CALENDERING.
The process of calendering is resorted to for producing a fine smooth surface on calicoes and other goods, and for rendering them sufficiently even to be printed upon (see “[Calico-printing”]). The calendering machine consists of a set of five rollers, constructed to revolve at unequal rates, so that the one which turns upon the face of the calico not only rolls it between itself and its fellow, but—turning faster—rubs it and gives a gloss to the surface similar to the effect which would be produced if the goods were laid on a table, and the roller rubbed over them instead of being rolled. These rollers are very curiously constructed. They are made by packing many hundreds of round pieces of pasteboard—having each a square hole in the centre, and several smaller circular ones in the margin—on to a central bar of iron, with similar bars through the smaller holes, until a sufficient number have been added to produce the length of roller required. Nuts are then fitted to the ends of the smaller iron bars, and these being screwed tightly, compress the whole into so solid a mass, that it can be turned in a lathe to a perfectly smooth surface, which is (unlike wood) not liable to crack, and, being slightly elastic, does not crush the goods, as metal rollers would.