320 RUDDER TRIALS, U. S. S. STERETT. 



9. A battery box of twelve dry cells, "Navy Type," with two cells in 

 series on each solenoid circuit giving 4 to 5 volts. 



The recording gear including clock, motor, pens, solenoids, revolution 

 counters, and helm indicator gave complete satisfaction in its operation. 



The general arrangement of pens, solenoids, paper rolls, etc., is shown 

 on Fig. 4, Plate 1 14; and a specimen record made when turning is shown on 

 Fig. 9, Plate 119. 



