1038 TUGMUTTON 



for this, and the result of the first rollings is to reduce the metal on the upper cr 

 under side to the same thickness as the sides. The oval billet being rolled into a 

 flat strip or bar, hns then one end opened to the length sufficient to admit of the intro- 

 duction of a thick-ended mandril. With this introduced, the opened end of the tube 

 is presented to the rolls ; the thick part of the mandril retained in the tube at the point 

 of pressure ; the tube is drawn on and opened throughout its entire length. The 

 position of the tube in the opening-up of the bar is the reverse of the previous operation, 

 being presented in its largest diameter to the action of the rolls, or at right angles to 

 the preceding operation. The adhering webs or fins consequent on this mode of produc- 

 tion being removed, the tube is again passed through rolls, to produce it in form per- 

 fectly cylindrical, a mandril in the interior assisting the operation. All the operations in 

 this variety of solid tube are conducted when the metal is at a low red heat, the metal 

 of which these tubes are made, or Muntz's metal, consisting of copper, with a large per- 

 centage of zinc or spelter, imparting to it the property of being rolled at the temperature 

 named, much facilitating the rapidity of production. 



It may not be uninteresting to know that nearly all the locomotive-engines in 

 use on the railroads of the United Kingdom are fitted up with seamless brass 

 tubes. If to these are added the quantity of seamless brass tubes in use in the steam- 

 boats of the United Kingdom also, the united weights of these tubes gives a total of 

 upwards of 20,000 tons of solid or seamless brass tubes in use by the various 

 railway companies, steam-boat proprietors, &c., of this country. The production of 

 solid brass tube in Birmingham, for these purposes alone, amounts to upwards of 

 8,000 tons annually. 



A very admirable variety of solid or seamless copper tube is now produced from 

 the worn-out copper rollers used by calico-printers for printing cotton fabrics. The 

 old roller, with the rib which holds the roller on the printing spindle, in the 

 operation of printing, taken out forms the billet ; it is reduced in outer diameter, its 

 internal diameter depending on the size of the internal mandril used, the 

 reduction being effected as in the manufacture of Green's tube by powerful draw- 

 beaches. As in Green's tube, also, repeated annealings are required in the opera- 

 tion of reduction or drawing down to the size of tube required. This method 

 of producing seamless copper tube from previously waste material was intro- 

 duced in 1850, by the late Thomas Attwood: the density of the material of which 

 the tube is formed, good at first, as being formed of wrought copper, is further 

 solidified by the modus operandi in converting the worn-out roller into a tube 

 for steam purposes. When subjected to great pressure it is unequalled in service. 



In conclusion, as regards the manufacture of brass and copper tube but little 

 remains to be stated. Messrs. Alexander and Henry Parkes patented the addition of 

 phosphorus and manganese to the alloy of brass and zinc, out of which locomotive 

 and marine boiler-tubes are made, which they state improves the metal, imparting 

 to it superior cohesive properties, and also solidity. The direction recently given 

 for locomotive and marine engine-tubes is towards tubes containing a larger pro- 

 portion of copper than even in those of 'Green's' mixture. It is stated, if the 

 percentage of copper is increased, the tubes may be made lighter in material, and 

 will be less likely to be operated upon by the sulphates in the fuel. Finally, if 

 certain preliminary details as to the casting of the ' billets,' from which the solid or 

 seamless tubes are drawn, or in raising the ' billets' up from thick disks of rolled 

 metal, but little remains to be recorded as respects the improved manipulatory opera- 

 tions in the manufacture of brass or copper tubes. 



TUBUZi AR BRIDGES. In the fourth edition the last published during the life- 

 time of Dr. Ure there was a long article bearing the heading of FAIRBAIRX'S TUBULAR 

 BRIDGES. This article no longer appears. In the first place, it ought never to have 

 found a place in a work which has nothing whatever to do with Engineering Science. 

 Such was the introduction to the article as it appeared in the fifth and sixth editions of 

 this Dictionary. The article, which was written with great care by the Editor himself, 

 after several interviews with both Mr. Robert Stephenson and Mr. Fairbairn, was 

 acknowledged by both these eminent engineers to give the most correct account of the 

 merits of each of them, in the construction of these remarkable works. Those who 

 may be interested in this question are referred to the last edition of the Dictionary : 

 the article having been withdrawn from this edition to make room for matter which 

 belongs more especially to Art, Manufactures, or Mines. 



TUB-IRON', also Tuiron and Tuarn. The old name for the blast-hole, or twyer, 

 or tuyere of a blast-furnace. 



TUTA. A deposit of calcareous carbonate from springs and streams. Also, a 

 volcanic product. See MORTAR, HYDRAULIC. 



TUGIVTUTTOW. A wood resembling box, which was imported and used for 

 making ladies' fans. It does not appear to be now known in the trade. 



