20 COMPENSATION CURB. 



lance being loatlcd, will have to encounter a confiderable 

 deal more friction, and confequently be impeded in its vibra- 

 tions : it worn in the pocket, it is alfo liable to error, as exr- 

 ercife will alter its diameter. The compound balance has 

 heretofore got the preference, becaufe artifts have not been 

 able to invent a compenfation curb adjuftable to the exa6t ex- 

 panfion required (which, by many experiments, I have proved 

 the inclofed to be fully competent to) ; therefore, the plain ba- 

 lance having no projecStions on the furface, muft certainly have 

 the advantage. As I am not in the habit of exprelfing my 

 ideas to the public, I hope you will have the goodnefs to rec- 

 tify any errors in the ilile, and alfo curtail any part which may 

 appear unnecelfary to you. 

 I remain. Sir, 



Your much obliged humble fervant, 



JAMES SCOTT. 

 39, Grafton Street^ Dublin. 



Hie folloxving is a Defcription of the Compenfation Curb. 



Defcription of The fteel index, PI. J J, Fig. 2, letter A, is for the purpofe of 

 a compenfation fypporting the curb, which is fallened by a fcrew and fteady pin 

 . * at R, the circle of which at A is turned with a dovetail, as fliewn 



at H, and is flit fo as to fnap into the frame-plate, by which 

 means it may be turned, and will carry the curb, fo as to re- 

 gulate the machine in the common way, D and E are two 

 » circles compofed of brafs and fteel foldered together, the out* 



fide of E brafs and the infide fteel; but the outfide of D h 

 ftcel and the infide brafs ; fo that the one circle expands when 

 the other contrails ; by which means the ading part of the 

 curb at C will (hift towards the index with heat, and prevent 

 the vibrations being flower, which the expanfion of P, the 

 regulating fpring and the balance, would otherwife occafiop ; 

 and on the contrary with cold, it will fliift its potition nearer 

 the ftud I, which the regulating fpring is pinned to j fo that 

 let it receive heat or cold, the afling part of the curb at C 

 will at all times keep the regulating fpring the exa6l length, 

 to counterafl the expanfion of thg balance and pendulum- 

 fpring. V is a piece of fteel, with a notch cut in it to receive 

 the expanfion circles D and E. F is a fcrew for taftening 

 V at any part of the circles; fo that, by ftpviiig the watch, 

 5 you 



