TUBES 



1027 



which the tube sliding on its progress, the inside find outside are perfected together. 

 Mr. Cort patented a similar process for tho manufacture of gun-barrels. 



Brass or copper tubes are formed of rolled metal, which is cut to the required 

 breadth by means of revolving disks : in tha large sizes of tubes tho metal is partially 

 curved in its length by menus of a pair of rolls ; when in this condition it is passed 

 through a steel hole or a die, a plug being held in such a position as allows the metal 

 to pass between it and the interior of the hole. Oil is used to lubricate the metal ; 

 tho motion is communicated by power, the drawing apparatus being a pair of huge 

 nippers, which holds the brass, and is attached to a chain and revolves round a wind- 

 lass or cylinder. The tube iu its unsoldered state is annealed, bound round at 

 intervals of a few inches with iron wirn, and solder and borax applied along the seam. 

 Tho operation of soldering is completed by passing the tube through an air-stove, 

 heated with ' cokes ' or ' breezes', which melts the solder, and unites the two edges 

 of the metal, and forms a perfect tube ; it is then immersed in a solution of sulphuric 

 acid, to remove scaly deposits on its surface, the wire and extra solder having been 

 previously removed : it is then drawn through a ' finishing hole plate,' when the tube 

 is completed. 



Mandril-drawn tubes, as tho name indicates, are drawn upon a very accurately 

 turned steel mandril ; by this means the internal diameter is rendered smooth ; the 

 tube formed by this process is well fitted for telescopes, syringes, small pump- 

 cylinders, &c. 



The manufacture in all its details is described by Mr. W. C. Aitken, of Birmingham, 

 in the following article : 



Manufacture of Tubes in Lead, Tin, Iron, Steel and Urass, whether soldered, 

 plain, taper, ornamental, solid, or seamless. 



The introduction of water into public and private establishments as provision for 

 heating and ventilating, the use of tubes for the conveyance of gas, the large demands 

 for tubes also required in the construction of locomotive and marine engine-boilers, 

 have been the means of developing what is now an important branch of national in- 

 dustry. Tubes or pipes are essential requisites of the day, and may be said to havo 

 originated in tho practical application of science to the wants of the present and coming 

 generations : as pipes to let pure water in and carry foul water out, pipes for warming, 

 ventilating, and drainage, pipes to bring in gas, and to carry away the results of its 

 combustion, pipes for the rich man's marble or earthenware bath, pipes for the poor 

 man's brick kitchen, pipes for fountains and cesspools, for arresting conflagration 

 and pestilence, for the locomotive on the iron road, and the steamboat as it cleaves tho 

 ocean-wave. This brief allusion to the multifarious uses to which pipes or tubes 

 are applied may be accepted either as introductory to the inodus operandi or means by 

 which tubes are produced from various metals. There is every reason to believe 

 that in the early stages of tube-manufacture tubes generally were formed by casting, 

 the. aperture being produced by means of a core of sand laid in a print in a mould. 

 They were cast in short lengths, and soldered together, or they were turned up from 

 flat sheet-metal and tho edges united by means of soldering if lead or brass; or if of 

 iron, they were welded ; the methods of manipulation now adopted arising from the 

 increasing demand for such forms of metal. 



Lead-pipes were formerly produced by being cast in sand-moulds, a cylinder or ' core ' 

 of sand being laid in corresponding to the internal diameter of the aperture. These 



2029 



2025 



2026 



were cast in short lengths and soldered together, or they were produced from milled 

 or rolled sheet lead and soldered together with soft or plumber's solder at the seam or 

 junction of the two edges of the sheet lead: then followed the process by which the 



3u2 



