HOROLOGY. 



the od of it. The tooth of the wing-wheel, which has 

 now got into the notch at the end of the driving pallet 

 arm, carries it forward until another tooth, meeting with 

 the hook of the leading pallet, cause* the wheel again to 

 recoil. Thi* allow* the notch of the driving pallet toast 

 free of the tooth, and the bras* piece, which is on the 

 pallet arbor, falU down, till it come* to rest on the pin 

 in the braa* cross piece, making the pallet notch get 

 quite clear of the top of the tooth, and to on. There i* 

 a great deal of ingenuity dianlayed in the contrivance 

 of thi* 'tcapeutent, yet the nice and tickli-h balancing 

 of the pallet* occasions tome degree of uncertainty in 

 their operation* ; and whether the great recoil which it 

 ha* may not be again*! the time-keeping of the clock, 

 remain*, perhaps, yet to be proved. Wa it thi* 'scape- 

 which wa* in a clock of Mr Harmon's, at hi* 



in Urange Street, of who*e going Mr Short *aid 

 " That be coukl depend on it to OK Mwarf im a month," 

 and ' that it had been going for fourteen year* at thi* 

 rate?" 



The properties of a good 'tcapement are, that the 



lied in the 



are, 



impelling force ebould be applied in the moat uniform 

 and direct way, and with the least friction and lea* of 

 litrce; that it require little oil. 



, or Done 



ai.iltli.it 



the oscillation* of the reyslaHr. whether it i* a pendu- 

 lum or a balance, be made in a* free and undisturbed a 

 r a* possible. The nice eneantion required in a 

 ...t. whether for a deck or a watch, formerly 

 of the attention of workmen, that 

 ure. lot **t of the properties of the 

 the 



they, in 



pendulum. * well a* that of the apiral or balance pen- 



iliilutu -prill.-. ..rul ll,., U4 :.t t)-,: tl,. tinic-krrnii >,: 



<>.,> ol!,r U.M.K. .iU,L 



puiUfli. lie* wholly, or 



that UIM, from 

 wholly, in the pen- 

 dulum and in the pir*J spring. Banhimd impulas a no- 

 tion kke this to Harruon, for attempting to make the 

 'caprment in hi* timekeeper so that the long and short 

 >M*M hould be ma*.e in eo.ua) time*. Whrrea* he 

 ay*, " lie ought to have looked for thi* in the iaochro- 

 nou property of the piral or balance *pnng. But this 

 property (headd*)wa* unknown at WM* ties* to toe Ena> 

 u*h artiftt* ; and wa* a diautveji of those hi France, 

 foam whom the Knglwh artist* afterwards obtained M." 

 . be the case, how d d it happen that Mr Mudge, 

 efdMtpnl Jong before the periud when Le Boy and Bcrthood &. 

 ?l*!"T.. pwUd about the property of tin. piral pring, each 

 daimiug the merit of having firt made the dicovery . 

 , pnhtobed in 1763, That the 



ID \l 



go,. 



nentiuncd in hi. lr t. [ 



ndulum or balance pnng. fn-m physical principle*, 

 the balance perform the long and the bort vibra- 

 '.earned thi. from Dr I looke". 

 which he waa well acquainted ; and tbu 

 property of tpring* wa> know oke, and point- 



edo.,1 i,, him iM-arU .11 hum!,,,! pma*. bxsoH MiMif 

 publsOiari hia pamphln It i* but too true, that lew or 

 naneofthengb*hartMU*eem toUvr been acquaint- 

 r.l with thne proyeHias till very lately, tbnugji Mr 

 Mudge (sad pointed them out ao long before, and 

 though they were ceemmed in the work* of I 

 . Lapaute* book wa* publuhed at Pan- 7, and 



daws net contain the meat d wtant bint of these proper- 

 tie* <' the balance spring ; hence they were net known 

 there at the time when I iB*eli wrote, otherwise he 

 would have mmtiened thorn. It wa* toon after thi.. 

 that UM diepnte* r usiii ni between Le Hoy and Her- 

 thoud regarding thie anhpML 



Watdl 6ni*hcx* always made the pendulum spring 

 for the watdte* of then- own iniahinsL while at the 



time knowing nothing of its properties, the gene- 

 ral practice was to taper them, so that the i.> N. when 

 bending or unbending, shouUl prcM-rve an equal dis- 

 tance with one another ; and this method has been used 

 evw since the application of the spiral spiring. Those 

 who finished watches for M udge aud Dutton, w,. rt> never 

 employed to make the pendulum spring. This w. 

 ways done at home by either Mudge or Dutton them- 

 st-lvci, who, no doubt, endeavoured to make them n 

 nearly isochronous as possible. This, among other causes, 

 perhaps gave their watches the celebrity which they at 

 that time had deservedly acqu 



The pallet* of the 'acapetnent at the turret clock in 

 Greenwich Hospital, are said to have been contrived by 

 Mr Sroeaton. The following narrative will show how 

 be came to be concerned in it. It may be obser.n!. 

 that at that time he wa* one of the comniusioner*. 



The turret clock, which is in the cupola of Greenwich 

 Hospital, was undertaken by the late Mr John Holmes, of the mr- 

 and executed under his directions by Mr Thwaites. m-clock at 

 Mut before any thing wa* dom , Mr Holmes consult- Greenwich 

 ed two gentlemen, who happened to be his most inti- Ho * pl * 

 male fhend* ; the one was the Rev. Mr Ludlam of 

 Cambridge, the other Mr John Smeaton, both of whom 

 ware very eminently qualified to give such advice a* 

 wa* wanted in thi* buainea*, not only about the 'scape- 

 ment, but bow every part of the cluck houlil U tiiuil 

 up, ao a* to insure talciy and utility in it> )>erlormance. 

 Several very long and masterly letters (>' which Mr 

 IUid-ha* copies, though uone of the originals were ever 

 Mhrd) pa*ed between them on that occasion, and 

 evince much ingeiiu a \ 'I'hey agreed that the 'tcapentent 

 aheuld have a recoil. Mr Smeaton recommended, that 

 the pal***, in place of having plann, a* wa* common for 

 their acting part*, ahould have i urved surfocrt, the lead- 

 ing |*llet beingconcat r. ami the driving one convex ; and 

 when the pendulum wa* at or near t ..n\ of 



the vibmUon. the '*cpemeat ahtM. l>e nearly 



dead. Thi* we*, a* be said, what "vldfathvr Himllty at 

 York had ullimat< Mr LudUun adviaed, 



that the swing wberl tttth hould be thick and deep, 

 and of such a shape a* to roll a* it were on the pallet*. 

 and not to lide on then, which would prevent biting 

 or wearing The pallet arms were of bra**, made *o a* 

 to not it in il.i- power of the clockmaker to take the 

 paOeto venr easily out, when repairing wa* necessary. 

 These methods IMM! lung before thi* U-en ucl l.\ llar- 

 rikon, and were advpted in a cloch of hi ( ol- 



<nbridge.a mentioned by Mr Lmlkm. Uruadrub- 

 bing ratface* were tivDgly ad i*ed by them. Mr Sroea- 

 ton at thi* period look away gudgeon* Irven a mill wheel 

 whoae diameter* were 01. i >, kiul put other* in 



their piece of 8 inch** with great MIC-CCM, a* it attir- 

 ward* proved. On the *awc priuci|ile* w ln> 



the 



ing 



ap- 



inee, one of 



now been mentian<d, wa tl . 

 clock. hul, Mr Ihoma* Reid pi 

 ch, Edinburgh . aud allhoiif 

 for about tin n-. \rar, U.tn 

 peaiunce of biting or wearing 011 t 



'ScapsmenU have been divide* 



wbtdi has been called tho*e ef the remontwir kind 

 Now, the mtthaiUMn of a rMnontoir may be app)K<l to 

 any 'intpiiimnt, an<l even then it can liardly be said to 

 form a part of it, more than the wheel* of the movement, 

 or the weight which moves them. 



The motive force pa**ing through the wheels, may R 

 at time* be unco/tally Mpr*i*cd upon the *orp- 

 mcnt either of clock or waU-h. Thi* idea gave 

 rise to the invention of what ha* been called re**- 



