jl^ OASifORkt OXIDE OP CAUtiON, 



Dkfciiption, il, through which the pendulum-fpring palTes ; and it is faf. 



to the^eng7avme. *^"^^ ^^ '^ ^Y means of a pin, and ftands perpendicular to 

 the curve oF the fpring. Let the balance be at refi, as re- 

 prcfenled in Fig, 1, the banking-pin at P, and the banking- 

 piece at s, Siippofe the balance is made to vibrate from P 

 towards O, when P arrives at the banking-piece s, it will 

 pafs if without touching j becaufe its extremity 5 lies wholly 

 within the circle traced out by the banking-pin. But when 

 the bdnking-pin P has arrived at Q, the banking-piece s will 

 have advanced to f, by the pendulum-fpring winding ilfelf 

 lip in(o the figure reprefented by the dotted curve ; and when 

 the banking-pin P (now at Q) returns back to P, and pafies 

 on from P towards Q, to approach B, and fo complete the 

 Other halt^arch of its vibration, before P can arrive at the 

 i)anking-cock B» the pendulum-fpring will have unwound 

 itfelf into the figure defcribed by the dotted curve, and the 

 banking-piece s will have advanced into the pofition at r 

 juft touching 4he banking-cock. Its extremity r, however, 

 being thrown beyond the dotted circle, muft necefTarily fall 

 in the way of the banking-pi*!, which arrives there almoft at 

 the fame moment, and is oppofed by it, without the ilighteft 

 fhock to the pendulum-fpring. The model* renders any 

 farther explanation unnecelfary. 



WILLIAM HARDY. 

 No. 61, Chapel-Street, near While- Conduit- Houfe, 

 Jan, 18, ISOk 



XVL 



Defcription of a neiD Apparatus for making the gafiform Oxide of 

 Carbon. Coimnunicakd by Mr, D£YEi;x.+ 



The progrefs of IT is generally admitted, that cheml/lry is indebted to th<j 



cheaijftry owing i^iventioii of various kinds ol apparatus and the perf-^^tion to 



chiefly to im- , . , , , , , , ' ,' , r 1 



proved appara- which they have been brought, tor much of the progrets u has 



tus. made within ihefe laft thirty yearj^. 



Inftancc in that For inftance, before Woulfe made known his apparatus for 



ot Woulfe. obtaining the aeriform fluids evolved fiom various lubftances, 



*• Which is preferved In tlie collefllon of the Society. 

 t Annales de Cinmiet Vol. LIII. p. 76. 

 • .'' - either 



