

E-text prepared by Chris Curnow, RichardW, and the Online Distributed
Proofreading Team (http://www.pgdp.net) from page images generously made
available by Internet Archive (https://archive.org)



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 deg.-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 Repousse 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 deg.-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