Page:A Letter on the Subject of the Cause (1797).djvu/19

 at bottom, or ſhut at top, and open at bottom; or whether both its ends are to be alike ſhut. Nor is he directed in what manner the ſteam is to be admitted into the cylinder, or in what manner diſcharged: there being no mention how, and in what part of the cylinder, the neceſſary inlets and outlets are to be contrived; notwithſtanding the eſſence of every Engine depends thereon. There is likewiſe no mention made of the form, and action of the Piſton, or the method of connecting it with the external and working parts of the machine; or whether the expanſive force of the ſteam is exerted on the upper or under ſide of the ſaid Piſton; or even whether there is a Piſton employed at all.

Thus I conceive that no Engineer whatever could derive the ſmalleſt benefit from this account, to aid his attempts to improve the Steam Engine.

The latter part of the above article, deſcribing the treatment of the cylinder or ſteam veſſel, appears to be equally vague, and uſeleſs.

It is there directed to “incloſe the cylinder in a caſe of wood, or other materials which tranſmit