m 



PASSAGE OF HEAT THROUGH FLUIDS. 



This heat, passing readily through the thin metallic sides of 

 that vessel, was given oif as fast as it was received to the par- 

 ticles of cold water contained in the vessel which were in con- 

 tact with its sides, and these particles rising to the surface of 

 the water contained in the annular vessel in consequence of 

 their acquired heat and levit}', the progress of the heat from 

 the wooden tube to the sides of the large vessel, KL, was 

 interrupted ; and all the heat that passed through the 

 sides of the wooden tube was by these means turned aside in 

 such a manner that it could no longer disturb the progress of 

 the experiment, nor affect the certainty of its results. 

 The apparatus Before 1 proceed to give an account of the result of this in- 

 ment.'^^ T ^^i^'' ^ ^^^^^ ^^^^ ^^^^ Hberty to recall the attention of tiie as- 



coniral metal- sembly to the most important circumstances of the experi- 



hc piece point- ^^^^ 



ing downwards * 



in water, was On pouring boiling water in a small uninterrupted stream 



gave heat to a '"^'^ ^^^^ funnel, the hollow conical point which terminates the 

 small portion of vertical tube belonging to the vessel, NO, was heated, and 

 bvTwo"olfen ^ ^"^P"^ ^^ ^ constant temperature little under that of boiling 

 cylinder, water. 



to"a\ar"ei-^ves- '^^^^^ point was surrounded by a small quantity of water con- 

 sel. Provision tained in the cavity of the lower part of the wooden tube, and 

 prevent heat ^^ ^'^'^ water could not change its place nor be displaced by 

 being carried the surrounding cold water, being enclosed and protected by 

 sides"of tlie ves- ^^'*^ ^^^^^^ °^ ^^^^ wooden tube, it would necessarily become very 

 sel. A ther- hot in a short time. 



small distance ^"^ ^^^'^ small quantity of hot water lay immediately upon 

 below was not a Stratum of cold water, w hich separated it from the bulb of 



the thermometer, placed directly under it at the distance of 



only half an inch. 



If heat could pass in the water from above downwards, it 



would no doubt pass from the lower stratum of hot water, 



contained in the open end of the wooden tube to the bulb of 



the thermometer, which lay immediately belovv it, and at so 



small a distance. 



Three experiments were made with this apparatus, and 



always with exactly the same results. In the first, a stream 



o£ boiling water was poured into the funnel during 10 minutes. 



In the second, during 1? minutes; and in the third, dtiring 15 



minutes. 



The 



