[ad. It. calcara ‘a lime-kill’ (Florio), ‘a kind of oven or furnace to calcine vitreous matter in’ (Baretti); cf. L. calcāria lime-kiln, fem. sing. of calcārius, f. calx, -cis lime.]
1. In Glass-making: ‘A small furnace, in which the first calcination is made of sand and potash, for the formation of a frit’ (Ure, s.v.).
1662. Merret, trans. Neri’s Art of Glass, 19. Mix & spread them well in the Calcar, with a rake, that they may be well calcined, and continue this till they begin to grow into lumps.
1712. trans. Pomet’s Hist. Drugs, I. 104. The English call the whole Quantity, bak’d at a time in the Calcar, a Batch.
1832. G. R. Porter, Porcelain & Gl., in Lardner’s Cab. Cycl., 155. The Calcar is in the form of an oven about ten feet long, seven feet wide, and two feet high.
1875. Ure, Dict. Arts, II. 654. A reverberatory furnace or calcar.
2. Metall. An annealing arch or oven.
