Analysis of the Lever

Escapement, by H. R. Playtner

Project Gutenberg's An Analysis of the Lever Escapement, by H. R.

Playtner This eBook is for the use of anyone anywhere at no cost and

with almost no restrictions whatsoever. You may copy it, give it away

or re-use it under the terms of the Project Gutenberg License included

with this eBook or online at www.gutenberg.org

Title: An Analysis of the Lever Escapement

Author: H. R. Playtner

Release Date: June 30, 2007 [EBook #21978]

Language: English

Character set encoding: ISO-8859-1

*** START OF THIS PROJECT GUTENBERG EBOOK AN

ANALYSIS OF THE LEVER ***

Produced by Sigal Alon, Fox in the Stars, Laura Wisewell and the

Online Distributed Proofreading Team at http://www.pgdp.net

[Illustration: THOMAS MUDGE

The first Horologist who successfully applied the Detached Lever

Escapement to Watches.

Born 1715--Died 1794.]

AN ANALYSIS

OF THE

LEVER ESCAPEMENT

BY H. R. PLAYTNER.

A LECTURE DELIVERED BEFORE THE CANADIAN

WATCHMAKERS' AND RETAIL JEWELERS' ASSOCIATION.

ILLUSTRATED.

CHICAGO:

HAZLITT & WALKER, PUBLISHERS.

1910.

PREFACE.

Before entering upon our subject proper, we think it advisable to

explain a few points, simple though they are, which might cause

confusion to some readers. Our experience has shown us that as soon as

we use the words "millimeter" and "degree," perplexity is the result.

"What is a millimeter?" is propounded to us very often in the course of

a year; nearly every new acquaintance is interested in having the metric

system of measurement, together with the fine gauges used, explained

to him.

The metric system of measurement originated at the time of the French

Revolution, in the latter part of the 18th century; its divisions are

decimal, 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 English

inch there are 39+3708/10000 inches in a meter, and there are

25.4 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 into

10ths and the 10ths into 100ths of a millimeter, which could be

continued indefinitely. The 1/100 millimeter is equal to the 1/2540 of

an inch. These are measurements with which the watchmaker is

concerned. 1/100 millimeter, written .01 mm., is the side shake for a

balance pivot; multiply it by 2¼ and we obtain the thickness for the

spring detent of a pocket chronometer, which is about 1/3 the thickness

of a human hair.

The metric system of measurement is used in all the watch factories of

Switzerland, France, Germany, and the United States, and nearly all the

lathe makers number their chucks by it, and some of them cut the

leading screws on their slide rests to it.

In any modern work on horology of value, the metric system is used.

Skilled horologists use it on account of its convenience. The millimeter

is a unit which can be handled on the small parts of a watch, whereas

the inch must always be divided on anything smaller than the plates.

Equally as fine gauges can be and are made for the inch as for the

metric system, and the inch is decimally divided, but we require

another decimal point to express our measurement.

Metric gauges can now be procured from the material shops; they

consist of tenth measures, verniers and micrometers; the finer ones of

these come from Glashutte, and are the ones mentioned by Grossmann

in his essay on the lever escapement. Any workman who has once used

these instruments could not be persuaded to do without them.

No one can comprehend the geometrical principles employed in

escapements without a knowledge of angles and their measurements,

therefore we deem it of sufficient importance to at least explain what a

degree is, as we know for a fact, that young workmen especially, often

fail to see how to apply it.

Every circle, no matter how large or small it may be, contains 360°; a

degree is therefore the 360th part of a circle; it is divided into minutes,

seconds, thirds, etc.

To measure the value of a degree of any circle, we must multiply the

diameter of it by 3.1416, which gives us the circumference, and then

divide it by 360. It will be seen that it depends on the size of that circle

or its radius, as to the value of a degree in any actual measurement. To

illustrate; a degree on the earth's circumference measures 60

geographical miles, while measured on the circumference of an escape

wheel 7.5 mm. in diameter, or as they would designate it in a material

shop, No. 7½, it would be 7.5 × 3.1416 ÷ 360 = .0655

Escapement, by H. R. Playtner

Project Gutenberg's An Analysis of the Lever Escapement, by H. R.

Playtner This eBook is for the use of anyone anywhere at no cost and

with almost no restrictions whatsoever. You may copy it, give it away

or re-use it under the terms of the Project Gutenberg License included

with this eBook or online at www.gutenberg.org

Title: An Analysis of the Lever Escapement

Author: H. R. Playtner

Release Date: June 30, 2007 [EBook #21978]

Language: English

Character set encoding: ISO-8859-1

*** START OF THIS PROJECT GUTENBERG EBOOK AN

ANALYSIS OF THE LEVER ***

Produced by Sigal Alon, Fox in the Stars, Laura Wisewell and the

Online Distributed Proofreading Team at http://www.pgdp.net

[Illustration: THOMAS MUDGE

The first Horologist who successfully applied the Detached Lever

Escapement to Watches.

Born 1715--Died 1794.]

AN ANALYSIS

OF THE

LEVER ESCAPEMENT

BY H. R. PLAYTNER.

A LECTURE DELIVERED BEFORE THE CANADIAN

WATCHMAKERS' AND RETAIL JEWELERS' ASSOCIATION.

ILLUSTRATED.

CHICAGO:

HAZLITT & WALKER, PUBLISHERS.

1910.

PREFACE.

Before entering upon our subject proper, we think it advisable to

explain a few points, simple though they are, which might cause

confusion to some readers. Our experience has shown us that as soon as

we use the words "millimeter" and "degree," perplexity is the result.

"What is a millimeter?" is propounded to us very often in the course of

a year; nearly every new acquaintance is interested in having the metric

system of measurement, together with the fine gauges used, explained

to him.

The metric system of measurement originated at the time of the French

Revolution, in the latter part of the 18th century; its divisions are

decimal, 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 English

inch there are 39+3708/10000 inches in a meter, and there are

25.4 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 into

10ths and the 10ths into 100ths of a millimeter, which could be

continued indefinitely. The 1/100 millimeter is equal to the 1/2540 of

an inch. These are measurements with which the watchmaker is

concerned. 1/100 millimeter, written .01 mm., is the side shake for a

balance pivot; multiply it by 2¼ and we obtain the thickness for the

spring detent of a pocket chronometer, which is about 1/3 the thickness

of a human hair.

The metric system of measurement is used in all the watch factories of

Switzerland, France, Germany, and the United States, and nearly all the

lathe makers number their chucks by it, and some of them cut the

leading screws on their slide rests to it.

In any modern work on horology of value, the metric system is used.

Skilled horologists use it on account of its convenience. The millimeter

is a unit which can be handled on the small parts of a watch, whereas

the inch must always be divided on anything smaller than the plates.

Equally as fine gauges can be and are made for the inch as for the

metric system, and the inch is decimally divided, but we require

another decimal point to express our measurement.

Metric gauges can now be procured from the material shops; they

consist of tenth measures, verniers and micrometers; the finer ones of

these come from Glashutte, and are the ones mentioned by Grossmann

in his essay on the lever escapement. Any workman who has once used

these instruments could not be persuaded to do without them.

No one can comprehend the geometrical principles employed in

escapements without a knowledge of angles and their measurements,

therefore we deem it of sufficient importance to at least explain what a

degree is, as we know for a fact, that young workmen especially, often

fail to see how to apply it.

Every circle, no matter how large or small it may be, contains 360°; a

degree is therefore the 360th part of a circle; it is divided into minutes,

seconds, thirds, etc.

To measure the value of a degree of any circle, we must multiply the

diameter of it by 3.1416, which gives us the circumference, and then

divide it by 360. It will be seen that it depends on the size of that circle

or its radius, as to the value of a degree in any actual measurement. To

illustrate; a degree on the earth's circumference measures 60

geographical miles, while measured on the circumference of an escape

wheel 7.5 mm. in diameter, or as they would designate it in a material

shop, No. 7½, it would be 7.5 × 3.1416 ÷ 360 = .0655