Daguerreotype
It is said that Daguerre has found the means to collect, on a plate prepared by him, the image produced by the camera obscura, in such a way that a portrait, a landscape, or any view, projected upon this plate by the ordinary camera obscura, leaves an imprint in light and shade there, and thus presents the most perfect of all drawings ... a preparation put over this image preserves it for an indefinite time ... the physical sciences have perhaps never presented a marvel comparable to this one.
A further clue to fixing the date of invention of the process is that when the Paris correspondent of the London periodical "The Athenaeum" reported the public announcement of the daguerreotype in 1839, he mentioned that the daguerreotypes now being produced were of considerably better quality than the ones he had seen "four years earlier".
Daguerreotype
By the late 18th century, small, easily portable box-form units equipped with a simple lens, an internal mirror, and a ground glass screen had become popular among affluent amateurs for making sketches of landscapes and architecture. The camera was pointed at the scene and steadied, a sheet of thin paper was placed on top of the ground glass, then a pencil or pen could be used to trace over the image projected from within. The beautiful but fugitive little light-paintings on the screen inspired several people to seek some way of capturing them more completely and effectively—and automatically—by means of chemistry.