We then have the picture in its finished form.
The story of the making of the camera is as interesting as that of the making of the pictures by the camera.
Back in 1732, J. H. Schulze discovered that chloride of silver was darkened by light and all unwittingly became the father of photography. In 1737, Hellot, of Paris, stumbled on the fact that characters written with a pen dipped in a solution of silver nitrate would be invisible, until exposure to light, when they would blacken and become perfectly legible. However, it was not until early in the nineteenth century that these two discoveries were put to any practical use, as far as photography was concerned.
People of an artistic turn of mind had been in the habit of making what were called “silhouettes.” The sitter was so posed that the light from a lamp threw the profile of his face in sharp shadow against a white screen. It was then easy enough to obtain a fairly accurate silhouette, by either outlining the profile or cutting it out from the screen.
It occurred to a man by the name of Wedgwood that this profile might be printed on the screen by using paper treated with silver nitrate, and he not only succeeded in accomplishing this, but also in perfecting what was then called the “camera obscura,” the forerunner of the kodak of today. The camera obscura consisted of a box with a lens at one end and a ground glass at the other, just like a modern camera. It was used by artists who found that by observing the picture on the ground glass they could draw it more easily. Wedgwood tried to make pictures by substituting his prepared paper for the ground glass, but the paper was too insensitive to obtain any result. Sir Humphrey Davy, continuing Wedgwood’s experiments, and using chloride of silver instead of nitrate, succeeded in making photographs through a microscope, by using sunlight. These were the first pictures made by means of a lens on a photographic material. But none of these pictures were permanent, and it was not until 1839 that Sir John Herschel found that “hypo,” which he had himself discovered in 1819, would enable him to “fix” the picture and make it permanent.
At about this time, Daguerre announced discoveries that gave photography at least a momentary impetus, but the Daguerre process did not long survive, as it was slow, costly and troublesome. The daguerreotype was made on a thin sheet of copper, silver plated on one side, polished to a high degree of brilliancy, and made sensitive by exposing it to the fumes of iodine. The first daguerreotype made in America, that of Miss Catherine Draper, was exposed for six minutes in strong sunlight, and the face of the sitter thickly powdered, to facilitate the exposure. An exposure today with a modern camera, under similar conditions, could be made in 1/1000 of a second.