LAMBERT, Johann Heinrich.

8vo, pp. (xvi), 547, (13), and 8 stilted and folding engraved plates. Woodcut device on title, woodcut headpiece and tailpieces. Contemporary vellum, blindstamped lozenge on sides, brown imitation morocco label on spine, marbled endpapers, blue sprinkled edges. Very faint dampstain in outer corners of first 30 leaves, very light scattered foxing up to gathering Ee, upper cover stained, otherwise a very good copy.

FIRST EDITION of the foundation for the science of photometry — the exact scientific measurement of light. “In the Photometria Lambert described his photometer and propounded the law of absorption of light named after him. He investigated the principles and properties of light, of light passing through transparent media, light reflected from opaque surfaces, physiological optics, the scattering of light passing through transparent media, the comparative luminosity of the heavenly bodies and the relative intensity of coloured lights and shadows. His discoveries are of fundamental importance in astronomy, photography and visual research generally. Even in the modern world of wave mechanics, the Photometria remains a significant book. Indeed there is hardly any aspect of photometry that was not fully covered by Lambert’s investigations” (PMM). “Photometria was the first work to accurately identify most fundamental photometric concepts, to assemble them into a coherent system of photometric quantities, to define these quantities with a precision sufficient for mathematical statement, and to build from them a system of photometric principles” (DiLaura). This is a copy with good margins (two leaves are unopened), and is almost entirely free of the foxing and browning so often seen in other copies. Printing and the Mind of Man 205. Horblit 62. DiLaura, Bibliotheca Opticoria, 449.