PARTS.

C, Cabinet, with sample-holder (H) and mirror (M), which may be removed and stored to left of dial (D) when instrument is closed for transportation.

D, Dial records color values in terms of standard white (100), the opposite end of the scale being absolute blackness (0).

E, Eye-peiece: to shield eye and sample from extraneous light while color determinations are being made. Fatigue of retina should be avoided.

G, Gear: actuates cat’s-eye shutter, which controls amount of light admitted to right half of instrument. Its shaft carries index-hand over dial.

H, Field-Holder: retains sample and standard white in same plane, and isolates them, Is hinged upon lower edge, and secured by pivot clamp.

M, Mirror: permits observation of the isolated halves of the holder, bearing standard white and the color to be measured. Should be clean and free from dust on both sides of central partition. 3