Transcriber’s note
Printer errors: A small number of printer errors have been corrected. These are marked by light underlining and a title attribute which can be accessed by hovering with the mouse. For example, text.In addition, some punctuation errors have been corrected, but inconsistent spacing of letter names referring to diagrams has been left as in the original.
Table of Contents: For the reader’s convenience, a Table of Contents has been provided after the Preface. This was not in the original.
Accessibility: Abbreviations have been expanded using the <abbr> tag. Unfortunately it proved impossible to provide long descriptions for the diagrams, because the originals were unclear or illegible. The following accesskeys are provided:
THOMAS MUDGE
The first Horologist who successfully applied the Detached LeverEscapement to Watches.
Born 1715—Died 1794.
AN ANALYSIS
OF THE
Lever Escapement
BY H. R. PLAYTNER.
A LECTURE DELIVERED BEFORE THE CANADIAN WATCHMAKERS’ AND RETAILJEWELERS’ ASSOCIATION.
ILLUSTRATED.
CHICAGO:
Hazlitt & Walker, Publishers.
1910.
PREFACE.
Before entering upon our subject proper, we think it advisable toexplain a few points, simple though they are, which might causeconfusion to some readers. Our experience has shown us that as soon aswe use the words “millimeter” and “degree,” perplexity is the result.“What is a millimeter?” is propounded to us very often in the course ofa year; nearly every new acquaintance is interested in having the metricsystem of measurement, together with the fine gauges used, explained tohim.
The metric system of measurement originated at the time of the FrenchRevolution, in the latter part of the 18th century; its divisions aredecimal, just the same as the system of currency we use in this country.
A meter is the ten millionth part of an arc of the meridian of Paris,drawn from the equator to the north pole; as compared with the Englishinch there are 393708⁄10000 inches in a meter, and there are25.4 millimeters in an inch.
The meter is sub-divided into decimeters, centimeters and millimeters;1,000 millimeters equal one meter; the millimeter is again divided into10ths and the 10ths into ...