MAGNETIC ALLOYS OF IRON, NICKEL, AND COBALT 437 



elements to the iron and nickel in order to determine their effect both 

 on the resistivity and the magnetic properties. Copper, chromium, 

 molybdenum, tungsten, and tantalum are a few of those we added; 

 also the magnetic element cobalt. The striking results obtained with 

 the addition of cobalt to the iron-nickel alloys led us to make a com- 



Fig. 1 — Composition diagram — Ni-Fe-Co series. Dots show compositions tested. 



plete survey of the whole field of alloys containing the three magnetic 

 metals. 



A convenient way of showing graphically the number of alloys we 

 investigated and the distribution of compositions of these alloys is 

 afforded by the equilateral composition triangle in Fig. 1. In this 

 triangle the metals — iron, nickel, and cobalt — are represented by the 

 corners; the binary alloys by points on the three sides, and the ternary 

 alloys by points within the area of the triangle. Each alloy we 

 investigated is indicated by a dot and the location of each dot indicates 

 the proportion in per cent of the three metals in the alloy. A glance 



