1889.] Note on the Thermo-electric Position of Platinoid. 289 



a height of 2J inches above the surface of the liquid the temperature 

 was often found to be as much as 8° or 10° C. cooler than it was just 

 above the surface. The difficulty could, to a certain extent, be over- 

 come by putting a cloak of fine flexible wire gauze all round the 

 upper part of the flask ; but the greatest watchfulness was needed to 

 avoid mistakes. 



In order to reduce the results obtained from the readings of the 

 galvanometer to absolute electromagnetic measure, a carefully pre- 

 pared standard Daniell's cell was kept with its current always flowing 

 through a known high resistance ; and from time to time the galvano- 

 meter which was being used was thrown into the circuit, and the 

 value of the galvanometer deflection determined. The electromotive 

 force of the Daniell's cell was valued at 1*072 volts. 



The results obtained are shown in the accompanying curves and 

 tables, 



In the curves the electromotive forces are shown as ordinates, the 

 differences of temperature between the hot and cold junctions being 

 indicated on the axis of abscissas. The electromotive forces are given 



t 2 



