116 



PROCEEDINGS OP THE AMERICAN ACADEMY 



The order of the experiment was as follows : — 



A 



o 



B 



-o 



c 



-o 



In A, B, and C, were placed glass tubes which contained equal vol- 

 umes of water. Each tube was provided with a thermometer, which 

 was designated by a number engraved upon it. In A, no metals were 

 placed ; and the thermometer in this tube consequently gave the change 

 of temperature which resulted from the heating of the coils by the 

 passage of the electric current. Subsequently, we devised an arrange- 

 ment shown in the accompanying figure. Fig. 1 is a section. The 

 vessel was made of tin with a cylindrical hole in which was placed the 



glass tube ; and the space b, Fig. 1, around it, was packed with infu- 

 sorial earth. A current of water entered at C, Fig. 1, and passed out 

 at D. A represents a section of the coil. This arrangement, however, 

 was not used ; for we found that, by limiting the exjjeriments to a 

 short time, no appreciable error resulted from the heating of the coils 

 themselves. Our object was only to observe the rise of temperature 

 in a given time, that of one minute. In the following table, the 

 temperature readings in Centigrade degrees are given from the tubes 

 placed in the coils A, B, and C. At the head of the columns B and C 

 are placed the names of the metals employed. The temperatures were 

 taken before and after the experiments. 



