Pigments, paint, and painting; a practical book for practical men (1893)
Terry, George · London, E. & F.N. Spon; New York, Spon & Chamberlain · leaf 51
BLUES. 31 the cobalt ore is first spalled and hand-picked to remove the ores of foreign metals which are associated with it ; and then reduced to a very fine state in an edge runner or mortar mill, and freed from earthy impurities by washing. The concentrated ore is then dried and dead-roasted in… … Fig. 12. — Furnace for Boasting Cobalt Ores. is the hearth on which the ore is spread ; 6, the fireplace, the products of combustion from which pass over the ore on the hearth, and thence into the flues c, which repeatedly circle round the furnace so as to provide abundant oppor- tunity for the…
Pigments · Paint
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
