Tube drawing is effected by cutting a strip of metal which is then passed through rolls to give it a gutter form. One end of the gutter is now beaten up to form a tang that can be gripped by the tongs of the draw bench, and the gutter is pulled through a conical hole which roughly forms the tube. The open seam of the tube is now brazed, and after cleaning, this roughly formed tube is slipped over a steel rod or mandril. Both mandril and tube are drawn through a smooth circular hole when a smooth uniform tube is formed. Fluted taper tubes are made as described at (B. p. 324[48]) by means of “tins,” but a novel method is now adopted for smooth taper tubes. A wedge-shaped piece of metal is roughly made into a conical tube which is put on a taper mandril revolving in a lathe. A flat steel burnisher is pressed on to the tube as it revolves pressing the metal to take the shape of the mandril. Twisted tubes are produced by drawing the tube through a revolving nut (B. p. 325[48]), embossed or ornamented tubes by drawing a plain tube through a die, composed of a series, four say, of small wheels or pulleys on the edge of each wheel being impressed the desired pattern. As the tube is drawn through the die, the wheels turn and impress on the tube the pattern they carry on their surface. As stated (B. p. 326[48]), the invention is due to Mr. Fearn. It should, however, be mentioned that the process failed in his hands, but was subsequently taken up by Messrs. Winfield and Co., who, with the help of their engineer, Mr. Thomas Preston, brought the process to perfection. PRESS TOOL WORK.--The next general process in the manufacture of many metallic articles is cutting out a blank into the requisite shape. This is done by what is called a press tool consisting of two parts; one a firm block of steel, in which is an aperture, circular, oval, or whatever shape may be desired, and the other a punch of corresponding shape, a piece of metal being placed over the aperture, the punch is forced down by a screw of high pitch on to the metal, when a blank is cut out at one blow, and falls into a pan placed to receive it.[49] STAMPING.--Used for hollowing blanks in a number of trades. The blank cut by hand or tool is placed on a mould or die, and a heavy weight, carrying on its lower surface the counterpart of the mould, working in guides so as to fall true, can be lifted up and allowed to fall on the blank until the metal is forced into the shape of the mould. As the metal hardens by successive blows, the blanks are annealed (that is heated and allowed to cool) as often as may be found necessary. The weight which gives the blow is supported by a strap passing over a wheel in constant motion. So long as the strap hangs loosely over the wheel, the friction of the moving wheel is insufficient to lift the weight, but immediately the workman makes the strap taut, the weight is carried up and is let fall by the workman releasing his hold on the strap.