To Francis Hopkinson
Paris May 9. 1786.
The only letter of yours the receipt whereof I have not yet acknoleged is the 31st. of Dec. Mine are of Sep. 25. Jan. 3. and Jan. 27 [i.e., 26]. With that of Jan. 27. I had sent the crayons &c. formerly desired. With the present I will send 2. doz. camelshair pencils, and a doz. black lead pencils which are desired in yours of Dec. 31. I at the same time sent the 14th. 15th. and 16th. livraisons of the Encyclopedie for yourself and Dr. Franklin. I now have for you both the 17th. and 18th. livraisons, but the opportunity is not favourable for sending them; and indeed I doubt whether you might not prefer receiving them once or twice a year, which would lessen the expences of package, postage, &c. Your pleasure on this head shall be my law.
I am just returned from a trip to England. I was in the shop of Mr. Broadwood the maker of your Harpsichord, and conversed with him about your newest jack. He shewed me instruments in his shop with precisely the same substitute for the quill, but I omitted to examine whether it had the same kind of spring on the back. He told me they had been made some time before your model came over; and I now recollect that when I advertized your improvement of the quill here a workman sent me a jack with buff leather as a substitute for the quill. Walker’s celestini stop is indeed a divine thing. A band of a single silk thread is made to pass over a pulley on the right and another on the left, so that one string of the band is almost in contact with the strings of the harpsichord. It is kept in motion by a treadle as in a flax wheel. A set of hammers is placed just above the band, and one end of each hammer being thrust up by it’s corresponding jack, the other is pressed down on the band, between the two unison strings of that note, so as to make it strike them and no others. The band being always in motion, it is as if you drew a fiddle bow over those strings, and produces a tone as different from the ordinary one of the harpsichord, as is that of a violin. To prevent the pressure of the hammer from impeding the motion of the band, a friction wheel is placed transversely in the end of every hammer, precisely in the point of contact. The whole can be shifted out of the way by a touch of the foot, and leaves the harpsichord in it’s usual state. It suits slow movements, and as an accompaniment to the voice, can be fixed in any harpsichord and, being under a patent, costs 8. guineas. I wait till I hear more particularly from you as to your last improvement before I order a harpsichord for my daughter. She is well, thinks much and gratefully of your mother, to whom as well as to your lady, she joins me in presenting respects. Accept yourself assurances of the esteem with which I am Dear Sir your sincere friend & servt.,
PrC (DLC); endorsed.