TRANSACTIONS OF THE SECTIONS. 209 



at eacli end, the engine power and machinery, the interest of outhiv during con- 

 struction and engineering superintendence, witli a large margin for contingencies, 

 is £8,000,000. 



The tube is capable of conveying, on the pneumatic plan of working the trains, 

 with ease, 10,000 tons of goodsper day, and we may reasonably calculate that the 

 amoimt of traffic will be limited only by the power which may exist of passing it 

 through the tube. 



The annual working expenses will consist of maintenance, wliich will be light, 

 of the cost and wear and tear of the pumping-eugines, and of the ordinary expenses 

 of management, the whole of which would be most amply covered by £150,000. 



It would be easy to enlarge on the advantages to the whole world which such a 

 bond of imion would Ijring about, especially to the two great nations which would 

 be thereby most intimately connected ; but in a dry and scientific description of 

 the means by which this" important work of communication is proposed to be 

 accomplished, such language would be out of place. Let it be proved to be a 

 practicable undertaking, and the best or most promising which has been suggested, 

 and it may well claim the support and the material assistance of the Governments 

 of England and France, as well as of all the nations of Europe. 



On the Utilization of Town Sewage. By T. D. Baeey. 



The author believed that, in the case of the irrigation system, it was the water, 

 and not the sewage, which promoted the growth of the crops, and that injmious 

 miasmata always arose from irrigated fields. He preferred a sj'stem of filtration. 

 The effluent water could be made clear and innocuous, whilst the suspended or 

 solid matter could be sold to the farmer at a price which would pay the cost of fil- 

 tration. At Leamington this course is successfuU}' adopted. 



On a Navigable Floating Docl: 

 Bg Yice-Admiral Sir Edwaed Belcher, K.G.B., F.R.A.S. 



On an Air-engine. By J. T. Chillen-gavorth. 



On the Birmingham Wire-Oauge. By Latimer Clark, 



This was a continuation of the subject which had been brought before the Asso- 

 ciation on two previous occa.sions, the object being to promote the establishment of 

 some universal wire-gauge. This the author considered would be satisfactorily 

 attained by reestablishing the Birmingham gauge on a rational basis, and recti- 

 fied from the irregularities which have crept into it, partly for want of some recog- 

 nized standard, and partly by reason of the impurities of the materials, from the 

 properties of which it was originally determined. 



On the Ilydranlic Buffer, and Expeiiments on the Flow of Liquids through 

 small Orifices at High Velocities. By Colonel H. Clerk, li.A., F.E.S. 



The hydraulic buffer was first applied for the purpose of checking the recoil of 

 guns in 1867. It consists of a wrouglit-iron cylinder closed at one end, the other 

 end fitted with a cap and stuffing-box, through which a piston-rod passes. The 

 piston fits well in the cylinder, and is perforated with four small holes. The dia- 

 meter of these holes, and the length of cylinder and piston-rod are determined by 

 the amount of recoil required, or the space in which the moving body has to be 

 brought to rest. 



The cylinder is not filled entirely with water, enough air-space being left to al- 

 low of the displacement of the piston-rod, and to act as an air-bufi'er, to take off 

 the first violence of the blow. In actual practice, oil is used instead of water. 



1869. 14 



