168 



The Calorimc- 

 ter described. 



—It consists of 

 a vessel having 

 a stove within 

 it, and a de- 

 scending flue 

 or chimney. 



Method of 

 ■•sing it. 



CALORIMETER, 



that it very essentially differs from the instrument invented 

 many years ago by Lavoisier and La Place. 



Description of the Calorimeter. 



Plate 5, exhibits a section of the Calorimeter ofMontgol- 

 fier. A B C D is a vessel or hox of tin, which .might, with 

 more economy and advantage be made of wood, sufficiently 

 well constructed to hold, water. In its cover A B, there is 

 an opening a b ; and so hkewise, in the bottom, is an open- 

 ing e/. Within this vessel is a small stove, a b c d e f, of 

 plate-iron, or, which is better, of copper, carefully closed, so 

 that no water can enter into it Its lower opening corresponds 

 with that of the exterior vessel or box, ef. The other open- 

 ing, in the other part is closed near a b, by a stopper which 

 can be taken out at pleasure. 



c ^ is a grate composed of iron wire, upon which the fuel is 

 put, the ashes fall through the grate, and escape at the open- 

 ing g- 



Near h i is fitted a tube, k k, through which the smoke 

 escapes by the opening /. This pipe must be made of iron or 

 copper plate, sufficiently close to prevent the water from pene- 

 trating, m 77} is a pipe of plate iron, surrounding the last- 

 mentioned in such a manner as that the water may be placed in 

 the place between them. E is a reservoir, of which the cover, 

 r s, can be taken off, in order to fill the apparatus with 

 water. 



t) is a pipe proceeding from the same reservoir, and com- 

 municating with the pipe m m. 



11 n is another pipe, which passes from in m into the vessel, 

 for the purpose of introducing water, after it has passed 

 through the pipe m w. 



p is a cock, through which boiling-water may be suffered to 

 escape ; and q is another cock, by means of which the appa- 

 ratus may be emptied when needful. 



F G are the legs which support the apparatus. 



Use of the Calorimeter. 

 When it is required to determine the time in which different 

 combustibles disengage, an equal quantity of heat, the reser- 

 voir e is to be filled with water. The fluid passes through the 

 tube o 0, rises through m in, and thence, by n n, into the 

 vessel A B C D. A sufficient quantity must be poured to fill 



the 



