258 Dr. A. 0. Orehore on the Construction of the 



the directions of the axes, by giving it the proper motion : 

 but one plane is not immediately above another in a similar 

 position. Where the wide spacing between planes occurs 



equal to 7 v^, the planes, including the directions of axes 



of rotation, do exactly coincide when moved vertically, but 

 this is not the case with the pairs of nearer planes. 



Fij?. 1. 



y\/\/\/\x\/\ 



\/\/\/\/\/\/ 

 y\/\/\/ , \/\/\ 

 \/\/\/\/\/\/ 

 x\/\/\/\/\/\ 



\s\/\s\/\y\s 



x\/\x\/\/\/\ 



\/\/\/\/\y\y 

 /\/\/\/\/\y\ 

 \/\/\/\/\/\x 

 s\/\x\/\/\/\ 

 \y\x\/\/\/\/ 

 x\/\/\/\/\/\ 



The arrows represent the axes of rotation, such that when, 

 the observer looks from the head of the arrow toward the 

 centre, the rotation of the electrons is clockwase. None of 

 the axes in fig. 2 lie in the plane of the paper, but three- 

 fourths of them take such directions as to point toward the 

 centres of the regular tetrahedra whose bases are the ele- 

 mental triangles and whose centres are above the plane of 

 the paper, as the point for example. The other one-fourth 



