OF THE NATIONAL RESEARCH COUNCIL 109 



be tested in the endeavor to keep a hair line in the sighting tele- 

 scope, which is mounted on the recording lever, on the center of 

 the target. The reaction latency of the person to be tested is 

 shown by the distance that the target and drum move before the 

 recording lever starts. His accuracy is shown by the approxima- 

 tion of his record to a normal line which is recorded when the lever 

 which carries the target is temporarily clamped to the recording 

 lever. The moment of firing is indicated by the perforation of the 

 record by a jump spark. 



"The practical utilization of this instrument remained con- 

 fined to the U. S. S. Georgia and U. S. S. Pennsylvania where 

 it was tried out. It never got by the Office of Gunnery Exer- 

 cises. Considerably later, I submitted a plan for a robust 

 training model of this instrument to Captain E. L. Bennett 

 of the Training Section of the Bureau of Navigation. The 

 instrument was intended for shore training to offset the lack 

 of dotter equipment in the naval training stations. Construc- 

 ted by authority and at the expense of the Committee on 

 Classification of Personnel, this instrument was set up in the 

 Armed Guard Camp of the New York Navy Yard. It proved 

 an instant success. Its use was developed to greatest effi- 

 ciency at this place under Lieutenant Norton. Under orders 

 from the Bureau of Navigation a number of replicas were 

 built by the Armed Guard Camp of the New York Navy Yard 

 for other training stations. 



"The instrument consists of a battery of four skeleton 

 guns, with training or pointing gear, a mechanism for giving 

 the targets a series of harmonic wave motions of great variety 

 and complexity, a recording device, that shows each move- 

 ment of the target and the corresponding movements of the 

 gun as the pointer or trainer tries to follow It, and a firing 

 device, that not only Indicates the accuracy of the pointing 

 but also the effect of the effort to fire on the pointing coord- 

 inations. 



"The object of the Instrument is to furnish land conditions 

 for teaching a recruit the coordinations of hand and eye essen- 

 tial to pointing and firing at a moving target at sea. It was 

 designed as a robust practice Instrument which could be repro- 



