414 DrfcriplwH of 



latter then affumes of itfelf a horizontal fituatioh. Yoii thcrt 

 fearch for the equilibrium of the lubftance put into this fhell, 

 by placing at the proper place, on the beam, the weight and 

 its fractious corresponding with the fvftem of weights adopt- 

 ed ; and when vou have found the equilibrium, you obferve 

 the weight indicated by the divifions on which each of the 

 weights employed is found, exactly in the fame manner as is 

 done in regard to the common fteel-yard. 



There may be fcen in the plate a glafs (bell fufpended in a 

 jar fdled to a certain height with water. This fliell is deftincd 

 for experiments in regard to the fpecific gravity of folids. It 

 is in equilibrium, if, when immerfed into water at 12 R, as 

 far as the junction of the three filver wires by which it is fup- 

 ported, it exactly balances the weight of the beam unloaded. 



When you with then to try the fpecific gravity of a folid, 

 you firft weigh it in air ; but by putting it into the brafs fhell, 

 and then fubftituting the glafs one, you weigh it in water. It 

 is well known that the difference of thefe weights, employed 

 as a divifor of the total weight in air, gives for quotient the 

 fpecific gravity. Care mull be taken, as in all experiments 

 of the kind, that no bubble of air adheres to that part of the 

 apparatus immerfed in the water, or to the Jubilance, the 

 weight of which is required, and which is immerfed alfo. 



The folid glafs ball II is deftined for the purpofe of afcer- 

 taining the fpecific gravity of liquids, in the following man- 

 ner: — This piece is furnilhed with a hook of fine gold, that 

 it may "be immerfed without inconvenience in acids. When 

 it is fufpended to the hook of the fteel-yard, and in the air, 

 it is in equilibrium with the beam loaded at its extremity 

 (either at the divifion marked O, on the fide of the beam 

 i'cen at F) with weights entitled fpecific, and T i Q of fpecific 

 hooked on at the other. 



This ball, immerfed indiftilled water at ia° R. as far as the 

 end of the ftraight metal wire which fufpend's it, is (till in 

 equilibrium with thelc two weights placed in the following 

 manner, viz. the large one at the divifion in the middle ot 



the 



