WATCH. 



mer-tails, and Q, or Q 5, the other, wliich is attached to 

 the hammer that ftrikes alfo the hours ; S is the quart cr- 

 fnail that determines the number of quarters to be (truck at 

 any time, when the hour-hammer has ftruck the hours, and 

 has three Heps or arcs of different radii, prefented fuccef- 

 fively to the part that a6ls on, or rather refts on it ; 7, 8, is 

 the loofe piece attached to, and fecured under the quarter- 

 fnail S ; a is the end of the middle lever of the cremaillere ; 

 b the jumper, that makes the ftar-wheel jump a whole fpace 

 when a tooth, in raifing it, has arrived at its angular point, 

 fo as to give its fpring d its full tenfion ; e is the chain 

 made fall at one end to the cremaillere at D, and after palF- 

 ing round the pulley E, attached at the other to a fecond 

 pulley Z, which is inferted on the arbor of the repeating 

 main-fpring, /is the quarter-piece fpriag, prefiing on a pin 

 in the quarter-piece M ; A is the quarter hammer-fpring ; i 

 its counter-fpring ; g the quarter hammer-tail fpring ; p the 

 hour-hammer fpring, and its counter-fpring ; g is the 

 hour-hammer quarter tail-fpring, and r the gathermg piece 

 or arm fixed on the arbor of the great wheel of the repeat- 

 ing train of wheels, over the pulley Z, that caufes the 

 quarter-piece to aft on the hammer-tails, and is the fame 

 arbor which we have before called the arbor of the repeat- 

 ing main-fpring. Thefe are the pieces of mechanifm that 

 lie under the face of the watch, and appear above the 

 frame when the face is removed, together with the dial- 

 work reprefented by the dotted circles tn Jig. i, but by 

 unfhaded wheels and pinions in Jig. 2, that the other parts 

 might not be concealed below them. Fig. 3. contains the 

 works under the upper plate of the frame, of which the 

 repetition-train {pelil rouage) only is fhaded, the ordinary 

 movement being given in outline. The conneftion between 

 the pieces exhibited in fgs. i. and 2, and the repetition 

 train in the frame, (hewn wjig. 3, is by means of the arbor 

 of the great wheel and its circular rack G, feen in this 

 figure, for this arbor prolrudmg above the upper plate of 

 the frame receives on its fquare the main-fpring of the re- 

 peating mechanifm, and alfo the gathering-piece r, fo that 

 whenever this main-fpring, exhibited in Jig. 4, is wound up, 

 the ratchet on the great wheel, feen in Jig. 5, allows the 

 great wheel to move with it without the rell of the repeat- 

 ing train ; but when the fpring unbends itfelf, and pulls the 

 chain and attached cremaillire back, the click of the ratchet 

 catches and aftuatcs the whole train, which terminates with 

 a fly on the lad pinion-arbor, as \n the (triking part of a 

 clock, and thus regulates the velocity with which the ham- 

 mers rcfpcftively ftrike. 



We will now proceed to explain the aftion of the repeat- 

 ing mechanifm, which we have defcribed above, and fee 

 how the effeft is produced by means that are thus appa- 

 rently complex. When the pendant has been pu(hed in 

 (lowly a (hort fpace, the end a of the middle prong of the 

 cremaillere, being kept down by the fmall cock Y, ap- 

 proaches one of the (leps of the hour-fnail F, and at the 

 fame time pulls the chain, by means of the prong D, round 

 the pulley or friftion-roUcr E, and winds up the main- 

 fpring coiled in the box of pulley Z, at the fame time 

 making the gathering-piece r retrograde from its pin, in- 

 ferted into the quarter-piece : mjig.x. this motion is juft 

 commencing from a Hate of quiefcence ; fuppofe now, the 

 retrograde motion of the gathering-piece to take place, 

 while the pendant is pufhed very (lowly in ; and conceive 

 the circular rack on the face of the large wheel within the 

 frame, 11/z. G in^^. 3, to be retrograding alfo, as being on 

 the fame common axis ; prefently the end n of the third 

 prong of the cremaillere meets with one of the (leps of the 

 hour-fnail, and pulhcs againll it; this fnail, and its at- 



tached (lar-wheel, having their common pivot borne by 

 the tout-ou-rien at H, communicate the pu(h received by 

 them to this piece, which turning on its centre of mo- 

 tion at I, has its remote or loofe end K carried from its 

 quiefcent pofition, notwithftanding the oppofing aftion 

 of its fpring ; and when confiderable force is applied to 

 pu(h the pendant home, this end K, which forms a detent 

 to the quarter-piece at the points of their contaft, quits its 

 hold, and leaves the quarter-piece at liberty to be urged by 

 its fpring/ till its heel-piece c drops upon one of the Iteps of 

 the quarter-fnail, as in Jig. 2, where it is feen refting on the 

 third ftep, or (horteft arc. At this inftant the repeating 

 main-fpring begins to relax itfelf, and brings forward the 

 concealed rack G, (Jig. 3. ) which had retrograded as many 

 teeth only as the hour-fnail permitted, before the tout-ou- 

 mn was difplaced ; its neareft tooth to the tail-piece 2, 3, 

 of the hour-hammer R R, catches now this tail-piece, and 

 makes the hammer ftrike on the circular rim of fteel, which 

 is fubftituted for a bell, and as many blows are given ia 

 fucceffion, as there arc teeth in the rack to fall againft the 

 hammer-tail, while the repeating train is running down ; 

 and during the time in which thefe ftrokes are going on, 

 the little pin between the hammer -tail fpring p, and its 

 connter-fpring 0, may be feen moving backwards and for- 

 wards, as though it gave the ft.rokes on the counter-fpring. 

 No fooner are the hours limited by the hour-fnail ftruck, 

 than the gathering piece r returns with the relaxing fpring, 

 till it catches the pin of the quarter-piece, which piece is 

 moveable roimd a pivot at M, and is now gradually brought 

 back by its pin till one of its teeth N catches O, the tail- 

 piece of the quarter-hammer P,Jig. 3, and then one of the 

 teeth at L, at the oppofite end of the quarter-piece, 

 catches Q the upper tail-piece of the hour-hammer, which 

 inftantly repeats the blow with the hour-hammer, and thus 

 as many double blows are given by the two hammers in im- 

 mediate fucceffion for the quarters, as there are teeth to ail 

 on »he faid tail-pieces, wlien the quarter-piece begins to 

 return ; and this number entirely depends on the ilep of 

 the quarter-fnail S, on which the heel-piece falls, when the 

 tout-ou-rien is difplaced ; hence if any blow is given, all the 

 blows that the two fnails limit will be given, from which 

 neceffity, the piece lout-ou-nen, (all-or-nothing,) takes its 

 name. But left tlic quarter-piece fhould return by a jerk 

 before the tout-ou-rien has produced its full effect, the 

 angular point m of the quarter-piece, in its return, Aides 

 down the interior face of the tout-ou-rien, in oppofition to 

 the aftion of its fpring G, while the ftrokes of the quarter* 

 are making, and arrives at the point K, at the termination 

 of the ftrokes, thus performing the office of a train and 

 fly, after which the tout-ou-rien refumes its quiefcent pofi- 

 tion, and its end becomes a detent to the quarter-piece. 

 It is not neceffary to dcfcribe the aftion and re-aftion of 

 the two hammer-tail pieces, which perform their opera- 

 tions, as in the ftriking work of a cluck heretofore de- 

 fcribed ; but it may be proper to (hew how the lower tail- 

 piece 3, 4, of the hour-hammer is detached from the rack 

 ^tfs-h while the quarters are ftruck, by means of the 

 upper tail-piece Q afting with the teeth of the quarter- 

 piece at L only ; this will be bcft undcrftood by a reference 

 to the detached figures in the group denoted hy Jig. 6, ag 

 will alfo the aftion of feveral other parts, which wc have 

 defcribed and explained as being in their places wjigs. I and 

 2 ; the three pieces marked Q <; are the fame quarter tail- 

 piece feen in diftcrent views, 2 C i R, is a part of tiic hour- 

 liammer, and its arbor 6 paffes the fockct of the piece 3, 4, 

 which we have called the lower tail-piece of the hour-ham- 

 mer, befoije it rcc«ivc8 the upper t.iil-picce (^ on its fqu.-ire ; 

 5 B 2 now 



