CONTENTS OF BOOK V.

Page A Quick Way to Bring a Clock to Time ...... 59 New Pendulum Rod ...... 59 To Calculate the Length of a Pendulum Rod ...... 59 Compensating Pendulum ...... 59 Description of a Balance Clock...... 60 Alarm Attachment ...... 61 Dissembling, Repairing and Assembling...... 61 The Lever Escapement ...... 62 The Pallet Action ...... 63 The Roller and Fork Action...... 63 The Guard Pin, or Safety Pin...... 63 Adjusting the Pallet Action...... 63 Setting in Beat...... 64 Adjusting the Roller Action...... 64 Oiling and Casing ...... 64 Watch Repairing ...... 65 Helpful Information ...... 65 Sizes of Movements...... 65 Watch Cases ...... 66 Watch Glasses ...... 67 Tweezers ...... 67 Staffs ...... 68 Shoulder Gauge ...... 68 Making Large Staff...... 68 Grinding and Polishing Slips...... 70 Small Staffs ...... 71 Grinding The Body ...... 71 Grinding the Pivots ...... 71 Cementing a Staff...... 72 Polishing a Staff...... 72

Copyright, 1914 and 1915, by JOHN DREXLER. A QUICK WAY TO BRING A CLOCK TO TIME. Write down the number of minutes the clock varied in a given time, and the amount of turns given to the ad­ justing device. For example, if a clock gains ten min­ utes a day, and the nut on the pendulum is given two turns, which causes the clock to lose ten minutes a day, it shows that one turn is equivalent to ten minutes' time change, so by reversing one turn the clock should be nearly on time. NEW PENDULUM ROD. Should it be necessary to replace a pendulum rod, bear in mind that the length of the pendulum and the number of escape wheel teeth have been calculated with reference to the length of the clock case. With a long pendulum, less escape wheel teeth are needed than with a short one. A meter pendulum beats once a second, or 3,600 times an hour. A beat, is a tooth striking on a pallet and takes place every time the pendulum swings one way. Its time is thus equal to that of a swing of the pendulum. TO CALCULATE THE LENGTH OF A PENDULUM. Multiply the number of the escape wheel teeth by 120 ( which gives the number of vibrations per hour) and divide 3,600 ( the number of vibrations of a second pen­ dulum per hour) by the result thus obtained. The result will be the length sought, in the fractional part of a meter. Thus, if an escape wheel has 40 teeth, it would require a ¾ meter pendulum, because- 3600 3

40 X 120 4 COMPENSATING PENDULUM. When clockmakers devised methods for calculating the length of pendulums, they noticed that the tempera­ ture change caused a variation in the time required. This variation was due to the expansion and contraction of the metal used for the pendulum rod. The difficulty was overcome by making the rods from wood, a method ex- 59 tensively employed at present; or by using a compensat­ ing pendulum that is constructed in such a way that a part of it expands upward and a part downward, render­ ing the center of gravity constant. The best form of compensating pendulums are used in astronomical clocks, which are provided with glass tubes filled with mercury. The mercury tubes form the bob and adjust themselves automatically. When the temperature is low, the rod shortens and the mercury falls in the tubes; when the temperature is high, the rod lengthens and the mercury rises in the tubes. In either case the center of gravity of the pendulum remains con­ stant and the swings therefore remain uniform. DESCRIPTION OF A BALANCE CLOCK. Thus far pendulum clocks have been explained, and we now direct our attention to balance clocks, in which the anchor, or verge, and fork are fastened on an arbor and controlled by a balance wheel and hair spring, in­ stead of a pendulum. Similar, but finer constructed es­ capements are also used in watches, and are termed de­ tached lever escapements, because the balance arbor is free from the lever, except at the instant the roller pin ( fastened to the balance), enters the fork and gives the impulse to it. The pallets may resemble those of the dead beat escapement, previously described, or be formed of pins, in which case the escapement is called a pin lever escape­ ment. This escapement, used in a balance clock, is con­ structed similar to the one shown in Fig. 103, in which E is the escape wheel, PP the pallet pins, A the anchor, F the fork, C the crescent, or bank, banking against the escape pinion L, B the balance, R the roller pin, and M the guard pin. The hairspring and collet are shown in Fig. 104, as they would confuse the illustration of the escapement. The regulator is shown in Fig. 105. The locking faces of the escape wheel teeth are slanted away from the center for the draw. ( See Fig. 103.) The lift is divided between the pallets and the teeth, which have long impulse faces, or inclines slanted toward the center of the escape wheel. 60 On one side of the anchor, which contains the hard steel pallet pins, is the counterpoise, that embraces the escape wheel arbor and acts as a bank or stop to prevent the fork from swinging too far. Fastened to the fork is the safety or guard pin, which, when jarred, prevents overbanking, or the roller pin getting on the outside of the fork. The balance arbor has hard, well polished, sharp pointed pivots, which rest in V shaped screws, fastened in the plates and made to adjust the end shake. The hair­ spring is made in a flat spiral form, and must be true in the flat and round. Its inner end is fastened into a brass ring, or collet, which is pressed on the balance arbor, and its outer end is pinned into a stud which is fastened in the plate. A short distance from its outer end, it passes midway between two regulator pins, that are closed and opened to artificially lengthen or shorten the spring when regulating the clock. (See Fig. 105.) ALARM ATTACHMENT. Some balance clocks have an alarm attachment, sim­ ilar to those in striking clocks, differing, however, in the unlocking device, as shown in Fig. 106, in which W is the cam wheel that gears into the pinion of the minute wheel; A the cam wheel arbor, to which is fastened the alarm hand and a disk D, resembling the male of a stop work; and S the spring that holds the cam wheel against the disk, and extends through the plate to lock the wire V, which is connected to the verge arbor X. The re­ mainder of the train is not shown, as it resembles closely the one of a pendulum clock. The illustration shows the cam wheel at its lowest point and when the train advances, the pin in the disk ( D) slides off the highest point of the cam, and the spring ( S) is allowed to raise, and release the verge. The alarm will then ring until stopped, either by the running down of the mainspring, or by the hammer lever being locked. DISSEMBLING, REPAIRING AND ASSEMBLING. After removing the movement from the case, remove the hands and dial, and let down the mainspring. With 61 a tracer, mark the hairspring where it is fastened in the brass stud; with a flat plier, withdraw the pin that holds it; loosen one of the s_crews that holds the balance and remove it. Mark the position of the hairspring collet on the arbor, rest the pivot on the filing block, and, embrac­ ing the arbor with a pair of tweezers, as shown in Fig. 104, press the collet off. If the conical pivots or points of the balance arbor are not sharp and well polished, fasten the arbor in the lathe, grind with an oil-stone slip, and polish with a little diamantine applied to a boxwood slip. Place the hairspring on a broach, and revolve it to see if it is true in the flat and round. If one coil pro­ jects above the others, take it off the broach, lay it on a flat surface, hold the high coil down with a pegwood, and carefully lift the others with a tweezer until the coils are all level. After truing in the flat, true in the round. Begin at the collet, make all the coils of equal distance from each other, by holding the spring, at the bend, with the tweezer, and straightening it with a pegwood. After truing the hairspring, unfasten the pillars from the plate, remove the fork and examine its slot and the pallet pins. If the slot is worn uneven, rest the fork on a filing block and burnish it smooth. If the pallet pins are worn, turn them half way around with a smooth flat plier, or punch them out, drive in needles of the same size, and cut or grind them off to the same length as the old ones. Dissemble the remainder of the train; examine and remedy any defects that may be present; clean and as­ semble ready for adjustment. Be careful and replace the hairspring on the balance arbor correctly. Pull the end of the hairspring between the regulator pins, through the stud, and pin it where it was marked. Bend it ( as at S, Fig. 105) near the stud, so that it touches the regulator pins equally when vibrating between them. Make it true in the flat ( as at XX), and if the second coil, when in motion, touches the inside regulator pin or the stud, where it is fastened, bend it ( as at L) opposite the stud until it does not touch. THE LEVER ESCAPEMENT. In order that you may understand the adjustment of pin lever escapement, we have divided it into the action 62 of the escape wheel and pallets, called the pallet action, and the action of the roller pin and fork, called the roller. or fork action. THE PALLET ACTION. The lock is the distance the escape wheel tooth over­ laps the pallet, when the fork rests against the bank. Draw is the amount of slant of the locking face of a tooth away from the center of the escape wheel and the amount of slant of the pallet away from the center of the pallet frame. It is for drawing the pallet toward the center of the escape wheel and the fork toward the bank, when a tooth locks on a pallet. The lift is the distance an escape wheel tooth causes the fork to travel from the instant of lock until the drop takes place. THE ROLLER AND FORK ACTION. Part of the energy imparted to the balance by the roller pin engaging in the fork winds the hairspring, which, when unwinding, causes the balance to swing back, and, in turn give impulse to the fork. THE GUARD PIN, OR SAFETY PIN. This pin is fastened in the fork and extends a trifle beyond the slot in the middle of the fork horns and faces the balance, and hollow of the roller table. Its purpose is to prevent overbanking, or the fork shifting from one bank to the other, before the roller pin has had a chance to enter the slot and continue its action, as shown at Y, Fig. 107. The guard pin must not be too long and must not touch the safety roller, when in motion, but must be long enough to prevent overbanking, and have equal free­ dom on both sides of the roller when the fork is against the bank. The dotted lines in Fig. 107 and 108 show the correct length of the safety pin, and the full lines in Fig. 107 show it too short, while the full lines in 108 show it too long, and too near the roller table. ADJUSTING THE PALLET ACTION. Wind the mainspring a turn, and with the finger on the balance, lead it back and forth, to examine the escape- 63 ment. Try the action of the pallets on each tooth of the escape wheel, and if a pallet pin falls on the impulse face of a tooth, as shown at B, Fig. 109, instead of locking on the locking face, as shown at 0, Fig. 103, indicating that the escapement is too shallow, bring the verge closer to the escape wheel. If the verge arbor is not set in bridges that can be moved, bend the arbor itself with a plier, but not enough to make the escapement too deep, as shown at X, Fig. 110. If a pallet pin touches the back of a tooth when it recoils, as shown at R, in Fig. 111, bend the pallet pin so that the pallets are separated a trifle. If the counterpoise strikes the escape wheel arbor too soon, not allowing the tooth to drop, bend the counterpoise from the arbor until the tooth drops. SETTING IN BEAT. After adjusting the pallet action, lock the train with a pegwood, and, when the balance comes to rest, see if the roller pin and the fork are in one line between the bal­ ance arbor and that of the fork ( called the line of cen­ ters). If it is not, place a screw driver in the slot of the hairspring collet, and turn the balance without bending the hairspring until it will assume that position when at rest. ADJUSTING THE ROLLER ACTION. Remove the pegwood and see if the roller pin enters the slot in the fork freely. If it touches at Z, Fig. 103, when it is to give the impulse at K on the other side of the slot, bend the fork a trifle toward Z. The same ap­ plies to the other side. If the safety pin is too long, as at X, Fig. 108, and will not pass through the crescent or hollow in the safety roller, make a bend in it to shorten it. If it is too short, and allows overbanking, as at Y, in Fig. 107, stretch it a little, or lengthen it artificially by bending it forward or straightening the fork. OILING AND CASING. After adjusting the pallet and roller action, the reg­ ulator and hairspring, according to the instructions, oil the movement ( taking care not to oil the hairspring). 64 Adjust the alarm by turning the cam wheel until the pin drops from its highest point into its slot, fasten the dial, place and fasten all the hands at twelve, fasten the move­ ment in the case, adjust the alarm hammer and regulate by moving the regulator towards F to make it go fast and towards S to make it go slow. If you shifted the reg­ ulator as far as it will go and it still runs too slow, or too fast, remove from the case and shorten the hairspring a trifle, or close the regulator pins if it runs too slow, and lengthen a trifle or open the regulator pins if it runs too fast. Again notice if in beat and adjust so the regulator will stand midway between F and S when regulated. These instructions on the pin lever escapement and their application to alarm clocks have been given, hop­ ing you will study them well, and thus be better prepared to understand the escapement's action in watches, for its principle of action is the same. If you have applied yourself to the elementary work according to instructions, we are satisfied that you will profit greatly by the instructions on clock work, and we wish to assure you that what you have learned from them will be of great assistance in watch work. We reason­ ably expect that you will apply yourself to the advanced instructions with greater enthusiasm, as they are more interesting.

WATCH REPAIRING

HELPFUL INFORMATION. There are a few facts about watches which you should know before beginning watch work. These are ordinarily acquired in a repair shop through extended experience; but by noting the following, you can learn them in a shorter time. SIZES OF MOVEMENTS. The American watch factories name the sizes of watches according to the outside diameter of the bottom plate, which is the one next to the dial. The sizes are as 65 follows: 0 size measures one and :five-thirtieths ( 1 5/30) inches. Each one-thirtieth of an inch that is added to this measurement is an additional size, and therefore one and six-thirtieths ( 1 6/30) inches is the diameter of the One size movement. Six size should measure 1 11/30 inches, a Twelve size 1 17/30 inches, an Eighteen size 1 23/30, etc. The principal sizes on the market are the Eighteen size; the Sixteen size, old model (discontinued), and new model, which is somewhat thinner than the old model; Fourteen size, old model ( discontinued) ; Twelve size, new model; Eight size, old model (discontinued) ; Six size, old model ( discontinued) ; and new model One size, Waltham (discontinued) ; 0 size, new model; Three 0 size; Ten O size, Jewel Series, Waltham, and Lady Elgin. "Discontinued" movements are no longer made by the factories, but are still brought in for repairs. Movement plates and bridges are made of brass or nickel; the brass are gilded and the nickel are dameskined, or spotted, to improve their appearance. WATCH CASES. Cases are made of silverine, solid silver and solid gold. Filled cases are made of brass and covered with a thin plate of lOK or 14K gold, which is warranted to wear ten, twenty or twenty-five years. Solid gold cases are made of lOK or 14K and rarely of 18K. They wear indefinitely, for they are the same material clear through. The word karat determines the quality of gold. The finer the gold and less other metals it contains, the higher is the karat. 24 karat ( 24 Kt) is considered pure gold; thus 10 karat (l0Kt) contains ten parts of pure gold and fourteen parts of other metals, etc. Cases may be classified according to construction, as Hunting and Open face. Those which have a cover over the glass are Hunting cases and the others are Open face which have a snap or screw bezel. In some open face cases both the back and front bezels unscrew, while in others the back is solid and the movement is fastened in a ring that will swing out when the stem is pulled out 66 and the bezel is unscrewed. They are made in different designs, known as Plain or Polished cases; Satin Finish Roman Gilt; Engine Turned and Engraved. They are made by case factories to fit the various sizes of move­ ments, and are interchangeable for movements of the same size, except those smaller than O size, which are made to fit individual makes of movements. An old model move­ ment will not fit in a new model case and vice versa, for the old model is thicker than the new. WATCH GLASSES. The watch glasses on the market are the Geneva, which is a glass for Hunting cases that comes in sizes from nine to twenty-five and heights from five to eight; Mi con­ cave, for Open face, which comes in regular and extra thickness, in sizes from three to twenty-five, with the edges beveled; Lentille, for Open face, one thickness, in sizes from three to twenty-five, with the edge rounded; and Patent Geneva, which is like the Lentille, except that it is higher with the center ground. The foregoing has been given with the hope that it will be of interest and benefit to you as a matter of gen­ eral information, for it is made up of facts essential to the watch repairer's knowledge. TWEEZERS. There are many forms of tweezers. Get two, one of brass, marked (AM), for handling polished parts, and one of steel, marked (MM), with medium points, for general work. Keep the points of the tweezers sharp, flat on the inside and rounding on the outside. If a point breaks, as at S, in A, Fig. 112, grind on the facing plate until both points are the same length, and round the out­ side to a point. If the points are separated, as at L L in C, press the parts of the tweezer sidewise until the points meet. If the extreme points are bent and separated, as at A in B, straighten them and correct the inside flat faces. When handling small parts, especially round ones, with a tweezer, hold them lightly, for, if the tweezers are pressed together hard, the points will open, as in B, and snap the part away. 67 STAFFS. The pinions, pallet arbor and balance staff of a watch movement have their pivots made hard to resist wear. To train you to handle pivots without breaking or bending them, we find it advisable that you, as a beginner, turn large arbors or staffs from soft steel, then smaller ones from harder steel, and finally one the size of a sample, with thin pivots. Turning staffs trains the eye to judge small measurements, and the hand to execute them with­ out bending or breaking the pivots. SHOULDER GAUGE. Use the Grossman gauge for measuring the thickness of the staff. As it is not satisfactory for measuring the height of shoulders, we have designed a gauge ( See Fig. 113) which is easily made and very useful. It consists of a threaded steel wire about 2.5 m.m. in diameter, mounted in a wood handle, and two spool-like nuts, made of soft steel, and slotted to fit friction tight on this thread­ ed wire. The shoulders of the nuts must be perfectly straight to insure accuracy. The shoulders that come to­ gether are each 0.5 m.m. thick, so that the distance the nuts open can be readily calculated. To measure a shoulder, hold the gauge against it, as at S, in Fig. 113, turn the back nut until its shoulder touches the outer nut, turn the outer nut until its outer surface is even with tlie flat end of the threaded wire, measure the distance B B (Fig 113) with a Grossman gauge, subtract the thickness of the shoulder and the result will be the measurement desired. To take a measurement with one nut extending over the end of the wire, make the end of the nut even with the flat end of the wire, bring the nuts together; turn the outer nut out, the distance desired; measure at B B and subtract as before. To set the gauge for a measurement on the inside of the nut, set both nuts together with the outer one even with the flat end of the wire, and screw out the outer nut until the desired distance is obtained at B B. MAKING LARGE STAFF. Fig. 114 shows an Elgin 18 size balance staff that you can use as a pattern. The dimensions given in the drawing are again the size of the actual staff. A shows 68 the balance shoulder.," B the balance seat.,- C the hairspring collet shoulder underturned for riveting over the balance; D the hairspring collet seat/Ethe upper shoulder/ F the upper oil clzampfer/ G the cone, and H the cylindrical pivot. Then reading back from the balance shoulder, M is the body or hub/ L the roller table shoulder/ 0 the roller table seat.,- F the lower oil champfer, and P the pivot. (The letters on the drawings for staff work cor­ respond, and the black shows the amount taken away in each operation.) Allow about 1.5 c.m. of soft steel wire to protrude from a chuck and turn it to 3.6 m.m. in diameter with the end flat. Begin 4.4 m.m from the end and turn away as A and X, shown by the black in Fig. 115. This will be the balance seat. 3.2 m.m. from the end turn another shoulder, as from C to X, in Fig. 116, for the hairspring collet seat, 1.9 m.m. in diameter at the shoulder C and 1.7 m.m. at the end of the wire. With a lozenge graver, underturn the shoulder C, Fig. 123, and with a round graver, as shown in Fig. 118, turn the pivot. ( Fig. 117 shows the upper part of the staff turned.) Cut the oil champfer with a square graver, as in Fig. 119, and slightly bevel the edge of the shoulder E, Fig. 123. The dotted lines in Fig. 119 show how deep to cut the oil champfer. ( Be careful to have the cylindrical part of the pivot of uniform thickness throughout its entire length; that is, do not allow it to be thinner at its end than at the cone, as at C, Fig. 120, or thicker at the end, as at X, Fig. 121.) From the balance shoulder, measure 2.2 m.m. to­ ward the chuck and turn the slant of the hub between A and L ( See Fig. 122) 3.6 m.m. in diameter at the bal­ ance shoulder A, Fig. 123, and 3 m.m. in diameter at the roller table shoulder L. Turn out between the hub and the chuck and turn it off as at Y and Z, 6.6 m.m. from the hub. Fasten the hairspring collet seat in a well fit­ ting chuck, and if the staff does not run true, loosen the chuck slightly, run the lathe rapidly and with a slight pressure hold a pegwood against the staff, as in Fig. 124, to true it. (It may be necessary to turn the staff 6, partly around in the chuck to give it a new hold.) (Fig. 125 shows a pivot turned off center, caused by im­ proper centering.) When exactly true, tighten the chuck, turn the roller table shoulder straight. Turn the roller table seat 1.26 m.m. in diameter at the shoulder and 1 m.m. at the other end. Shorten the lower part of the staff to 5.4 m.m. from the roller table shoulder and turn the pivot and oil champfer the same as on the upper end. (Take care to have both pivots the same length and thickness.) The staff is now complete, and will measure 12 m.m. in length if the measurements have been properly taken. Make a few staffs for practice.

GRINDING AND POLISHING SLIPS. Shape a slip of bell metal and one of soft steel or iron, like Fig. 126. File the ends off straight, with the lower side narrower than the top side, as shown by the dotted line, and taper the end with the wide surface rounding, also with the lower side narrower than the top for clearance. Round one straight edge a trifle ( that has not been tapered) and grind the top surfaces crosswise on an India oil stone until dead flat. This will produce marks, as shown in the illustration. These marks will hold the grinding or polishing material. Use oil stone dust mixed with oil on the steel. slip for grinding; diamantine on the bell metal for the first polish and diamantine, mixed with crocus, on the bell metal for the final pq_lish, which will be a dark mirror­ like gloss if directions are followed carefully. Cleanli­ ness is absolutely essential to obtain a satisfactory polish/ and therefore the slips used for polishing should be washed in benzine and laid on a clean paper, as particles from grinding or dust of any kind that they might pick up from the bench, would scratch instead of polishing. The amount of diamantine paste to use on the bell metal is about one-fourth the size of a pinhead. If the paste is too thin, or too much is used, and the scratches do not disappear, wipe the surplus diamantine from the staff and bell metal with a piece of clean pith, dipped in benzine. Then continue the polishing.

70 SMALL STAFFS. Be more accurate in measuring, turning and center­ ing the small staffs. Make them the size of a sample, using the steel tempered greenish for the first few, that are to be only ground. The steel for the others is to be tempered dark blue. The last staff you will grind and polish. ( Staffs softer than blue will not take a high pol­ ish, but fine rings will appear.) GRINDING THE BODY. On a steel wire, tempered greenish, turn the upper part of a small staff on which to practice grinding. (Do not turn the oil champfer until after grinding.) Apply a little oil stone dust, mixed with oil, to the wide, round­ ing, flat surface of the iron slip, run the lathe rapidly and with short, slow strokes, up and down and occasionally sidewise, grind the hairspring collet seat lightly with the wide surface of the slip until all the rings have disap­ peared and the surface appears smooth and frosted. Hold the slip beneath the staff, exactly as in Fig. 127, allowing only the highest part of its rounding edge X, to be against the shoulder near the center of the staff. This grinds the shoulder straight, while a slip with a straight edge would grind the corners rounding. GRINDING THE PIVOTS. Grind the conical and cylindrical parts of the pivot at the same time. Hold the iron or oil-stone slip at an angle with the pivot as shown in Fig. 128, and move it back and forth, allowing the rounding edge of the slip to grind the conical part, and the flat surface to grind the cylindrical part. Hold the slip at all times level with the cylindrical part of the pivot, to prevent tapering its ends. If the slip is not held properly, long scratches will appear on the surface of the slip indicating that the cylindrical part of the pivot has been ground more near its end than near the cone, which causes the pivot to appear as at C, Fig. 120. If this occurs again, grind the slip on the oil­ stone until the marks have disappeared. Then be careful to grind the pivot a uniform thickness throughout its length. When the upper part of the staff is ground, turn the 71 oil champfer, turn the lower portion of the staff near to the required size, turn it off, fasten the hairspring collet seat into a chuck, and, turn and grind the lower part of the staff. However, if a chuck is not true, it will be im­ possible to make the staff run true, and it is necessary to cement the upper part of the staff into a cement brass, be­ fore turning and grinding. CEMENTING A STAFF. Clean the staff with benzine. Screw a cement brass tight into a screw chuck, and turn a V, 3 m.m. deep, with rings on the sides to give a hold for the cement. (The V must be perfect to secure accurate centering.) While the lathe revolves, hold a small flame near the end of the brass and fill the V with lathe wax. Press the finished pivot into the V ( See Fig. 129) while the wax is still soft and hold the staff in place with a piece of hard pith, cut flat on the end ( See Fig. 130), or with the point of a pegwood pressed lightly against the staff. Start the lathe and with a small flame that will not burn the wax or pith, heat the brass until the wax is soft. When perfectly cen­ tered, allow to cool while the lathe revolves. POLISHING A STAFF. From steel tempered dark blue, turn and grind the upper part of a small staff. Without removing the staff from the lathe, and while it is in motion, clean it with soft pith and polish the upper part of the staff, except the balance shoulder, with diamantine on a bell metal or copper slip, giving the same motion to the slip as while grinding. Both in grinding and in polishing, be careful to retain the corners on the shoulders A and C ( Fig. 114) sharp. Occasionally wipe the staff with soft pith and examine the surface. Should fine rings appear, the staff may be too soft, the diamantine may be too coarse or you may have polished with the edge of the slip instead of with its flat surface. If a scratch appears on the slip, grind it on a coarse India oil stone, clean and repeat the polishing. When the diamantine becomes black, it is polishing. When you have polished the upper part of the staff, cut the oil champfer, and turn, grind and polish the lower part. 72 7

Fig. 104 Fig. 105

Correct Position Of Hair- . Removing Hairspring spring And Regulator Pins

Fig. 106

s Fig. 108 Fig. 107

Alarm Attachment

Safty Pin Too Long Overbanking Saf ty Pin Too Short Fig. 109

Fig. 110 Fig. 111

Insufficient Lock

Lock Too Great Insufficient Drop

Copyrie;ht 1914-1915 ------,7Fig. 112 Is Fig. 118

C Tweezers With Incorrect Points Fig. 113

CiJ Fig. 114 -< ...CiJ Shoulder Gauge

Fig. 115 X ! 1 1 Fig. 116 First Shoulder Turned Fig. 120 ¥ l Second Shoulder Turned' Fig. 117

Pivot End Too Thin >< Shoulders And-= Pivot Finished Staff Turned Fig. 119 121 Fig. 122 L A

Turning Oil Champfer Upper Part Finished Pivot End Too Thick

Copyright 1914-1915 ------~77 Fig. 125

Upper Part Finished Fig. 132 Pivot Off Center

Fig. 131 ~ t Unset Train Jewel Fig. 133 '\ ,c Jewel Hole ~ Off Center Unset Balance Jewel Truing Staff With Peg­ wood 130

Fig. 129 CJ ~~~~~~~~ij WAX Metal Polishing Slip ~~--- Fig. 128 Cementing Unfinished Staff

Grinding Conical Pivot Polishing Straight Shoulder

Copyright 1914-1915