How To Lessons In Horology Mainsprings & Gearing

Chapter I - General Principles Of Cosmography Relating To Horology

Principles of the measurement of time
Units of time. Sidereal day. Solar day
True time. Mean time.
Laying out of a meridian line
Determination of the position of a point on the terrestrial sphere

General Principles Of Mechanics

Forces
Law of inertia
Definition of mechanics
Motion
Rotary motion
Mass of a body
Work of a force
Definition
Work of a force tangent to a wheel
Unit of work
Active power
Moment of a force
Lever
Transmission of work in machines
The oscillations of the balance and their relation to the motive force
Wheel-work- Its purpose in the mechanism of clocks and watches
Escapements

Chapter II - Maintaining Or Motive Forces

The weight as a motive force
The barrel spring as a motive force
Measurement of the force of a spring
Theoretical study of the moment of a spring's force
Coefficient of elasticity
Variation of the coefficient of elasticity
Values of the coefficient of elasticity E
Limit of elasticity
Moment of the elastic force of a spring subjected to a flexion
Inequality of the elastic force of the spring
Length of the spring
Development of a spring
Diameter of the hub
Work produced by spring
The fusee
Calculation of the variable radius of the fusee's helix
Uniformity of the force of the spring in fusee watches
stop-work
Geometrical construction of the Maltese cross stop-work

Chapter III - Wheel-Work

Purposes of wheel-work
Calculations of trains
Calculations of the number of turns
Calculation of the number of oscillations of the balance
Calculations of the numbers of teeth
Problems relative to the preceding questions
Numbers of turns
Numbers of oscillations of the balance
Numbers of teeth
Numbers of teeth of the minute wheels. Description of this mechanism
Numbers of teeth of an astronomical clock
Numbers of teeth of lost mobiles
Indicator of the development of the spring in fusee timepieces
Simple calendar watches
Decimal watches
Calculation of numbers comprising the teeth-ranges of the wheels of a watch with independent second hand
Wheel-work of the stem-winding mechanism
Calculation of the train in a watch of the Roskopt Type

Chapter IV - Gearings

Definition
Practical examination of a gearing
First-Distance of the centers
Primitive radii
Applications
Calculation of the primitive radii
Application of the theory of primitive radii to the escapements
Second- Shape of the teeth and leaves
General study of the transmission of force in gearings
Determination of the forms of contact in gearings
First- Graphic method - Exterior gearing
Interior gearing
Second- Method of the envelopes
Eveolvents of circle gearings
Third - Roller method
Flank gearings
Determination of the profile of a tooth corresponding to a profile chosen arbitrarily
Gearings by the evolvent of a circle
Teeth-range
Third- Total diameters
Cycloid
Definition
Drawing of the cycloid
Drawing of the cycloid of a continuous movement
Normal and tangent to the cycloid
Evolution and radius of curvature of the cycloid
Length of the cycloid
Epicycloid
Definition
Drawing of the epicycloid
Drawing of the epicycloid of a continuous movement
To draw a normal, then a tanget to the epicycloid
Evolute and radius of curvature of the epicycloid
Length of the epicycloid
Applications
Relation of the radius vector to the angle formed by the variable radius vector and the initial radius vector
Table showing the angle traversed by the pinion of several ordinary gearings during the contact of a tooth of the wheel with the leaf of this pinion
Calculation of the total radius of the wheel
Form of the excess of the pinion leaf in a flank gearing
Radius of curvature of an elipse
Total radius of the pinion
Graphical construction of gearings
Practical applications of the theory of gearings
The proportional compass and its use
Table for using the proportional compass
Verification of a proportional compass
Determination of the distance of the centers of a gearing by means of the proportional compass and of a depthing tool
The proportional compass and stem-winding wheel gearings
Gearing of the crown wheel in the ratchet wheel
Gearing of the winding pinion in th ecrown teeth of the contrate wheel
Gearing of the sliding pinion and of the small setting wheel
Gearings of the dial wheels
Various calculations relative to gearings
Conical Gearings
Form of the teeth
Construction of conical gearings
Defects which present themselves in these gearings
Passive resistances in gearings
General ideas
Friction
The two kinds of friction
Laws of friction
Experimental determination of the force of friction
Table of the coefficients of friction
Work of friction
Angle of friction
Calculation of the friction in gearins
Friction of the teeth ranges
Friction before and after the line of centers
The wheel drives the pinion after the line of centers
The pinion drives the wheel before the line of centers
The wheel drives the pinion before the line of centers
The pinion drives the wheel after the line of centers
Recapitulation of the preceding calculations
Calculations of th efriction of pivots
Work absorbed by the friction of the plane surface of the shoulder of a pivot
Work absorbed by the friction of the cylindrical surface ofa pivot
Determination of the lateral pressure received by the pivots of the mobiles in a train
Influence of the oil
Application of the theory of gearings
Functions of the heart in chronographs