STATIONARY ENGINES.

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which so rapidly destroy all other pumps. (7.) The large sizes willadmit the passage of solid bodies 6 inches in diameter withoutinjury, and the smaller sizes in proportion. (8.) It will pump hotor cold liquids equally well. (9.) It requires a very light and inex-pensive foundation, as there is no Vibration while working.

A striking proof of the great superiority of these noiseless machines,working at a high speed, over the beam pumping engine, may beseen in the draining of the Haarlem Lake . The weight of thepumps and valves attached to one of these latter engines was about200 tons, the pumps were adapted to raise about 70 tons of waterper minute a height of 15 feet when working their usual speed ofeight or ten strokes; but a centrifugal pump of the above descrip-tion, doing the same amount of work, will weigh only 5 tons.

The Pulsometer Pump has been recently introduced with goodresults in many situations where other forms of pump would havebeen more troublesome to keep in order. It is a steam pump with-out moving parts except certain valves. The Operation consists inforcing water to a height by the direct pressure of the steam, andthe lifting of the supply into the pump by the after condensation ofthe same steam; this is accomplished through the medium of a ballvalve above and clack valves below, arranged in two verticalchambers.

WINDING ENGINES.

In modern practice the use of the flat hempen ropes with theseengines has been discarded, in favour of the wire rope of a roundform. The drums and pulleys for these ropes must be of largediameter, and the angle of the rope from the drum to the pulley onthe pit-head frame should not be too acute. Where the weightlifted is about 1 ton, the thickness of rope will be about 1% inch,and will weigh about 4)4 lbs. to the foot, the diameters of drum beingabout 5 feet and 16 feet, and the time taken to lift through from250 to 300 fathoms about 1 minute.

The engines used at collieries for winding purposes should be ofthe simplest construction, strong, and free from all unnecessaryand expensive complications. With this view spur gearing hasbeen discarded by many first-class manufacturers, although gearedengines are still in extensive use: the object of using a pinion on theengine shaft working into a spur wheel on the drum shaft being to