Chapter II
we gave a rule for determining the outside diameter of a cylinder from the diameter of the escape wheel; but such rules and tables will, in nine instances out of ten, have to be modified by attendant circumstances--as, for instance, the thickness of the shell of the cylinder, which should be one-tenth of the outer diameter of the shell, but the shell is usually thicker. A tolerably safe practical rule and one also depending very much on the workman's good judgment is, when the escape-wheel teeth have been shortened, to select a cylinder giving ample clearance inside the shell to the tooth, but by no means large enough to fill the space between the teeth. After studying carefully the instructions just given we think the workman will have no difficulty in selecting a cylinder of the right diameter.
MEASURING THE HEIGHTS.
The next thing is to get the proper heights. This is much more easily arrived at: the main measurement being to have the teeth of the escape wheel clear the upper face of the lower plug. In order to talk intelligently we will make a drawing of a cylinder and agree on the proper names for the several parts to be used in this chapter. Such drawing is shown at Fig. 171. The names are: The hollow cylinder, made up of the parts _A A' A'' A'''_, called the shell--_A_ is the great shell, _A'_ the half shell, _A''_ the banking slot, and _A'''_ the small shell. The brass part _D_ is called the collet and consists of three parts--the hairspring seat _D_, the balance seat _D'_ and the shoulder _D''_, against which the balance is riveted.
[Illustration: Fig. 171]
The first measurement for fitting a new cylinder is to determine the height of the lower plug face, which corresponds to the line _x x_, Fig. 171. The height of this face is such as to permit the escape wheel to pass freely over it. In selecting a new cylinder it is well to choose one which is as wide at the banking slot _A''_ as is consistent with safety. The width of the banking slot is represented by the dotted lines _x u_. The dotted line _v_ represents the length to which the lower pivot _y_ is to be cut.
[Illustration: Fig. 172]
[Illustration: Fig. 173]
There are several little tools on the market used for making the necessary measurements, but we will describe a very simple one which can readily be made. To do so, take about a No. 5 sewing needle and, after annealing, cut a screw thread on it, as shown at Fig, 172, where _E_ represents the needle and _t t_ the screw cut upon it. After the screw is cut, the needle is again hardened and tempered to a spring temper and a long, thin pivot turned upon it. The needle is now shaped as shown at Fig. 173. The pivot at _s_ should be small enough to go easily through the smallest hole jewel to be found in cylinder watches, and should be about 1/16" long. The part at _r_ should be about 3/16" long and only reduced in size enough to fully remove the screw threads shown at _t_.
[Illustration: Fig. 174]
[Illustration: Fig. 175]
[Illustration: Fig. 176]
[Illustration: Fig. 177]
We next provide a sleeve or guard for our gage. To do this we take a piece of hard brass bushing wire about ½" long and, placing it in a wire chuck, center and drill it nearly the entire length, leaving, say, 1/10" at one end to be carried through with a small drill. We show at _F_, Fig. 174, a magnified longitudinal section of such a sleeve. The piece _F_ is drilled from the end _l_ up to the line _q_ with a drill of such a size that a female screw can be cut in it to fit the screw on the needle, and _F_ is tapped out to fit such a screw from _l_ up to the dotted line _p_. The sleeve _F_ is run on the screw _t_ and now appears as shown at Fig. 175, with the addition of a handle shown at _G G'_. It is evident that we can allow the pivot _s_ to protrude from the sleeve _F_ any portion of its length, and regulate such protrusion by the screw _t_. To employ this tool for getting the proper length to which to cut the pivot _y_, Fig. 171, we remove the lower cap jewel to the cylinder pivot and, holding, the movement in the left hand, pass the pivot _s_, Fig. 175, up through the hole jewel, regulate the length by turning the sleeve _F_ until the arm of the escape wheel _I_, Fig. 176, will just turn free over it. Now the length of the pivot _s_, which protrudes beyond the sleeve _F_, coincides with the length to which we must cut the pivot _y_, Fig. 171. To hold a cylinder for reducing the length of the pivot _y_, we hold said pivot in a pair of thin-edged cutting pliers, as shown at Fig. 177, where _N N'_ represent the jaws of a pair of cutting pliers and _y_ the pivot to be cut. The measurement is made by putting the pivot _s_ between the jaws _N N'_ as they hold the pivot. The cutting is done by simply filing back the pivot until of the right length.
TURNING THE PIVOTS.
We have now the pivot _y_ of the proper length, and what remains to be done is to turn it to the right size. We do not think it advisable to try to use a split chuck, although we have seen workmen drive the shell _A A'''_ out of the collet _D_ and then turn up the pivots _y z_ in said wire chuck. To our judgment there is but one chuck for turning pivots, and this is the cement chuck provided with all American lathes. Many workmen object to a cement chuck, but we think no man should lay claim to the name of watchmaker until he masters the mystery of the cement chuck. It is not such a very difficult matter, and the skill once acquired would not be parted with cheaply. One thing has served to put the wax or cement chuck into disfavor, and that is the abominable stuff sold by some material houses for lathe cement. The original cement, made and patented by James Bottum for his cement chuck, was made up of a rather complicated mixture; but all the substances really demanded in such cement are ultramarine blue and a good quality of shellac. These ingredients are compounded in the proportion of 8 parts of shellac and 1 part of ultramarine--all by weight.
HOW TO USE A CEMENT CHUCK.
The shellac is melted in an iron vessel, and the ultramarine added and stirred to incorporate the parts. Care should be observed not to burn the shellac. While warm, the melted mass is poured on to a cold slab of iron or stone, and while plastic made into sticks about ½" in diameter.
[Illustration: Fig. 178]
[Illustration: Fig. 179]
We show at Fig. 178 a side view of the outer end of a cement chuck with a cylinder in position. We commence to turn the lower pivot of a cylinder, allowing the pivot _z_ to rest at the apex of the hollow cone _a_, as shown. There is something of a trick in turning such a hollow cone and leaving no "tit" or protuberance in the center, but it is important it should be done. A little practice will soon enable one to master the job. A graver for this purpose should be cut to rather an oblique point, as shown at _L_, Fig. 179. The slope of the sides to the recess _a_, Fig. 178, should be to about forty-five degrees, making the angle at _a_ about ninety degrees. The only way to insure perfect accuracy of centering of a cylinder in a cement chuck is center by the shell, which is done by cutting a piece of pegwood to a wedge shape and letting it rest on the T-rest; then hold the edge of the pegwood to the cylinder as the lathe revolves and the cement soft and plastic. A cylinder so centered will be absolutely true. The outline curve at _c_, Fig. 178, represents the surface of the cement.
The next operation is turning the pivot to the proper size to fit the jewel. This is usually done by trial, that is, trying the pivot into the hole in the jewel. A quicker way is to gage the hole jewel and then turn the pivot to the right size, as measured by micrometer calipers. In some cylinder watches the end stone stands at some distance from the outer surface of the hole jewel; consequently, if the measurement for the length of the pivot is taken by the tool shown at Fig. 175, the pivot will apparently be too short. When the lower end stone is removed we should take note if any allowance is to be made for such extra space. The trouble which would ensue from not providing for such extra end shake would be that the lower edge of the half shell, shown at _e_, Fig. 171, would strike the projection on which the "stalk" of the tooth is planted. After the lower pivot is turned to fit the jewel the cylinder is to be removed from the cement chuck and the upper part turned. The measurements to be looked to now are, first, the entire length of the cylinder, which is understood to be the entire distance between the inner faces of the two end stones, and corresponds to the distance between the lines _v d_, Fig. 171. This measurement can be got by removing both end stones and taking the distance with a Boley gage or a douzieme caliper.
A CONVENIENT TOOL FOR LENGTH MEASUREMENT.
[Illustration: Fig. 180]
A pair of common pinion calipers slightly modified makes as good a pair of calipers for length measurement as one can desire. This instrument is made by inserting a small screw in one of the blades--the head on the inner side, as shown at _f_, Fig. 180. The idea of the tool is, the screw head _f_ rests in the sink of the cap jewel or end stone, while the other blade rests on the cock over the balance. After the adjusting screw to the caliper is set, the spring of the blades allows of their removal. The top pivot _z_ of the cylinder is next cut to the proper length, as indicated by the space between the screwhead _f_ and the other blade of the pinion caliper. The upper pinion _z_ is held in the jaws of the cutting pliers, as shown in Fig. 177, the same as the lower one was held, until the proper length between the lines _d v_, Fig. 171, is secured, after which the cylinder is put back into the cement chuck, as shown at Fig. 178, except this time the top portion of the cylinder is allowed to protrude so that we can turn the top pivot and the balance collet _D_, Fig. 171.
The sizes we have now to look to is to fit the pivot _z_ to the top hole jewel in the cock, also the hairspring seat _D_ and balance seat _D'_. These are turned to diameters, and are the most readily secured by the use of the micrometer calipers to be had of any large watchmakers' tool and supply house. In addition to the diameters named, we must get the proper height for the balance, which is represented by the dotted line _b_. The measurement for this can usually be obtained from the old cylinder by simply comparing it with the new one as it rests in the cement chuck. The true tool for such measurements is a height gage. We have made no mention of finishing and polishing the pivots, as these points are generally well understood by the trade.
REMOVING THE LATHE CEMENT.
One point perhaps we might well say a few words on, and this is in regard to removing the lathe cement. Such cement is usually removed by boiling in a copper dish with alcohol. But there are several objections to the practice. In the first place, it wastes a good deal of alcohol, and also leaves the work stained. We can accomplish this operation quicker, and save alcohol, by putting the cylinder with the wax on it in a very small homeopathic bottle and corking it tight. The bottle is then boiled in water, and in a few seconds the shellac is dissolved away. The balance to most cylinder watches is of red brass, and in some instances of low karat gold; in either case the balance should be repolished. To do this dip in a strong solution of cyanide of potassium dissolved in water; one-fourth ounce of cyanide in half pint of water is about the proper strength. Dip and rinse, then polish with a chamois buff and rouge.
[Illustration: Fig. 181]
In staking on the balance, care should be observed to set the banking pin in the rim so it will come right; this is usually secured by setting said pin so it stands opposite to the opening in the half shell. The seat of the balance on the collet _D_ should be undercut so that there is only an edge to rivet down on the balance. This will be better understood by inspecting Fig. 181, where we show a vertical section of the collet _D_ and cylinder _A_. At _g g_ is shown the undercut edge of the balance seat, which is folded over as the balance is rivetted fast.
About all that remains now to be done is to true up the balance and bring it to poise. The practice frequently adopted to poise a plain balance is to file it with a half-round file on the inside, in order not to show any detraction when looking at the outer edge of the rim. A better and quicker plan is to place the balance in a split chuck, and with a diamond or round-pointed tool scoop out a little piece of metal as the balance revolves. In doing this, the spindle of the lathe is turned by the hand grasping the pulley between the finger and thumb. The so-called diamond and round-pointed tools are shown at _o o'_, Fig. 182. The idea of this plan of reducing the weight of a balance is, one of the tools _o_ is rested on the T-rest and pressed forward until a chip is started and allowed to enter until sufficient metal is engaged, then, by swinging down on the handle of the tool, the chip is taken out.
[Illustration: Fig. 182]
[Illustration: Fig. 183]
In placing a balance in a step chuck, the banking pin is caused to enter one of the three slots in the chuck, so as not to be bent down on to the rim of the balance. It is seldom the depth between the cylinder and escape wheel will need be changed after putting in a new cylinder; if such is the case, however, move the chariot--we mean the cock attached to the lower plate. Do not attempt to change the depth by manipulating the balance cock. Fig. 183 shows, at _h h_, the form of chip taken out by the tool _o o'_, Fig. 182.
INDEX
A
Acid frosting, 46
"Action" drawings, 90
## Action of a chronometer escapement, 142
## Acting surface of entrance lip, 127
## Actions of cylinder escapement, 112
Adhesion of parallel surfaces, 94
Adjustable pallets, 98
Adjusting screw for drawing instruments, 21
Analysis of principles involved in detent, 137
Analysis of the action of a lever escapement, 86
Angle-measuring device, 68
Angular extent of shell of cylinder, 122
Angular motion, drawing an escapement to show, 91 How measured, 69 Of escape wheel, 37
Antagonistic influences, 133
Arc of degrees, 9
Atmospheric disturbances, 74
Attainment of isochronism, 159
B
Balance, how it controls timekeeping, 73 Weight and inertia of, 133
Balance spring, inventor of, 132
Banking slot of cylinder, 112
Bankings, effect of opening too wide, 63
Bar compasses, 21
Barometric pressure, 74
Basis for close measurements, 96
C
Cement chuck, how to use, 173
Chronometer detent, importance of light construction, 136
Chronometer escapement, 131, 155 Four principal parts of, 134
Circular pallets, 27
Club-tooth escapement, 30, 34
Club-tooth lever escapement with circular pallets and tangential lockings, 83
Crown-wheel escapement, 155
Cylinder, drawing a, 120 Outer diameter of, 116 Putting in a new, 169
Cylinder escapement, 155 Date of invention, etc., 111 Forms and proportions of several parts of, 111 Names of various parts, 112
Cylinder lips, proper shape of, 124
D
Dead-beat escapement, 131, 135 Only one true, 112
Depth, between cylinder and escape wheel, 129 Effect of changing, 176
Designing a double roller, 77
Detached escapement, 155
Detent, functions of the, 137
Detent escapement, 131, 155 Faults in, 132
Detent spring dimensions, 138
Detent springs, width of, 147
Discharging jewel, setting the, 142
Discharging roller, 136
Dividers, 9 Making, 10
Double pendulum, 160
Double-roller escapement, 75
Draw defined, 85
Drawing-board, 11
Drawing instruments, 9
Drawings, advantage of large, 29
Drop and draw, 150
Duplex escapement, 131, 155
E
Elasticity of spring, 133
Engaging friction, 81
English recoil anchor, 167
Entrance lip of cylinder escapement, 125
Escapement angles, measuring, 101
Escapement error, study of, 64
Escapement matching tool, 106
Escapement model, 40 Balance, 42 Balance staff, 44 Bridges, 41, 42 Escape wheel, 43 Extra balance cock, 45 "Frosting", 46 Hairspring, 42 Jewel for, 43 Lower plate, 41 Main plate, 41 Movement for, 41 Pallet staff, 42 Pillars, 43 Regulator, 46 Uses of, 44 Wood base for, 41
Escapements compared, 103
Escapement of Dutertre, 160
Escape-wheel action, 30
Escape-wheel, delineating an, 11
Escape-wheel teeth vs. cylinder, 169
Escape-wheel tooth in action, delineating an, 126
Exit pallet, 26
Experiments of Galileo, 158
Experiments with a chronometer, 142
Extent of angular impulse, 118
F
"Fall" defined, 106
Faults in the detent escapement, 132
Fixed rules, of little value to student, 137
Flexure of gold spring, 146
Foot, fitting up the, 151
Fork, testing the, 71
Fork action, 30 Theory of, 59
Fork and roller action, 54
Formulas for delineating cylinder escapement, 115
Frictions, 24
Frictional escapement, 131, 132
Frictional surfaces, 63
Fusee, 131
G
Gable escapement, 167
Gage, a new, 172
Graham anchor escapement, 155
Gold spring, 146
Guard point, 79 Material for, 79
Gummy secretion on impulse and discharging stones, 147
H
Heights in cylinders, how obtained, 171
Hole jewels, distance apart, 140
I
Imaginary faults in cylinders, 129
Impulse angle, 118
Impulse arc, extent of, 134
Impulse jewel set oblique, 147
Impulse planes, locating outer angle of, 39
Impulse roller, 136
Incline of teeth, 122
Inertia of balance, 133
Inventions of Berthoud, 163 Béthune, 165 Clement, 166 Dr. Hook, 162 Harrison, 161 Hautefeuille, 161 Huygens, 158 Leroy, 163 Thiout, 165
J
Jewel pin, determining size, 58 Cementing in, 67 Settings, 66
Jewel-pin setters, 67
L
Lathe cement, 173 Removing, 175
Lever, proper length of, 61
Lever fork, horn of, 61 prongs of, 60
Lift, real and apparent, 112
Lifting angle, 114
Lock, amount of, 28 Defined, 85
Lock and drop testing, 69
Locking jewel, moving the, 149
Locking stone, good form of, 144
Lower plate, circular opening in, 56
M
Marine chronometer, number of beats to hour, 148
Mathematics, 95
Measuring tools, 171
Metal drawings, advantages of, 140
Motion, how obtained, 16
Movement holder, 110
N
Neutral lockings, 84
O
Original designing, 148
P
Pallet action, locating the, 90
Pallet-and-fork action, 12, 13, 17, 18
Pallet stones, how to set, 104
Pallets, adjusting to match the fork, 65
Paper for drawing, 11
Parts, relations of the, 32
Passing hollow, 62
Perfected lever escapement, 87
Pivots, turning, 172
Point of percussion, 139
Points for drawing instruments, 20
Polishing materials, 52
Power leaks, 16
Power lost in lever escapement, 87
Practical problems in the lever escapement, 98
R
Radial extent of outside of cylinder, 125
Ratchet-tooth escape wheel, 12
Recoil anchor escapement, 155
Recoil escapement, 154
Reduced gable escapement, 167
Retrograde motion, 36
Roller action, why 30 degrees, 55 Of double roller, 78
Roller diameter, determining the, 55
Ruling pen, 9
S
Safety action, 56
Scale of inches, 9
Screws, making extra large, 45
Screwheads, fancy, 45
Selecting new cylinder, 170
Shaping, advantages gained in, 116
Sheet steel, cutting, 48
Short fork, 100
Sound as indicator of correct action, 144
Spring, elasticity of, 133
Staking on a balance, 175
Steel, polishing, 49 Tempering, 49
Study drawings, 124
Systems of measurements, 114
T
Tangential lockings, 80, 148
Test gage for angular movement, 65
Theoretical action of double roller, 76
Timekeeping, controlled by balance, 73
Tool for length measurement, 174
Tools, measuring, 171
Triangle, 18
T-square, 9
U
Unlocking action, 56
Unlocking roller, 136
V
Verge escapement, 131, 155
W
Weight and inertia of balance, 133
Working model of cylinder escapement, 123
* * * * * *
THE WATCH ADJUSTER'S MANUAL
[Illustration]
A Complete and Practical Guide for Watchmakers in Adjusting Watches and Chronometers for Isochronism, Position, Heat and Cold.
BY CHARLES EDGAR FRITTS (EXCELSIOR),
Author of "Practical Hints on Watch Repairing," "Practical Treatise on Balance Spring," "Electricity and Magnetism for Watchmakers," etc., etc.
This well-known work is now recognized as the standard authority on the adjustments and kindred subjects, both here and in England. It contains an exhaustive consideration of the various theories proposed, the mechanical principles on which the adjustments are based, and the different methods followed in actual practice, giving all that is publicly known in the trade, with a large amount of entirely new practical matter not to be found elsewhere, obtained from the best manufacturers and workmen, as well as from the author's own studies and experiences.
Sent postpaid to any part of the world on receipt of $2.50 (10s. 5d.)
THE KEYSTONE (SOLE AGENT), 19TH AND BROWN STREETS, PHILADELPHIA, U.S.A.
* * * * *
THE ART OF ENGRAVING
[Illustration]
A Complete Treatise on the Engraver's Art, with Special Reference to Letter and Monogram Engraving. Specially Compiled as a Standard Text-Book for Students and a Reliable Reference Book for Engravers.
This work is the only thoroughly reliable and exhaustive treatise published on this important subject. It is an ideal text-book, beginning with the rudiments and leading the student step by step to a complete and practical mastery of the art. Back of the authorship is a long experience as a successful engraver, also a successful career as an instructor in engraving. These qualifications ensure accuracy and reliability of matter, and such a course of instruction as is best for the learner and qualified engraver.
The most notable feature of the new treatise is the instructive character of the illustrations. There are over 200 original illustrations by the author. A very complete index facilitates reference to any required topic.
Bound in Silk Cloth--208 Pages and 216 Illustrations.
Sent postpaid to any part of the world on receipt of price, $1.50 (6s. 3d.)
PUBLISHED BY THE KEYSTONE, THE ORGAN OF THE JEWELRY AND OPTICAL TRADES, 19TH & BROWN STS., PHILADELPHIA, U.S.A.
* * * * *
THE KEYSTONE PORTFOLIO OF MONOGRAMS
[Illustration: C.B.R.]
[Illustration: A.O.U.W]
[Illustration: I.R.C.]
[Illustration: G.H.I.]
This portfolio contains 121 combination designs. These designs were selected from the best of those submitted in a prize competition held by The Keystone, and will be found of value to every one doing engraving.
The designs are conceded to be the best in the market, excelling in art and novelty of combination and skill in execution.
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The portfolio is a bench requirement that no jeweler can afford to be without. It is a necessary supplement to any text-book on letter engraving.
Price, 50 Cents (2s.)
PUBLISHED BY THE KEYSTONE, THE ORGAN OF THE JEWELRY AND OPTICAL TRADES, 19TH & BROWN STS., PHILADELPHIA, U.S.A.
* * * * *
THE OPTICIAN'S MANUAL
VOL. I.
BY C.H. BROWN, M.D.
Graduate University of Pennsylvania; Professor of Optics and Refraction; formerly Physician in Philadelphia Hospital; Member of Philadelphia County, Pennsylvania State and American Medical Societies.
[Illustration]
The Optician's Manual, Vol. I., has proved to be the most popular work on practical refraction ever published. The knowledge it contains has been more effective in building up the optical profession than any other educational factor. A study of it is essential to an intelligent appreciation of Vol. II., for it lays the foundation structure of all optical knowledge, as the titles of its ten chapters show:
## Chapter I .--Introductory Remarks.
## Chapter II .--The Eye Anatomically.
## Chapter III .--The Eye Optically; or, The Physiology of Vision.
## Chapter IV .--Optics.
## Chapter V .--Lenses.
## Chapter VI .--Numbering of Lenses.
## Chapter VII .--The Use and Value of Glasses.
## Chapter VIII .--Outfit Required.
## Chapter IX .--Method of Examination.
##