Washington Jan. 10. 05.
The bearer hereof mr Cosa is an Italian Physico-mechanic. he employs himself chiefly in instruments of glass, and executes ingenious thing in that line. he has been here about a month, during which time, as far as I have learnt, he has conducted himself correctly. being desirous to go to Philadelphia where he expects to find more employment, he has asked to be made known to some one who might put him in the way of being tried & of shewing what he can do. supposing you might possibly have occasion for something in his line, and might advise him to some of the chemical gentlemen, who have occasion for works of glass, I have taken the liberty of authorising him to present himself to you in order to gain an introduction to business, in doing which I have supposed it possible I might administer to your convenience as well as his. he has a companion who is his aid as well as interpreter.
Accept my friendly salutations & assurances of great esteem.
DLC: Papers of Thomas Jefferson.