428 On the Capacity for Heat, or 



founded in the changes which take place in the temper- 

 ature of liquids, in the vase and in the bottle, by taking 

 a uniform temperature, when the bottle is immersed in 

 the water contained in the vessel. 



In order that this equality of temperature may be 

 speedily brought about, the form of the bottle is such 

 that it has a very great surface relative to its small 

 capacity, and in order to manage it without touching it, 

 its neck, which is small, is closed by a long cork, which 

 serves as a handle. 



In order to diminish as much as possible the effect 

 of the atmosphere and of surrounding bodies upon the 

 apparatus, while the experiment is going on, the quan- 

 tity of water in the vessel is regulated so as to keep the 

 bottle wholly submerged in the liquid, and even the 

 upper end of the neck covered, when the bottle is im- 

 mersed. The vessel which contains this water is placed 

 and suspended by a ring of cork in another vessel larger 

 and higher, and the interval between the two is filled 

 with eider-down. 



The form of the bottle is such that its horizontal 

 section presents the figure of a rectangular cross. Some 

 idea may be conceived of its form and dimensionSj if 

 we suppose a square piece of stick, each facet of which 

 is four lines broad by four inches three lines in length, 

 upon the four faces of which we have fixed four sticks of 

 the same length (i. e. four inches three lines), but each 

 of them being four lines thick by eight broad. 



The four sticks last described will exhibit the figure 

 of the bottle ; for the square piece of stick will be con- 

 cealed by them from our view. 



The neck of the bottle is in the prolongation of its 

 axis ; it is four lines diameter by four high ; it ought to 



