Charles Nicholas Cochin, the younger
Cochin was an accomplished draughtsman and illustrator, a brilliant portraitist, a writer on art theory, and the scion of a family of engravers. His sketch of Franklin, which must have been made by observing Franklin soon after his arrival in Paris, was engraved by Augustin de Saint Aubin. It is one of the most widely copied and adapted, and certainly one of the most widely recognized.
See www.artnet.com, and www.groveart.com for examples of his work and information about him.