One of two known bookplates designed by Doolittle for the Mechanic Library Society in New-Haven. The image was also printed as a woodcut in advertisements for the Society. It features a gently ironic vignette of two quite buff, and yet winged cherubs, beating out metal across a large anvil. Their faces are well-defined, and may therefore be actual portraits of well-known "mechanics" (or more appropriately "mechanicals"), who were in this case natural philosophers and amateur scientists, rather than manual labourers.

The Society was preceded by the New Haven Young Men's Institute, which changed its name to the Mechanic Library Society in 1793, when it described itself as: "a public library in the city of New Haven", although it was for the use of subscribers only. In 1801, it published its 'Constitution and bye-laws... with a catalogue of books', suggesting that this bookplate was prepared in advance of that.

A native of Cheshire Connecticut, where he lived his entire life, Amos Doolittle (1754-1832) was apprenticed as a young man to silversmith Eliakim Hitchcock, also of Cheshire. He is best known as an early American engraver of maps: those in Jedidiah Morse's 'Geography Made Easy' (1784), the first American geography, are his earliest. However, they were preceded by a famous series of engravings of 'The Battles of Lexington and Concord', New Haven, December 1775. Doolittle participated in the fight, but the engravings are after drawings by Ralph Earle. They remain the only pictorial record, by a contemporary American, of these important revolutionary battles.

Doolittle became a versatile engraver, and in addition to maps he created political cartoons, invitations, bank notes, labels, music, bookplates, diplomas, certificates, tickets, Masonic aprons and ephemera, charts, book and magazine illustrations, religious and moralizing prints, portraits, and historic scenes; and was also known as a printer and publisher, a "jeweler, a calico printer, and an engraver of clock faces" (Steinway).

Rare: only two institutional examples known, at Colonial Williamsburg, and Yale; the Virginia Museum Fine Arts holds an example of the earlier bookplate.