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. 
9 
Pig. ade 
Before closing, the author wishes to express his appreciation of the 
‘ 
efforts of Messrs. IF. C. Weaver, G. T. Shoemaker and E. BE. Thomas, mem- 
bers of the present Senior Electrical Class at Purdue University. whose 
kindly assistance made this paper possible. 
Purdue University, 
Lafayette, Ind. 
