274 
Proceedings of the Royal Society of Edinburgh. [Sess. 
XIV. — On the Magnetic Properties of certain Copper Alloys. By 
Alexander D. Ross, M.A., B.Sc., Assistant to the Professor of 
Natural Philosophy in the University of Glasgow, and Robert 0. 
Gray, Thomson Experimental Scholar in the University of Glasgow. 
(MS. received February 5, 1909. Read February 15, 1909.) 
In May 1907 a paper was read before this Society by one of us on the 
magnetic properties of the Heusler alloy.* After that date the investiga- 
tion was extended to two other copper-manganese-aluminium alloys, and 
latterly the scope of the research has been further extended by a series of 
tests carried out by the present authors conjointly on simple aluminium and 
manganese bronzes, and on the constituent metallic elements in the pure 
form, while additional tests have been made on the manganese-aluminium 
bronze. Some of the more interesting results obtained since the 1907 paper 
are given in the present communication. 
Specimens . — The specimens referred to in this paper were cast by 
Gray and Caldwell, Paisley, and Steven and Struthers, Glasgow, and had 
the following compositions : — 
(1) Casting B. — 62 per cent, copper, 25 per cent, manganese, 125 per 
cent, aluminium, and a trace of lead. 
(2) Casting D. — 76 per cent, copper, 16 per cent, manganese, and 8 per 
cent, aluminium. 
(3) Casting E. — 55 per cent, copper, 30 per cent, manganese, and 15 per 
cent, aluminium. 
(4) 5 per cent, aluminium-bronze (that is, 5 per cent, aluminium, 95 per 
cent copper). 
(5) 10 per cent, aluminium-bronze. 
(6) 60 per cent, aluminium-bronze. 
(7) 70 per cent, aluminium-bronze. 
(8) 30 per cent, manganese-bronze. 
(9) Pure aluminium. 
(10) Pure manganese. 
It will be observed that B is the ordinary Heusler alloy, and that in D 
and E the same relative proportions (viz., those of the atomic weights) of 
manganese and aluminium have been maintained, while the amount of 
* A. D. Ross, “ Heusler’s Magnetic Alloy,” Proc. Roy. Soc. Edin., xxvii. part 2, p. 88. 
