Page:A Letter on the Subject of the Cause (1797).djvu/28

 and maintained during the working of the Engine. And this water (contrary to what your Lordſhip was informed in Court) it is the practice of the beſt Engineers to apply hot: This was chiefly to prevent the too frequent neceſſity of renewing the packing above mentioned, which from the great quantity of rub on the ſides of the cylinder, is apt ſoon to loſe that perfection neceſſary to render them air and ſteam tight. Your Lordſhip being in poſſeſſion of theſe facts, I need not aſk what would become of this packing, ſhould any perſon led by an implicit confidence in the judgment and candour of Mr. Watt, have the monſtrous ſtupidity to pour on this piſton (part of which conſiſts of Hemp, and tallow) metals in their fluid ſtate. Suppoſe lead, relatively the mildeſt; it would inſtantly deſtroy the perfection of the Engine, if not by burning the packing, by adhering to every part of the Machine; and when the heat ſlackened, totally defeat the poſſibility of ſtarting it again. What then would be the conſequence of uſing melted braſs or iron? It would burn the packing in an inſtant. Was it poſſible to make one ſtroke, which it would not, a ſecond could not be made. And when the Engine returned