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Ward L. Goodrich. The Modern Clock
The Modern Clock
Table of Contents
CHAPTER I. THE NECESSITY FOR BETTER SKILL AMONG CLOCKMAKERS
CHAPTER II. THE NATURAL LAWS GOVERNING PENDULUMS
CHAPTER III. COMPENSATING PENDULUMS
CHAPTER IV. THE CONSTRUCTION OF MERCURIAL PENDULUMS
CHAPTER V. REGULATIONS, SUSPENSIONS, CRUTCHES. AND MINOR POINTS
CHAPTER VI. TORSION PENDULUMS FOR FOUR-HUNDRED DAY CLOCKS
CHAPTER VII. PECULIARITIES OF ANGULAR MEASUREMENT— HOW TO READ DRAWINGS
CHAPTER VIII. THE GRAHAM OR DEAD BEAT ESCAPEMENT
CHAPTER IX. LE PAUTE’S PIN WHEEL ESCAPEMENT
CHAPTER X. THE RECOIL OR ANCHOR ESCAPEMENT
CHAPTER XI. THE DENNISON OR GRAVITY ESCAPEMENT
CHAPTER XII. THE CYLINDER ESCAPEMENT AS APPLIED TO CLOCKS
CHAPTER XIII. THE DETACHED LEVER ESCAPEMENT. AS APPLIED TO CLOCKS
CHAPTER XIV. PLATES, PIVOTS AND TIME TRAINS
CHAPTER XV. SPRINGS, WEIGHTS AND POWER
CHAPTER XVI. MOTION WORK AND STRIKING TRAINS
CHAPTER XVII. CLEANING AND REPAIRING CUCKOO CLOCKS
CHAPTER XVIII. SNAIL STRIKING WORK, ENGLISH, FRENCH AND AMERICAN
CHAPTER XIX. THE CONSTRUCTION OF SIMPLE. AND PERPETUAL CALENDARS
CHAPTER XX. HAMMERS, GONGS AND BELLS
CHAPTER XXI. ELECTRIC CLOCKS AND BATTERIES
CHAPTER XXII. THE CONSTRUCTION AND REPAIR OF DIALS
CHAPTER XXIII. CLOCK CASING AND CASE REPAIRS
CHAPTER XXIV. SOME HINTS ON MAKING A REGULATOR
LIST OF ILLUSTRATIONS
INDEX
Отрывок из книги
Ward L. Goodrich
A Study of Time Keeping Mechanism; Its Construction, Regulation and Repair
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The Circular Error.—As the pendulum swings over a greater arc it will occupy more time in doing it and thus the rate of the clock will be affected, if the barometric changes are very great. This is called the circular error. In ancient times, when it was customary to make pendulums vibrate at least fifteen degrees, this error was of importance and clock makers tried to make the bob take a cycloidal path, as is shown in Fig. 4, greatly exaggerated. This was accomplished by suspending the pendulum by a cord which swung between cycloidal checks, but it created so much friction that it was abandoned in favor of the spring as used to-day. It has since been proved that the long and short arcs of the pendulum’s vibration are practically isochronous (with a spring of proper length and thickness) up to about six degrees of arc (three degrees each side of zero on the degree plate at the foot of the pendulum) and hence small variations of power in spring operated clocks and also the barometric error are taken care of, except for greatly increased variations of power, or for too great arcs of vibration. Here we see the reasons for and the amount of swing we can properly give to our pendulum.
Temperature Error.—The temperature error is the greatest which we shall have to consider. It is this which makes the compound pendulum necessary for accurate time, and we shall consequently give it a great amount of space, as the methods of overcoming it should be fully understood.
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