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diff --git a/44838-0.txt b/44838-0.txt new file mode 100644 index 0000000..e79ff3d --- /dev/null +++ b/44838-0.txt @@ -0,0 +1,2272 @@ +*** START OF THE PROJECT GUTENBERG EBOOK 44838 *** + +Note: Project Gutenberg also has an HTML version of this + file which includes the numerous original illustrations. + See 44838-h.htm or 44838-h.zip: + (http://www.gutenberg.org/files/44838/44838-h/44838-h.htm) + or + (http://www.gutenberg.org/files/44838/44838-h.zip) + + + Images of the original pages are available through + Internet Archive. See + https://archive.org/details/timeitsmeasureme00arth + + +Transcriber's note: + + Text enclosed by underscores is in italics (_italics_). + + The notation "_{n}" means that n is a subscript. + + Small capital text has been converted to all uppercase. + + + + + +TIME AND ITS MEASUREMENT + +by + +JAMES ARTHUR + + + + + + + +Reprinted from +Popular Mechanics Magazine + +Copyright, 1909, By H. H. Windsor + +Chicago, 1909 + + + + +CONTENTS + + + CHAPTER I + + HISTORIC OUTLINE + + Time as an abstraction. -- Ancient divisions of day and night. + -- Night watches of the Old Testament. -- Quarter days and hours + of the New Testament. -- Shadow, or sun time. -- Noon mark dials. + -- Ancient dials of Herculaneum and Pompeii. -- Modern dials. -- + Equation of time. -- Three historic methods of measuring time. -- + "Time-boy" of India. -- Chinese clepsydra. -- Ancient weather and + time stations. -- Tower of the winds, Athens, Greece Page 13 + + + CHAPTER II + + JAPANESE CLOCKS + + Chinese and Japanese divisions of the day. -- Hours of varying + length. -- Setting clocks to length of daylight. -- Curved line + dials. -- Numbering hours backwards and strange reasons for + same. -- Daily names for sixty day period. -- Japanese clock + movements practically Dutch. -- Japanese astronomical clock. -- + Decimal numbers very old Chinese. -- Original vertical dials + founded on "bamboo stick" of Chinese clepsydra. -- Mathematics + and superstition. -- Mysterious disappearance of hours 1, 2, 3. + -- Eastern mental attitude towards time. -- Japanese methods of + striking hours and half hours Page 25 + + + CHAPTER III + + MODERN CLOCKS + + De Vick's clock of 1364. -- Original "verge" escapement. -- + "Anchor" and "dead beat" escapements. -- "Remontoir" clock. -- + The pendulum. -- Jeweling pallets. -- Antique clock with earliest + application of pendulum. -- Turkish watches. -- Correct designs + for public clock faces. -- Art work on old watches. -- 24-hour + watch. -- Syrian and Hebrew hour numerals. -- Correct method of + striking hours and quarters. -- Design for 24-hour dial and + hands. -- Curious clocks. -- Inventions of the old clock-makers + Page 37 + + + CHAPTER IV + + ASTRONOMICAL FOUNDATION OF TIME + + Astronomical motions on which our time is founded. -- Reasons + for selecting the sidereal day as a basis for our 24-hour + day. -- Year of the seasons shorter than the zodiacal year. -- + Precession of the equinoxes. -- Earth's rotation most uniform + motion known to us. -- Time stars and transits. -- Local time. + -- The date line. -- Standard time. -- Beginning and ending of + a day. -- Proposed universal time. -- Clock dial for universal + time and its application to business. -- Next great improvement + in clocks and watches indicated. -- Automatic recording of + the earth's rotation. -- Year of the seasons as a unit for + astronomers. -- General conclusions Page 53 + + + + +ILLUSTRATIONS + + + Page + Portrait of James Arthur 8 + + Interpretation of Chinese and Japanese Methods of Time Keeping 15 + + Portable Bronze Sundial from the Ruins of Herculaneum 16 + + Noon-Mark Sundials 17 + + Modern Horizontal Sundial for Latitude 40°-43´ 18 + + The Earth, Showing Relation of Dial Styles to Axis 18 + + Modern Sundial Set Up in Garden 18 + + "Time-Boy" of India 19 + + "Hon-woo-et-low," or "Copper Jars Dropping Water"--Canton, China 19 + + Modern Sand Glass or "Hour Glass" 20 + + Tower of the Winds, Athens, Greece 20 + + Key to Japanese Figures 25 + + Japanese Dials Set for Long and Short Days 25 + + Japanese Striking Clock with Weight and Short Pendulum 26 + + Japanese Striking Clock with Spring, Fusee and Balance 26 + + Japanese Clock with Vertical Dial, Weight and Balance 27 + + Japanese Clock with Vertical Dial Having Curved Lines, Weight + and Balance 27 + + Japanese Vertical Dials 28 + + Japanese Striking Clock with Two Balances and Two Escapements 29 + + "Twelve Horary Branches" and "10 Celestial Stems" as Used in + Clocks 30 + + Key to "12 Horary Branches" and "10 Celestial Stems" 30 + + Dial of Japanese Astronomical Clock 31 + + Use of "Yeng Number" and Animal Names of Hours 32 + + Public Dial by James Arthur 37 + + Dial of Philadelphia City Hall Clock 37 + + Verge Escapement 37 + + De Vick's Clock of 1364 38 + + Anchor Escapement 38 + + American Anchor Escapement 39 + + Dead Beat Escapement 39 + + Remontoir Clock by James Arthur 40 + + Remontoir Clock Movement 40 + + Antique Clock, Entirely Hand-Made 41, 42 + + Double-Case Watch of Repoussé Work 42 + + Triple-Case Turkish Watches 43 + + Watch Showing Dutch Art Work 43 + + Triple-Case Turkish Watch 44 + + Watches Showing Art Work 45 + + Antique Watch Cock 46 + + "Chinese" Watch 46 + + Musical Watch, Repeating Hours and Quarters 47 + + Syrian Dial 47 + + Hebrew Numerals 48 + + Twenty-four Hour Watch 48 + + Domestic Dial by James Arthur 49 + + Local Time--Standard Time--Beginning and Ending of the Day 57 + + Universal Time Dial Set for Four Places 61 + + +[Illustration: James Arthur + +Mr. Arthur is an enthusiastic scientist, a successful inventor and +extensive traveler, who has for years been making a study of clocks, +watches, and time-measuring devices. He is not only a great authority +on this subject, but his collection of over 1500 timepieces gathered +from all parts of the globe has been pronounced the finest collection +in the world. Mr. Arthur is a pleasing exception to the average +business man, for he has found time to do a large amount of study and +research along various scientific lines in addition to conducting an +important manufacturing business in New York City, of which he is +president. Mr. Arthur is 67 years of age.--H. H. Windsor.] + + + + +CHAPTER I + +HISTORIC OUTLINE + + Time as an abstraction. -- Ancient divisions of day and night. + -- Night watches of the Old Testament. -- Quarter days and hours + of the New Testament. -- Shadow or sun time. -- Noon mark dials. + -- Ancient dials of Herculaneum and Pompeii. -- Modern Dials. -- + Equation of time. -- Three historic methods of measuring time. -- + "Time-boy" of India. -- Chinese clepsydra. -- Ancient weather and + time stations. -- Tower of the winds, Athens, Greece. + + +Time, as a separate entity, has not yet been defined in language. +Definitions will be found to be merely explanations of the sense in +which we use the word in matters of practical life. No human being +can tell how long a minute is; only that it is longer than a second +and shorter than an hour. In some sense we can think of a longer +or shorter period of time, but this is merely comparative. The +difference between 50 and 75 steps a minute in marching is clear to +us, but note that we introduce motion and space before we can get a +conception of time as a succession of events, but time, in itself, +remains elusive. + +In time measures we strive for a uniform motion of something and +this implies equal spaces in equal times; so we here assume just +what we cannot explain, for space is as difficult to define as time. +Time cannot be "squared" or used as a multiplier or divisor. Only +numbers can be so used; so when we speak of "the square of the time" +we mean some number which we have arbitrarily assumed to represent +it. This becomes plain when we state that in calculations relating +to pendulums, for example, we may use seconds and inches--minutes +and feet--or seconds and meters and the answer will come out right +in the units which we have assumed. Still more, numbers themselves +have no meaning till they are applied to something, and here we are +applying them to time, space and motion; so we are trying to explain +three abstractions by a fourth! But, happily, the results of these +assumptions and calculations are borne out in practical human life, +and we are not compelled to settle the deep question as to whether +fundamental knowledge is possible to the human mind. Those desiring +a few headaches on these questions can easily get them from Kant +and Spencer--but that is all they will get on these four necessary +assumptions. + +Evidently, man began by considering the day as a unit and did not +include the night in his time keeping for a long period. "And the +evening and the morning were the first day" Gen. 1, 5; "Evening and +morning and at noonday," Ps. LV, 17, divides the day ("sun up") in +two parts. "Fourth part of a day," Neh. IX, 3, shows another advance. +Then comes, "are there not twelve hours in a day," John XI, 9. The +"eleventh hour," Matt. XX, 1 to 12, shows clearly that sunset was +12 o'clock. A most remarkable feature of this 12-hour day, in the +New Testament, is that the writers generally speak of the third, +sixth and ninth hours, Acts II, 15; III, 1; X, 9. This is extremely +interesting, as it shows that the writers still thought in quarter +days (Neh. IX, 3) and had not yet acquired the 12-hour conception +given to them by the Romans. They thought in quarter days even +when using the 12-hour numerals! Note further that references are +to "hours;" so it is evident that in New Testament times they did +not need smaller subdivisions. "About the third hour," shows the +mental attitude. That they had no conception of our minutes, seconds +and fifth seconds becomes quite plain when we notice that they +jumped down from the hour to nowhere, in such expressions as "in an +instant--in the twinkling of an eye." + +Before this, the night had been divided into three watches, Judges +VII, 19. Poetry to this day uses the "hours" and the "watches" as +symbols. + +This 12 hours of daylight gave very variable hours in latitudes some +distance from the equator, being long in summer and short in winter. +The amount of human ingenuity expended on time measures so as to +divide the time from sunrise to sunset into 12 equal parts is almost +beyond belief. In Constantinople, to-day, this is used, but in a +rather imperfect manner, for the clocks are modern and run 24 hours +uniformly; so the best they can do is to set them to mark twelve at +sunset. This necessitates setting to the varying length of the days, +so that the clocks appear to be sometimes more and sometimes less +than six hours ahead of ours. A clock on the tower at the Sultan's +private mosque gives the impression of being out of order and about +six hours ahead, but it is running correctly to their system. Hotels +often show two clocks, one of them to our twelve o'clock noon system. +Evidently the Jewish method of ending a day at sunset is the same +and explains the command, "let not the sun go down upon thy wrath," +which we might read, do not carry your anger over to another day. I +venture to say that we still need that advice. + +This simple line of steps in dividing the day and night is taken +principally from the Bible because everyone can easily look up the +passages quoted and many more, while quotations from books not in +general use would not be so clear. Further, the neglect of the Bible +is such a common complaint in this country that if I induce a few +to look into it a little some good may result, quite apart from the +matter of religious belief. + +Some Chinese and Japanese methods of dividing the day and night are +indicated in Fig. 1. The old Japanese method divides the day into +six hours and the night also into six, each hour averaging twice as +long as ours. In some cases they did this by changing the rate of the +clock, and in others by letting the clock run uniformly and changing +the hour marks on the dial, but this will come later when we reach +Japanese clocks. + +It is remarkable that at the present time in England the "saving +daylight" agitation is virtually an attempt to go back to this +discarded system. "John Bull," for a long period the time-keeper +of the world with headquarters at Greenwich, and during that time +the most pretentious clock-maker, now proposes to move his clocks +backward and forward several times a year so as to "fool" his workmen +out of their beds in the mornings! Why not commence work a few +minutes earlier each fortnight while days are lengthening and the +reverse when they are shortening? + +This reminds me of a habit which was common in Scotland,--"keeping +the clock half an hour forward." In those days work commenced at six +o'clock, so the husband left his house at six and after a good walk +arrived at the factory at six! Don't you see that if his clock had +been set right he would have found it necessary to leave at half +past five? But, you say he was simply deceiving himself and acting +in an unreasonable manner. Certainly, but the average man is not a +reasonable being, and "John Bull" knows this and is trying to fool +the average Englishman. + +[Illustration: Fig. 1--Interpretation of Chinese and Japanese Methods +of Time Keeping] + +Now, as to the methods of measuring time, we must use circumstantial +evidence for the pre-historic period. The rising and the going down +of the sun--the lengthening shadows, etc., must come first, and we are +on safe ground here, for savages still use primitive methods like +setting up a stick and marking its shadow so that a party trailing +behind can estimate the distance the leaders are ahead by the changed +position of the shadow. Men notice their shortening and lengthening +shadows to this day. When the shadow of a man shortens more and +more slowly till it appears to be fixed, the observer knows it +is noon, and when it shows the least observable lengthening then +it is just past noon. Now, it is a remarkable fact that this crude +method of determining noon is just the same as "taking the sun" to +determine noon at sea. Noon is the time at which the sun reaches his +highest point on any given day. At sea this is determined generally +by a sextant, which simply measures the angle between the horizon +and the sun. The instrument is applied a little before noon and the +observer sees the sun creeping upward slower and slower till a little +tremor or hesitation appears indicating that the sun has reached his +height,--noon. Oh! you wish to know if the observer is likely to make +a mistake? Yes, and when accurate local time is important, several +officers on a large ship will take the meridian passage at the same +time and average their readings, so as to reduce the "personal +error." All of which is merely a greater degree of accuracy than that +of the man who observes his shadow. + +[Illustration: Fig. 2--Portable Bronze Sundial from the Ruins of +Herculaneum] + +The gradual development of the primitive shadow methods culminated +in the modern sundial. The "dial of Ahas," Isa. XXXVIII, 8, on which +the sun went back 10 "degrees" is often referred to, but in one of +the revised editions of the unchangeable word the sun went back 10 +"steps." This becomes extremely interesting when we find that in +India there still remains an immense dial built with steps instead of +hour lines. Figure 2 shows a pocket, or portable sundial taken from +the ruins of Herculaneum and now in the Museo National, Naples. It +is bronze, was silver plated and is in the form of a ham suspended +from the hock joint. From the tail, evidently bent from its original +position, which forms the gnomon, lines radiate and across these wavy +lines are traced. It is about 5 in. long and 3 in. wide. Being in the +corner of a glass case I was unable to get small details, but museum +authorities state that names of months are engraved on it, so it +would be a good guess that these wavy lines had something to do with +the long and short days. + +In a restored flower garden, within one of the large houses in the +ruins of Pompeii, may be seen a sundial of the Armillary type, +presumably in its original position. I could not get close to it, as +the restored garden is railed in, but it looks as if the plane of the +equator and the position of the earth's axis must have been known to +the maker. + +Both these dials were in use about the beginning of our era and were +covered by the great eruption of Vesuvius in 79 A.D., which destroyed +Pompeii and Herculaneum. + +Modern sundials differ only in being more accurately made and a few +"curiosity" dials added. The necessity for time during the night, +as man's life became a little more complicated, necessitated the +invention of time machines. The "clepsydra," or water clock, was +probably the first. A French writer has dug up some old records +putting it back to Hoang-ti 2679 B.C., but it appears to have been +certainly in use in China in 1100 B.C., so we will be satisfied +with that date. In presenting a subject to the young student it +is sometimes advisable to use round numbers to give a simple +comprehension and then leave him to find the overlapping of dates and +methods as he advances. Keeping this in mind, the following table may +be used to give an elementary hint of the three great steps in time +measuring: + + Shadow time, 2000 to 1000 B. C. + + Dials and Water Clocks, 1000 B. C. to 1000 A. D. + + Clocks and watches, 1000 to 2000 A. D. + +I have pushed the gear wheel clocks and watches forward to 2000 A.D., +as they may last to that time, but I have no doubt we will supersede +them. At the present time science is just about ready to say that +a time measurer consisting of wheels and pinions--a driving power +and a regulator in the form of a pendulum or balance, is a clumsy +contrivance and that we ought to do better very soon; but more on +this hoped-for, fourth method when we reach the consideration of the +motion on which we base all our time keeping. + +It is remarkable how few are aware that the simplest form of sundial +is the best, and that, as a regulator of our present clocks, it is +good within one or two minutes. No one need be without a "noon-mark" +sundial; that is, every one may have the best of all dials. Take a +post or any straight object standing "plumb," or best of all the +corner of a building as in Fig. 3. In the case of the post, or tree +trunk, a stone (shown in solid black) may be set in the ground; +but for the building a line may often be cut across a flagstone of +the footpath. Many methods may be employed to get this noon mark, +which is simply a north and south line. Viewing the pole star, using +a compass (if the local variation is known) or the old method of +finding the time at which the shadow of a pole is shortest. But the +best practical way in this day is to use a watch set to local time +and make the mark at 12 o'clock. + +[Illustration: Fig. 3--Noon-Mark Sundials] + +On four days of the year the sun is right and your mark may be set at +12 on these days, but you may use an almanac and look in the column +marked "mean time at noon" or "sun on meridian." For example, suppose +on the bright day when you are ready to place your noon mark you read +in this column 11:50, then when your watch shows 11:50 make your noon +mark to the shadow and it will be right for all time to come. Owing +to the fact that there are not an even number of days in a year, it +follows that on any given yearly date at noon the earth is not at +the same place in its elliptical orbit and the correction of this +by the leap years causes the equation table to vary in periods of +four years. The centennial leap years cause another variation of 400 +years, etc., but these variations are less than the error in reading +a dial. + + SUN ON NOON MARK, 1909 + ------------------------------------------------------- + Clock Clock Clock + Date Time Date Time Date Time + ------------------------------------------------------- + Jan. 2 12:04 May 1 11:57 Sep. 30 11:50 + " 4 12:05 " 15 11:56 Oct. 3 11:49 + " 7 12:06 " 28 11:57 " 6 11:48 + " 9 12:07 June 4 11:58 " 10 11:47 + " 11 12:08 " 10 11:59 " 14 11:46 + " 14 12:09 " 14 12:00 " 19 11:45 + " 17 12:10 " 19 12:01 " 26 11:44 + " 20 12:11 " 24 12:02 Nov. 17 11:45 + " 23 12:12 " 29 12:03 " 22 11:46 + " 28 12:13 July 4 12:04 " 25 11:47 + Feb. 3 12:14 " 10 12:05 " 29 11:48 + " 26 12:13 " 19 12:06 Dec. 1 11:49 + Mar. 3 12:12 Aug. 11 12:05 " 4 11:50 + " 8 12:11 " 16 12:04 " 6 11:51 + " 11 12:10 " 21 12:03 " 9 11:52 + " 15 12:09 " 25 12:02 " 11 11:53 + " 18 12:08 " 28 12:01 " 13 11:54 + " 22 12:07 " 31 12:00 " 15 11:55 + " 25 12:06 Sep. 4 11:59 " 17 11:56 + " 28 12:05 " 7 11:58 " 19 11:57 + Apr. 1 12:04 " 10 11:57 " 21 11:58 + " 4 12:03 " 12 11:56 " 23 11:59 + " 7 12:02 " 15 11:55 " 25 12:00 + " 11 12:01 " 18 11:54 " 27 12:01 + " 15 12:00 " 21 11:53 " 29 12:02 + " 19 11:59 " 24 11:52 " 31 12:03 + " 24 11:58 " 27 11:51 + ------------------------------------------------------- + The above table shows the variation of the sun from "mean" + or clock time, by even minutes. + +[Illustration: Fig. 4--12-Inch Modern Horizontal Sundial for Latitude +40°-43´] + +[Illustration: Fig. 5--The Earth, Showing Relation of Dial Styles to +Axis] + +The reason that the table given here is convenient for setting clocks +to mean time is that a minute is as close as a dial can be read, but +if you wish for greater accuracy, then the almanac, which gives the +"equation of time" to a second for each day, will be better. The +reason that these noon-mark dials are better than ordinary commercial +dials is that they are larger, and still further, noon is the only +time that any dial is accurate to sun time. This is because the +sun's rays are "refracted" in a variable manner by our atmosphere, +but at noon this refraction takes place on a north and south line, +and as that is our noon-mark line the dial reads correctly. So, +for setting clocks, the corner of your house is far ahead of the +most pretentious and expensive dial. In Fig. 4 is shown a modern +horizontal dial without the usual confusing "ornamentation," and in +Fig. 5 it is shown set up on the latitude of New York City for which +it is calculated. This shows clearly why the edge FG of the style +which casts the shadow must be parallel to the earth's axis and why +a horizontal dial must be made for the latitude of the place where +it is set up. Figure 6 is the same dial only the lines are laid +out on a square dial plate, and it will give your young scientific +readers a hint of how to set up a dial in the garden. In setting up a +horizontal dial, consider only noon and set the style, or 12 o'clock +line, north and south as described above for noon-mark dials. + +[Illustration: Fig. 6--Modern Sundial Set Up in Garden] + +A whole issue of Popular Mechanics could be filled on the subject +of dials and even then only give a general outline. Astronomy, +geography, geometry, mathematics, mechanics, as well as architecture +and art, come in to make "dialing" a most charming scientific and +intellectual avocation. + +During the night and also in cloudy weather the sundial was useless +and we read that the priests of the temples and monks of more modern +times "went out to observe the stars" to make a guess at the time +of night. The most prominent type after the shadow devices was the +"water clock" or "clepsydra," but many other methods were used, such +as candles, oil lamps and in comparatively late times, the sand +glass. The fundamental principle of all water clocks is the escape +of water from a vessel through a small hole. It is evident that such +a vessel would empty itself each time it is filled in very nearly +the same time. The reverse of this has been used as shown in Fig. 7, +which represents the "time-boy" of India. He sits in front of a large +vessel of water and floats a bronze cup having a small hole in its +bottom in this large vessel, and the leakage gradually lowers this +cup till it sinks, after which he fishes it up and strikes one or +more blows on it as a gong. This he continues and a rude division of +time is obtained,--while he keeps awake! + +[Illustration: Fig. 7--"Time-Boy" of India] + +[Illustration: Fig. 8--"Hon-woo-et-low" or "Copper Jars Dropping +Water"--Canton, China] + +The most interesting of all water clocks is undoubtedly the "copper +jars dropping water," in Canton, China, where I saw it in 1897. +Referring to the simple line sketch, which I make from memory, Fig. +8, and reading four Chinese characters downwards the translation is +"Canton City." To the left and still downwards,--"Hon-woo-et-low," +which is,--"Copper jars dropping water." Educated Chinamen inform me +that it is over 3,000 years old and had a weather vane. As they +speak of it as "the clock of the street arch" this would look quite +probable; since the little open building, or tower in which it stands +is higher than surrounding buildings. It is, therefore, reasonably +safe to state that the Chinese had a _weather and time station_ +over 1,000 years before our era. It consists of four copper jars +partially built in masonry forming a stair-like structure. Commencing +at the top jar each one drops into the next downward till the water +reaches the solid bottom jar. In this lowest one a float, "the bamboo +stick," is placed and indicates the height of the water and thus in +a rude way gives the time. It is said to be set morning and evening +by dipping the water from jar 4 to jar 1, so it runs 12 hours of +our time. What are the uses of jars 2 and 3, since the water simply +enters them and drips out again? No information could be obtained, +but I venture an explanation and hope the reader can do better, as +we are all of a family and there is no jealousy. When the top jar is +filled for a 12-hour run it would drip out too fast during the first +six hours and too slow during the second six hours, on account of +the varying "head" of water. Now, the spigot of jar 2 could be set +so that it would gain water during the first six hours, and lose +during the second six hours and thus equalize a little by splitting +the error of jar 1 in two parts. Similarly, these two errors of jar 2 +could be again split by jar 3 making four small variations in lowest +jar, instead of one large error in the flow of jar 1. This could +be extended to a greater number of jars, another jar making eight +smaller errors, etc., etc. But I am inclined to credit our ancient +Chinese inventor with the sound reasoning that a human attendant, +being very fallible and limited in his capacity, would have all he +could properly do to adjust four jars, and that his record would +average better than it would with a greater number. Remember, this +man lived thousands of years before the modern mathematician who +constructed a bell-shaped vessel with a small hole in the bottom, +and proportioned the varying diameter in such a manner that in +emptying itself the surface of the water sank equal distances in +equal times. The sand glass, Fig. 9, poetically called the "hour +glass," belongs to the water-clock class and the sand flows from one +bulb into the other, but it gives no subdivisions of its period, so +if you are using one running an hour it does not give you the half +hour. The sand glass is still in use by chairmen, and when the oldest +inhabitant gets on his feet, I always advise setting a 20-minute +glass "on him." + +[Illustration: Fig. 9--Modern Sand Glass or "Hour Glass"] + +[Illustration: Fig. 10--"Tower of the Winds"--Athens, Greece] + +In the "Tower of the Winds" at Athens, Greece (Fig. 10), we have a +later "weather bureau" station. It is attributed to the astronomer +Andronicos, and was built about 50 B. C. It is octagonal in plan +and although 27 ft. in diameter and 44 ft. high, it looks like a +sentry box when seen from one of the hills of Athens. It had a +bronze weather vane and in later times sundials on its eight sides, +but all these are gone and the tower itself is only a dilapidated +ruin. In making the drawing for this cut, from a photograph of the +tower, I have sharpened the weathered and chipped corners of the +stones so as to give a view nearly like the structure as originally +built; but nothing is added. Under the eaves it has eight allegorical +sculptures, representing wind and weather. Artists state that +these sculptures are inferior as compared with Grecian art of an +older period. But the most interesting part is inside, and here +we find curious passages cut in solid stone, and sockets which +look as if they had contained metal bearings for moving machinery. +Circumstantial evidence is strong that it contained a complicated +water clock which could have been kept running with tolerable +accuracy by setting it daily to the dials on the outside. Probably +during a few days of cloudy weather the clock would "get off quite a +little," but business was not pressing in those days. Besides, the +timekeeper would swear by his little water wheel, anyway, and feel +safe, as there was no higher authority wearing an American watch. + +Some very interesting engravings of Japanese clocks and a general +explanation of them, as well as a presentation of the Japanese mental +attitude towards "hours" and their strange method of numbering them +may be expected in the next chapter. + + + + +CHAPTER II + +JAPANESE CLOCKS + + Chinese and Japanese divisions of the day. -- Hours of varying + length. -- Setting clocks to length of daylight. -- Curved line + dials. -- Numbering hours backwards and strange reasons for + same. -- Daily names for sixty day period. -- Japanese clock + movements practically Dutch. -- Japanese astronomical clock. -- + Decimal numbers very old Chinese. -- Original vertical dials + founded on "bamboo stick" of Chinese clepsydra. -- Mathematics + and superstition. -- Mysterious disappearance of hours 1, 2, 3. + -- Eastern mental attitude towards time. -- Japanese methods of + striking hours and half hours. + + +The ancient methods of dividing day and night in China and Japan +become more hazy as we go backwards and the complications grow. The +three circles in Fig. 1 (Chapter I) are all taken from Japanese +clocks, but the interpretation has been obtained from Chinese and +Japanese scholars. The Japanese obtained a great deal from the +Chinese, in fact nearly everything relating to the ancient methods of +time keeping and the compiling of calendars. I have not been able to +find any Chinese clocks constructed of wheels and pinions, but have a +number of Japanese. These have a distinct resemblance to the earlier +Dutch movements, and while made in Japan, they are practically Dutch, +so far as the "works" are concerned, but it is easy to see from the +illustrations that they are very Japanese in style and ornamentation. +The Dutch were the leaders in opening Japan to the European nations +and introduced modern mathematics and clocks from about 1590 A. D. +The ancient mathematics of Japan came largely from China through +Corea. In Fig. 11 are given the Japanese figures beside ours, for the +reader's use as a key. The complete day in Japan was divided into +twice six hours; that is, six for daylight and six for night, and +the clocks are set, as the days vary in length, so that six o'clock +is sunrise and sunset. The hour numerals on Fig. 12 are on little +plates which are movable, and are shown set for a long day and a +short night. + +[Illustration: Fig. 11] + +[Illustration: Fig. 12 Fig. 13. + +Japanese Dials Set for Long and Short Days] + +In Fig. 13 they are set for short days and long nights. The narrow +plates shown in solid black are the half-hour marks. In this type +the hand is stationary and always points straight upward. The dial +rotates, as per arrow, once in a full day. This style of dial is +shown on complete clocks, Fig. 14 being a weight clock and Fig. 15 a +spring clock with chain and fusee. The hours are 9 to 4 and the dials +rotate to make them read backwards. The six hours of daylight are 6, +5, 4, 9, 8, 7, 6 and the same for night, so these hours average twice +as long as ours. Note that nine is mid-day and mid-night, and as +these do not change by long and short days they are stationary on the +dial, as you can easily see by comparing Figs. 12 and 13, which are +the same dial set for different seasons. Between these extremes the +dial hours are set as often as the owner wishes; so if he happens to +correspond with our "time crank" he will set them often and dispute +with his neighbors about the time. Figure 16 shows a clock with the +hour numerals on a vertical series of movable plates and it is set +for uniform hours when day and night are equal at the equinox. The +ornamental pointer is fastened to the weight through the vertical +slit, plainly visible in illustration, and indicates the time as it +descends. This clock is wound up at sunset, so the six on the top of +the dial is sunset the same as the six on the bottom. Figure 17 shows +how this type of dial is set for long and short days and explains +itself, but will become plainer as we proceed. This dial is virtually +a continuation of the old method of marking time by the downward +motion of the water in the clepsydras and will be noticed later. + +[Illustration: Fig. 14--Japanese Striking Clock with Weight and Short +Pendulum] + +[Illustration: Fig. 15--Japanese Striking Clock with Spring, Fusee and +Balance] + +Figure 18 represents a clock which is a work of art and shows great +refinement of design in providing for the varying lengths of days. +The bar lying across the dial is fastened to the weight through the +two slits running the whole length of the dial. On this cross bar +is a small pointer, which is movable by the fingers, and may be set +to any one of the thirteen vertical lines. The numerous characters +on the top space of dial indicate the dates on which the pointer is +to be set. This clock is wound up at sunset, and it is easy to see +that as the little pointer is set towards the right, the night hours +at the top of the dial become shorter and the day hours longer on +the lower part. The left edge of the dial gives the hours, reading +downwards, and as the pointer touches any one of the curved lines the +hour is read at the left-hand end. The curved lines formed of dots +are the half-hours. The right-hand edge of the dial has the "twelve +horary characters" which will be explained later. For dividing the +varying days into six hours' sunshine it would be difficult to +think of a more artistic and beautiful invention than this. It is +a fine example of great ingenuity and constant trouble to operate +a system which is fundamentally wrong according to our method of +uniform hours at all seasons. Clocks having these curved lines for +the varying lengths of days--and we shall find them on circular dials +as we go on--must be made for a certain latitude, since the days vary +more and more as you go farther from the equator. This will become +plain when you are reminded that a Japanese clock at the equator +would not need any adjustment of hour numerals, because the days and +nights are equal there all the year. So after such infinite pains in +forming these curved lines the clock is only good in the latitude +for which it was made and must not be carried north or south! Our +clocks are correct from pole to pole, but all clocks must be set to +local time if they are carried east or west. As this is a rather +fascinating phase of the subject it might be worth pointing out that +if you go north till you have the sun up for a month in the middle +of summer--and there are people living as far up as that--the Japanese +system would become absurd and break down; so there is no danger of +any of our polar expeditions carrying Japanese clocks. + +[Illustration: Fig. 16--Japanese Clock with Vertical Dial, Weight and +Balance.] + +[Illustration: Fig. 17--Japanese Vertical Dials] + +[Illustration: Fig. 18--Japanese Clock with Vertical Dial Having +Curved Lines, Weight and Balance.] + +Figure 19 shows a very fine clock in which the dial is stationary and +the hand moves just as on our dials. This hour hand corresponds to +the single hand of the old Dutch clocks. When the Japanese reached +the point of considering the application of minute and second hands +to their clocks they found that these refinements would not fit their +old method and they were compelled to lay aside their clocks and +take ours. On this dial, Fig. 19, nine is noon, as usual, and is on +top side of dial. Hand points to three quarters past _seven_, that +is, a quarter to _six_, near sunset. Between the bell and the top of +the clock body two horizontal balances, having small weights hung on +them, are plainly shown, and the clock has two verge escapements--one +connected with each balance, or "foliot." Let us suppose a long +day coming to a close at sunset, just as the hand indicates. The +upper balance, which is the slow one, has been swinging backwards +and forwards measuring the long hours of the day. When the clock +strikes six, at sunset, the top balance is thrown out of action and +the lower one, which is the fast one, is thrown into action and +measures the short night hours. At sunrise this is thrown out and +the top one in again to measure the next day's long hours. As the +days vary in length, the balances, or foliots, can be made to swing +faster or slower by moving the weights inwards or outwards a notch +or two. The balance with small weights for regulation is the oldest +known and was used in connection with the verge escapement, just +as in this clock, by the Dutch about 1364. All the evidence I can +find indicates that the Japanese clocks are later than this date. In +design, ornamentation and methods for marking varying days, however, +the Japanese have shown great artistic taste and inventiveness. +It is seen that this dial in addition to the usual six hours, +twice over, has on the outside circle of dial, the "twelve horary +branches" called by the Japanese the "twelve honorary branches," thus +indicating the whole day of twelve Japanese hours, six of them for +day and six for night. By this means they avoided repeating the same +hours for day and night. When it is pointed out that these "twelve +horary branches" are very old Chinese, we are not in a position to +boast about our twenty-four hour system, because these branches +indicate positively whether any given hour is day or night. When we +print a time table in the twenty-four hour system so as to get rid +of our clumsy A. M. and P. M., we are thousands of years behind the +Chinese. More than that, for they got the matter right without any +such pressure as our close running trains have brought to bear on +us. These branches have one syllable names and the "ten celestial +stems" have also one syllable names, all as shown on Fig. 20. Refer +now to Fig. 21 where two disks are shown, one having the "twelve +horary branches" and the other the "ten celestial stems." These disks +are usually put behind the dial so that one "branch" and one "stem" +can be seen at the same time through two openings. The clock moves +these disks one step each night, so that a new pair shows each day. +Running in this manner, step by step, you will find that it takes +sixty moves, that is sixty days, to bring the same pair around again. +Each has a single syllable name, as shown on Fig. 20, and we thus get +sixty names of two syllables by reading them together to the left. +The two openings may be seen in the dials of Figs. 15 and 19. So the +Japanese know exactly what day it is in a period of sixty which they +used in their old calendars. These were used by the Chinese over four +thousand years ago as the names of a cycle of sixty years, called the +"sexagenary." The present Chinese year 4606 is YU-KI which means the +year 46 of the 76th "sexagenary." That is, 76×60+46 = 4,606. In Fig. +20, we read TSU-KIAH, or the first year. If you will make two disks +like Fig. 21 and commence with TSU-KIAH and move the two together +you will come to YU-KI on the 46th move. But there is another way +which you might like better, thus: Write the twelve "branches," +or syllables, straight downwards, continuously five times; close +to the right, write the ten "stems" six times. Now you have sixty +words of two syllables and the 46th, counting downwards, will be +YU-KI. Besides, this method gives you the whole sixty names of the +"sexagenary" at one view. Always read _left_, that is, pronounce the +"stem" syllable first. + +[Illustration: Fig. 19--Japanese Striking Clock with Two Balances and +Two Escapements; Dial Stationary, Hand Moves] + +Calendars constitute a most interesting and bewildering part of time +measuring. We feel that we have settled the matter by determining +the length of the year to within a second of time, and keeping the +dates correctly to the nearest day by a leap year every fourth and +every fourth century, established by Pope Gregory XIII in 1582, and +known as the "Gregorian Calendar." In simple words, our "almanac" is +the "Gregorian." We are in the habit of saying glibly that any year +divisible by four is a leap year, but this is far from correct. Any +year leaving out the _even hundreds_, which is divisible by four +is a leap year. _Even hundreds_ are leap when divisible by four. +This explains why 1900 was a common year, because _19 hundreds_ is +not divisible by four; 2000 will be a leap because _20 hundreds_ +is divisible by four; therefore 2100, 2200 and 2300 will be common +years and 2400 a leap, etc., to 4000 which must be made common, to +keep things straight, in spite of the fact that it is divisible by +four both in its hundreds and thousands. But for practical purposes, +during more than two thousand years to come, we may simplify the +rule to: _Years_ and _even hundreds_ divisible by four are leaps. +But great confusion still exists as a result of several countries +holding to their own old methods. The present Chinese year has 384 +days, 13 months and 13 full moons. Compared with our 1909 it begins +on January 21st and will end on February 8, 1910. Last year the +China-Japan calendar had 12 months, or moons, but as that is too +short they must put in an extra every thirtieth month. We only allow +the error to reach one day and correct it with our leap years, but +they are not so particular and let the error grow till they require +another "moon." The Old Testament is full of moons, and even with all +our "modernity" our "feasts" and holy days are often "variable" on +account of being mixed up with moons. In Japan the present year is +the 42nd of Meiji, that is, the 42nd of the present Emperor's reign. +The present is the Jewish 5669. These and others of varying lengths +overlap our year in different degrees, so that in trade matters great +confusion exists. The Chinese and Japanese publish a trade almanac +in parallel columns with ours to avoid this. It is easy to say that +we ought to have a uniform calendar all over the world, but the same +remark applies just as much to money, weights, measures, and even to +language itself. Finally, the difficulty consists in the facts that +there are not an even number of days in a year--or in a moon--or moons +in a year. "These many moons" is a survival in our daily speech of +this old method of measuring by moons. Just a little hint as to the +amount of superstition still connected with "new moon" will be enough +to make clear the fact that we are not yet quite so "enlightened" as +we say we are. While our calendar, or almanac, may be considered as +final, we must remember that custom and religion are so mixed up with +the matter in the older countries of the East that they will change +very slowly. Strictly, our "era" is arbitrary and Christian; so we +must not expect nations which had some astronomical knowledge and a +working calendar, thousands of years before us, to change suddenly to +our "upstart" methods. + +[Illustration: Fig. 20--Key to "12 Horary Branches" and "10 Celestial +Stems"] + +[Illustration: Fig. 21--"12 Horary Branches" and "10 Celestial Stems" +as Used in Clocks] + +[Illustration: Fig. 22--Dial of Japanese Astronomical Clock] + +In Fig. 22 we have the dial of a very complicated astronomical +clock. This old engraved brass dial did not photograph well, so I +made a copy by hand to get clean lines. Commencing at the centre, +there is a small disk, B, numbered from 1 to 30, giving days of the +moon's age. The moon rises at A and sets at AA, later each day, of +course. Her age is shown by the number she touches on disk B, as +this disk advances on the moon one number each day. Her phases are +shown by the motion of a black disk over her face; so we have here +three motions for the moon, so differentiated as to show _phase_, +_ascension_ and _age_. Still further, as she is represented on the +dial when below the horizon, it can be seen when she will rise, and +"moonlight" parties may be planned. Just outside the moon's course +is an annulus having Japanese numbers 1 to 12, indicating months. +Note the recurring character dividing the months in halves, which +means "middle," and is much used. If you will carefully read these +numbers you will find a character where _one_ would come; this means +"beginning" or "primary" and is often used instead of one. The clock +hand is the heavy arrow and sweeps the dial once in a whole day, same +direction as our clocks. This circle of the months moves along with +the hand, but a little faster, so as to gain one number in a month. +As shown on the figure it is about one week into the sixth month. +Next outward is the broad band having twelve curved lines for the +hours ending outwardly in a ring divided into 100 parts, marked off +in tens by dots. These curved lines are numbered with the Japanese +numerals for hours which you must now be able to read easily. These +hour lines, and the dotted lines for half hours, are really the same +as the similar lines on Fig. 18 which you now understand. As the +hand sweeps the dial daily it automatically moves outward a little +each day, so it shortens the nights and lengthens the days, just as +previously explained for Fig. 18. But there is one difference, for +you will notice that the last night hour, on which the arrow hand +now stands, is longer than the other night hours before it, and that +it is divided into _three_ by the dotted lines. The last day hour, +on the left of dial, is also long and divided into _three_. That is, +while all the dials previously described have equal hours for any +given day, or night, this dial has a _last long hour_ in each case, +divided into three instead of the usual half-hours. This is a curious +and interesting point having its origin long before clocks. In the +early days of the clepsydra in China, a certain time was allowed +to dip up the water from the lowest jar, each morning and evening +about five o'clock of our time, see Fig. 8 (Chapter 1). During this +operation the clepsydra was not marking time, and the oriental +mind evidently considered it in some sense outside of the regular +hours, and like many other things was retained till it appeared +absurdly on the earlier clocks. This wonderful feat of putting an +interval between two consecutive hours has always been impossible to +modern science; yet President Roosevelt performed it easily in his +"constructive" interregnum! Referring to the Canton clepsydra, Fig. +8, we find that the float, or "bamboo stick," was divided into 100 +parts. At one season 60 parts for the day and 40 parts for the night, +gradually being changed to the opposite for short days. The day hours +were beaten on a drum and the night hours blown on a trumpet. + +Later the hour numerals were made movable on the "bamboo stick." +This is virtually a vertical dial with movable hour plates, so their +idea of time measuring at that date, was of something moving up or +down. This was put on the first clocks by the Japanese; so that the +dial of Fig. 16 is substantially the float of the Chinese clepsydra. +Further, in this "bamboo stick" of 100 parts, we have our present +system of decimal numbers, so we can afford to be a little modest +here too. Before leaving Fig. 22 note the band, or annulus, of stars +which moves with the month circle. I cannot make these stars match +our twelve signs of the Zodiac, but as I have copied them carefully +the reader can try and make order out of them. The extreme outer edge +of the dial is divided into 360 parts, the tens being emphasized, as +in our decimal scales. + +As we are getting a little tired of these complicated descriptions, +let us branch off for a few remarks on some curiosities of Eastern +time keeping. They evidently think of an hour as a _period of time_ +more specifically than we do. When we say "6 o'clock" we mean a +point of time marked by the striking of the clock. We have no names +for the hour periods. We must say "from 5 to 6" or "between 5 and +6" for an hour period. The "twelfth hour" of the New Testament, I +understand to mean a whole hour ending at sunset; so we are dealing +with an oriental attitude of mind towards time. I think we get that +conception nearly correct when we read of the "middle watch" +and understand it to mean _during_ the middle third of the night. +Secondly, why do the Japanese use no 1, 2, 3 on their dials? These +numbers were sacred in the temples and must not be profaned by use on +clocks, and they mentally deducted these from the clock hours, but +ultimately became accustomed to 9, 8, 7, 6, 5, 4. Thirdly, why this +reading of the hours backwards? Let us suppose a toiler commencing +at sunrise, or six. When he toiled one hour he felt that there was +one less to come and he called it five. This looks quite logical, for +the diminishing numbers indicated to him how much of his day's toil +was to come. Another explanation which is probably the foundation +of "secondly" and "thirdly" above, is the fact that mathematics and +superstition were closely allied in the old days of Japan. If you +take the numbers 1 to 6, Fig. 23, and multiply them each into the +uncanny "yeng number," or nine, you will find that the last digits, +reading downwards, give 9, 8, 7, 6, 5, 4. Stated in other words: +When 1 to 6 are multiplied into "three times three" the last figures +are 9, 8, 7, 6, 5, 4, and _1, 2, 3, have disappeared_; so the common +people were filled with fear and awe. Some of the educated, even now, +are mystified by the strange results produced by using three and nine +as factors, and scientific journals often give space to the matter. +We know that these results are produced by the simple fact that nine +is one less than the "radix" of our decimal scale of numbers. Nine is +sometimes called the "indestructible number," since adding the digits +of any of its powers gives an even number of nines. But in those days +it was a mystery and the common people feared the mathematicians, and +I have no doubt the shrewd old fellows took full advantage of their +power over the plebeians. In Japan, mathematics was not cleared of +this rubbish till about 700 A. D. + +[Illustration: Fig. 23--Use of "Yeng Number" and Animal Names of +Hours] + +On the right-hand side of Fig. 23 are given the animal names of +the hours, so the day and night hours could not be mistaken. In +selecting the _rat_ for night and the _horse_ for day they showed +good taste. Their forenoon was "before horse" and their afternoon +"after horse." Japanese clocks are remarkable for variety. It looks +as if they were always made to order and that the makers, probably +urged by their patrons, made extreme efforts to get in wonderful +motions and symbols relating to astronomy and astrology. Anyone +examining about fifty of them would be likely to conclude that it was +almost hopeless to understand them all. Remember, this is the old +Japanese method. Nearly all the clocks and watches I saw in Japan +were American. It will now be necessary to close this chapter with a +few points on the curious striking of Japanese clocks. + +In those like Figs. 14, 15, 19, the bell and hammer can be seen. In +the type of Fig. 16, the whole striking mechanism is in the weight. +In fact, the striking part of the clock is the weight. On each of the +plates, having the hour numerals, Fig. 16, a pin projects inwards and +as the weight containing the striking mechanism, descends, a little +lever touches these and lets off the striking just when the pointer +is on the hour numeral. Keeping this in mind, it is easy to see that +the clock will strike correctly when the hour is indicated by the +pointer, no matter how the hour plates are set for long or short +days. Similar pins project inwards from movable plates on Figs. 12, +13, 14, 15, so they strike correctly as each hour plate comes to the +top just under the point of the fixed hand. In Fig. 19, the striking +is let off by a star wheel just as in old Dutch clocks. Clocks +like Figs. 18-22 do not strike. In all cases the hours are struck +backwards, but the half-hours add another strange feature. The _odd_ +numbered hours, 9, 7, 5, are followed by one blow at the half hour; +and the _even_ hours, 8, 6, 4 by two blows, or stated altogether-- + + 9_{1} 8_{2} 7_{1} 6_{2} 5_{1} 4_{2}. + +Here the large figures are the hours and the small ones the +half-hours. Only one bell is used, because there being no one and +two among the hours, the half-hours cannot be mistaken. This is not +all, for you can tell what half hour it is within two hours. For +example, suppose you know approximately that it is somewhere between +9 and 7 and you hear the clock strike 2, then you know it is half +past 8. See the large and small figures above. This is far superior +to our method of one at each half-hour. + +By our method the clock strikes _one_ three times consecutively, +between 12 and 2 o'clock and thus mixes up the half hours with one +o'clock. Some interesting methods of striking will be explained in +the third chapter when we deal with modern time keeping. + + + + +CHAPTER III + +MODERN CLOCKS + + DeVick's clock of 1364. -- Original "verge" escapement. -- + "Anchor" and "dead beat" escapements. -- "Remontoir" clock. + -- The pendulum. -- Jeweling pallets. -- Antique clock with + earliest application of pendulum. -- Turkish watches. -- Correct + designs for public clock faces. -- Art work on old watches. -- + Twenty-four hour watch. -- Syrian and Hebrew hour numerals. -- + Correct method of striking hours and quarters. -- Design for + twenty-four hour dial and hands. -- Curious clocks. -- Inventions + of the old clockmakers. + +[Illustration: Public Dial by James Arthur Dial of Philadelphia City +Hall Clock + +Fig. 24] + + +Modern clocks commence with De Vick's of 1364 which is the first +unquestioned clock consisting of toothed wheels and containing the +fundamental features of our present clocks. References are often +quoted back to about 1000 A. D., but the words translated "clocks" +were used for bells and dials at that date; so we are forced to +consider the De Vick clock as the first till more evidence is +obtained. It has been pointed out, however, that this clock could +hardly have been invented all at once; and therefore it is probable +that many inventions leading up to it have been lost to history. The +part of a clock which does the ticking is called the "escapement" +and the oldest form known is the "verge," Fig. 25, the date of which +is unknown, but safely 300 years before De Vick. The "foliot" is on +the vertical verge, or spindle, which has the pallets A B. As the +foliot swings horizontally, from rest to rest, we hear one tick, but +it requires two of these single swings, or two ticks, to liberate +one tooth of the escape wheel; so there are twice as many ticks +in one turn of the escape wheel as it has teeth. We thus see that +an escapement is a device in which something moves back and forth +and allows the teeth of an "escape wheel" to escape. While this +escapement is, in some respects, the simplest one, it has always +been difficult to make it plain in a drawing, so I have made an +effort to explain it by making the side of the wheel and its pallet +B, which is nearest the eye, solid black, and farther side and its +pallet A, shaded as in the figure. The wheel moves in the direction +of the arrow, and tooth D is very near escaping from pallet B. The +tooth C on the farther side of wheel is moving left, so it will fall +on pallet A, to be in its turn liberated as the pallets and foliot +swing back and forth. It is easy to see that each tooth of the wheel +will give a little push to the pallet as it escapes, and thus keep +the balance swinging. This escapement is a very poor time-keeper, +but it was one of the great inventions and held the field for about +600 years, that is, from the days when it regulated bells up to the +"onion" watches of our grandfathers. Scattered references in old +writings make it reasonably certain that from about 1,000 to 1,300 +bells were struck by machines regulated with this verge escapement, +thus showing that the striking part of a clock is older than the +clock itself. It seems strange to us to say that many of the earlier +clocks were strikers, only, and had no dials or hands, just as if +you turned the face of your clock to the wall and depended on the +striking for the time. Keeping this action of the verge escapement +in mind we can easily understand its application, as made by De +Vick, in Fig. 26, where I have marked the same pallets A B. A tooth +is just escaping from pallet B and then one on the other side of +the wheel will fall on pallet A. Foliot, verge and pallets form one +solid piece which is suspended by a cord, so as to enable it to +swing with little friction. For the purpose of making the motions +very plain I have left out the dial and framework from the drawing. +The wheel marked "twelve hours," and the pinion which drives it, are +both outside the frame, just under the dial, and are drawn in dash +and dot. The axle of this twelve-hour wheel goes through the dial +and carries the hand, which marks hours only. The winding pinion and +wheel, in dotted lines, are inside the frame. Now follow the "great +wheel"--"intermediate"--"escape wheel" and the two pinions, all in +solid lines, and you have the "train" which is the principal part +of all clocks. This clock has an escapement, wheels, pinions, dial, +hand, weight, and winding square. We have only added the pendulum, +a better escapement, the minute and second hands in over 500 years! +The "anchor" escapement, Fig. 27, came about 1680 and is attributed +to Dr. Hooke, an Englishman. It gets its name from the resemblance of +the pallets to the flukes of an anchor. This anchor is connected to +the pendulum and as it swings right and left, the teeth of the escape +wheel are liberated, one tooth for each two swings from rest to rest, +the little push on the pallets A B, as the teeth escape, keeping the +pendulum going. It is astonishing how many, even among the educated, +think that the pendulum drives the clock! The pendulum must always be +driven by some power. + +[Illustration: Fig. 25--Verge Escapement] + +[Illustration: Fig. 26--De Vick's Clock of 1364] + +[Illustration: Fig. 27--Anchor Escapement] + +[Illustration: Fig. 28--American Anchor Escapement] + +This escapement will be found in nearly all the grandfather clocks in +connection with a seconds pendulum. It is a good time-keeper, runs +well, wears well, stands some rough handling and will keep going +even when pretty well covered with dust and cobwebs; so it is used +more than all the numerous types ever invented. Figure 28 gives the +general American form of the "anchor" which is made by bending a +strip of steel; but it is not the best form, as the acting surfaces +of the pallets are straight. It is, therefore, inferior to Fig. 27 +where the acting surfaces are curved, since these curves give an +easier "recoil." This recoil is the slight motion _backwards_ which +the escape wheel makes at each tick. The "dead beat" escapement is +shown in Fig. 29, and is used in clocks of a high grade, generally +with a seconds pendulum. It has no recoil as you can easily see that +the surfaces O O on which the teeth fall, are portions of a circle +around the center P. The beveled ends of these pallets are called the +impulse surfaces, and a tooth is just giving the little push on the +right-hand pallet. It is found in good railroad clocks, watch-makers' +regulators and in many astronomical clocks. These terms are merely +comparative, a "regulator" being a good clock and an "astronomical," +an extra good one. Figure 30 gives the movement of a "remontoir" +clock in which the dead beat shown is used. The upper one of the +three dials indicates seconds, and the lever which crosses its center +carries the large wheel on the left. + +[Illustration: Fig. 29--Dead Beat Escapement] + +[Illustration: Fig. 31--Remontoir Clock by James Arthur] + +[Illustration: Fig. 30--Remontoir Clock Movement] + +This wheel makes the left end of the lever heavier than the right, +and in sinking it drives the clock for one minute, but at the +sixtieth second it "remounts" by the action of the clock weight; +hence the name, "remontoir." Note here that the big weight does +not directly drive the clock; it only rewinds it every minute. The +minutes are shown on the dial to the right and its hand jumps forward +one minute at each sixtieth second as the lever remounts; so if you +wish to set your watch to this clock the proper way is to set it to +the even minute "on the jump." The hour hand is on the dial to the +left. By this remounting, or rewinding, the clock receives the same +amount of driving force each minute. The complete clock is shown +in Fig. 31, the large weight which does the rewinding each minute +being plainly visible. The pendulum is compensated with steel and +aluminum, so that the rate of the clock may not be influenced by hot +and cold weather. Was built in 1901 and is the only one I can find +room for here. It is fully described in "Machinery," New York, for +Nov., 1901. I have built a considerable number, all for experimental +purposes, several of them much more complicated than this one, but +all differing from clocks for commercial purposes. Pallets like O +O in Fig. 29 are often made of jewels; in one clock I used agates +and in another, running thirteen months with one winding, I used +pallets jeweled with diamonds. This is done to avoid friction and +wear. Those interested in the improvement of clocks are constantly +striving after light action and small driving weights. Conversely, +the inferior clock has a heavy weight and ticks loud. The "gravity +escapement" and others giving a "free" pendulum action would require +too much space here, so we must be satisfied with the few successful +ones shown out of hundreds of inventions, dozens of them patented. +The pendulum stands at the top as a time measurer and was known to +the ancients for measuring short periods of time just as musicians +now use the metronome to get regular beats. Galileo is credited with +noticing its regular beats, but did not apply it to clocks, although +his son made a partially successful attempt. The first mathematical +investigation of the pendulum was made by Huyghens about 1670, and +he is generally credited with applying it to clocks, so there is a +"Huyghens" clock with a pendulum instead of the foliot of De Vick's. +Mathematically, the longer and heavier the pendulum the better is +the time-keeping, but nature does not permit us to carry anything to +the extreme; so the difficulty of finding a tower high enough and +steady enough, the cumbersomeness of weight, the elasticity of the +rod, and many other difficulties render very long and heavy pendulums +impracticable beyond about 13 ft. which beats once in two seconds. +"Big Ben" of Westminster, London, has one of this length weighing 700 +lb. and measuring, over all, 15 ft. + +It runs with an error under one second a week. This is surpassed +only by some of the astronomical clocks which run sometimes two +months within a second. This wonderful timekeeping is done with +seconds pendulums of about 39 in., so the theoretical advantage of +long pendulums is lost in the difficulties of constructing them. +Fractions are left out of these lengths as they would only confuse +the explanations. At the Naval observatory in Washington, D. C., +the standard clocks have seconds pendulums, the rods of which are +nickel steel, called "Invar," which is little influenced by changes +of temperature. These clocks are kept in a special basement, so +they stand on the solid earth. The clock room is kept at a nearly +uniform temperature and each clock is in a glass cylinder exhausted +to about half an atmosphere. They are electric remontoirs, so no +winding is necessary and they can be kept sealed up tight in their +glass cylinders. Nor is any adjustment of their pendulums necessary, +or setting of the hands, as the correction of their small variations +is effected by slight changes in the air pressure within the glass +cylinders. When a clock runs fast they let a little air into its +cylinder to raise the resistance to the pendulum and slow it down, +and the reverse for slow. Don't forget that we are now considering +variations of less than a second a week. + +The clock room has double doors, so the outer one can be shut before +the inner one is opened, to avoid air currents. Visitors are not +permitted to see these clocks because the less the doors are opened +the better; but the Commander will sometimes issue a special permit +and detail a responsible assistant to show them, so if you wish +to see them you must prove to him that you have a head above your +shoulders and are worthy of such a great favor. + +[Illustration: Fig. 32--Antique Clock, Entirely Hand-Made] + +[Illustration: Fig. 33--Antique Clock, Entirely Hand-Made] + +[Illustration: Fig. 34--Triple-Case Turkish Watches] + +The best thing the young student could do at this point would be +to grasp the remarkable fact that the clock is not an old machine, +since it covers only the comparatively short period from 1364 to the +present day. Compared with the period of man's history and inventions +it is of yesterday. Strictly speaking, as we use the word clock, its +age from De Vick to the modern astronomical is only about 540 years. +If we take the year 1660, we find that it represents the center of +modern improvements in clocks, a few years before and after that date +includes the pendulum, the anchor and dead beat escapements, the +minute and second hands, the circular balance and the hair spring, +along with minor improvements. Since the end of that period, which +we may make 1700, no fundamental invention has been added to clocks +and watches. This becomes impressive when we remember that the last +200 years have produced more inventions than all previous known +history--but only minor improvements in clocks! The application +of electricity for winding, driving, or regulating clocks is not +fundamental, for the timekeeping is done by the master clock with +its pendulum and wheels, just as by any grandfather's clock 200 +years old. This broad survey of time measuring does not permit us to +go into minute mechanical details. Those wishing to follow up the +subject would require a large "horological library"--and Dr. Eliot's +five-foot shelf would be altogether too short to hold the books. + +A good idea of the old church clocks may be obtained from Fig. +32 which is one of my valued antiques. Tradition has followed it +down as the "English Blacksmith's Clock." It has the very earliest +application of the pendulum. The pendulum, which I have marked by a +star to enable the reader to find it, is less than 3 in. long and +is hung on the verge, or pallet axle, and beats 222 per minute. +This clock may be safely put at 250 years old, and contains nothing +invented since that date. Wheels are cast brass and all teeth +laboriously filed out by hand. Pinions are solid with the axles, or +"staffs," and also filed out by hand. It is put together, generally +by mortise, tenon and cotter, but it has four original screws all +made by hand with the file. How did he thread the holes for these +screws? Probably made a tap by hand as he made the screws. But the +most remarkable feature is the fact that no lathe was used in forming +any part--all staffs, pinions and pivots being filed by hand. This is +simply extraordinary when it is pointed out that a little dead center +lathe is the simplest machine in the world, and he could have made +one in less than a day and saved himself weeks of hard labor. It is +probable that he had great skill in hand work and that learning to +use a lathe would have been a great and tedious effort for him. So we +have a complete striking clock made by a man so poor that he had only +his anvil, hammer and file. The weights are hung on cords as thick +as an ordinary lead pencil and pass over pulleys having spikes set +around them to prevent the cords from slipping. The weights descend +7 ft. in 12 hours, so they must be pulled up--not wound up--twice a +day. The single hour hand is a work of art and is cut through like +lace. Public clocks may still be seen in Europe with only one hand. +Many have been puzzled by finding that old, rudely made clocks often +have fine dials, but this is not remarkable when we state that art +and engraving had reached a high level before the days of clocks. +It is worthy of note that clocks in the early days were generally +built in the form of a church tower with the bell under the dome +and Figs. 32, 33 show a good example. It is highly probable that the +maker of this clock had access to some old church clock--a wonderful +machine in those days--and that he laboriously copied it. It strikes +the hours, only, by the old "count wheel" or "locking plate" method. +Between this and our modern clocks appeared a type showing quarter +hours on a small dial under the hour dial. No doubt this was at that +time a great advance and looked like cutting time up pretty fine. As +the hand on the quarter dial made the circuit in an hour the next +step was easy, by simply dividing the circle of quarters into sixty +minutes. The old fellows who thought in hours must have given it up +at this point, so the seconds and fifths seconds came easily. + +[Illustration: Fig. 35--Triple-Case Turkish Watch] + +[Illustration: Fig. 36--Double-Case Watch of Repoussé Work] + +The first watches, about 1500, had the foliot and verge escapement, +and in some early attempts to govern the foliot a hog's bristle was +used as a spring. By putting a ring around the ends of the foliot +and adding the hair spring of Dr. Hooke, about 1640, we have the +verge watches of our grandfathers. This balance wheel and hair spring +stand today, but the "lever" escapement has taken the place of the +verge. It is a modification of the dead beat, Fig. 29, by adding +a lever to the anchor, and this lever is acted on by the balance, +hence the name "lever watch." All this you can see by opening your +watch, so no detailed explanation is necessary. Figure 34 shows two +triple-cased Turkish watches with verge escapements, the one to the +left being shown partly opened in Fig. 35. The watch with its inner +case, including the glass, is shown to the right. This inner case +is complete with two hinges and has a winding hole in the back. The +upper case, of "chased" work, goes on next, and then the third, or +outer case, covered with tortoise shell fastened with silver rivets, +goes on outside the other two. When all three cases are opened and +laid on the table, they look like a heap of oyster shells, but they +go easily together, forming the grand and dignified watch shown to +the left in Fig. 34. Oliver Cromwell wore an immense triple-case +watch of this kind, and the poor plebeians who were permitted to +examine such a magnificent instrument were favored! + +[Illustration: Fig. 37--Watches Showing Art Work] + +[Illustration: Fig. 38--Watch Showing Dutch Art Work] + +[Illustration: Fig. 39--Antique Watch Cock] + +[Illustration: Fig. 40--"Chinese" Watch] + +Our boys' watches costing one dollar keep much better time than this +type of watch. Comparing the Syrian dial, Fig. 42, with that on +Fig. 35, it is evident that the strange hour numerals on both are a +variation of the same characters. These, so-called, "Turkish watches" +were made in Europe for the Eastern trade. First-class samples of +this triple-case type are getting scarce, but I have found four, two +of them in Constantinople. Figure 36 shows the double-case style, +called "pair cases," the outer case thin silver, the figures and +ornaments being hammered and punched up from the inside and called +"repoussé." Before we leave the old watches, the question of art work +deserves notice, for it looks as if ornamentation and time-keeping +varied inversely in those days--the more art the worse the watch. I +presume, as they could not make a good time-keeper at that date, the +watch-maker decided to give the buyer something of great size and +style for his money. In Fig. 37 four old movements are shown, and +there is no doubt about the art, since the work is purely individual +and no dies or templates used. In examining a large number of these +watches, I have never found the art work on any two of them alike. +Note the grotesque faces in these, and in Fig. 39 which is a fine +example of pierced, engraved work. Figure 38 is a fine example of +pierced work with animals and flowers carved in relief. Figure 40 +is a "Chinese" watch but made in Europe for the Chinese market. In +Fig. 41 we have what remains of a quarter repeater with musical +attachment. Each of the 24 straight gongs, commencing with the +longest one, goes a little nearer the center of the large wheel, +so a circle of pins is set in the wheel for each gong, or note, +and there is plenty of room for several tunes which the wearer can +set off at pleasure. Figure 43 is a modern watch with Hebrew hour +numerals. Figure 44 is a modern 24-hour watch used on some railroads +and steamship lines. I have a pretty clean-cut recollection of one +event in connection with the 24-hour system, as I left Messina +between 18 and 19 o'clock on the night of the earthquake! Dials and +hands constitute an important branch of the subject. The general +fault of hands is that they are too much alike; in many instances +they are the same, excepting that the minute hand is a little longer +than the hour. The dial shown on the left of Fig. 24 was designed by +me for a public clock and can be read twice as far away as the usual +dial. Just why we should make the worst dials and hands for public +clocks in the United States is more than I can find out, for there +is no possible excuse, since the "spade and pointer" hands have been +known for generations. Figure 45 is offered as a properly designed +dial for watches and domestic clocks, having flat-faced Gothic +figures of moderate height, leaving a clear center in the dial, and +the heavy "spade" hour hand reaching only to the inner edges of the +figures. For public clocks the Arabic numerals are the worst, for at +a distance they look like twelve thumb marks on the dial; while the +flat-faced Roman remain distinct as twelve clear marks. + +[Illustration: Fig. 41--Musical Watch, Repeating Hours and Quarters] + +Do you know that you do not read a public clock by the figures, but +by the position of the hands? This was discovered long ago. Lord +Grimthorp had one with twelve solid marks on the dial and also speaks +of one at the Athenæum Club, both before 1860. The Philadelphia City +Hall clock has dials of this kind as shown on right side of Fig. 24. +It has also good hands and can be read at a great distance. Very few +persons, even in Philadelphia, know that it has no hour numerals on +its dials. Still further, there is no clock in the tower, the great +hands being moved every minute by air pressure which is regulated by +a master clock set in a clock room down below where the walls are 10 +ft. thick. Call and see this clock and you will find that the City +Hall officials sustain the good name of Philadelphia for politeness. +Generally, we give no attention to the hour numerals, even of our +watches, as the following proves. When you have taken out your watch +and looked at the time, for yourself, and put it back in your pocket, +and when a friend asks the time you take it out again to find the +time for him! Why? Because, for yourself, you did not read hours and +minutes, but only got a mental impression from the position of the +hands; so we only read hours and minutes when we are called on to +proclaim the time. + +[Illustration: Fig. 42--Syrian Dial] + +We must find a little space for striking clocks. The simplest is one +blow at each hour just to draw attention to the clock. Striking the +hours and also one blow at each half hour as well as the quarter +double blow, called "ting tong" quarters, are too well known to need +description. The next stage after this is "chiming quarters" with +three or more musical gongs, or bells. One of the best strikers I +have has three trains, three weights and four bells. It strikes +the hour on a large bell and two minutes after the hour it strikes +it again, so as to give you another chance to count correctly. At +the first quarter it repeats the last hour followed by a musical +chord of three bells, which we will call _one triple blow_: at the +second quarter the hour again and two triple blows and at the third +quarter, the hour again and three triple blows. Suppose a sample +hour's striking from four o'clock, this is what you hear, and there +can be no mistake. "Four" and in two minutes "four"--"four and one +quarter"--"four and two quarters"--"four and three quarters," and the +same for all other hours. This is definite, for the clock proclaims +the hour, or the hour and so much past. It can be set silent, but +that only stops it from striking automatically, and whether so set +or not, it will repeat by pulling a cord. You awake in the night +and pull the cord, and then in mellow musical tones, almost as if +the clock were speaking, you hear--"four and two quarters." This I +consider a perfect striking clock. It is a large movement of fine +workmanship and was made in the department of the Jura, France. +When a clock or watch only repeats, I consider the old "five-minute +repeater" the best. I used this method in a clock which, on pulling +the cord, strikes the hour on a large bell and if that is all it +strikes, then it is less than five minutes past. If more than five +minutes past it follows the hour by one blow on a small bell for +every five minutes. This gives the time within five minutes. It is +fully described and illustrated in "Machinery," New York, for March, +1905. Just one more. An old Dutch clock which I restored strikes the +hour on a large bell; at the first quarter it strikes one blow on a +small bell; at the half hour it strikes the last hour over again on +the small bell; at the third quarter it strikes one blow on the large +bell. But this in spite of its great ingenuity, only gives definite +information at the hour and half hour. + +[Illustration: Fig. 43--Hebrew Numerals] + +[Illustration: Fig. 44--24-Hour Watch] + +Of curious clocks there is no end, so I shall just refer to one +invented by William Congreve, an Englishman, over one hundred years +ago, and often coming up since as something new. A plate about 8 in. +long and 4 in. wide has a long zigzag groove crosswise. This plate +is pivoted at its center so either end can be tipped up a little. +A ball smaller than a boy's marble will roll back and forth across +this plate till it reaches the lower end, at which point it strikes +a click and the mainspring of the clock tips the plate the other way +and the ball comes slowly back again till it strikes the disk at the +other end of the plate, etc. Every time the plate tips, the hands +are moved a little just like the remontoir clock already described. +Clocks of this kind are often used for deceptive purposes and those +ignorant of mechanics are deceived into the belief that they see +perpetual motion. The extent to which modern machine builders are +indebted to the inventions of the ancient clock-maker, I think, has +never been appreciated. + +[Illustration: Fig. 45--Domestic Dial by James Arthur] + +In its earlier stages the clock was almost the only machine +containing toothed gearing, and the "clock tooth" is still necessary +in our delicate machines. It is entirely different from our standard +gear tooth as used in heavy machines. The clock-makers led for a +long time in working steel for tools, springs and wearing surfaces. +They also made investigations in friction, bearings, oils, etc., +etc. Any one restoring old clocks for amusement and pleasure will +be astonished at the high-class mechanics displayed in them--nearly +always by unknown inventors. Here is an example: The old clock-maker +found that when he wished to drill a hole in a piece of thick wire +so as to make a short tube of it, he could only get the hole central +and straight by rotating the piece and holding the drill stationary. +By this method the drill tends to follow the center line of +rotation; and our great guns as well as our small rifles are bored +just that way to get bores which will shoot straight. The fourth and +last chapter will deal with the astronomical motions on which our +time-keeping is founded, our present hour zones of time, and close +with suggestions for a universal time system over the whole world. + + + + +CHAPTER IV + +ASTRONOMICAL FOUNDATION OF TIME + + Astronomical motions on which our time is founded. -- Reasons + for selecting the sidereal day as a basis for our 24-hour + day. -- Year of the seasons shorter than the zodiacal year. -- + Precession of the equinoxes. -- Earth's rotation most uniform + motion known to us. -- Time Stars and Transits. -- Local time. + -- The date line. -- Standard time. -- Beginning and ending of + a day. -- Proposed universal time. -- Clock dial for universal + time and its application to business. -- Next great improvement + in clocks and watches indicated. -- Automatic recording of + the earth's rotation. -- Year of the seasons as a unit for + astronomers. -- General conclusions. + + +The mystery of time encloses all things in its folds, and our grasp +of its infinite bearings is measured by our limitations. As there +are no isolated facts in the Universe, we can never get to the end +of our subject; so we know only what we have capacity to absorb. +In considering the foundation on which all our time measuring +is based, we are led into the fringe of that Elysian field of +science--astronomy. A science more poetical than poetry--more charming +than the optimistic phantasies of youth. That science which leaves +our imagination helpless; for its facts are more wonderful than our +extremest mental flights. The science of vastness and interminable +distances which our puny figures fail to express. "The stars sang +together for joy," might almost be placed in the category of facts; +while the music of the spheres may now be considered a mathematical +reality. Our time keeping is inevitably associated with these +motions, and we must select one which has periods not too long. That +is, no _continuous_ motion could be used, unless it passed some +species of milestones which we could observe. Consequently, our +clocks do not--in the strict sense--measure time; but are adjusted +to _divide_ periods which they do not determine. We are constantly +correcting their errors and never entirely succeed in getting them +to run accurately to _periods of time_ which exist entirely outside +of such little things as men and clocks. So a clock is better as it +approximates or bears a regular _relation_ to some motion in nature. +The sidereal clock of the astronomer _does_ run to a regular motion; +but our 24-hour clocks _do not_, as we shall see later. Now consider +the year, or the sun's apparent motion in the Zodiac, from any given +star around to the same one again. This is altogether too long to be +divided by clocks, as we cannot make a clock which could be depended +on for anywhere near a year. The next shorter period is that of a +"moon." This is also a little too long, is not easily observed, and +requires all sorts of corrections. Observations of the moon at sea +are so difficult and subject to error that mariners use them only +as a last resort. If a little freedom of language is permissible, I +would say that the moon has a bad character all around, largely on +account of her long association with superstition, false theology +and heathen feasts. She has not purged herself even to this day! +The ancients were probably right when they called erratic and +ill-balanced persons "luny." Now we come to the day and find that it +is about the right practical length--but what kind of a day? As there +are five kinds we ought to be able to select one good enough. They +are:-- + + 1st. The solar day, or noon to noon by the sun. + + 2nd. An imaginary sun moving uniformly in the ecliptic. + + 3rd. A second imaginary sun moving uniformly parallel to the + equator at all seasons of the year. + + 4th. One absolute rotation of the earth. + + 5th. One rotation of the earth measured from the node, or + point, of the spring equinox. + +The difference between 1st and 2nd is that part of the sun's error +due to the elliptical orbit of the earth. + +The other part of the sun's error--and the larger--between 2nd and 3rd +is that due to the obliquity of the ecliptic to the equator. + +The whole error between 1st and 3rd is the "equation of time" as +shown for even minutes in the first chapter under the heading, "Sun +on Noon Mark 1909." + +Stated simply, for our present purpose, 1st is sundial time, and 3rd +our 24-hour clock time. + +This 2nd day is therefore a refinement of the astronomers to +separate the two principal causes of the sun's error, and I think we +ought to handle it cautiously, or my friend, Professor Todd, might +rap us over the knuckles for being presumptuous. + +This 5th day is the sidereal day of the astronomers and is the basis +of our time, so it is entitled to a little attention. I shall confine +"sidereal day" to this 5th to avoid confusion with 4th. If you will +extend the plane of the equator into the star sphere, you have the +celestial equator. When the center of the sun passes through this +plane on his journey north, in the Spring, we say, "the sun has +crossed the line." This is a distant point in the Zodiac which can +be determined for any given year by reference to the fixed stars. To +avoid technicalities as much as possible we will call it the point +of the Spring equinox. This is really the point which determines +the common year, or year of the seasons. Using popular language, +the seasons are marked by four points,--Spring equinox--longest day--; +Autumnal equinox--shortest day. This would be very simple if the +equinoctial points would stay in the same places in the star sphere; +but we find that they creep westward each year to the extent of 50 +seconds of arc in the great celestial circle of the Zodiac. This is +called the precession of the equinoxes. The year is measured from +Spring equinox to Spring equinox again; but each year it comes 50 +seconds of arc less than a full revolution of the earth around the +sun. Therefore _if we measured our year by a full revolution_ we +would displace the months with reference to the seasons till the +hot weather would come in January and the cold weather in July in +about 13,000 years; or a complete revolution of the seasons back to +where we are, in 26,000 years. Leaving out fractions to make the +illustration plain, we have:-- + + (1) 360 degrees of Zodiac } + --------------------- = 26,000 years } + 50 seconds of arc } + } + (2) 1 day of time } + ------------- = 26,000 years } + 3-1/3 seconds } All + } Approximate + (3) 1 year of time } + -------------- = 26,000 years } + 20-1/3 minutes } + } + (4) 3-1/3 seconds } + ------------- = 1/110 of a second} + days in a year } + +In (1) we see that a "precession" of 50 seconds of arc will bring the +Spring equinox around in 26,000 years. + +In (2) we see, as 50 seconds of arc represents the distance the earth +will rotate in 3-1/3 seconds, a difference of one day will result +in 26,000 years. That is since the clock regulated by the stars, or +absolute rotations of the earth, would get behind 3-1/3 seconds per +year, it would be behind a day in 26,000 years, as compared with a +sidereal clock regulated by the Spring equinoctial point. + +In (3) we see that as 50 seconds of arc is traversed by the earth, in +its annual revolution, in 20-1/3 minutes, a complete circle of the +Zodiac will be made in 26,000 years. + +In (4) we see that as the difference between the year of the seasons +and the Zodiacal year is 3-1/3 seconds of the earth's rotation, it +follows that if this is divided by the number of days in a year +we have the amount which a sidereal day is less than 4th, or an +absolute rotation of the earth. That is, any meridian passes the +Spring equinoctial point 1/110 of a second sooner than the time of +one absolute rotation. These four equations are all founded on the +precession of the equinoxes, and are simply different methods of +stating it. Absolutely and finally, our time is regulated by the +earth's rotation; but strange as it may appear, we do not take one +rotation as a unit. As shown above, we take a rotation to a _movable +point_ which creeps the 1/110 of a second daily. But after all, it is +the _uniform_ rotation which governs. This is the one "dependable" +motion which has not been found variable, and is the most easily +observed. When we remember that the earth is not far from being as +heavy as a ball of iron, and that its surface velocity at the equator +is about 17 miles per minute, it is easy to form a conception of its +uniform motion. Against this, however, we may place the friction +of the tides, forcing up of mountain ranges, as well as mining and +building skyscrapers--all tending to slow it. Mathematicians moving in +the ethereal regions of astronomy lead us to conclude that it _must_ +become gradually slower, and that _it is_ slowing; but the amount may +be considered a vanishing quantity even compared with the smallest +errors of our finest clocks; so for uncounted generations past--and to +come--we may consider the earth's rotation uniform. Having now found +a uniform motion easily observed and of convenient period, why not +adopt it as our time unit? The answer has been partially given above +in the fact that we are compelled to use a year, measured from the +Spring equinoctial point, so as to keep our seasons in order; and +therefore as we must have some point where the sidereal clocks and +the meantime clocks coincide, we take the same point, and that point +is the Spring equinox. Now we have three days:-- + + 1st. A sidereal day 1/110 of a second less than one rotation of + the earth. + + 2nd. One rotation of the earth in 23 hours, 56 minutes and 4 + seconds, nearly, of clock time. + + 3rd. One mean time clock day of 24 hours, which has been explained + previously. + +Now, isn't it remarkable that our 24-hour day is purely artificial, +and that nothing in nature corresponds to it? Our real day of 24 +hours is a _theoretical_ day. Still more remarkable, this theoretical +day is the unit by which we express motions in the solar system. A +lunar month is days--hours--minutes--and seconds of this theoretical +day, and so for planetary motions. And still more remarkable, the +earth's rotation which is _itself_ the foundation is expressed in +this imaginary time! This looks like involution involved, yet our +24-hour day is as real as reality; and the man has not yet spoken who +can tell whether a mathematical conception, sustained in practical +life, is less real than a physical fact. Our legal day of practical +life is therefore deduced from the day of a fraction _less_ than one +earth rotation. In practice, however, the small difference between +this and a rotation is often ignored, because as the tenth of a +second is about as near as observations can be made it is evident +that for single observations 1/110 of a second does not count, but +for a whole year it does, and amounts to 3-1/3 seconds. Now as to +the setting of our clocks. While the time measured by the point of +the Spring equinox is what we must find it is found by noting the +transits of fixed stars, because _the relation_ of star time to +equinoctial time is known and tabulated. Remember we cannot take +a transit of the equinoctial point, because there is nothing to +see, and that _nothing_ is moving! But it can be observed yearly +and astronomers can tell where it is, at any time of the year, by +calculation. The stars which are preferred for observation are +called "time stars" and are selected as near the celestial equator +as possible. The earth's axis has a little wabbling motion called +"nutation" which influences the _apparent_ motion of the stars near +the pole; but this motion almost disappears as they come near the +equator, because nutation gives the plane of the equator only a +little "swashplate" motion. The positions of a number of "time stars" +with reference to the equinoctial point, are known, and these are +observed and the observations averaged. The distance of any time +star from the equinoctial point, _in time_, is called its "right +ascension." Astronomers claim an accuracy to the twentieth part of +a second when such transits are carefully taken, but over a long +period, greater exactness is obtained. Really, the time at which any +given star passes the meridian is taken, _in practical life_, from +astronomical tables in the Nautical Almanacs. Those tables are the +result of the labors of generations of mathematicians, are constantly +subject to correction, and cannot be made simple. Remember, the +Earth's rotation is the only uniform motion, all the others being +subject to variations and even compound variations. This very subject +is the best example of the broad fact that science is a constant +series of approximations; therefore, nothing is exact, and nothing +is permanent but change. But you say that mathematics is an exact +science. Yes, but it is a _logical abstraction_, and is therefore +only the universal solvent in physical science. + +With our imaginary--but real--time unit of 24 hours we are now ready +to consider "local time." Keeping the above explanation in mind, we +may use the usual language and speak of the earth rotating in 24 +hours clock time; and since motion is relative, it is permissible to +speak of the motion of the sun. In the matter of the sun's apparent +motion we are compelled to speak of his "rising," "setting," etc., +because language to express the motion in terms of the earth's +rotation has not been invented yet. For these reasons we will assume +that in Fig. 47 the sun is moving as per large arrow and also that +the annulus, half black and half white, giving the 24 hours, is +fastened to the sun by a rigid bar, as shown, and moves around the +earth along with him. In such illustrations the sun must always be +made small in proportion, but this rather tends to plainness. For +simplicity, we assume that the illustration represents an equinox +when the sun is on the celestial equator. Imagine your eye in the +center of the sun's face at A, and you would be looking on the +meridian of Greenwich at 12 noon; then in one hour you would be +looking on 15° west at 12 noon; but this would bring 13 o'clock to +Greenwich. Continue till you look down on New York at 12 noon, then +it is 17 o'clock at Greenwich (leaving out fractions for simplicity) +etc. If you will make a simple drawing like Fig. 47 and cut the +earth separate, just around the inside of the annulus, and stick a +pin at the North Pole for a center, you may rotate the earth as per +small arrow and get the actual motion, but the result will be just +the same as if you went by the big arrow. We thus see that every +instant of the 24 hours is represented, at some point, on the earth. +That is, the earth has an infinity of local times; so it has every +conceivable instant of the 24 hours at some place on the circle. +Suppose we set up 1,410 clocks at uniform distances on the equator, +then they would be about 17 miles apart and differ by minutes. Now +make it 86,400 clocks, they would be 1,500 feet apart and differ by +seconds. With 864,000 clocks they would be 150 feet apart and vary +by tenths of seconds. It is useless to extend this, since you could +always imagine more clocks in the circle; thus establishing the +fact that there are an infinity of times at an infinity of places +always on the earth. It is necessary to ask a little patience here +as I shall use this local time and its failure later in our talk. +Strictly, local time has never been used, because it has been found +impracticable in the affairs of life. This will be plain when we draw +attention to the uniform time of London, which is Greenwich time; yet +the British Museum is 30 seconds slow of Greenwich, and other places +in London even more. This is railroad time for Great Britain; but +it is 20 minutes too fast for the west of England. This led to no +end of confusion and clocks were often seen with two minute hands, +one to local and the other to railroad time. This mixed up method +was followed by "standard time," with which we are all pretty well +acquainted. Simply, standard time consists in a uniform time for each +15° of longitude, but this is theoretical to the extreme, and is not +even approached in practice. The first zone commences at Greenwich +and as that is near the eastern edge of the British Islands, their +single zone time is fast at nearly all places, especially the west +coast of Ireland. When we follow these zones over to the United +States we find an attempt to make the middle of each zone correct to +local time, so at the hour jumping points, we pass from half an hour +slow to half an hour fast, or the reverse. We thus see that towns +about the middle of these four United States zones have sunrise and +sunset and their local day correct, but those at the eastern and +western edges average half an hour wrong. As a consequence of this +disturbance of the working hours depending on the light of the day, +many places keep two sets of clocks and great confusion results. Even +this is comprehensible; but it is a mere fraction of the trouble +and complication, because the hour zones are not separated by +meridians in practice, but by zig-zag lines of great irregularity. +Look at a time map of the United States and you will see the zones +divided by lines of the wildest irregularity. Now question one of +the brightest "scientific chaps" you can find in one of the great +railroad offices whose lines touch, or enter, Canada and Mexico. +Please do not tell me what he said to you! So great is the confusion +that no man understands it all. The amount of wealth destroyed in +printing time tables, _and failing to explain them_, is immense. The +amount of human life destroyed by premature death, as a result of +wear and tear of brain cells is too sad to contemplate. And all by +attempting the impossible; for local time, _even if it was reduced to +hourly periods_ is not compatible with any continental system of time +and matters can only get worse while the attempt continues. For the +present, banish this zone system from your mind and let us consider +the beginning and ending of a day, using strictly local time. + +[Illustration: Fig. 47--Local Time--Standard Time--Beginning and +Ending of the Day] + +A civil, or legal, day ends at the instant of 24 o'clock, midnight, +and the next day commences. The time is continuous, the last instant +of a day touching the first instant of the next. This is true for +all parts of the earth; but something _in addition_ to this happens +at a certain meridian called the "date line." Refer again to Fig. 47 +which is drawn with 24 meridians representing hours. As we are taking +Greenwich for our time, the meridians are numbered from 0°, on which +the observatory of Greenwich stands. When you visit Greenwich you +can have the pleasure of putting your foot on "the first meridian," +as it is cut plainly across the pavement. Degrees of longitude are +numbered east and west, meeting just opposite at 180°, which is +the "date line." Our day begins at this line, so far as _dates_ are +concerned; but the _local day_ begins everywhere at midnight. Let +us start to go around the world from the date line, westward. When +we arrive at 90° we are one quarter around and it takes the sun 6 +hours longer to reach us. At 0° (Greenwich) we are half around and +12 hours ahead of the sun motion. At 90° west, three quarters, or 18 +hours, and when back to 180° we have _added_ to the length of all +days of our journey enough to make one day; therefore our date must +be one day behind. Try this example to change the wording:--Let us +start from an island B, just west of the date line. These islanders +have their 24-hour days, commencing at midnight, like all other +places. As we move westward our day commences later and later than +theirs, as shown above. Suppose we arrive at the eastern edge of +the 180° line on Saturday at 12 o'clock, but before we cross it we +call over to the islanders,--what day is it? We would get answer, +"Sunday;" because all our days have been longer, totalling one day in +the circuit of the globe. So if we step over the line at 12 o clock +Saturday, presto, it is 12 o'clock Sunday. It looks like throwing out +24 hours, but this is not so, since we have lived exactly the same +number of hours and seconds as the islanders. In this supposition +we have all the _dates_, however, but have jumped half of Saturday +and half of Sunday, which equals one day. In practice this would not +have been the method, for if the ship was to call at the island, the +captain would have changed date on Friday night and thrown Saturday +out, all in one piece, and would have arrived on their Sunday; so +his log for that week would have contained only 6 days. It is not +necessary to go over the same ground for a circuit of the globe +eastward, but if you do so you will find that you _shorten_ your days +and on arriving at the date line would have a day too much; so in +this case you would _double_ a date and have 8 days in that week. In +both cases this is caused by compounding your motion with that of the +sun; going with him westward and lengthening your days, or eastward +meeting him and shortening them. Figure 47 shows Greenwich noon, we +will say on Monday, and at that instant, Monday only, exists from 0 +to 24 o'clock on the earth; but the next instant, Tuesday begins at +180° B. In one hour it is noon of Monday at 15° West, and midnight +at 165° East; so Tuesday is one hour old and there is left 23 hours +of Monday. Monday steadily declines to 0 as Tuesday steadily grows +to 24 hours; so that, except at the instant of Greenwich noon, there +are always two days on the world at once. If we said that there are +_always_ two days on the world at once, we could not be contradicted; +since there is no conceivable time between Monday and Tuesday; it +is an instantaneous change. As we cannot conceive of _no time_, +the statement that there is only one day on the earth at Greenwich +noon is not strictly permissible. Since there are always two days +on the world at once let us suppose that these two are December +31st and January 1st; then we have _two years_ on the world at once +for a period of 24 hours. Nine years ago we had the 19th and 20th +centuries on the world at once, etc. As a mental exercise, you may +carry this as far as you please. Suppose there was an impassable sea +wall built on the 180° meridian, then there would be two days on the +world, just as explained above; but, _practically_, there would be +no date line, since in sailing west to this wall we would "lengthen +our days," and then shorten them the same amount coming around east +to the other side of the wall, but would never jump or double a date. +This explanation is founded, as it ought to be, on uniform local +time, and is the simplest I can give. The date line is fundamentally +simple, but is difficult to explain. When it is complicated by the +standard time--or jumping hour system--and also with the fact that +some islands count their dates from the wrong side of the line for +their longitudes, scientific paradoxes arise, such as having three +dates on the world at once, etc.; but as these things are of no more +value than wasting time solving Chinese puzzles, they are left out. +Ships change date on the nearest night to the date line; but if they +are to call at some island port in the Pacific, they may change +either sooner or later to correspond with its date. Here is a little +Irish date line wit printed for the first time,--I was telling my +bright friend about turning in on Saturday night and getting up for +breakfast on Monday morning. "Oh," said he, "I have known gentlemen +to do as good as that without leaving New York City!" + +As what is to follow relates to the growing difficulties of local +time and a proposed method of overcoming them, let us recapitulate:-- + + 1st. Local time has never been kept, and the difficulties of + using it have increased as man advanced, reaching a climax of + absurdity on the advent of the railroad; so it broke down and + became impractical. + + 2nd. To make the irregular disorder of local time an orderly + confusion, the "standard time"--jumping by hours--has helped a + little, but only because we can tell how much it is wrong at + any given place. This is its only advantage over the first + method, where we had no means of knowing what to expect on + entering any new territory. That is, we have improved things by + throwing out local time to the extent of an hour. + +My proposal is to throw local time out _totally_ and establish one, +invariable, _universal time_. Greenwich time being most in use now, +and meridians numbered from it, may be taken in preference to any +other. Still another reason is that the most important timekeepers in +modern life--ship's chronometers--are set to Greenwich time. Universal +time--no local time--only local day and night. Our 24-hour system is +all right, so do not disturb it, as it gets rid of A.M. and P.M. and +makes the day our unit of time. Our railroad time now throws out +local time to the extent of one hour; but I propose to throw it out +entirely and never change the clock hands from Greenwich time. The +chronometers do that now, so let us conduct all business to that time. + +Now refer to Fig. 46, in which Greenwich is taken as universal time. +The annulus, half white and half black, indicates the average day and +night, and is a separate ring in the dial which can be set so that +"noon" is on the meridian of the place, as shown for four places in +the illustration. It is the same dial in all four cases set to local +day and night. Strictly, the local time conception is dropped and the +local day left for regulating working and sleeping time. All business +would have the same time. In traveling east we would not have the +short hours; or west, the long hours. All clocks and watches would +show the same time as ship's chronometers do now. The only change +would be the names of the hours for the parts of the local day. +This is just the difficulty, for we are so accustomed to _associate_ +a certain number, as seven, with the morning and breakfast time. +Suppose breakfast time in London is 7 o'clock, then according to the +local day it would be 12 o'clock breakfast time in New York; but in +both cases it would be the same time with reference to the _local +daylight_. Let it be distinctly understood that our association of +_12 o'clock_ with _noon_ is not necessary. The Japanese called it +"horse" and "nine"--the ancient Romans, the New Testament writers, +and the Turks called it the "sixth hour"--the astronomers now call it +24 o'clock, and the Chinese represent it by several characters; but, +in all cases, it is simply the middle of the day at any place. By +the proposed universal time, morning, noon, and evening would be--_at +any given place_--the same hours. There would be no necessity of +establishing legal noon with exactness to the meridian, because that +would only regulate labor, meals, etc., and would not touch universal +time. This is an important part of the proposal and is worth +elaborating a little. Sections in manufacturing districts could make +their working hours correspond at pleasure and no confusion would +result. That is, local working hours to convenience but by the same +universal time. Note how perfectly this would work in traveling,--you +arrive in Chicago from the effete east and your watch corresponds +all along with the railroad clocks. As you leave the station you +glance up at the clock and see that Chicago noon is 17.30, so you +set the day and night ring of your watch to match the same ring on +the clock, but no disturbance of the hands. As you register at the +hotel you ask,--dinner? and get answer, 24.30--then breakfast, 12.30. +These questions are necessary now, so I do not add complication +here. When you arrive in a strange city you must ask about meals, +business hours, theater hours, "doors open" hours, etc., etc.; so +all this remains the same. Let us put the matter forcibly,--while we +count days, or _dates_, _something_ must vary with east and west; +I propose the fixing of hours for business and sleep to suit each +locality, but an invariable time. Get rid of the idea that a certain +number, as 7 o'clock, represents the age of the day _at all places_. +See how this would wipe out the silly proposal to "save daylight" +by setting the clock back and forward. Suppose workmen commenced at +12.30 in New York; for the long summer days make it 11.30, but no +change in universal time. As this is the only difference from our +present time system, keep the central conception, firmly,--universal +time--local day and night. + +[Illustration: Fig. 46--Universal Time Dial Set for Four Places] + +Suppose Chicago decided that "early to bed and early to rise" was +desirable; then it could establish its legal noon as 17.30, which +would be about 20 minutes early for its meridian. You could do +business with Chicago for a lifetime and not find this out, unless +you looked up the meridian of Chicago and found that it was 17.50 +o'clock. None of the railroads or steamship lines of the city would +need to know this, except as a matter of scientific curiosity, +for the time tables would all be printed in universal time. For +hiring labor, receiving and delivering goods, etc., they would +only need to know Chicago _business hours_. To state the matter in +different words,--Chicago would only need to decide what portion of +the universal 24 hours would suit it best for its day and which +for its night, and if it decided, as supposed above, to place its +working day forward a little to give some daylight after labor, +nothing would be disturbed and only the scientific would ever +know. Certainly, "save daylight," but do not make a fool of the +clock! Having shown the great liberty which localities could take +without touching the working of the system, the same remarks apply +to ultra-scientific localities. A city might establish its noon to +the instant; so it is possible--even if a little improbable--that +the brilliant and scientific aldermen of New York might appoint +a commission with proper campfollowers and instrument bearers to +determine the longitude of the city to the Nth of a second and tell +us where we "are at." The glory of this achievement--and especially +its total cost--would be all our own and incorruptible time would be +untouched! We thus see that great local freedom and great accuracy +are alike possible. With our present system, accuracy in local time +is impracticable and has never even been attempted, and is confusion +confused since we added the railroad hour jumps. Why did we nurse +this confusion till it has become almost intolerable? Because man +has always been a slave to _mental associations, and habits_. +Primitive man divided the local day into parts and gave them names +and this mental attitude sticks to us after it has served its day. +The advantages of universal time could hardly be enumerated, yet we +can have them all by dropping our childish association of 7 o'clock +with breakfast time! Another example,--you visit a friend for a few +days and on retiring the first night you ask "what is your breakfast +hour"--"8 o'clock." You have to ask this question and recollect the +answer. Now tell me what difference it would make if the answer had +been 13 o'clock? None whatever, unless, perhaps, that is, you do not +like thirteen! You ask, how about ships? Ships now carry universal +time and only change the clock on deck to please the simple minded +passengers. How about the date line? No change whatever, so long +as we use _dates_ which means numbering local days. It is useless +multiplying examples; all difficulties disappear, as if by magic, the +moment we can free our minds of local time and the association of +the _same hour_ with the _same portion_ of the day at _all places_. +The great interest at present manifested in the attempts to reach +the North Pole calls for some consideration of universal time in +the extreme north. Commencing at the equator, it is easy to see +that the day and night ring, Fig. 46, would represent the days and +nights of 12 hours at all seasons. As we go north, however, this +ring represents the _average_ day and night. When we reach the Polar +Circle, still going north, the _daily_ rising and setting of the sun +gradually ceases till we reach the great one-year day at the Pole, +consisting of six months darkness and six months light. Let us now +assume that an astronomical observatory is established here and the +great equatorial placed precisely on the pole. At this point, _local +time_, _day and night_, and _the date line_, almost cease to have +a meaning. For this very reason universal time would be the only +practical method; therefore, it _more_ than stands the test of being +carried to the extreme. Universal time would regulate working and +sleeping here the same as at all other places. Strictly local time in +this observatory would be an absurdity, because in walking around the +telescope (pole) you would be in all instants of the 24 hours within +five seconds! At the pole the day would commence at the same instant +as at some assumed place, and the day and night ring would represent +working and sleeping as at that place. Suppose this observatory to +be in telegraphic communication with New York, then it would be +best for the attendants to set their day and night to New York, so +as to correspond with its business hours. Many curious suppositions +might be made about this polar observatory with its "great night" +and equally "great day." It is evident that to keep count of itself +it would be compelled to note _dates_ and 24-hour _days_ to keep in +touch with us; so it would be forced to adopt the local day of some +place like New York. This choice would be free, because a polar +observatory would stand on all the meridians of the earth at once. + +We are now in a position to consider the next possible--and even +probable--improvement in our clocks and watches. To minimize the +next step it might be well to see what we can do now. Clocks are +often regulated by electric impulses over wires. Electricians inform +me that they can do this by wireless; but that owing to the rapid +attenuation of the impulses it cannot be done commercially, over +great distances. In the history of invention the first step was _to +do something_ and then find a way of doing it cheaply enough for +general use. So far as I know, the watch in the wearer's pocket has +not yet been regulated by wireless; but I am willing to risk the +statement that the editor of Popular Mechanics can name more than one +electrician who can do this. A watch to take these impulses might be +larger than our present watches, but it would not stay larger and +would ultimately become much smaller. You know what has happened +since the days of the big "onions" described in the third chapter. +Fig. 34; so get your electric watch and make it smaller at your +leisure. We have made many things commercially practicable, which +looked more revolutionary than this. Now throw out the mainspring, +wheels, pinions, etc., of our watches and reduce the machinery part +to little more than dial and hands and do the driving by wireless, +say, once every minute. I feel certain that I am restraining the +scientific imagination in saying that the man lives among us who can +do this. I repeat, that we now possess the elementary knowledge--which +if collated and applied--would produce such a watch. + +Now I have a big question to ask--the central note of interrogation +in this little scientific conversation with you,--does the man +live who can make the earth automatically record its rotation? +Do not be alarmed, for I am prepared to make a guess as to this +possibility. A _direct_ mechanical record of the earth's rotation +seems hopeless, but let us see what can be done. You are aware +that some of the fixed stars have a distinct spectrum. It is not +unreasonable to suppose that an instrument could be made to record +the passage of such a star over the meridian. Ah, but you say, there +is no mechanical force in this. Do not hurry, for we have long been +acquainted with the fact that things which, apparently, have no +force can be made to liberate something which manifests mechanical +force. We could now start or stop the greatest steam engine by a +gleam of sunlight, and some day we might be able to do as much by the +lately discovered pressure of light. That is, we can now liberate +the greatest forces by the most infinitesimal, by steps; the little +force liberating one greater than itself, and that one another still +greater. A good example is the stopping of an electric train, from a +distance, by wireless. The standard clock in Philadelphia, previously +referred to, is a delicate instrument and its most delicate part, +having the least force, moves a little valve every minute, and by +several steps liberates the air pressure, 200 feet higher in the +tower, to move the four sets of great hands. I am not traveling +beyond the record when I say that the invisible actinic rays could be +used to liberate a great force; therefore what is there unreasonable +in the supposition that the displacement of the sodium line in the +spectrum of a star might be made to record the earth's rotation? So +I say to the electrician--the optician--the photographer--the chemist +and the mechanic.--get together and produce this watch. Permit me, +with conventional and intentional modesty, to name the new timepiece +_Chroncosmic_. For pocket use, it would be _Cosmic watch_. In the +first chapter I allowed to the year 2,000 for the production of this +watch, but it is likely we will not need to wait so long. + +Having stated my proposal for universal time as fully as space will +permit and given my guess as to the coming cosmic watch, let us in +this closing paragraph indulge in a little mental exercise. Suppose +we copy the old time lecturer on astronomy and "allow our minds to +penetrate into space." Blessed be his memory, he was a doer of good. +How impressive as he repeatedly dropped his wooden pointer, and lo! +It always moved straight to the floor; thus triumphantly vindicating +universal gravitation!!! + +We can think of a time system which would discard months, weeks and +days. What is the meaning of the financial almanac in which the +days are numbered from 1 to 365 or 366? Simply a step in the right +direction, _away from the months and weeks_, so that the distance +between any two dates may be seen at a glance. We would really be +better without months and weeks. Now let us consider the year of +the seasons as a unit--long since proposed by the astronomers--and +divide it into 3,000 chrons. Clocks regulated by star transits, as +at present, would divide this decimally, the fourth place being near +enough to make the new pendulums of convenient length. This would +throw out months, weeks and days, local time and the date line. +Each of these chrons would represent the same time in the year, +permanently. For example, 464.6731 would mark to a _dixmilliemechron_ +(a little more than one second) the point reached in the year; while +the date does not, as I have shown in the first chapter. But you +still object that this is a great number of figures to use in fixing +a point in the year. Let us see what it takes to fix a point in the +year now, _August 24th, 11-16-32 P. M., New York standard time_. A +pretty long story, but it does not fix the point of the year even +then; for it would require the assistance of an astronomer to fix +such a point in _any given_ year, say 1909. But 464.6731 would be +eternally right in _absolute time_ of the seasons, and has only one +meaning, with no qualifications for any year whatever. I believe +the astronomers should use a method something like this. Ah, but +there is a difficulty in applying this to the affairs of daily life +which looks insurmountable. This is caused by the fact that the +_day_ and _year_ are incommeasurable. One of them cannot be exactly +expressed in terms of the other. They are like the diagonal and side +of a square. The day is now the unit and therefore the year has an +interminable fraction; conversely, if we make the year the unit, then +the day becomes an endless fraction. This brings us face to face with +the local day which we ignored in our scientific year unit. We _must_ +regulate our labors, in this world, to day and night and, with the +year unit, the chrons would bear no fixed relation to day and night, +even for two days in succession. So the year unit and absolute time +must be left to the astronomers; but the _day unit_ and the uniform +world day of _universal time_ as explained in connection with Fig. 46 +I offer as a practical system. + +I am satisfied that all attempts to measure the year and the day +by the same _time yard stick_ must fail and keep us in our present +confusion. Therefore separate them once for all time. Brought down to +its lowest terms my final proposal is:-- + + 1st. An equinoctial year unit for the astronomers, divided + somewhat as suggested, but no attempt to make the divisions + even approximate to days and hours. This would fix all + astronomical events, absolutely. A variation in the length of + the year would not disturb this system, since the year _itself_ + would be the unit. In translating this astronomical, or year + unit time, into clock time, no difficulties would be added, as + compared with our present translation of sidereal time into + clock time. Deal with the _year unit_ and _day unit_ separately + and convert them mutually when necessary. + + 2nd. A universal mean time day of 24 hours, as now kept at + Greenwich, all human business being regulated by this time. + Dates and the date line as well as leap years all being + retained as at present. + + 3rd. Weight and spring clocks and watches to be superseded by + the cosmic clocks and watches regulated by wireless impulses + from central time stations, all impulses giving the same + invariable time for all places. + + 4th. Automatic recording of the earth's rotations to determine + this time. + +To avoid any possibility of misunderstanding, I would advise never +counting a unit till it is completed. We do this correctly with our +hours, as we understand 24 o'clock to be the same as 0 o'clock. But +we do not carry this out logically, for we say 24.30. How can this +be so, since there is nothing more than 24 o'clock? It ought to be +simply 30 minutes, or 0 hour 30 minutes. How can there be any _hour_ +when a new day is only 30 minutes old? This brings up the acrimonious +controversy, of some years ago, as to whether there was any "year +one." One side insisted that till one year was completed there could +only be months and days. The other side argued that the "year one" +commenced at 0 and that the month and date showed how much of it had +passed. Test yourself,--is this the year 1909, of which only 8 months +have passed; or is it 1909 and 8 months more? Regarding the centuries +there appears to be no difference of opinion that 1900 is completed, +and that we are in the 20th century. But can you tell whether we are +8 years and 8 months into the 20th century or 9 years and 8 months? +It ought to be, logically 1909 years _complete_ and 8 months of the +next year, which we must not count till it is completed. Take a +carpenter's rule, we say 1/4 in.--1/2 in.--3/4 in., but do not count +an inch till we complete it. When the ancients are quoted,--"about +the middle of the third hour" there is no mistake, because that means +2-1/2 hours since sunrise. If we said the 1909th year that would be +definite too, and mean some distance into that year. Popular language +states that Greenwich is on the "first meridian"; strictly, it is on +the zero meridian, or 0°. These matters are largely academic and I do +not look on them as serious subjects of discussion; but they are good +thought producers. Bidding you good-bye, for the present, it might +be permissible to state that this conversational article on Time was +intended to be readable and somewhat instructive; but especially to +indicate the infinity of the subject, that thought and investigation +might be encouraged. + + + + + * * * * * * + + + + +Transcriber's note: + +Original spelling and grammar have mostly been retained. However, on +page 31, "clepsydral" was changed to "clepsydra". + +Figures were moved from within paragraphs to between paragraphs. In +addition, some figures were originally out of numerical sequence; +they are now in sequence. + +*** END OF THE PROJECT GUTENBERG EBOOK 44838 *** |