Megalograph, type of camera lucida invented by G. Revoil and made by Secretan
Megalograph, type of camera lucida invented by G. Revoil and made by Secretan, Paris, its components disjoined in fitted box for portability
Megalograph, type of camera lucida invented by G. Revoil and made by Secretan, Paris, its components disjoined in fitted box for portability