810 REPORT— 1886. 



SATURDAY, SEPTEMBER 4. 

 The following Papers were read : — 



1. On the Manufacture of Metal Tubes. 5?/ James Robertson. 



This paper described a novel method especially applicable to the manufacture 

 of seamless copper tubes, which has been recently invented by the author and 

 brouo:ht into practical use by Messrs. Ralph Heaton & Sons, of Birmingham. 



By revolving a smooth steel rod, on which a gland was fitted that could be clamped 

 more or less tightly and drawn along the rod by a weight passing over a pulley, it 

 was shown that, whereas a weight of 60 lbs. was required to move the gland while 

 the rod was in a quiescent state, on revolving the rod a single pound sufficed to 

 produce this result. This circumstance depends on what the author calls the 

 ' cross surface motion frictional contact of solid bodies,' and it was shown that by 

 increasing the velocity of revolution the weight required to produce this end- 

 movement may be still further reduced as compared with that in a state of rest, 

 the practical limit being about one-eightieth. 



In applying this principle to the manufacture of copper tubes a revolving 

 mandrel (corresponding to the steel rod in the experiment described above) is 

 forced by hydrauhc pressure into a copper billet fixed coaxially with it. Round 

 cast billets of 4, 5, and 7 in. in diameter and about 2 ft. 4 in. in length are 

 employed, and, although not essential, it is found most economical first to pierce a 

 hole \\ in. in diameter the entire length of the billet. This is done without removing 

 metal, for it is ' laved ' aside as the mandrel forces its way through the billet. On 

 passing a three-inch mandrel through the billet in this form it is elongated to a 

 length of about four feet, when it is known as a ' shell,' and passes to the draw- 

 bench. The primary object of the initial hole is in order that the mandrel may be 

 lubricated. This is done with oil so efl'ectively that the mandrel never gets over- 

 heated, and the shell can be handled immediately after the operation. 



The necessary end pressure of from 40 to 150 tons is given by a ram, and the 

 water within the hydravdic cylinder is at the same time used as a back centre, thus 

 avoiding excessive waste of power from friction. The ram, carrying the mandrel 

 attached to its front face by a clutch-plate, is caused to revolve by gearing, the 

 driven spur-wheel being also fixed to the front end of the ram. 



The copper billet is held in a pair of half-round dies, while end-traverse is pre- 

 vented by steel holding-dogs fitted in the front end of these dies. The mandrel ia 

 enlarged at its extremity in a bulbous form, having a sharp point and three cam- 

 shaped inclined working edges on its surface. Each inclined edge as it revolves 

 spirally causes a wave of metal to roll before it, and thus widens out the hole and 

 elongates the billet, the direction of rotation being, of course, the converse of that 

 which would be adopted in drilling. The mandrel revolves at a rate of about 

 twenty revolutions per minute in making a hole three inches in diameter, and the 

 traverse endwise is from six to ten inches in the same interval according to the 

 temper or ' pitch ' of the copper operated upon. 



2. On the Blackpool Electric Tramway.^ By M. Holeotd Smith. 



3. Automatic Pumping of Sewage by High-pressure Water. 

 By Baldwin Latham, M.Inst.G.E., F.G.S. 



The author in this paper shortly described a method of transmitting power from 

 a central point by the use of high-pressure water, and using such power as a con- 

 venient mode for automatically raising sewage in any district. Two machines were 

 placed vertically in one chamber, and so arranged by means of floats that when. 



' Published in Electrician, Sept. 10, 1886. 



