Glass-making. Also 8–9 lear, 9 lier. An annealing-furnace. Also attrib., as lear-annealing; leer-pan = FRACHE.
1662. Merrett, trans. Neri’s Art of Glass, 243. The Leer (made by Agricola, the third furnace, to anneal and cool the vessels…) comprehends two parts, the tower and leer.
1727–51. Chambers, Cycl., s.v. Furnace, The leer is an avenue five or six yards long, continued to the tower.
1797. P. Wakefield, Mental Improv. (1801), I. 143. The lear or third furnace.
1797. Encycl. Brit. (ed. 3), VII. 768/2. The third oven or leer.
1832. G. R. Porter, Porcelain & Gl., 158. The annealing oven, or lier, is a long low rectangular chamber … furnished with numerous shallow iron trays…. These trays are called lier pans, or fraiches.
1839. Ure, Dict. Arts, 579. The cooling or annealing arch, or leer, is often built independent of the glass-house furnace…. The leer pans or trays of sheet iron.
1890. W. J. Gordon, Foundry, 140. The tunnel is the ‘lear,’ and the process is known as lear-annealing.
Hence Leering, treatment in the ‘leer.’
1889. Standard, 5 Jan., 2/1. The English glass is brighter and better from lead being used, instead of lime, for ‘learing,’ the lead ‘learing’ being more expensive.
