Page:A Letter on the Subject of the Cause (1797).djvu/20

 tranſmit heat ſlowly;” but there is not a hint given in any degree adequate to inſtruct the practitioner in what mode this caſe is to be applied; whether it muſt be in contact with the external ſurface of the ſaid cylinder, or placed at ſome given diſtance from it. Thus, my Lord, it is left to every Engine Builder to invent, and determine for himſelf; and it ſeems to me that the idea in this caſe moſt likely to preſent itſelf, would be to have ſtaves of wood nicely fitted to the external circle of the cylinder, and then bind them on with iron hoops, or cordage. And having thus incloſed the iron cylinder in a Wooden Caſe, proceed to the ſubſequent directions in the ſame clauſe, termed Secondly, which orders that the cylinder (ſeeming to include wood alſo) ſhall be then ſurrounded with ſteam, or other heated bodies; but does not expreſs in what manner any of theſe garments are to be procured or applied in its circumambient form.

Neither does it expreſs by what means theſe heated bodies are to receive their heat, or the manner of perpetuating this heat, during the periods the Engine works.

This part of the Specification appears more calculated to miſlead and perplex than the former