( 410 )• 



sure that the copper or the German-silver wires did not separately 

 touch the bismuth. 



The observations were made in the following way : 



1. Observe for five minutes the deflection by the thermo-element 



without magnetic field. 



2. Observe for five minutes with the magnetic field in one direction. 



3. „ „ „ „ without 



I with the 

 , without 

 And so on. 



other 



During the five minutes after interrupting the magnetising current 

 the temperature returns slowly to its original value. 



Mainly by help of the deflections just before applying the mag- 

 netic field, the remaining variation of the deflection without magnetic 

 field was represented graphically and from this was interpolated the 

 value of that deflection at a moment five minutes after the closing 

 of the current. 'J he difference of this value and the deflection 

 observed just before interrupting the current gives the fall of tem- 

 perature we require. 



By taking the mean for the two directions of magnetisation the 

 error is avoided, which would otherwise be caused by the rotation 

 of the isothermals. 



Here follow some of the results obtained. ^1, B and C again 

 indicate the three fixed places on the plate; the temperatures above 

 each column give approximately the values as they occurred during 

 the observations. 



The temperature of the water-jacl^et in all these observations 

 was about 8°. 



The following are tlie results from whicli the number 0°,28 for 

 C. was deduced, given in order that we may judge of the accuracy 

 of the separate determinations. 



