188 Mr Laws, Experiments on the Thomson Effect 



Other results obtained are : 



o- 40 o. 2 = - 10,700 ergs per C.G.S. unit current per 1° C. 

 °"53°-8= — 12,600 „ „ „ „ 



a 6f . 5 = - 14,600 „ 

 -14,700 „ 



These values increase much more rapidly than the absolute 

 temperature ; in fact a straight line drawn through the points cuts 

 the axis of temperature at — 40° C. (fig. 2). 



It will be observed that these values are about 12 times as 

 large as those found for bismuth ; the largest value previously 

 found was obtained by Le Roux for an alloy of bismuth and 

 antimony and is about 2-4 times that given for bismuth. 



Alloy No. 2, containing 3 per cent, of tin. 

 Mean diameter of rods = 4 - 82 mm. 

 Mean resistance of rods = 0000177 ohms per mm. 



From the data given in Tables V and VI the value 

 o- 42 o. 7 = —12,900 is obtained. 



Table V. 



Thomson effect. 

 (7=3 amperes. 



= 42°-7. 

 d6 



dx 



0-585. 



Mean value for 8 : 9-96 

 Correction — -06 



IhJO 



