A Double-faced Wedge-shaped Sluice-Valve for Main Street Water-pipes.

The late Mr. Wicksteed, engineer of the East London Water Company, having stated to me the inconvenience which had been experienced from the defects in respect of water-tightness, as well as the difficulty of opening and closing the valves of the main water-pipes in the streets, I turned my attention to the subject. The result was my contrivance of a double-faced wedge-shaped sluice-valve, which combined the desirable property of perfect water-tightness with ease of opening and closing the valve.

This was effected by a screw which raised the valve from its bearings at the first partial turn of the screw, after which there was no further resistance or friction, except the trifling friction of the screw in its nut on the upper part of the sluice-valve. When screwed down again, it closed simultaneously the end of the entrance pipe and that of the exit pipe attached to the valve case in the most effective manner.

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• Mr. Wicksteed was so much pleased with the simplicity and efficiency of this valve that he had it applied to all the main pipes of his Company. When its advantages became known, I received many orders from other water companies, and the valves have since come into general use. The prefixed figure will convey a clear idea of the construction. The wedge form of the double-faced valve is conspicuous as the characteristic feature of the arrangement.

NOTE At a meeting of the Institution of Civil Engineers, May 23, 1883, when various papers were read on Waterworks, Mr. H. I. Marten observed in the course of the discussion:-- "It has been stated in Mr. Gamble's paper (on the waterworks of Port Elizabeth) that the sluice valves are of the usual pattern. The usual patterns of the present day are in wonderful advance of those of thirty or forty years since. The great improvement originated with the introduction of 'the double-faced sluice-cock.' This sluice-cock, which had now superseded every other description, was the creation of Mr. James Nasmyth's inventive genius. Mr. Marten said he well remembered the first reception of this useful invention, as he happened at that time to be a pupil of Mr. Thomas Wicksteed. He was present when Mr. Wicksteed explained to Mr. Nasmyth the want he had experienced of a sluice-cock for Waterworks purposes, which should shut and remain perfectly tight against a pressure coming from either side. Mr. Marten had a lively recollection of the instantaneous rapidity with which Mr. Nasmyth not only grasped but provided for the requirement; so that almost by the time Mr. Wicksteed had completed the statement of his want, Mr. Nasmyth had drawn upon the back of an old letter a rough sketch of the first double-faced sluice-cock; and in less than an hour had converted this rough sketch into a full-sized working drawing; in the preparation of which it fell to Mr. Marten's lot to have the honour to assist. In his 'Autobiography' Mr. Nasmyth referred to the conversation with Mr. Wicksteed, and introduced a print of the drawing made upon the occasion. The invention has been of the greatest use to the Waterworks Engineer, especially in connection with the constant supply system, in which it frequently happened that the pressure was sometimes against one face of the sluice-cock, and sometimes against the other." -- See Proceedings and Discussions of the Institution of Civil Engineers, 1883, pp. 88, 89.

A Hydraulic Mattress Press, capable of exerting a pressure of Twenty thousand tons.

The principle of this enormously powerful compressing machine is similar to that of the Hydraulic Press; the difference consisting principally in the substitution of what I term a Hydraulic Mattress in place of the