Lot 45: Jefferson, Thomas. Autograph letter signed as President, 1 page (9 ¾ x 7 7/8 in.; 248 x 200 mm.)
December 18, 2012
Calabasas Hills, CA, USALive Auction
45. Jefferson, Thomas.Autograph letter signed (“Th: Jefferson”) as President, 1 page (9 ¾ x 7 7/8 in.; 248 x 200 mm.), Washington, 16 November 1808 to Mr. John McAlister Optician, Phila a well-known Philadelphia optician who took over Benjamin Franklin’s optical practice; docketed on the verso in another hand: light browning.
President Thomas Jefferson orders spectacles based upon inventor Benjamin Franklin’s bi-focals from Franklin’s successor, optician John McAlister.
Jefferson writes in full: I am extremely satisfied with Dr. Franklin’s method of fixing the spectacles, by composing each glass of two half glasses of different magnifying powers, and those you made for me answer perfectly except that the frames being circular, the glasses are always twisting round & bringing the seam between the two half glasses in the way of the eye. to prevent this the frame should be oval. I send you therefore the oval frames you last made for me, being much approved in their size, and I pray you to furnish a set of half glasses for them from the magnifying power of the glasses now in them up to the greatest. those now in them suit the present state of my vision. I think the larger of the two magnifiers put into the same frame should differ but a single number from each other, the largest magnifier being uppermost. altho these glasses are very small, & consequently the half glasses uncommonly so, I am not afraid but that they will prevent full space enough for reading, writing, etc. as I am satisfied that the pencil of rays in these cases occupies little more than a speck on the glass. the spectacles may be safely returned by post, if done up in the way they now are. be so good as to send with them a note of the cost, of which I will direct paiment to be made.
A fine letter in which the great statesman shares his knowledge of optical lenses with his Philadelphia optician. His detailed request that his oval frames be fitted with a set of half glasses (i.e., bifocals) to prevent the problem previously encountered with a round frame in which the lenses twisted around, obstructing vision, stands as a remedy worthy of Franklin himself.
McAllister worried that the half lenses of the bifocals would be too small to see through. Nevertheless, he forwarded two pairs to Jefferson nine days after receiving this letter. Jefferson was still using McAllister’s spectacles in 1815 when he requested a small correction be made to the lenses by McAllister’s firm.