In the same patent as the connecting apparatus just described, this very able and original minded inventor has included a novel method of checking the speed of the engine, or stopping it altogether. It is effected by introducing a throttle valve, slide, or damper, into the blast pipe, which is usually placed in the chimney in front of the engine, and which throttle valve may be most conveniently introduced where the two exhausting pipes are united into one, below the place where the pipe is contracted in area for the purpose of producing a blast to the furnace. From the throttle valve must proceed a rod or long handle extending through the chimney to the back part of the boiler, so as to lie within convenient reach of the engine-man, who, by moving the said handle, can close the slide or throttle valve, either partially, or altogether, as may be required. And the throttle valve need not be altogether steam-tight, but should be made to work freely in its place. The engine-man, when he wishes to stop or slacken the speed of the engine, closes or contracts his throttle valve without shutting off the steam in its passage from the boiler to the engine.

The pistons, by that means, are speedily, but not suddenly or violently checked, and the driving wheels of the engine no longer revolving, or revolving very slowly, the engine is soon brought to a stand.