Any needles which may have been bent in the several processes are straightened by rolling under a steel bar, and are hardened by heating in a furnace, and suddenly cooled in cold water or oil. After hardening they are tempered by being slightly heated, and if any are bent during hardening, they are straightened by being hammered on anvils with small hammers; finally, the whole are polished by laying twenty or thirty thousand side by side upon a piece of thick canvas, smearing them with oil and emery, rolling up the canvas, and rubbing them under a press for several hours or even days. [Illustration: Soft Straightening. Needles placed ready to be filed. Needles in different Stages of Manufacture.] Drilled-eyed needles undergo another operation—a fine _drill_ is made to revolve rapidly in the eye of each, to take off the rough edge and to prevent their cutting the thread when used; finally, the points are finished on a revolving stone, and polished on a wheel covered with leather, and enclosed in a paper for sale. Simple as the construction of a needle may appear, it has to pass through the hands of 120 workmen, from the time it leaves the iron mine until the manufacture is completed. The chief seat of the needle manufacture in this country is Redditch, in Worcestershire, where upwards of seventy millions are made weekly. English needles are far superior to those of foreign manufacture. [Illustration] THE CALENDERER AND HOTPRESSER. [Illustration: MILL.] The business of the Calenderer and Hotpresser in so many respects resembles part of that already described as preceding the printing of calico, that only a brief notice of it will be necessary. The singeing and bleaching of the cotton has been explained, and calendering is the name generally applied in the manufacturing districts to the processes of smoothing, dressing, and glazing cotton and linen goods; the object being either to prepare them for the operations of the calico printer, or to impart the last finish to the goods before they are folded and packed for the market. The earlier calenders, or calendering machines, closely resembled a common mangle in their action, but were very large and heavy, and worked by a horse-wheel or other sufficient power, but the process was greatly improved by the invention of a machine in which the pressure is produced between rollers, instead of between rollers and flat surfaces, and in which consequently the alternating movement is got rid of, and also it is easier to give a uniform and equal pressure. [Illustration: Singeing Cotton Goods before Calendering. Iron Plate. Roller. Windlass. Scissors. Tongs.] [Illustration: Embossed Roller for Machine Printing. Presses.]