Handwritten manuscript on X-ray experiments by Thomas A. Edison, accomplished in pencil in his unmistakable hand and incorporating his surname twice, totaling eight pages plus a hand-drawn diagram and an original photograph, 6 x 9, circa 1896. Edison drafts a contribution to an article that would appear in the May 1896 issue of The Century Magazine, entitled 'Photographing the Unseen: A Symposium on the Roentgen Rays.' Edison begins by outlining the purpose of his work: "[E]dison's experiments with the Roentgen Ray have been almost entirely devoted to understanding the phenomenon with a view of obtaining the most practicable and powerful form of apparatus—especially the fluorescent lamp—the photographic plates and the best form of electric oscillation to energize the lamp. Having all the appliances for working with Incandescent lamp vacuo he has been enabled to try a large number of experiments with the end in view. He has not as yet attempted to take pictures [o]ther than a standard figure [o]f a number of bars of metal...[H]e is now fitting up a [c]omplete apparatus and [e]xpects soon to conduct a number of accurate experiments in the photography of animals & inanimate objects, from the rough experiments recorded in Edison's note book I 'brief' the following."
The next five pages record his observations of these experiments, in part: "1st. The ray proceeds from all parts of the glass illuminated by fluorescence. 2nd. With same degree of fluorescence it is independent of the size or position of electrodes. 3d. Under same conditions as to distance of lamps from plate the distortion increases with increase in size of lamp bulb. 4th. Records taken every 3 inches up to 36 inches show that the photographic effect of the ray diminishes at the square of the distance as stated by Roentgen—5th. Commercial dry plates vary much in their sensitiveness to the ray—the most rapid plates for light are the slowest for the ray. 6th. As near as can be ascertained at present the power of the ray to photograph varies as to the square of the illuminating power of the fluorescence. 7th. The phosphoresce of the lamp after current is stopped does not photograph—powerful after phosphoresce of a lamp is no indication of its value for photographic work." He concludes by noting: "A good lamp should give [a] clear photograph of thin metallic strips through 8 inches of Georgia pine in 15 minutes."
Additionally includes Edison's hand-drawn diagram of the lamp, accomplished on the reverse of a color illustration of New York, captioned in pencil in another hand: "Sketch of the first Roentgen Ray lamp in the world. Drawn by Edison's own hand at his laboratory for George H. Guy." The sketch closely corresponds with the official diagram that Edison submitted for his 'Fluorescent Electric Lamp' patent, filed May 19, 1896. Guy's New York address is stamped in the upper right corner; Guy was manager of the Bureau of Scientific and Electrical Information, and a technical newspaper columnist/editor for several notable newspapers of the day, including the New York Times. Also accompanying is a rare contemporary 6 x 8.5 mounted albumen portrait of Edison, captioned on the mount in pencil: "Edison under his Fluorescent Lamp, May 29/96."
Browned, brittle, and in good to very good condition, with varying degrees of chipping, splitting, tears, and losses affecting some of Edison's writing; the original photograph is heavily worn, with splits to the mount repaired on the reverse with tape. Accompanied by a photocopy of the piece as it appeared in The Century Magazine.
German engineer and physicist Wilhelm Röntgen discovered X-rays in 1895, and scientists and inventors around the world clamored to investigate the newfound phenomenon. Edison was principal among them, and—as he notes here, already having developed apparatus for testing the electric incandescent light—made fast progress. He quickly developed a fluorescent lamp which used X-rays, or "Roentgen Rays," to excite the phosphor, which he used to conduct experiments in X-ray imaging. He soon set to work on an early fluoroscope, but abandoned the project upon realizing the dangers of radiation: Edison nearly lost his sight, and his laboratory assistant Clarence Dally became an early victim of radiation dermatitis and subsequent medical complications, eventually losing his left arm and right hand due to radiation exposure, and dying of mediastinal cancer. These unfortunate events led Edison to famously announce: 'Don't talk to me about X-rays; I am afraid of them.'
