268 
(10) A suggestion is given that the stream consists of heated air 
molecules and ions, in which the latter soon lose their velocity, due to 
encountering air molecules, and travel to the opposite point with a speed 
too much decreased to set up an air current, along a route determined by 
the two fields, while the un-ionized air moves in the direction given it by 
the ions at the point. 
The above investigation was suggested by Professor Arthur L. Foley, 
of Indiana University. I wish to thank him and Professor R. R. Ramsey 
for their helpful suggestions during the course of the investigation. I wish 
also to thank Professore A. T. Jones and C. M. Smith, of Purdue University, 
for their criticism during the preparation of this report. 
Physical Laboratory of Indiana University, 
Bloomington, Ind. 
