[ 51 ]
pumps conſtructed without regard to proportion, &c. as above-mentioned, will not anſwer in Engines made with condenſers.
Suppoſe, my Lord, I conſtructed an Engine on the plan of Mr. Watt, with a ſteam cylinder exactly equal to one of Newcomen, to which I have annexed a pump of proper ſize; I ſhould be very naturally led to make this ſecond one from the ſame patterns; experience having ſhewn me the propriety of its dimenſions, and to ſave alſo the expence of new patterns, tools, &c. This done, I come to determine the ſize of my condenſer. If I am at a loſs in this, I go to Mr. Watt’s Specification; there I find not a word to help me. I then poſt off, perhaps from Mancheſter to Cornwall, to ſee a condenſer; when I come there, I traverſe the whole county in the character of a ſpy, and none will even permit me to enter their works, (and ſhould I intrude without a licence, I ſhould ſoon get myſelf expelled) much leſs ſtop the Engine, and diſorganize the whole, to give me the knowledge I am ſeeking. My own reaſon, by this time more awake, makes this inference: That provided I did ſucceed in meeting with a perſon friendly enough to ſuffer my ſcrutiny, I muſt, of courſe, pay the loſs accruing from ſuch an
