On Crystallographic Projections. 85 



for all fields, but in the other four specimens the resistance 

 is increased at low fields and diminished at high fields. The 



specimen 70 per cent., 



change of resistance is greatest in tin 

 and it wi 



be noticed that the initial increase is much greater 

 in this specimen than in nickel. 



Fie. 7. 



10000 



Chamre of Resistance of Iron, Nickel, and Nickel-Steel for 

 Transverse Magnetization. 



All the experiments described above were carried out in 

 the Physical Laboratory of the University of Glasgow ; and 

 I desire to express my best thanks to Prof. Gray for placing 

 the necessary apparatus at my disposal, and also for much 

 valuable help and advice given in the course of the work. 



VI. On Crystallograplur, Projections. 

 By Hakold Hiltox*. 



1. T ET crystallographic axes OA, OJ3, OC meet at 



I J A, B, C a sphere of unit radius with centre O 



whose equation referred to any three mutually orthogonal 



axes through O is ar +//'-' + z 2 =l. Let Y be the pole of the 



crystal-face whose indices are if, >\ w ; and let the points 



* Communicated by the Author. 



