182 PROCEEDINGS OF THE AMERICAN ACADEMY 



adequate carbon in the bottom of a graphite crucible and covered by 

 the proper weight of pure grain nickel. All was then covered with 

 borax, the lid of the crucible was placed on, and the crucible was 

 heated until reduction and fusion were completed. 



Method. 



As the suspected influence of the tungsten would be to affect the 

 magnetic moment of the bars, these were magnetized to saturation and 

 their specific magnetism then determined, i. e. the magnetic moment 

 for each gram of metal. 



The magnetization was effected by placing the bars separately in a 

 hollow coil whose length was 15 cm. and outside and inside diametei's 

 respectively 6 and 3 cm. It consisted of 6 layers of wire having 63 

 turns each. A dynamo current of 40 amperes was then sent through 

 the coil for one minute, and the circuit then broken and the bars 

 removed. 



For the determination of the magnetic moment, use was made of a 

 reflecting magnetometer, and deflections were observed with a telescope 

 and scale at a scale-distance of 100 cm. Measurements of the hori- 

 zontal intensity, H, of the earth's magnetism were first made. The 

 results from these determinations by means of the first and second 

 Gauss arrangements were, respectively, 



H= 0.1724 cm. g. s. 

 ^=0.1720 



The freshly magnetized bars were then placed in the second Gausa 

 position relative to the magnetometer, and the angular deflection de- 

 termined. The specific magnetism, S. was then calculated by the 

 formula 



o r^ H tan ^ 

 o = , 



1)1 



where 



r = distance from bar to magnetometer =: 72.68 cm. 



H ^= earth's horizontal intensity = 0.1722. 



m = mass of the bar. 



<^ = angular deflection of magnetometer. 



Results. 



The mean results of two sets of observations on Group I., and also 

 upon a similar bar of soft tool steel are given in the following table. 



