Remarkable technical notes and diagrams by Thomas Edison, accomplished in pencil on an off-white 8.5 x 10.5 lightly lined sheet, unsigned, dated to February 5, 1922. The sheet features what appears to be a pair of steam-powered devices with layered coils and a drainage system that feeds to the sewer. Edison’s notes, in part: “1920 sqr inch of water surface in platters, 13 square foot cold + 330° F steam blowing over it—+it’s all lost because to[o] blown out & don’t add to heat of platter—,” “Closed, water all thru system,” “Cooling rate is proportion to velocity of the water over surface—,” and “If coils arranged for drainage OK if not water pockets.” Edison writes “Diagram” to left side and adds notations to various parts. In fine condition, with three small tears to right edge, the largest roughly 1.25″ in length, not affecting handwriting. Not long after the date of this diagram, a film crew traveled to West Orange, New Jersey to document the 75-year-old Edison going about a typical day. In this silent film, a six-part documentary entitled A Day with Thomas A. Edison, the camera captures the prolific inventor discussing new ideas with employees, conferring with his secretary, and checking in on the newest production techniques for producing one of his most famous inventions: the incandescent light bulb. Technical notes and designs in the hand of Edison are exceedingly rare, with this example particularly attractive given its bold realization and wealth of handwriting.
