Page:A Letter on the Subject of the Cause (1797).djvu/44

 ſpace comprehended between the rings. The contrary end of this tube is joined to the ſteam pipe or boiler, where the Steam is always active; and by this means a conſtant ſupply of Steam is thrown into the ſpace aforeſaid, which Steam preſerves the rod air tight: being kept as ſtrong or ſtronger than the preſſure of the outward air. Thus the ſteam here does the office of water, &c. on the piſton of the Engine, when the packing becomes rather inſufficient.

I think, my Lord, I need not ſay more on this point, to prove the neceſſity of a full and clear Specification; and the practicability of giving one had there been a willing mind.

, I obſerve the lower end of the Steam cylinder to be alſo cloſed; and that the Steam has alternate communication with the cylinder above and below the piſton, juſt a contrary to that of Newcomen.

To detail the true nature of all this, would be tireſome to your Lordſhip; and as Mr. Watt has not done it, I ſhall decline doing it for him: though certainly well able. ,