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HERBERT F. ROBERTS 



cylinders are placed, in the left hand one, the substance the 

 color of which is to be determined, in the other, the calcium sul- 

 fate used as the standard white reflecting surface. The spindles 



J? 



Fig. 1. Tintometer as reconstructed and mounted. B, binocular; X, case 

 containing drive mechanism; M, motor; C, three-arm support; R, point of 

 rotation. 



are rotated at high rate of speed by a friction drive mechanism 

 which is reversible. By this rotation of the substance the color 



