Roll.
1. (Metal-working.) One of the pair of cylinders between which metal is passed to draw it into bar, or to flatten it out into a sheet. See rolling-mill. The largest known to the writer is a pair of iron rolls for Sir John Brown's works at Sheffield, England. These rolls are 15 feet 6 inches in extreme length, and 3 feet in diameter, and each weighs 18 tons. They are used for rolling armor-plates.
2. (Engraving.) The cylindrical die in a transferring-press. See bank-note engraving. See roller.
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| Seller's rod-planer. |
3. (Wool-working.) A carding of wool, delivered broadside from the cards, and somewhat compacted in the process. Rolls are prepared for handspin-ning. The doffing-cylinder of a wool-carding machine has longitudinal bands of cards with intervening spaces. The doffing-knife removes the fibers from these bands in slivers which are of the length of the doffing-cyl- [1962] inder. They fall into the roller-bowl, which rolls and compacts them, bringing them into the condition of rolls or cardings, which are taken to the slubbing-machine.
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| Rolls. |
4. (Bookbinding.) A tool (a) for hand embossing or gilding where a continuous line or pattern is to be impressed upon a bookcover. It is a brass wheel, whose edge is of the pattern desired, either in single, double, or triple line, or having fillets, interlacing, or scroll pattern engraved thereon. It is mounted in a holder and heated over gas or charcoal. The handle rests against the shoulder of the operator, and the wheel is passed along the place to be embossed. For gilding, the surface is previously spread with glaire, and gold-leaf is laid thereon.
5. (Metallurgy.) One of a pair or series of rollers arranged in pairs, between which ores are crushed. That shown at b (Fig. 4396) has an interior longitudinal slot to receive the key by which it is held on the shaft.
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| Bookbinder's roll. |
6. (Building.) A strip with a rounded top laid over a roof at the ridge or at lateral joints, to raise the sheet-lead at those points.
7. (Paper-making.) A cylinder mounted with blades for working paper-pulp in the tub.
