Popular Science Monthly 



425 



either of running toward the thing it sees, or of fleeing from it. That is the basic idea of the weapon 

 here pictured. Its movements are absolutely controlled by the beam that comes from a searchlight 



less from shore now ; can be made to 

 stop, start, stop and swerve to right and 

 left. Nevertheless, the secret of a re- 

 liable, light-controlled torpedo — for 

 light-rays are more desiral)le tlian wire- 

 less — has not yet been entirely solved. 



John Hayes Hammond, Jr., who has 

 been widely heralded for his wireless ex- 

 periments, joined hands not long ago 

 with B. F. Meissner, an electrical engi- 

 neering student of Purdue University, 

 and together they designed and con- 

 structed an ingenious mechanism on 

 wheels that would trail after a pocket 

 lamp held before its selenium eyes in a 

 most uncanny way. Using this same 

 principle, a torpedo with selenium eyes 

 that will follow the directions of light 

 rays from shore, will eventually be de- 

 veloped ; soon, it is to be hoped. 



There have been two big obstacles to 



prevent the e\oiulion of a controllable 

 torpedo : 



One is the lack of a suitable appa- 

 ratus for transmitting sufficient light 

 to control the mechanism at useful dis- 

 tances; the other is to accomplish the 

 directing without interference from the 

 enemy's ship. The solution of the prob- 

 lem demands a more scientific knowledge 

 of selenium and its chemical properties. 



Suppose that day had come and a hos- 

 tile ship was booming into the harbor of 

 New York, grimly determined to scatter 

 our fair buildings to the four winds. 



"Sic !" says the man on shore. 



Almost with human intelligence, the 

 glistening steel cylinder darts out to- 

 wards the enemy, at a forty-mile-an-hour 

 clip. Though at present such an occur- 

 rence is only a fancy, it may become 

 a reality. 



