WATCH. 



now the part 3,4, is that which takes hold of the circular 

 rack G mfg. 3, and is thus occaGonally detached from the 

 faid rack ; wz. its pin 3 afcends through the upper plate 

 of the frame, fo that its fuperior end is vifible at 3 both in 

 fg, I. and fig. 2, and falls in the way of the extreme end of 

 the quarter-piece, which, on its return from the quarter- 

 fnail, catches it and turns the piece 3, 4, round the central 

 arbor 6 of the hour-hammer, and thereby takes the end 4 

 out of the circular rack, while the quarters are being ftruck, 

 but whenever the hours are to be ftruck, the proper fpring 

 reftores the due pofition of the tail-piece. As the repeat- 

 ing train of five wheels, and as many pinions, are introduced 

 to give motion to the regulating fly, it is of no confequence 

 what the numbers of their teeth be, provided they be duly 

 proportioned to aft fmoothly, and to produce the requifite 

 velocity for the proper intervals between the fucceflive 

 ftrokes. The dial-work for hours and minutes is the fame 

 as in any ordinary watch, except that the quarter-fnail is 

 attached to the cannon-pinion, and lies under it, fo as to 

 partake of its hourly motion, together with that of the 

 minute-hand, ihewn in dots, as being above the face, the 

 piece, however, \njig. 6, denoted by the figures 7, 8, and 

 called the loofe-piece, (or furprife,) is alfo faft by friftion 

 to the fame hour-arbor, and revolves contemporaneoufly 

 with the fnail and minute-hand, and when its pin 8 meets 

 with one of the points of the flar-wheel H, it moves it for- 

 wards until the angular point on the face of the jumper b 

 has paffed an oppofite point of the ftar, when it will jump 

 or move at once the remainder of the fpace ; in this ftar are 

 twelve points, and as the hour-fnail, which has twelve fteps, 

 is made faft to it, the fnail alfo jumps to the fucceeding 

 ftep once every hour, while the three fteps of the quarter- 

 fnail follow one another by a conftant flow motion, keeping 

 pace with the minute-hand. Hence the times at which the 

 refpeftive hours and quarters are to be ftruck, eorrefpond- 

 ing with the pofitions of their proper fnails, are guided by 

 the common dial-work, and when once they are duly ad- 

 jufted, a motion given to the minute-hand, by a fuitable key, 

 will always keep both the fnails in their requifite pofitions 

 for regulating the number of hour and quarter ftrokes, that 

 the face of the clock has indicated by the hour and minute- 

 hands ; and in the fame way the quarters even of the mi- 

 nute might be repeated, if fuch addition were deemed de- 

 firable. In our Jigs, l and 2, we have put the charafters 

 of the hours on the rim or edge of the cafe, as the face is 

 removed, merely to fliew how the hands, pointing to the 

 divided fpaces, are connefted with the fnails of the repeating 

 mechanifm. From this explanation, it will appear that the 

 movement of the watch is not at all affefted by pufhing in the 

 pendant, nor yet by the motions of the repeating parts, other- 

 wife than as the heel of the quarter-piece falls againll the 

 quarter-fnail carried by the cannon-pinion, and at the mo- 

 ments when the loofe-piece, under this fnail, moves the ftar 

 at its hourly period ; but trifling as thefe obftacles may ap- 

 pear in a common watch, they arc feldom, if ever, introduced 

 into a chronometer. 



In the conftruftion which we have here defcribed, a large 

 femi-circular rack and pinion are fometimes fubftituted for 

 the chain and pulleys, in which cafe the rack is attached to 

 the cremaill^re, and the pinion to the arbor of the repeating 

 main-fpring ; and it is obvious that fuch a fubftitution will 

 remove the objeftion to the liability of the chain's breaking, 

 and the confequent dei-angement of the works. 



Engl'ifi Repeater. — The conftruftion of the repeating mo- 

 tion, called, after the name of its inventor, a Stociten motion, 

 differs in many refpefts from and is very fuperior to the ori- 

 ginal repeating motion, which, with a very little alteration 



in the mode of arranging its parts, is now generally known 

 by the term French motion : this appellation is however im- 

 proper, fince the repeating watch is indifputably an EBglifli 

 invention, the merit of which was difputed by Tompion, 

 Quare, and other Englifti watch-makers of celebrity of the 

 laft century. 



Stockten was an Englifliman, bufhis hiftory, like that of 

 many other ingenious m.en, is fo little known to pofterity, 

 that even his fponforial appellation is loft, and his birth- 

 place unknown ; all that can with any certainty be recorded 

 refpefting him is, that he lived in London, and worked for 

 the celebrated Mr. George Graham, watch-maker and F. R. S. 

 the fucceflbr to Mr. Tompion, the motions of whole re- 

 peaters were always made upon this conftruftion. The 

 houfes of Mudge and Dutton, Fleet-ftreet ; of EUicott, 

 Royal Exchange ; and of Vulliamy, Pall-mall ; who, for 

 many years after the death of Mr. Graham, were the princi- 

 pal makers of repeaters in London, conftantly employed 

 this conftruftion of motion ; and it is now generally made 

 ufe of by all the London watch-makers in the manufafture 

 of their beft repeaters. 



To enumerate very briefly the advantages of this repeat- 

 i[ig work, its main-fpring is wound up by a rack and pinion; 

 from its conftruftion the aftion of the parts is uniform and 

 gradual, and not depending on feveral fprings, whofe aftions 

 interfere with each other ; and moreover it is fufceptible of 

 being made to ftrike the half-quarters, without inconvenience 

 or additional work. 



To underftand the general aftion of this repeating motion, 

 it is neceffary to be well acquainted with its conftruftion, the 

 detail of its parts, the manner in which the different pieces 

 come together, and their feparate aftions. The pieces com- 

 pofing the pendant work, and the aftion of the puftiing-piece 

 upon the cremaillere, or, as it is generally termed in this con- 

 ftruftion of a repeating motion, the rack ; the brafs edge, 

 and its ufe and mode of being fixed to the pillar-plate ; the 

 dial, and the manner of fixing it to the brafs edge, and the 

 hands ; the repeating main-fpring and its barrel ; the barrel 

 arbor, and the mode of hooking the fpring into the barrel ; 

 the repeating train of wheels, or, as they are frequently 

 called, the running train, and the fituations of the hammers, 

 relative to the wheels between the plates, and their refpec- 

 tive ufes and aftions are all fo nearly the fame as in the 

 common motion, previoufly defcribed, that any further de- 

 fcription becomes unneceffary : the ratchet, click, and click- 

 fpring of the great wheel of the repeating train, are alfo the 

 fame ; but the ratchet-wheel G, of twelve teeth (Jig-'i- Plate 

 XLV.) which in the common motion afts upon the honr- 

 hammer, is in thisconftruftion of the repeating motion omitted. 

 In Plate XLVI. Jig. i. reprefents the repeating work 

 complete in its quiefcent ftate, with the wheel Q of 48, the 

 hour-fnail F, retrograding ratchet P, and wheel of com- 

 munication R ; and alfo the lantern-pinion w, quarter-fnail 

 G, and hour-wheel S ; by which parts the motion is com- 

 municated to the hour-hand, and the hands carried round, 

 perfeftly detached from the other parts of the motion. 



Fig. 2. reprefents the repeating work complete, as it ap- 

 pears at the inftant of unlocking ; the arm^/ of the piece D 

 bearing on the hour-fnail F, the arm y of the quarter-rack 

 on the quarter-fnail G, the little all-or-nothing piece I dif- 

 engaged from the piece K, and the hammer-tails L and M 

 in a proper fituation to be afted upon by the hour and quar- 

 ter ratchets N and O. 



Fig. 3. reprefents merely the rack A B and pinion C ; the 

 piece D ; and the two all-or-nothing pieces H and I, in their 

 relative fituations to one another on the pillar-plate, the reft; 

 of the work being fuppofed to be taken off. 



Fig. 4. 



