Philadelphia 14 January 1807.—
I was very sorry that I could not send both watches by Captn. Tingey, but having met with a safe Opportunity to send the other one yesterday by Doctor Moore, I hope they have both come safely to hand? An accident happened to the latter one a few days after I had it by the breaking of the main–spring, I was therefore obliged to take it to pieces, & found that it was the outer eye of the spring which had opened, there having been too little substance left to withstand the force of the Spring when wound up; this however was rectified a few days before Captn. Tingey called, but the watch not being then so well regulated as I could wish, I thought proper to keep her for another safe Opportunity, which I hope this has proved itself.
The first watch sent by Captn. Tingey, I had not so good an opportunity for observation to ascertain her precise rate of going; but by my time pieces she went about 30" fast in 24 hours, but I am certain she will vary from that for some time to come, so long as the main spring is not fully settled, as is the case with all new watches, & which must be brought too from time to time by regulating.
The last watch sent by Doctr. Moore, was made in Geneva, for a gentleman then living in Basel by name of Hassler, who came to Philada about nine months since; a man of science, who brought besides this watch, many beautiful & excellent Astronomical Instruments for his own use; but unfortunately he could but little make use of them here, as himself & his family fell sick, & remained so for a long time, which compelled him to part not only with his watch, but likewise his Instruments, & even his Books: Mr. Patterson is well acquainted with him, & purchased some of the Instruments. After I had this watch regulated she went very well & varied but little & that regularly; in the cold of the night, she would gain according to the degree thereof, but I did not alter her on that account, as she was so regulated as to come back to the true time in my pocket. I have not moved the hands for two weeks, and when I sent her by Docr Moore she was about 45" fast.
I hereby acknowledge the receipt of Drs. 145. for these two watches, the first I sent was $78. and the latter one 67$=145:—I hope they may answer your expectations, as I for my part have done the best in my power to serve you; and shall at all times be ready & willing to do so whenever you may think me capable of rendering you any services.
I have the honor to be Sir, Your very obt humble Servant
MHi: Coolidge Collection.