This day I had prepared to ship your Time-piece &c on board the Happy Return, Capt Hand, for Richmond, to be addressed to Mr Gibson, as you direct in your favour of the 27th Ult. But our river is now frozen over, & we must wait for an opening, when the shipment will be made:—

The pendulum has a compensating thermometer attached to it; the invention, I believe, of Mr Rittenhouse, and such as the time-piece in his observatory (& now in possession of the Phil. Socy) is furnished with.—I have besides had a cylindrical pendulum made agreeably to your desire, which can be suspended in place of the other, in a few minutes. It has a regulating screw at the top, & from a tryal of several days appears to perform very well

You may, Sir, possibly have observed, in some of our news-papers, that the Legislature of this State have appointed a committee of eight persons, (of whom I am one) “to make a strict examination of the machine invented by Charles Readhefer, and to make as specific a representation respecting it as its alleged importance & the public expectation require.” The committee have made a formal application to Mr R. to appoint the time & place for this examination; but this he has not yet done—and most probably never will submit his machine to the examination required, as he must be conscious it would issue in the detection of the fraud he has so successfully practised.— Several models of this machine, and one of the exact dimensions of the original, have been made in this city—but all, except one, entirely destitute of any self-moving power. This one, made by an ingenious artist of this city, a Mr Lukins, had the source of motion so artfully concealed, that it deceived (as the maker intended) Mr Duane, Mr Matlock, and many others, of the believers, as they are now termed, in Readhefers perpetual motion. Mr Lukins candidly confessed to me, the day after his machine was put in motion, that it was a deception, which he would discover after he had diverte[d] himself a little with the credulity of R’s believers.

Several pieces have been published in our newspaper[s] tending to demonstrate the impossibility of a self-moving machine. One, under the signature of “Rittenhouse,” appeared in the Aurora; & was said to be written by my son Robert, which no doubt you have seen—but all to no effect—the mania seems still rather to increase—Some pieces have been published, particularly one by Mr Adrain Prof. of Math. &c in the college of New Brunswick N. J. pointing out the probable source of motion, namely, a very slow, & scarce perceptible descent of the great horizontal wheel, by means of a particular arrangement of the cogs in the train of wheels;—but this cannot be the cause of motion, as it is totally inadequate to the effect produced.

Excuse, Sir, my saying so much on this silly subject. It being at present almost the sole topic of conversation amongst us must be my apology.