramidal paradoxes, is an astronomer +of well deserved repute) could recognize sufficient reason for regarding +the comet as portentous.</p> + +<p>Many others, indeed, both in America and in Europe, shared his opinion +in this respect. A very slight retardation of the course of the comet of +1880, during its passage close by the surface of the sun, would have +sufficed to alter its period of revolution from the thirty-seven years +assigned on the supposition of its identity with the comet of 1843 to +the two and a half years indicated by its apparent return in 1882, and +if this had occurred in 1880, a similar interruption in 1832 would have +caused its return in less than two and a half years.</p> + +<p>Thus, circling in an ever narrowing (or rather shortening) orbit, it +would presently, within a quarter of a century or so perhaps, have +become so far entangled among the atmospheric matter around the sun that +it would have been unable to resist absolute absorption. What the +consequences to the solar system might have been, none ventured to +suggest. Newton had expressed his belief that the effects of such +absorption would be disastrous, but the physicists of the nineteenth +century, better acquainted with the laws associating heat and motion, +were not so despondent. Only Professor Smyth seems to have felt assured +(not being despondent, but confident) that the comet portended, in a +very decisive way, the beginning of the end.</p> + +<p>However, we were all mistaken. The comet of 1882 retreated on such a +course, and with such variation of velocity, as to show that its real +period must be measured, not by months, as had been supposed, nor even +by years, but by centuries. Probably it will not return till 600 or 700 +years have passed. Had this not been proved, we might have been not a +little perplexed by the return of apparently the same comet in this +present year. A comet was discovered in the south early in January, +whose course, dealt with by Professor Kruger, one of the most zealous of +our comet calculators, is found to be partially identical with that of +the four remarkable comets we have been considering. Astronomers have +not been moved by this new visitant on the well-worn track as we were by +the arrival of the comet of 1882, or as we should have been if either +the comet of 1882 had never been seen or its path had not been shown to +be so wide ranging. Whatever the comet of the present year may be, it +was not the comet of 1882 returned. No one even supposes that it was the +comet of 1880, or 1843, or 1668. Nevertheless, rightly apprehended, the +appearance of a comet traveling on appreciably the same track as those +four other comets is of extreme interest, and indeed practically +decisive as to the interpretation we must place on these repeated +coincidences.</p> + +<p>Observe, we are absolutely certain that the five comets are associated +together in some way; but we are as absolutely certain that they are not +one and the same comet which had traveled along the same track and +returned after a certain number of circuits. We need not trouble +ourselves with the question whether two or more of the comets may not +have been in reality one and the same body at different returns. It +suffices that they all five were not one; since we deduce precisely the +same conclusion whether we regard the five as in reality but four or +three or two. But it may be mentioned in passing as appearing altogether +more probable, when all the evidence is considered, that there were no +fewer than five distinct comets, all traveling on what was practically +the selfsame track when in the neighborhood of the sun.</p> + +<p>There can be but one interpretation of this remarkable fact—a fact +really proved, be it noticed (as I and others have maintained since the +retreat of the comet of 1882), independently of the evidence supplied by +the great southern comet of the present year. These comets must all +originally have been one comet, though now they are distinct bodies. For +there is no reasonable way (indeed, no possible way) of imagining the +separate formation of two or more comets at different times which should +thereafter travel in the same path.</p> + +<p>No theory of the origin of comets ever suggested, none even which can be +imagined, could account for such a peculiarity. Whereas, on the other +hand, we have direct evidence showing how a comet, originally single, +may be transformed into two or more comets traveling on the same, or +nearly the same, track.</p> + +<p>The comet called Biela's, which had circuited as a single comet up to +the year 1846 (during a period of unknown duration in the past—probably +during millions of years), divided then into two, and has since broken +up into so many parts that each cometic fragment is separately +undiscernible. The two comets into which Biela's divided, in 1846, were +watched long enough to show that had their separate existence continued +(visibly), they would have been found, in the fullness of time, +traveling at distances very far apart, though on nearly the same orbit. +The distance between them, which in 1846 had increased only to about a +quarter of a million of miles, had in 1852 increased to five times that +space.</p> + +<p>Probably a few thousands of years would have sufficed to set these +comets so far apart (owing to some slight difference of velocity, +initiated at the moment of their separation) that when one would have +been at its nearest to the sun, the other would have been at its +farthest from him. If we could now discern the separate fragments of the +comet, we should doubtless recognize a process in progress by which, in +the course of many centuries, the separate cometic bodies will be +disseminated all round the common orbit. We know, further, that already +such a process has been at work on portions removed from the comet many +centuries ago, for as our earth passes through the track of this comet +she encounters millions of meteoric bodies which are traveling in the +comet's orbit, and once formed part of the substance of a comet +doubtless much more distinguished in appearance than Biela's.</p> + +<p>There can be little doubt that this is the true explanation of the +origin of that family of comets, five of whose members returned to the +neighborhood of the sun (possibly their parent) in the years 1668, 1843, +1880, 1882, and 1887.<a name="FNanchor_17"></a><a href="#Footnote_17"><sup>1</sup></a></p> + +<p>But it is not merely as thus explaining what had been a most perplexing +problem that I have dealt with the evidence supplied by the practical +identity of these five comets' orbits. When once we recognize that this, +and this only, can be the explanation of the associated group of five +comets, we perceive that very interesting and important light has been +thrown on the subject of comets generally. To begin with: what an +amazing comet that must have been from which these five, and we know not +how many more, were formed by disaggregative processes—probably by the +divellent action of repulsive forces exerted by the sun! Those who +remember the comets of 1843 and 1882 as they appeared when at their full +splendor will be able to imagine how noble an appearance a comet would +present which was formed of these combined together in one. But the +comet of 1880 was described by all who saw it in the southern hemisphere +as most remarkable in appearance, despite the faintness of its head. The +great southern comet of the present year was a striking object in the +skies, though it showed the same weakness about the head. That of 1668 +was probably as remarkable in appearance as even the comet of 1882. A +comet formed by combining all these together would certainly surpass in +magnificence all the comets ever observed by astronomers.</p> + +<p>And then, what enormous periods of time must have been required to +distribute the fragments of a single comet so widely that one would be +found returning to its perihelion more than two centuries after another! +When I spoke of one member of the Biela group being in aphelion when +another would be in perihelion, I was speaking of a difference of only +three and one-third years in time; and even that would require thousands +of years. But the scattered cometic bodies which returned to the sun's +neighborhood in 1668 and 1887 speak probably of millions of years which +have passed since first this comet was formed. It would be a matter of +curious inquiry to determine what may have been the condition of our +sun, what even his volume, at that remote epoch in history.</p> + + +<p><a name="Footnote_17"></a><a href="#FNanchor_17">[1]</a></p> +<div class="note"><p>It may be interesting to compare the orbital elements of +the five comets above dealt with. They may be presented as follows; but +it should be noticed that the determinations must be regarded as rough +in the case of Comets I. and V., as the observations were insufficient +for exact determination of the elements:</p> + +<table border="0" width="90%" summary=""> +<tr><td align='left'></td><td align='center'>I.</td><td align='center'>II.</td><td align='center'>III.</td><td align='center'>IV.</td><td align='center'>V.</td></tr> +<tr><td align='left'></td><td align='center'>1668.</td><td align='center'>1843.</td><td align='center'>1880.</td><td align='center'>1882.</td><td align='center'>1887.</td></tr> +<tr><td align='left'>Perih. Passage.</td><td align='center'>Feb. 29</td><td align='center'>Feb. 27</td><td align='center'>Jan. 27</td><td align='center'>Sep. 17</td><td align='center'>Jan. 11</td></tr> +<tr><td align='left'>Log. Per. Dist.</td><td align='center'>7.6721</td><td align='center'>7.8395</td><td align='center'>7.7714</td><td align='center'>7.8895</td><td align='center'>8.1644</td></tr> +<tr><td align='left'>Long. Per.</td><td align='center'>80° 15'</td><td align='center'>73° 30' 46"</td><td align='center'>74° 11' 13"</td><td align='center'>55° 37' 29"</td><td align='center'>89° 41'</td></tr> +<tr><td align='left'>Long. Node.</td><td align='center'>357° 17'</td><td align='center'>355° 46' 48"</td><td align='center'>356° 17' 4"</td><td align='center'>346° 1' 27"</td><td align='center'>359° 41'</td></tr> +<tr><td align='left'>Inclination.</td><td align='center'>125° 58'</td><td align='center'>143° 1' 31"</td><td align='center'>143° 7' 31"</td><td align='center'>141° 59' 40"</td><td align='center'>141° 16'</td></tr> +<tr><td align='left'>Eccentricity.</td><td align='center'>0.9999</td><td align='center'>0.9991</td><td align='center'>0.9995</td><td align='center'>0.999</td><td align='center'>......</td></tr> +<tr><td align='left'>Calculator.</td><td align='center'>Henderson</td><td align='center'>Plantamour</td><td align='center'>Meyer</td><td align='center'>Kreutz</td><td align='center'>Finlay</td></tr> +</table></div> + +<hr /> + +<h2><a name="art06"></a>THE ISOLATION OF FLUORINE.</h2> + +<p>The element fluorine has at last been successfully isolated, and its +chief chemical and physical properties determined. Many chemists, +notably Faraday, Gore, Pflaunder, and Brauner, have endeavored to +prepare this element in the free state, but all attempts have hitherto +proved futile. M. Moissau, after a long series of researches with the +fluorides of phosphorus, and the highly poisonous arsenic trifluoride, +has finally been able to liberate fluorine in the gaseous state from +anhydrous hydrofluoric acid by electrolysis. This acid in the pure state +is not an electrolyte, but when potassium fluoride is dissolved in it, a +current from ninety Bunsen elements decomposes it, evolving hydrogen +from the negative and fluoride from the positive electrode.</p> + +<div class="figcenter" style="width: 519px;"> +<img src="images/15a.png" alt="U tube" title="" /> +</div> + +<p>The apparatus employed in this process is constructed of platinum, and +is made in the form of a U tube, as shown in the accompanying +illustration, with fluorspar stoppers, through which the battery +terminals, made of platinum iridium alloy, are led. The gas is liberated +at about the rate of two liters per hour, and has very powerful chemical +properties. It smells somewhat like hypochlorous acid, etches dry glass, +and decomposes water, liberating ozone, and forming hydrofluoric acid. +The non-metallic elements, with the exception of chlorine, oxygen, +nitrogen, and carbon, combine directly with it, evolving in most cases +both light and heat. It combines with hydrogen, even in the dark, +without the addition of any external energy, and converts most metals +into their fluorides. Gold and platinum are not attacked in the cold, +but when gently heated are easily corroded. Mercury readily dissolves +the gas, forming the protochloride; iron wire also completely absorbs +the gas, while powdered antimony and lead take fire in it. It is +necessary in the electrolysis of the liquid hydrofluoric acid to cool +the electrolytic cell by means of methyl chloride to -50° C. Fluorine +appears to thus fully confirm the predictions which have been made by +chemists concerning its properties. It is by far the, most energetic of +all the known elements, and its position in the halogen series is +established by its property of not liberating iodine from the iodides of +potassium, mercury, and lead, and also of setting free chlorine from +potassium chloride. With iodine it appears to form a fluoride. No +compound with oxygen has yet been obtained.—<i>Industries.</i></p> + +<hr /> + +<h2><a name="art04"></a>AN APPARATUS FOR PREPARING SULPHUROUS, CARBONIC, AND PHOSPHORIC +ANHYDRIDES.</h2> + +<h3>By <span class="smcap">H.N. Warren</span>, Research Analyst.</h3> + +<p>Having had occasion to prepare a quantity of sulphurous anhydride, for +the purpose of reducing chromates previous to their analysis, I made use +of the following apparatus, as represented in the accompanying figure. +It consists of a glass vessel, A, provided with three tubulars, +otherwise resembling a large Wolff bottle, the large tube, B, being +provided with a stopper for the purpose of introducing pieces of sulphur +from time to time into the small dish, C, intended for its reception, +and fed with air by means of the delivery tube, D, thus allowing the +stream of gas caused by the consumption of the sulphur to escape by +means of the exit tube, E, to the vessel desired to receive it.</p> + +<div class="figcenter" style="width: 404px;"> +<img src="images/15b.png" alt="Bottle with two tubes entering" title="" /> +</div> + +<p>In using the apparatus the sulphur is first kindled by introducing a red +hot wire through the tube, B, and replacing the stopper that has been +momentarily removed for the introduction of the same. A slight blast is +now maintained from the bellows that are in connection with the pipe, D, +until the whole of the sulphur is thoroughly kindled, when a somewhat +more powerful blast may be applied. When the apparatus above described +is in full working order, from 2 to 3 lb. of sodium carbonate may be +converted into sodium sulphite in less than half an hour, or several +gallons of water saturated. I have also on connecting the apparatus with +a powerful refrigerator obtained in a short time a large quantity of +liquid SO<sub>2</sub>. It will be found advantageous, however, during the +preparation of sulphurous anhydride, to employ a layer of water covering +the bottom of the vessel to about 1 inch in depth. Carbonic anhydride +and phosphoric anhydride may also be readily obtained in any desired +quantity by slight alteration; but in case of phosphorus the air must be +allowed to enter only gently, since a rapid current would at all times +determine the fracture of the vessel.—<i>Chem. News</i>.</p> + +<hr /> + +<h2><a name="art05"></a>THE ARRANGEMENT OF ATOMS IN SPACE IN ORGANIC MOLECULES.<a name="FNanchor_18"></a><a href="#Footnote_18"><sup>1</sup></a></h2> + +<p>The expression "chemical structure," as commonly used by chemists, has, +as is well known, nothing to do with the arrangement of atoms in space. +The structural formula does not profess to represent spatial relations, +but simply the connections which, after a careful study of the +transformations and modes of formation of the compound represented, are +believed to exist between the atoms. Nevertheless, although we do not +commonly consider the question of space relations, it is clear that +atoms must have some definite positions in space in the molecules, and +the only reason why we do not represent these positions is because we +know practically nothing about them. The most definite suggestion +concerning space relations of atoms which has been made is that of Le +Bel and Van't Hoff. The well known hypothesis of these authors was put +forward to account for a certain kind of so-called physical isomerism +which shows itself in the action of substances upon polarized light. +Since this hypothesis was proposed, the number of cases of "abnormal +isomerism," that is to say, of cases of isomerism which cannot be +accounted for by the commonly accepted method of explaining structure, +has increased to a considerable extent, and the necessity for some new +hypothesis, or for some modification of the old ones, has come to be +pretty generally recognized. Among the cases of isomerism which it is at +least difficult to explain by the aid of the prevailing views are those +of maleic and fumaric acids; citraconic and mesaconic acids; certain +halogen derivatives of crotonic acid and of cinnamic acid; and coumaric +and coumarinic acids.</p> + +<p>More than one hypothesis has been proposed to account for these cases of +isomerism, but no one has shown itself to be entirely satisfactory. +Quite recently Johannes Wislicenus, Professor of Chemistry in the +University of Liepsic, has made what has the appearance of being an +important contribution toward the solution of the problem referred to. +The author shows that many of the facts known in regard to the relations +between maleic and fumaric acids, and the other <a name="Page_10118"></a> substances which +furnish examples of "abnormal isomerism," may be explained by the aid of +an extension of the Le Bel-Van't Hoff hypothesis. It is difficult +without the aid of models to give a clear idea concerning the hypothesis +of Wislicenus, but some idea of it may be gained from the following. If +we suppose a carbon atom to exert its affinities in the directions of +the solid angles of a tetrahedron, as is done in the Le Bel-Van't Hoff +hypothesis, then, when two carbon atoms unite, as in ethane, the union +will be between two solid angles of two tetrahedrons. If the two carbon +atoms unite by the ethylene kind of union, the union will be along a +line corresponding to one of the edges of each tetrahedron. In the +former case, in which single union exists, the two parts of the molecule +represented by the two tetrahedrons can be supposed to be capable of +revolving around an axis either in the same direction or in opposite +directions. This axis corresponds to the straight line joining the two +carbon atoms. In the case in which double union exists no such +revolution is possible. Again, if, by addition to an unsaturated +compound like ethylene, a saturated compound is formed, the kind of +union between the carbon atoms is changed, and the possibility of +revolution of the two parts of the compound is given. Whether such +revolution take place or not will be determined largely by the structure +of the compound. The tendency will be for those parts of the molecule +which have the greatest specific affinity for one another to take those +positions in which they are nearest to one another. Thus, suppose that +chlorine is added to ethylene. By following the change on the model, it +is seen that in the resulting figure the two chlorine atoms in ethylene +chloride are situated at angles of the two tetrahedrons which are +nearest each other. But chlorine has a stronger affinity for hydrogen +than it has for chlorine, and therefore each chlorine atom would tend to +get as near a hydrogen atom as possible. This involves a partial +revolution of the two tetrahedrons in opposite directions around their +common axis. So also hydrogen would tend to take a position as near as +possible to hydroxyl and to carboxyl, while hydroxyl would avoid +hydroxyl, and carboxyl would avoid carboxyl. These views are suggested +as a result of a careful application of the original Le Bel-Van't Hoff +hypothesis, and are, of course, of little value unless they can be shown +to be in accordance with the facts.</p> + +<p>The chief merit of the work of Wislicenus consists in the fact that he +has shown that a large number of phenomena which have been observed in +the study of such cases of isomerism as were mentioned above find a +ready explanation in terms of the new hypothesis, whereas for most of +these phenomena no explanation whatever has thus far been presented. The +most marked case presented is that of maleic and fumaric acids. One by +one, the author discusses the transformations of these acids and their +substitution products, and becomes to this conclusion: "There is not to +my knowledge a single fact known in regard to the relations between +fumaric and maleic acids which is not explained by the aid of the above +geometrical considerations, not one which does not clearly support the +new hypothesis." Among the facts which he discusses in the light of the +hypothesis are these: The formation of fumaric and maleic acids from +malic acid; the quantitative transformation of maleic into fumaric acid +by contact with strong acids; the transformation of the ethereal salts +of maleic acid into those of fumaric acid by the action of a minute +quantity of free iodine; the formation of brommaleic acid and +hydrobromic acid from the dibromsuccinic acid formed by the addition of +two bromine atoms to fumaric acid; the formation of dibromsuccinic acid +from brommaleic acid and of isodibromsuccinic acid from bromfumaric acid +by the action of fuming hydrobromic acid; the conversion of brommaleic +acid into fumaric and then into succinic acid by the action of sodium +amalgam; the formation of one and the same tribromsuccinic acid by the +action of bromine on brommaleic and on bromfumaric acid; and finally, +the conversion of maleic into inactive tartaric acid, and of fumaric +into racemic acid by potassium permanganate. All these facts are shown +to find a ready explanation by the aid of the new hypothesis. Further, +it is shown that the decompositions of the salts of certain halogen +derivatives of organic acids, which give up halogen salt and carbon +dioxide, as well as the formation of lactones and of anhydrides of +dibasic acids, are in perfect harmony with the hypothesis. But the only +way to get a clear conception in regard to the mass of material which +the author has brought together and which he has shown to support his +hypothesis is by a careful study of the original paper, and the object +of this notice is mainly to call the attention of American chemists to +it.</p> + +<p>As to the question what value to attach to the speculations which +Wislicenus has brought to our notice, it is difficult to give any but a +general answer. No one can well have a greater fear of mere speculation, +which is indulged in independently of the facts, than the writer of this +notice. Great harm has been done chemistry, and probably every other +branch of knowledge, by unwarranted speculation, and every one who has +looked into the matter knows how extremely difficult it is to emancipate +one's self from the influence of a plausible hypothesis, even when it +can be shown that it is not in accordance with the facts. It behooves +every one, therefore, before accepting a new hypothesis, no matter how +fascinating it may appear at first sight, to look carefully into the +facts, and to endeavor to determine independently whether it is well +founded or not. On the other hand, there is some danger to be +apprehended from a tendency, sometimes observed, to denounce everything +speculative, no matter how broad the basis of facts upon which it rests +may be. Without legitimate speculation, it is clear that there could be +no great progress in any subject. As far as the hypothesis under +consideration is concerned, the writer is firmly of the opinion that it +is likely to prove of great value in dealing with a large number of +chemical facts, and that, as it suggests many lines of research, it will +undoubtedly in the course of a few years exert a profound influence on +chemistry. Whether the evidence which will be accumulated will or will +not confirm the view that the tetrahedron form is characteristic of the +simplest molecules of carbon compounds is not the most important +question to be asked under the circumstances. We should rather ask +whether the testing of the hypothesis is or is not likely to bring us +nearer to the truth. It is a proposition that admits of no denial that a +hypothesis which can be tested by experiment, and which suggests lines +of work and stimulates workers to follow them, is a gain to science, no +matter what the ultimate fate of the hypothesis may be.—<i>Amer. Chem. +Jour.</i></p> + +<p><a name="Footnote_18"></a><a href="#FNanchor_18">[1]</a></p> +<div class="note"><p>Ueber die raumliche Anordnung der Atome in organischen +Molekulen, and ihre Bestimmung in geometrisch-isomeren ungesattigten +Verbindungen. Von Johannes Wislicenus.—Abhandlungen der +mathemalisch-physischen Klasse der Konigl. Sachsischen Gesellschaft der +Wissenechaften. Band XIV., No. 1.</p></div> + +<hr /> + +<h2><a name="art16"></a>GREAT WARMTH IN PAPER.</h2> + +<p>It should be thoroughly understood by all that any common paper, coarse +wrapping paper, new or old newspapers, etc., are admirable to keep out +cold or keep in warmth. The blood of <i>all</i> domestic animals, as well as +of human beings, <i>must</i> be always kept very near 98 degrees, just as +much in winter as in summer. And this heat always comes from <i>within</i> +the body, whenever the atmosphere is not above 98 degrees temperature. +So long as the air is cooler than this, the heat produced inside the +body is escaping. Heat seeks a level. If there is more in one of two +bodies or substances side by side, the heat will pass from the warmer +into the colder, until they are both of the same temperature.</p> + +<p>Moving air carries away vastly more heat than still air. The thin film +of air next to the body soon gets warm from it. But if that air is moved +along, slowly or swiftly, by a breeze, be it ever so gentle, new cooler +air takes its place, and abstracts more heat from the body. Anything +that keeps the air next to the bodies of men and of animals from moving, +checks the escape of heat.</p> + +<p>The thinnest paper serves to keep the air quiet. A newspaper laid on a +bed acts much as a coverlid to keep a film or layer of air quiet, and +thus less heat escapes from the bodies of the sleepers. If paper is +pasted up over the cracks of a house, or of a barn or stable, or under +the joists of a house floor, it has just the same effect. Every person +who keeps animals will find it a wonderful and paying protection to +them, to put against the walls one, two, three, or more layers of +newspapers during cold weather. If a person in riding finds his garments +too cool, a newspaper placed under the coat or vest, or under or over +the trousers, even if only on the side next the wind, will do a great +deal to check the outflow of heat, and keep him warm. Two or three +thicknesses of newspaper crumpled a little, and put under the coat or +overcoat, are almost as effective in keeping in warmth as an extra +garment. A slight crumpling keeps them a little separate, and makes +additional thin layers of air.</p> + +<p>Further: Heat does not pass through films of <i>still</i> air. Fibrous +woolens, furs, loosely woven cotton, down, and the like, contain a great +deal of air <i>confined</i> in the meshes, and are therefore excellent +conservers of heat. Double walls of stone, brick, or wood, or even of +wall or roofing paper, double glass, double layers of anything that will +have thin layers of still air between them, prevent the escape of heat +greatly.</p> + +<hr /> + +<h3>THE SCIENTIFIC AMERICAN</h3> + +<h2>Architects and Builders Edition.</h2> + +<p class="center"><b>$2.50 a Year. Single Copies, 25 cts.</b></p> + +<p>This is a Special Edition of the <span class="smcap">Scientific American</span>, issued +monthly—on the first day of the month. Each number contains about forty +large quarto pages, equal to about two hundred ordinary book pages, +forming, practically, a large and splendid <b>Magazine of Architecture</b>, +richly adorned with <i>elegant plates in colors</i> and with fine engravings, +illustrating the most interesting examples of modern Architectural +Construction and allied subjects.</p> + +<p>A special feature is the presentation in each number of a variety of the +latest and best plans for private residences, city and country, +including those of very moderate cost as well as the more expensive. +Drawings in perspective and in color are given, together with full +Plans, Specifications, Costs, Bills of Estimate, and Sheets of Details.</p> + +<p>No other building paper contains so many plans, details, and +specifications regularly presented as the <span class="smcap">Scientific American</span>. +Hundreds of dwellings have already been erected on the various plans we +have issued during the past year, and many others are in process of +construction.</p> + +<p>Architects, Builders, and Owners will find this work valuable in +furnishing fresh and useful suggestions. All who contemplate building or +improving homes, or erecting structures of any kind, have before them in +this work an almost <i>endless series of the latest and best examples</i> +from which to make selections, thus saving time and money.</p> + +<p>Many other subjects, including Sewerage, Piping, Lighting, Warming, +Ventilating, Decorating, Laying out of Grounds, etc., are illustrated. +An extensive Compendium of Manufacturers' Announcements is also given, +in which the most reliable and approved Building Materials, Goods, +Machines, Tools, and Appliances are described and illustrated, with +addresses of the makers, etc.</p> + +<p>The fullness, richness, cheapness, and convenience of this work have won +for it the <b>Largest Circulation</b> of any Architectural publication in the +world.</p> + + +<p class="center"> <b>MUNN & CO., Publishers,<br /> +361 Broadway, New York.</b></p> + + +<p>A Catalogue of valuable books on Architecture, Building, Carpentry, +Masonry, Heating, Warming, Lighting, Ventilation, and all branches of +industry pertaining to the art of Building, is supplied free of charge, +sent to any address.</p> + +<hr /> + +<h3>Building Plans and Specifications.</h3> + +<p>In connection with the publication of the <span class="smcap">Building Edition</span> of +the <span class="smcap">Scientific American</span>, Messrs. Munn & Co. furnish plans and +specifications for buildings of every kind, including Churches, Schools, +Stores, Dwellings, Carriage Houses, Barns, etc.</p> + +<p>In this work they are assisted by able and experienced architects. Full +plans, details, and specifications for the various buildings illustrated +in this paper can be supplied.</p> + +<p>Those who contemplate building, or who wish to alter, improve, extend, +or add to existing buildings, whether wings, porches, bay windows, or +attic rooms, are invited to communicate with the undersigned. Our work +extends to all parts of the country. Estimates, plans, and drawings +promptly prepared. Terms moderate. Address</p> + +<p class="center">MUNN & CO., 361 <span class="smcap">Broadway, New York.</span></p> + +<hr /> + +<h3>THE</h3> + +<h2>Scientific American Supplement.</h2> + +<p class="center"><b>PUBLISHED WEEKLY.</b></p> + +<p class="center">Terms of Subscription, $5 a year.</p> + +<p>Sent by mail, postage prepaid, to subscribers in any part of the United +States or Canada. Six dollars a year, sent, prepaid, to any foreign +country.</p> + +<p>All the back numbers of <span class="smcap">The Supplement</span>, from the commencement, +January 1, 1876, can be had. Price, 10 cents each.</p> + +<p>All the back volumes of <span class="smcap">The Supplement</span> can likewise be +supplied. Two volumes are issued yearly. Price of each volume, $2.50 +stitched in paper, or $3.50 bound in stiff covers.</p> + +<p><span class="smcap">Combined Rates.</span>—One copy of <span class="smcap">Scientific American</span> and +one copy of <span class="smcap">Scientific American Supplement</span>, one year, postpaid, +$7.00.</p> + +<p>A liberal discount to booksellers, news agents, and canvassers.</p> + +<p class="center"> <b>MUNN & CO., Publishers,<br /> +361 Broadway, New York, N.Y.</b></p> + +<hr /> + + +<h2>PATENTS.</h2> + +<p>In connection with the <b>Scientific American</b>, Messrs. MUNN & CO. are +solicitors of American and Foreign Patents, have had 42 years' +experience, and now have the largest establishment in the world. Patents +are obtained on the best terms.</p> + +<p>A special notice is made in the <b>Scientific American</b> of all inventions +patented through this Agency, with the name and residence of the +Patentee. By the immense circulation thus given, public attention is +directed to the merits of the new patent, and sales or introduction +often easily effected.</p> + +<p>Any person who has made a new discovery or invention can ascertain, free +of charge, whether a patent can probably be obtained, by writing to MUNN +& CO.</p> + +<p>We also send free our Hand Book about the Patent Laws, Patents, Caveats, +Trade Marks, their costs, and how procured. 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