vbl. sb. [f. as prec. + -ING1.]
1. The action or process of making flat. In Glass-making, the process of laying out (sheet-glass) flat.
1879. J. Paton in Encycl. Brit. (9 ed.), X. 660/2. The opening, flattening, or spreading of the glass. Ibid., 661/1.
2. The process of becoming flat; the condition of being flattened.
1726. Monro, Anat., II. 199. This Flatning on their Sides, which makes the Figure of these Vertebræ near an half Oval, is of good Use, as it affords a firmer Articulation to the Ribs.
1854. W. K. Kelly, trans. Arago’s Astron., 100–1. The degree, or the space which it is necessary to go over between two verticles to have a degree, is not the same in all latitudes: it is longer the more we approach the poles, and it is at its minimum at the equator; which indicates very plainly a flattening at the poles, and not an elongation, as had at first been supposed by a strange mistake.
1860. Tyndall, Glac., II. xxiv. 359. These disks [in ice] have been mistaken for bubbles containing air, and their flattening has been ascribed to the pressure to which they have been subjected.
1878. Huxley, Physiography, xix. 325. The earth’s flattening is very much less proportionally than that of the orange.
3. attrib. and Comb. (chiefly in Glass-making: see 1), as flattening arch, furnace, iron, kiln, oven, stone, tool.
1879. J. Paton in Encycl. Brit., X. 661/2. The waggon then goes back to the *flattening arch.
1874. Knight, Dict. Mech., I. 878/2. *Flattening-furnace. A furnace into which cylinder glass split longitudinally is placed to flatten out by heat.
1858. Simmonds, Dict. Trade, *Flattening-iron, a laundress’s or workman’s smoothing-iron.
1871. W. R. Greg, Enigmas, 272. That as they enter the immortal state, God will pass a flattening-iron over all who ‘shall be found worthy to attain to the resurrection of the Just,’ and smooth out every salient individuality whether of capacity or aspiration.
1879. J. Paton in Encycl. Brit., X. 661/2. The *flattening kiln … consists of two chambers built together, the one for flattening the cylinders, the other for annealing the sheets…. The cylinder, after being gradually reheated, is placed in the centre of the *flattening oven, upon a smooth stone. Ibid. The *flattening stone or table, mounted on a movable waggon.
