Page:A Letter on the Subject of the Cause (1797).djvu/41

 Having thus prepared your Lordſhip, I will how deſcribe that which Mr. Watt ſhould have done, i. e. The manner in which the internal piſton is connected with the working beam without.

This is by an iron rod of a ſufficient diameter, turned and otherwiſe worked ſo as to be perfectly ſmooth and parallel from one end to the other, and of a length ſufficient to allow the full ſtroke of the piſton within; and I think it neceſſary to remark, that if in this rod there ſhould be the ſmalleſt rag or flaw, it is totally unfit for its purpoſe; for reaſons that will appear hereafter. And I am certain, from my own knowledge, that Mr. Watt in his firſt outſet on this buſineſs, found more difficulty in procuring theſe rods in all reſpects perfect, than he would have done in conſtructing all the parts of Newcomen’s Engine: although this article, like the reſt, is not mentioned in his Specification.


 * I ſhall proceed to explain to your Lordſhip a circumſtance in this part of the Engine, in my opinion, as material and of equal conſequerice with the preceding, or any other article