Nickel and Tungsten Alloys. 463 



having respectively 3 and 4 per cent of tungsten in alloy. 

 These bars were rolled from cast ingots, which were toughened 

 by the addition of magnesium after Fleitmann's method, the 

 magnesium being added just before pouring. They were hot 

 when rolled. The one of pure nickel was afterwards planed 

 into regular shape. Those containing tungsten were too brittle 

 to allow of this manipulation. They were, however, of suffi- 

 cient regularity to permit accurate measurements. This group 

 contained also an octagonally shaped bar with 8 per cent of 

 tungsten, which was prepared like the others, and was after- 

 wards ground into shape. 



The second group, received in May, 1889, contained bars 

 which were simple castings, made without the addition of mag- 

 nesium, and consisted of pure nickel and alloys with 1, 2, 3, 

 and 6 per cent of tungsten. All the bars in this group were 

 extremely hard and brittle. In making them, tungsten oxide, 

 of weight calculated to yield the desired percentage of tungs- 

 ten in the resulting alloy, was placed with 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 sepa- 

 rately in a hollow coil whose length was 15 cm. and outside and 

 inside diameters 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 ob- 

 served with a telescope and scale at a scale-distance of 100 cm. 

 Measurements of the horizontal intensity, H, of the earth's 

 magnetism were first made. The results from these determin- 

 ations by means of the first and second Gauss arrangements 

 were, respectively, 



11= 0-1724 cm. g. s. 

 H= 0-1720 " 



The freshly magnetized bars were then placed in the second 

 Gauss position relative to the magnetometer, and the angular 

 deflection determined. The specific magnetism, S, was then 

 calculated by the formula 



