Watch and Clock Escapements

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Watch and Clock Escapements

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Title: Watch and Clock Escapements A Complete Study in Theory and
Practice of the Lever, Cylinder and Chronometer Escapements,
Together with a Brief Account of the Origin and Evolution of the
Escapement in Horology
Author: Anonymous

Release Date: November 6, 2005 [eBook #17021]
Language: English
Character set encoding: ISO-8859-1
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WATCH AND CLOCK ESCAPEMENTS
A Complete Study in Theory and Practice of the Lever, Cylinder and
Chronometer Escapements, Together with a Brief Account of the
Origin and Evolution of the Escapement in Horology
Compiled from the well-known Escapement Serials published in The
Keystone
Nearly Two Hundred Original Illustrations

Published by The Keystone The Organ of the Jewelry and Optical
Trades 19th & Brown Sts., Philadelphia, U.S.A.
1904
All Rights Reserved Copyright, 1904, By B. Thorpe, Publisher of the
Keystone.

PREFACE
Especially notable among the achievements of The Keystone in the
field of horology were the three serials devoted to the lever, cylinder

and chronometer escapements. So highly valued were these serials
when published that on the completion of each we were importuned to
republish it in book form, but we deemed it advisable to postpone such
publication until the completion of all three, in order that the volume
should be a complete treatise on the several escapements in use in
horology. The recent completion of the third serial gave us the
opportunity to republish in book form, and the present volume is the
result. We present it to the trade and students of horology happy in the
knowledge that its contents have already received their approval. An
interesting addition to the book is the illustrated story of the
escapements, from the first crude conceptions to their present
perfection.

CONTENTS
CHAPTER I.
THE DETACHED LEVER ESCAPEMENT 9
CHAPTER II.
THE CYLINDER ESCAPEMENT 111
CHAPTER III.
THE CHRONOMETER ESCAPEMENT 131
CHAPTER IV.
HISTORY OF ESCAPEMENTS 153
CHAPTER V.
PUTTING IN A NEW CYLINDER 169
INDEX 177

WATCH AND CLOCK ESCAPEMENTS
CHAPTER I.
THE DETACHED LEVER ESCAPEMENT.
In this treatise we do not propose to go into the history of this
escapement and give a long dissertation on its origin and evolution, but
shall confine ourselves strictly to the designing and construction as
employed in our best watches. By designing, we mean giving full
instructions for drawing an escapement of this kind to the best
proportions. The workman will need but few drawing instruments, and
a drawing-board about 15" by 18" will be quite large enough. The
necessary drawing-instruments are a T-square with 15" blade; a scale of
inches divided into decimal parts; two pairs dividers with pen and
pencil points--one pair of these dividers to be 5" and the other 6"; one
ruling pen. Other instruments can be added as the workman finds he
needs them. Those enumerated above, however, will be all that are
absolutely necessary.
[Illustration: Fig. 1]
We shall, in addition, need an arc of degrees, which we can best make
for ourselves. To construct one, we procure a piece of No. 24 brass,
about 5½" long by 1¼" wide. We show such a piece of brass at A, Fig.
1. On this piece of brass we sweep two arcs with a pair of dividers set
at precisely 5", as shown (reduced) at a a and b b. On these arcs we set
off the space held in our dividers--that is 5"--as shown at the short
radial lines at each end of the two arcs. Now it is a well-known fact that
the space embraced by our dividers contains exactly sixty degrees of
the arcs a a and b b, or one-sixth of the entire circle; consequently, we
divide the arcs a a and b b into sixty equal parts, to represent degrees,
and at one end of these arcs we halve five spaces so we can get at half
degrees.
[Illustration: Fig. 2]

Before we take up the details of drawing an escapement we will say a
few words about "degrees," as this seems to be something difficult to
understand by most pupils in