91 



centrated into lines, k would be equal to 

 2 000 ; if they occupied half the available 

 space, it would be 1.635. As will be 

 seen from the diagram, they occupy 

 rather less than half the available space, 

 and k should, therefore, be greater than 

 1.635, though smaller than 2. The 

 author has not been able to obtain the 

 constructive data of this machine, and 

 can, therefore, not give the exact value 

 of the coefficient k for it. 



The Kennedy Alternatok. 

 This, too, is a disk machine of the iron- 

 clad type, the field being stationary and 

 the armature revolving (Figs. 17, 18, and 

 19). The latter has an iron core, A, 

 round which the armature- conductor is 

 wound, forming radial coils with parallel 

 sides. The field-magnet consists of an 

 external yoke-ring y bounded by flat 

 annular disks, which on their inner faces 

 are provided with polar projections N S, 

 occupying relatively to each other inter- 

 mediate angular positions. There is only 

 one coil of exciting wire, which is, how- 



