[see BLAST sb. 4 b.] A blast of cold air forced into a furnace. Also attrib., and short for cold-blast furnace, process, etc.
1835. Mechanic’s Mag., XXIII. 341. (heading) Coal employed in the crude state in the Welsh Iron Works. Cold Blast. Ibid. (1837), 316. The holders of metal manufactured by the cold-blast now regularly demand 20/- per ton extra for it.
1873. Ure, Dict. Arts, II. 956. The superior power of a hot over a cold blast in fusing refractory lumps of cast iron was accidentally observed by Mr. J. B. Neilson … about the year 1827. Ibid., 963. The density of cold-blast iron is less than that of hot.
