The description and use of a proportional camera obscura, with a solar microscope adapted thereto. Invented and sold by B. Martin in Fleet-Street.

[London : s.n., 1770?]

1 sheet ; 1/80.

ESTC N24882

Electronic reproduction. Farmington Hills, Mich. : Thomson Gale, 2003. (Eighteenth century collections online). Available via the World Wide Web. Access limited by licensing agreements.