A Rudimentary Treatise on Clocks, Watches and Bells

Edmund Beckett Grimthorpe

Informations

• Publié par: dazod
• Publié le: 08 décembre 2010
• Nombre de lectures: 33
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

Project Gutenberg’s A Rudimentary Treatise on Clocks, Watches and Bells, by Edmund Beckett.

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.net

Title: A Rudimentary Treatise on Clocks, Watches and Bells

Author: Edmund Beckett

Release Date: January 22, 2006 [EBook #17576]

Language: English

Character set encoding: TeX

*** START OF THIS PROJECT GUTENBERG EBOOK CLOCKS, WATCHES, BELLS

Produced by Robert Online Distributed

Cicconetti, Laura Proofreading Team

Wisewell and the at http://www.pgdp.net

***

Transcriber’s Notes:The original of this book had its table of contents, running headers, and headings in the text all independent. The table of contents given here is as in the original, as are the head ings in the text. However, the PDF bookmarks reflect the structure of the headings in the text, and, owing to repagination, it has proved very difficult to match the running headers, although I have aimed to as far as possible. Some of the book’s headers seemed to refer to a figure on the page; these are preserved here as figure captions, which did not appear in the original.

All page references, including those in the index, have been re generated to point to anchors placed in the source text; in some cases their placement was ambiguous, but every effort has been made to place them directly beside the text referred to. Phrases such as “this figure” or “on the next page” have been left as in the original, but may no longer be accurate after repagination. However, I have ensured that a hyperlink is always given.

Two pages of the original copy used had corners missing, therefore the words “see” on page10and “They” and “where” on page11are uncertain, and there could be another word following “languished” on page21. On page29I have changed “signify” to “significantly” as suggested by the sense. In an equation on page61thelin the denominator had been printed as a /. The word “scrapewheel” on page75Finally, the word “exhas been changed to “scapewheel”. plored” on page97had been printed as “exploded”. All of these words have been highlighted in the text like this , and also in the source file with two asterisks (**).

i

A RUDIMENTARY TREATISE

ON

CLOCKS, WATCHES, & BELLS

FOR PUBLIC PURPOSES

BY EDMUND BECKETT, LORD GRIMTHORPE LL.D. K.C. F.R.A.S.

PRESIDENT OF THE BRITISH HOROLOGICAL INSTITUTE, AUTHOR OF ‘ASTRONOMY WITHOUT MATHEMATICS,’ ETC.

EIGHTH EDITION, MOSTLY REPRINTED FROM THE SEVENTH EDITION OF1883,WITH A NEW PREFACE AND NEW LIST OF GREAT BELLS, AND AN APPENDIX ON WEATHERCOCKS

WITH NUMEROUS ILLUSTRATIONS

LONDON CROSBY LOCKWOOD AND SON 7 STATIONERS’ HALL COURT, LUDGATE HILL 1903

All Rights reserved by the Author

D. VAN NOSTRAND COMPANY.

PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, LONDON AND BECCLES.

PREFACE TO THE EIGHTH EDITION.

There have been so many editions or reprints of this book (including the articles on Horology in two editions of theEncyclopædia Britannica) that I cannot count them rightly, especially as several were issued under my former names of Denison and Beckett (Lord Grimthorpe since 1886). At least, I suppose so. This is certainly, in substance, at least the tenth issue. The book led to my designing, either directly or indirectly, not only the Westminster and St. Paul’s clocks, and the great peal of bells there, but those of many other Cathedrals and Churches, as well as Townhall, Railwaystation, and others in several of our Colonies, by special request. As I did all that work gratuitously, I have no means of tracing them, or probably remembering the names of them all. I know that I once counted above forty. The Publishers have received from my friend Canon Nolloth, of Beverley Minster, some further information about Bells, which (as it could not be inserted in the stereotype plates) has been inserted, with some remarks of my own, as Addenda, at pp.281–282. Canon Nolloth has also completed (pp.278–280) my own last list of large bells in various countries. I have also added a short Appendix (p.283) on Weathercocks. GRIMTHORPE.

Batch Wood, St. Alban’s. May, 1903.

ii

PREFACE.

As this is not unlikely to be the last time that I shall revise this book, considering my age and the number of copies printed in each edition of late (3000), and as I have had more leisure than for many years, I have endeavoured to make it as complete as possible, and have introduced more new matter and alterations than in any edition since the fourth. This was one of the first ‘Rudimentary Treatises,’ undertaken with great spirit by the late Mr. Weale, at the suggestion of my friend and connec tion, Colonel Sir W. Reid, K.C.B., the author of the ‘Law of Storms,’ and the chief manager of the Exhibition of 1851, at the request of the Prince Consort; and 7000 copies were printed of the first edition. The articles on Clocks and Watches, but not on Bells, in the eighth and ninth editions of theEncyclopædia Britannica, were abridgments of this book, and therefore make this edition practically the ninth written by me. It should be understood that this professes to be a rudimentary treatise in the sense of teaching the principles of horology, and so much practical knowledge as may be useful both to clockmakers and to amateurs who wish to make, or direct the making of, their own clocks of superior character; and I have had abundant information that it has been useful in that way, besides vastly improving the general character of public clocks especially, in all the Englishspeaking world, and wherever large English clocks go. Nobody can learn the details of watchmaking from a book, and at any rate in no such space as could be given to it in a volume like this. There have been, from time to time, useful letters on various details of the art in theEnglish Mechanicand theHorological Journal.I have never heard of any amateur taking up watchmaking as many do the making or designing of clocks; and it depends much more on manual dexterity and practice. Therefore that part of the book deals more with principles than with working details. I leave the chapter on Bells to speak for itself, as the only English treatise on their proper construction, shape, composition, and the best modes of hanging; and as the result of long experience and many special experiments,

iii

PREFACE.

iv

to revive an art which had sunk to a lower ebb thirty or forty years ago than it had ever reached in the thousand years or more since large bells were first made. E. B.

Batch Wood, St. Alban’s, and 33, Queen Anne Street, W: Jan,1883.

CONTENTS.

MEASURES OF TIME Sidereal day Solar day and transit instrument Mean time and year Equation of time Astronomical and civil day Table of equation of time Sidereal time Table of local time Sidereal and mean dials useless Sundials Meridian dial simplest Dipleidoscope Water and sand clocks

Clocks, History of Early English ones Common clock train Fanfly instead of pendulum Conical pendulum, or governor Relation of length to gravity Barker’s mill governor Revolving pendulum Balancewheel, earliest

Pendulums,history of Crownwheel escapement Cycloidal theory Cheeks, a failure Circular error

v

fig.1 fig.2

figs.3and4

fig.5 fig.6

fig.7 fig.8

page 1 1 2 2 3 4 5 4 6 6 8 9 10 11

12 13 14,15 17 17 17 19 18 20

21 22 23 24 24

CONTENTS.

Mathematics of pendulum theory Lengths of various pendulums Centre and radius of oscillation Moment of inertia Standards of length French metre a bad measure Egyptian and Jewish cubits Short and slow pendulums Shape and material of pendulums Suspension of them Where they may be Pendulum springs Regulation of clocks

Compensated pendulums Table of expansions and specific gravities Zinc and steel pendulum Weights of some A mistake about compensation Wood and lead compensation Wood, zinc, and lead Smeaton’s glass pendulum Compound bar compensation Homogeneous and Ellicott’s Mercurial; Baily’s mistake A new kind of jar Castiron jars best; calculation for Barometric error and compensation Westminster pendulum fully compensated Airtight clock cases Compensation by thermometer tube Greenwich plan

Anchor pallets Harrison’s recoil escapement Clocks out of beat

Dead escapements General theory of Importance of dead friction Sir G. Airy’s calculations His conclusion erroneous Proper construction Halfdead escapement

fig.9

fig.10 fig.11

fig.12

fig.13

fig.14

vi

25 25 26 26 27 28 28 29 29 31 32 33 34

36 36 37 39 39 40 41 42 43 44 45 46 47 48 49 50 50 51

53 54 54

56 55 57 59 62 62 63

CONTENTS.

Loseby’s isochronal spring fails Large and small arcs Value of firm fixing of pendulum Materials for scapewheels Weight of them Pallets should be short Rules for construction Pinwheel dead escapement Pin pallets Singlepin escapement Sir E. Beckett’s threelegged one Another form of it Detached escapements, Airy’s Beckett’s Singlebeat escapements waste no force

Gravity escapements, value of Mudge’s Sir G. Airy’s calculations Proper conclusion therefrom Effect of a close case Failure of early gravity escapements Cumming’s and Hardy’s Kater’s, Gowland’s, Gannery’s Bloxam’s Correction of Airy’s mistakes Beckett’s gravity escapements Fourlegged Banking pins, useful Fly to be light and large Double threelegged Most successful for large clocks

Going part of clocks, generally Section of one Dial work Regulator clocks Winding keys should be long Year clocks Clock cases and Moon dials Day of the month clocks Chronoscopic dials without hands Equation of time clocks Maintaining powers

fig.15

fig.16 fig.17 fig.18 fig.19 fig.20

fig.21

fig.22

fig.23

fig.24

fig.25

fig.26

fig.27

vii

63 64 64 65 65 66 66 69 68 70 71 72 73 74 75

75 78 77 80 80 80 81 82 84 83 85 86 88 89 91 92

93 95 96 96 97 97 97 99 101 103 104

CONTENTS.

Endless chain Springgoing barrel Bolt and shutter Beckett’s improved one Sunandplanet power Spring clocks American clocks and Austrian Improved French clocks Selfwinding clocks Water clocks Electrical, Bain’s Shepherd’s Jones’s controlled Ritchie’s His pendulums Lund & Blockley’s Timeballs and guns

Striking Clocks, for one only Common striking part Repeating method New French form of it Strike and silent Locking plate Halfhour striking one With rack movement Quarters on two bells Quarter chimes Best construction for them Telltale clocks, and musical

CHURCH OR TURRET CLOCKS Pendulums long and heavy Position of clock Frame, old form Some of the largest clocks Small turret clock with gravity escapement Clock towers and architects Wire ropes Striking from great wheel Two hammers Stops for weights Number of lines and pulleys Bushes, various forms

fig.28 fig.29

fig.30

fig.31 fig.32

fig.33 fig.34

fig.35

fig.36

fig.37

fig.38

viii

105 106 104 107 108 108 109 109 110 111 111 111 112 113 114 115 115

116 118 117 119 119 121 120 122 123 124 125 127

127 128 128 129 129 131 130 133 133 133 134 135 136