I have never given much attention to machines of any kind, and therefore cannot pretend to decide concerning your proposal for the improvement of the fire engine. It appears to me to deserve attention. But I do not for want of a drawing see in what manner the steam is to be let into the cylinder, or discharged from it. There would be, I fear, an objection to it from the force necessary to raise the column of mercury, and from the evaporation of the mercury in the requisite heat. I have found that it loses weight in 70° Fahrenheit. If the mercury was pure, I should not
apprehend much from the calcination of it, though, as I have observed, the agitation of it in water, converts a part of it into a black powder, which I propose to examine farther.
If travelling was attended with no fewer inconveniences here than it is in England, I should certainly wait upon you and some other friends at New York. But this, and my age, render it impossible, and it would be unreasonable to expect many visitors in this back woods.
I shall be very happy to be favoured with your correspondence, and am,
Sir,
Yours sincerely,
J. PRIESTLEY
Northumberland April 16, 1799.
In this period Thomas Cooper was convicted of libel. He was thrown into prison. Priestley regarded him as a rising man in the Country.[7] He said the act was the last blow of the Federal party "which is now broke up."
Priestley's daughter, in England, was ill at this time. Her life was despaired of and tidings from her were few and most distressing, but the Doctor maintained a quiet and calm assurance of her recovery.
Subsequent correspondence between Mr. Jefferson and Priestley had much in it about the new College which the former contemplated for the State of Virginia. Indeed, the thought was entertained that Priestley himself might become a professor in it, but his advanced age, he contended forbade this, although he was agreeable to the idea of getting professors from Europe.