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The Modern Clock
A Study of Time Keeping Mechanism;
Its Construction, Regulation and Repair.
by
WARD L. GOODRICH
Author of the Watchmaker’s Lathe, Its Use and Abuse.
With Numerous Illustrations and Diagrams
CHICAGO
Hazlitt & Walker, Publishers
1905
Copyrighted
1905
by Hazlitt & Walker.
TABLE OF CONTENTS
CHAP. PAGE
I. THE NECESSITY FOR BETTER SKILL AMONG CLOCKMAKERS. 3
II. THE NATURAL LAWS GOVERNING PENDULUMS. 10
III. COMPENSATING PENDULUMS. 23
IV. THE CONSTRUCTION OF MERCURIAL PENDULUMS. 53
V. REGULATIONS, SUSPENSIONS, CRUTCHES AND MINOR POINTS. 79
VI. TORSION PENDULUMS FOR FOUR-HUNDRED DAY CLOCKS. 91
VII. PECULIARITIES OF ANGULAR MEASUREMENT—
HOW TO READ DRAWINGS. 98
VIII. THE GRAHAM OR DEAD BEAT ESCAPEMENT. 109
IX. LE PAUTE’S PIN WHEEL ESCAPEMENT. 135
X. THE RECOIL OR ANCHOR ESCAPEMENT. 141
XI. THE DENNISON OR GRAVITY ESCAPEMENT. 150
XII. THE CYLINDER ESCAPEMENT AS APPLIED TO CLOCKS. 163
XIII. THE DETACHED LEVER ESCAPEMENT AS APPLIED TO CLOCKS. 184
XIV. PLATES, PIVOTS AND TIME TRAINS. 198
XV. SPRINGS, WEIGHTS AND POWER. 264
XVI. MOTION WORK AND STRIKING TRAINS. 293
XVII. CLEANING AND REPAIRING CUCKOO CLOCKS. 319
XVIII. SNAIL STRIKING WORK, ENGLISH, FRENCH AND AMERICAN. 330
XIX. THE CONSTRUCTION OF SIMPLE AND PERPETUAL CALENDARS. 347
XX. HAMMERS, GONGS AND BELLS. 367
XXI. ELECTRIC CLOCKS AND BATTERIES. 376
XXII. THE CONSTRUCTION AND REPAIR OF DIALS. 426
XXIII. CLOCK CASING AND CASE REPAIRS. 446
XXIV. SOME HINTS ON MAKING A REGULATOR. 463
LIST OF ILLUSTRATIONS 495
INDEX 497
CHAPTER I.
THE NECESSITY FOR BETTER SKILL AMONG CLOCKMAKERS.
The need for information of an exact and reliable character in regard
to the hard worked and much abused clock has, we presume, been felt by
every one who entered the trade. This information exists, of course,
but it is scattered through such a wide range of publications and is
found in them in such a fragmentary form that by the time a workman
is sufficiently acquainted with the literature of the trade to know
where to look for such information he no longer feels the necessity of
acquiring it.
The continuous decrease in the prices of watches and the consequent
rapid increase in their use has caused the neglect of the pendulum
timekeepers to such an extent that good clock men are very scarce,
while botches are universal. When we reflect that the average ‘life’ of
a worker at the bench is rarely more than twenty years, we can readily
see that information by verbal instruction is rapidly being lost, as
each apprentice rushes through clock work as hastily as possible in
order to do watch work and consequently each “watchmaker” knows less of
clocks than his predecessor and is therefore less fitted to instruct
apprentices in his turn.
The striking clock will always continue to be the timekeeper of the
household and we are still dependent upon the compensating pendulum,
in conjunction with the fixed stars, for the basis of our timekeeping
system, upon which our commercial and legal calendars and the movements
of our ships and railroad trains depend, so that an accurate knowledge
of its construction and behavior forms the essential basis of the
largest part of our business and social systems, while the watches
for which it is slighted are themselves regulated and adjusted at the
factories by the compensated pendulum.
The rapid increase in the dissemination of “standard time” and the
compulsory use of watches having a maximum variation of five seconds
a week by railway employees has so increased the standard of accuracy
demanded by the general public that it is no longer possible to make
careless work “go” with them, and, if they accept it at all, they are
apt to make serious deductions from their estimate of the watchmaker’s
skill and immediately transfer their custom to some one who is more
thorough.
The apprentice, when he first gets an opportunity to examine a clock
movement, usually considers it a very mysterious machine. Later on,
if he handles many clocks of the simple order, he becomes tolerably
familiar with the time train; but he seldom becomes confident of his
ability regarding the striking part, the alarm and the escapement,
chiefly because the employer and the older workmen get tired of telling
him the same things repeatedly, or because they were similarly treated
in their youth, and consider clocks a nuisance, any how, never having
learned clock work thoroughly, and therefore being unable to appreciate
it. In consequence of such treatment the boy makes a few spasmodic
efforts to learn the portions of the business that puzzle him, and then
gives it up, and thereafter does as little as possible to clocks, but
begs continually to be put on watch work.
We know of a shop where two and sometimes three workmen (the best
in the shop, too) are constantly employed upon clocks which country
jewelers have failed to repair. If clock work is dull they will go upon
watch work (and they do good work, too), but they enjoy the clocks and
will do them in preference to watches, claiming that there is greater
variety and more interest in the work than can be found in fitting
factory made material into watches, which consist of a time train only.
Two of these men have become famous, and are frequently sent for to
take care of complicated clocks, with musical and mechanical figure
attachments, tower, chimes, etc. The third is much younger, but is
rapidly perfecting himself, and is already competent to rebuild minute
repeaters and other sorts of the finer kinds of French clocks. He now
totally neglects watch work, saying that the clocks give him more money
and more fun.
We are confident that this would be also the case with many another
American youth if he could find some one to patiently instruct him in
the few indispensable facts which lie at the bottom of so much that is
mysterious and from which he now turns in disgust. The object of these
articles is to explain to the apprentice the mysteries of pendulums,
escapements, gearing of trains, and the whole technical scheme of these
measurers of time, in such a way that hereafter he may be able to
answer his own questions, because he will be familiar with the facts on
which they depend.
Many workmen in the trade are already incompetent to teach clockwork
to anybody, owing to the slighting process above referred to; and the
frequent demands for a book on clocks have therefore induced the writer
to undertake its compilation. Works on the subject—nominally so, at
least—are in existence, but it will generally be found on examination
that they are written by outsiders, not by workmen, and that they
treat the subject historically, or from the standpoint of the artistic
or the curious. Any information regarding the mechanical movements
is fragmentary, if found in them at all, and they are better fitted
for the amusement of the general public than for the youth or man who
wants to know “how and why.” These facts have impelled the writer to
ignore history and art in considering the subject; to treat the clock
as an existing mechanism which must be understood and made to perform
its functions correctly; and to consider cases merely as housings of
mechanism, regardless of how beautiful, strange or commonplace those
housings may be.
We have used the word “compile” advisedly. The writer has no new ideas
or theories to put forth, for the reason that the mechanism we are
considering has during the last six hundred years had its mathematics
reduced to an exact science; its variable factors of material and
mechanical movements developed according to the laws of geometry and
trigonometry; its defects observed and pointed out; its performances
checked and recorded. To gather these facts, illustrate and explain
them, arrange them in their proper order, and point out their relative
importance in the whole sum of what we call a clock, is therefore all
that will be attempted. In doing this free use has been made of the
observations of Saunier, Reid, Glasgow, Ferguson, Britten, Riefler and
others in Europe and of Jerome, Playtner, Finn, Learned, Ferson, Howard
and various other Americans. The work is therefore presented as a
compilation, which it is hoped will be of service in the trade.
In thus studying the modern American clocks, we use the word American
in the sense of ownership rather than origin, the clocks which come to
the American workmen to-day have been made in Germany, France, England
and America.
The German clocks are generally those of the Schwartzwald (or Black
Forest) district, and differ from others in their structure, chiefly in
the following particulars: The movement is supported by a horizontal
seatboard in the upper portion of the case. The wooden trains of many
of the older type instead of being supported by plates are held in
position by pillars, and these pillars are held in position by top
and bottom boards. In the better class of wooden clocks the pivot
holes in the pillars are bushed with brass tubing, while the movement
has a brass ’scape wheel, steel wire pivots and lantern pinions of
wood, with steel trundles. In all these clocks the front pillars are
friction-tight, and are the ones to be removed when taking down the
trains. Both these and the modern Swartzwald brass movements use a
sprocket wheel and chain for the weights and have exposed pendulums and
weights.
The French clocks are of two classes, pendules and carriage clocks,
and both are liable to develop more hidden crankiness and apparently
causeless refusals to go than ever occurred to all the English, German
and American clocks ever put together. There are many causes for this,
and unless a man is very new at the business he can tell stories of
perversity, that would make a timid apprentice want to quit. Yet the
French clocks, when they do go, are excellent timekeepers, finely
finished, and so artistically designed that they make their neighbors
seem very clumsy by comparison. They are found in great variety, time,
half-hour and quarter-hour strike, musical and repeating clocks being
a few of the general varieties. The pendulums are very short, to
accommodate themselves to the artistic needs of the cases, and nearly
all have the snail strike instead of the count wheel. The carriage
clocks have watch escapements of cylinder or lever form, and the
escapement is frequently turned at right angle by means of bevel gears,
or contrate wheel and pinion, and placed on top of the movement.
The English clocks found in America are generally of the “Hall”
variety, having heavy, well finished movements, with seconds pendulum
and frequently with calendar and chime movements. They, like the
German, are generally fitted with weights instead of springs. There are
a few English carriage clocks, fitted with springs and fuzees, though
most of them, like the French, have springs fitted in going barrels.
The American clocks, with which the apprentice will naturally have
most to do, may be roughly divided into time, time alarm, time
strike, time strike alarm, time calendar and electric winding. The
American factories generally each make about forty sizes and styles of
movements, and case them in many hundreds of different ways, so that
the workman will frequently find the same movement in a large number of
clocks, and he will soon be able to determine from the characteristics
of the movement what factory made the clock, and thus be able to at
once turn to the proper catalogue if the name of the maker be erased,
as frequently happens.
This comparative study of the practice of different factories will
prove very interesting, as the movement comes to the student after a
period of prolonged and generally severe use, which is calculated to
bring out any existing defects in construction or workmanship; and
having all makes of clocks constantly passing through his hands, each
exhibiting a characteristic defect more frequently than any other, he
is in a much better position to ascertain the merits and defects of
each maker than he would be in any factory.
Having thus briefly outlined the kinds of machinery used in measuring
time, we will now turn our attention to the examination of the
theoretical and mechanical construction of the various parts.
The man who starts out to design and build a clock will find himself
limited in three particulars: It must run a specified time; the arbor
carrying the minute hand must turn once in each hour; the pendulum
must be short enough to go in the case. Two of these particulars are
changeable according to circumstances; the length of time run may be
thirty hours, eight, thirty, sixty or ninety days. The pendulum may be
anywhere from four inches to fourteen feet, and the shorter it is the
faster it will go. The one definite point in the time train is that the
minute hand must turn once in each hour. We build or alter our train
from this point both ways, back through changeable intermediate wheels
and pinions to the spring or weight forming the source of power, and
forward from it through another changeable series of wheels and pinions
to the pendulum. Now as the pendulum governs the rate of the clock we
will commence with that and consider it independently.