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. [Illustration: ARTOTYPE COPY OF THE EARLIEST SUNLIGHT PICTURE OF A HUMAN FACE Miss Dorothy Catherine Draper, taken by her brother, Prof. John W. Draper, M.D., LL.D., in 1840.] It was impossible, of course, to find many sitters as patient as Miss Draper--try keeping perfectly quiet for even a minute if you would know why Miss Draper should be ranked as a photographic martyr--and many experiments were made in an attempt to materially shorten the time of exposure. The only real solution, of course, was to find some method where the light had to do only a little of the work, leaving the production of the image itself to chemical action. [Illustration: OLD-FASHIONED PHOTOGRAPHIC EQUIPMENT]