224 



closed through battery by a clock. The record is thus made automatically 

 and needs no correction. 



The accelerometer may be made self-contained and is easily trans- 

 ferred from one car to another. 



Fig. 13. 



Before closing, the author wishes to express his appreciation of the 

 efforts of Messrs. F. C. Weaver, G. T. Shoemaker and E. E. Thomas, mem- 

 bers of the present Senior Electrical Class at Purdue University, whose 

 kindly assistance made this paper possible. 



Purdue University, 

 Lafayette, Ind. 



