[DAGUERRE, LOUIS JACQUES MANDÉ]. "Practical description of the process called the Daguerreotype, which consists in the spontaneous reproduction of images of natural objects, in the Camera Obscura; not with their colours, but with great delicacy in gradation of the tints." In: Journal of the Franklin Institute of the State of Pennsylvania and Mechanics' Register. Edited by Thomas P. Jones. New Series. Vol. XXIV. [pp. 303-311]. Philadelphia, 1839. 8vo, rebound in buckram; ex-library copy (Library of Congress). Translated by J.F. Frazer. A translation under a similar title was separately published in London the same month and year. See Gernsheim 644.