Potentiometer Pyrometers 1930
POTENTIOMETER PYROMETERS CATALOG NO. 87 1930, LEEDS & NORTHRUP COMPANY, PHILADELPHIA, PA.
Two shades of light red or salmon and black to cover design. About 10-1/2 x 8 with 44 pp. Solid binding with unmarked pages, a tiny bottom corner tip page bump and a mild glue mark insider rear cover where chart was attached. Photographic illustrations. Scarce!