OF ARTS AND SCIENCES. 181 



XYI. 



THE MAGNETISM OF NICKEL AND TUNGSTEN 



ALLOYS. 



By John Trowbridgp: and Samuel Sheldon. 



Presented May 28, 1889. 



Introductory. 



The fact that different kinds of steel, alloyed in small proportions with 

 Tungsten or AVolfram, and magnetized to saturation, increase in spe- 

 cific masnetisra,* has long been known. Whether the same effect 

 would result from the use of Nickel alloyed with Tungsten has never 

 been investigated. This paper has for its object a partial answer to the 

 query. It was instigated by Mr. Wharton, proprietor of the American 

 Nickel Works, whose chemist, Mr. Riddle, kindly prepared the alloys 

 which have been employed. These alloys were in two groups. The 

 first, received in November, 1888, consisted of three bars of the same 

 shape, one being of pure nickel and the other two 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 tiiis manipulation. They were, however, of 

 suflficient 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 afterwards ground into 

 shape. 



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

 were simple castings, made without the addition of magnesium, 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 de- 

 sired percentage of tungsten in the resulting alloy, was placed with 



* Jour. Chem. Soc, 1868, xxi. 284, says 300 per cent. 



