IIEMONTOIU. 



pcnded by pallet L, before the pallot K of the balance re- 

 turned to its place to receive it. Mr. Hardy, however, has 

 lately contrived a fpeciea of locking that is quite certain, 

 as well as fafe, which we fliall prefently have occafion to 

 defcribe. 



Bre^uet's We have not been able to afccrtain the exaft 



date of tlie French watch-maker Breguet's invention of a 

 remontoir efcapement, but as Berthoud has placed it after 

 Haley's in his " Hiltoirc de la Mefure du Temps," we muft 

 conclude that it is of more recent origin. The mechanifm 

 is fo complex, that thedefcription given in the French work 

 is divided into three parts, which plan we propofe to follow. 

 Figs. 5. and 6. of Plate XLI. of Horology, will fuffice to ex- 

 plain the different parts of Breguet's remontoir ; Jig. 5. be- 

 uig a plan of the whole, aud/^r. 6. exhibiting a perfpeftive 

 view of fuch parts as could not be well underftood without 

 fuch reprefentation. Tlie firll portion of the mechanifm 

 confills of two wheels of unequal numbers of teeth, with 

 their planes in contaft, and revolving on one common arbor 

 concentrically, namely, the wheel B B', and the wheel D, 

 the tirll having many teeth and alarger diameter, and the lecond 

 having few, for a reafon which will appear hereafter : thefe 

 wheels are aftuated by a pinion ^f, connefted with the train, 

 and having jull fo many leaves as there are teeth in the large 

 wheel B B', contained in the fpace between two contiguous 

 teeth of the fmall wheel D ; on the arbor of this pinion, 

 near the pivot, is inferted a fly with unequal arms, repre- 

 fented by t!ie letters ig h in both figures, the longer arm of 

 which, g h, is arm.d with a piece of Heel of peculiar ihape, 

 feen in Jig. 6. A fpring-detent ;• F, made fait to the 

 cock at y^^lies at right angles to the fly, when in a ilate of 

 relt, and has a ruby pallet V at about one-third ofits 

 length from its interior end, which Hops the fly by oppofing 

 its end h near 0, and confequently prevents the train from 

 urging the double wheel, fo long as no force unlocks the 

 pallet from the end of the fly ; but if any impulfe happen 

 to bend the detent in a direaion towards the pinion g, then 

 the ruby pallet flips through a notch made in the fteel part 

 • of the fly, and the fly makes an entire revolution, while the 

 pinion revolves and urges the large wheel the fpace of as 

 many teeth as the pinion contains ; that is, a fpace corre- 

 fponding to the dillance between two contiguous large teeth 

 in the fmall wheel, which wheel alfo moves the fame quantity, 

 before the fly is again oppofed and llopt. 



The fecond portion confills of the following parts ; a 

 fpring G, curved at the interior, or moveable end, fcrves 

 at the fame time for a remontoir -fpring, and alfo for a pallet 

 to give the impulf> to the balance ; it has confequently a 

 heel-piece n, by which it is urged into a ftate of tenfion by 

 the fmall wheel D, at every revolution of the fly, and alfo a 

 ruby pallet m, with a locking notch cut in it ; a H, made 

 fafl; at a, is a detent-fpring, placed nearly at right angles 

 to the fpring G, and having a (lender fpring N made 

 fafl; to its fide; this detent-fpj-ing carries a fmall ruby/, 

 which locks into the notch of the piece m in the fpring G, 

 when this is in a Itate of tenfion. Another ruby, inferted 

 into the extreme end of the detent « H at j, is fo placed, 

 that the flender fpring N can move from right to left with- 

 out impediment, but when urged in an oppofite direftion 

 againfl: the ruby s, it takes the large or detent-fpring along 

 with it, and unlocks the remontoir-fpring G, by removing 

 the fmall ruby / from the notch of m. The detent-fpring H 

 has at its extreme end a claw, againft which the ruby m 

 falls when this detent efcapes back from a tooth of wheel 

 D ; and this claw has a pin in it, againll which the (lender 

 fprino- N rcfls ; again, at the extreme end of the flender 

 tpring N are fixed two parallel chamfered plates, fo contrived, 



that any prefFurc made on the upper (lope, or inclined edge, 

 will deprefs the (pring, but a fimilar preflTure made on the 

 under (lope will elevate it again, the downward preflure 

 being employed to difengagc the ruby m from the claw, and 

 the contrary. 



The third portion confifts of the pieces or pallets K and 

 b, borne by the fuperior end of the verge of the balance, 

 and fixed at a quarter of a circle from each other. When 

 the ofciUation of the balance is from right to left, or in the 

 direilion from i to K, the unlocking pallet piece K, in its- 

 motion, bends the flender fpring, and pafFcs over it, but as 

 the pallet b is placed above the plane of the wheel B B', and 

 under the fpring H, thisofcillation from right to left is per- 

 formed in freedom, except that the flender fpring N requires 

 to be a little bent out of the way ; but when the ofcillation 

 is made from left to right, the pin at H prefles this flender 

 fpring againft the ruby s, the fpring H then gives way, 

 and bending, allows th; ruby p to efcape from the notch at 

 m, and the fpring G, being unlocked, is at liberty to per- 

 form its office, which we now proceed to defcribe. 



The adf ion of thefe three portions of the mechanifm may 

 be thus explained : at the inltant that the ruby/, in the de- 

 tent a II, is difengaged from the notch at m in the remon- 

 toir-fpring G, the pallet b of the balance is found pointing 

 towards the common centre of the wheelj, and ready to re- 

 ceive an impulfe from the extreme end q of the curved part 

 of the remontoir-fpring G, which end now gives its ftrokc 

 to the balance through the medium of pallet b ; immediately 

 after which ftroke, the fame end q proceeds till it falls on 

 the end Fof the fly's detent, to which it now gives a pufli, 

 and remains quiet ; this pufli unlocks the fly, as has been 

 before explained, and an entire revolution is immediately per- 

 formed by it, wliile its pinion^, now at liberty to advance, 

 urges on the double wheel, till another tooth in the fmall 

 wheel, catching the heel-piece « of the remontoir-fpring, 

 puts this fpring again into a (late ef tenfion ; and the ruby/, 

 fulling into the notch of m, locks it as before, the balance 

 in the interim completing its ofcillations : and in this manner 

 the operation is repeated. 



De Lajons. — In the year 1801, the Adelphi Society for 

 the Encouragement of Arts, &c. rewarded Mr. John de La- 

 fons with thirty guineas for his invention of a new remontoir 

 watch efcapement, which comes next under our notice. 

 Figs. I and 2 of Plate XLII. of Horology, are a plan and 

 feftlon of this efcapement, as given by the inventor in the 

 Society's Tranfaftions of the year above-mentioned. In 

 both thefe figures, A is the efcapement wheel ; B, the lever- 

 pallet on an arbor with fine pivots, which has, at its lower end, 

 the remontoir fpiral fpting C, fixed with a collar and ftud in 

 the ufual way ; D is the pallet of the verge, having a roller 

 turning in fmall pivots, for the lever-pallet to aft againft 

 without fricf ion ; at E are the pallets for difcharging the 

 locking, with a roller betvveen, containing a fmall notch ; 

 F is the arm of the locking pallets, continued at the other 

 end beyond the centre of motion, to preferve the equipoife, 

 and having ftuds and fcrews for adjuitment of the banking; 

 a and b are the locking pallets, being portions of circles 

 faftened on an arbor, turning on fine pivots at the mid- 

 way between the pallets ; G is the triple fork, at the end 

 of the arm of the locking pallets. In Jig. i, tooth i of 

 the wheel having caught the interior end of the lever, 

 pallet B, has urged it forwards and wound up the remon- 

 toir-fpring, and the inftant that the verge pallet D comes 

 nearly in contaft with the remote end of the lever-pallet, 

 the difcharging pallet E, taking one prong of the fork, 

 removes the arm F, thereby relieving the tooth 3 from 

 the convex part of the claw «, that locks the wheels. 

 12 The 



