Fig. 10 is an external elevation of their latest design of this size and type of engine. It differs from fig. 9 in that each engine is provided with independent gears, so that either engine can be disconnected. This design enables the makers to dispense with right and left hand combustion chambers, and makes a thoroughly well designed engine.

Fig. 11 is a 25 H.P. NOM. engine, having a cylinder 16 inches diameter and a stroke of 21 inches; it is capable of indicating as a maximum 64 H.P. The arrangement of the valves and gearing is approximately the same as in the girder type engine; but its

own distinctive feature is the firm grip it has upon the foundation, whilst the centre line is kept very low. It, however, has the same defect in the angle and direction of its bearings as fig. 8, which neutralizes many of its otherwise valuable points. This design of bed is also used in 40 and 50 H.P. NOM. engines, the cylinders of which and combustion chambers are separate, with the exhaust valve box cast on the side of the latter. One heavy flywheel instead of two lighter ones, as in fig. 11, is used, and an outer bearing arranged to take the weight.

In fig. 12 is shown a typical engine made by this firm for

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the special purpose of driving a dynamo direct from the flywheel for electric lighting, for which purpose their practice is to have large diameters in the cylinders, comparatively short strokes, and heavy flywheels running at a very high rate of speed-viz. from 250 to 350 revolutions per minute. The crank shaft is balanced by means of weights placed in the flywheels, so that they move at the same mean velocity as the parts to be balanced, although at considerable distance from the centre line of the cylinder. The gas, air, and timing valves are placed horizontally

on the side of the cylinder, with the exhaust valve vertical. A centrifugal governor is used combined with the pecker action. The same proportions and practice are used in a tandem and quadruple design; the former being, like fig. 10, a combination of a right and left hand engine, having, however, only one flywheel and outer bearing. The quadruple engine giving two impulses per revolution when working at full power is practically a double tandem engine, with one flywheel between the two engines, having discs and overhanging crank pins instead of the ordinary

crank shaft with double jaws, and one governor to control the whole.

It seems more than possible that makers of these excessively high-speed engines will find that much better results can be obtained by using a long stroke, balanced engine, with larger flywheels running at a slower speed.

The misleading term of 'NOMINAL HORSE-POWER' is happily not used in these engines, each size being rated at its effective

power. And it would be well if the same principle were applied to all sizes, and instead of calling-say, fig. 13— H.P. NOM., it were rated as a 2 B.H.P. This engine contains some of the features of the high-speed type, in that the air and gas valves being placed horizontally in one box are easily disconnected from the engine if necessary, although the horizontal position is not good practice. It is governed by Holt's effective inertia governor, worked by a small crank on the end of the cross

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