ON Blasters ajmd soaps, g31 



L. The click which works in the teetli of the ratchet wheel. 



IJ. The lower part of the arm of the hanimer. 



M. The bell, within which the hammer strikes* 



N. The cock in which the pivot of the axis of the pallets 

 acts, and to which the hammer is connected. 



Fig. S, shows a section of the ratchet wheel and spring 

 barrel, which are screwed together, and move at the same 

 time, bat are kept in their place by two pieces e, e, which fit 

 a groove in the barrel. 



K. The button or finger piece;; 



I. The ratchet wheel. 



P. The box for the spring; 

 'R* The cap which covers the spring box; 



V. The axis on which the main spring is wound* 



Fig, 4. R. The cap, under which is the spring. On th8 

 edge of this cap, at S, is an indent to retain the spring when 

 wound up; 



T. A lever, with a hook at its end. 



At the end of this lever, on a line v/ith the hook, is a small 

 piece of steel, which goes through a hole in the box, and 

 presses upon the main spring; so that, when the main 

 Spring is wound up on the axis V, the hook is at liberty to 

 fall into the way of the indent S, and is there stopped. 



Under the lever T is a small spring, which presses it 

 against the main spring within the barrel. 



Fig. 5} shows the' index of the larum ; the outside circle 

 of which is divided into 120 parts, which index serves for 

 three concentric circles; that next the centre is for a watch 

 fusee of four hours a turn, the next five, and the last six, as 

 explained in the letter* ' 



XI. 



Ohservatioris on the Comhination of fixed Oils ivlth the Oxides 

 of Lead, and with Alkalis: by Mr. F. Fremy, Apothecary ^ 

 of Versailles*. 



CHEELE was the first who observed, that the water, ^y^^^j. ^^^^ .^^ 



which serves as an intermedium when fat oils are combined making ti 



tkarg'^ plaster 

 • Annales de Chimie, Vol. LXII, p. 25j April, 1807. is sweet. 



with 



