STATIONARY ENGINES. 191

into extensive use, and, although cheaper in first cost, we unhesi-

Fig. 122.—Direct-acting Pumping Engine. End Elevation.

tatingly give the preference to the beam engine, or the morerecent example the side-lever Cornish engine, when the depth ofthe mine is considerable.

Figs. 121 and 122 show side and end elevations of a pit enginewhich may be considered an improvement on the foregoingexample. The steam cylinder has a diameter of 84 inches,