Experimental Fleming valve in wooden mount. This valve was preserved as a "relic" by Fleming, who sent it to a magazine editor in 1926. A glass tube containing a filament and cylindrical electrode mounted in a wooden stand. Two binding posts are set on top, a third is on a side arm, and a spring maintains tension on the tube. The mount is an experimental piece that can be used to test different tubes of this design.
The completion of the first transatlantic telegraph cable in 1858 was a cause for much celebration on both sides of the Atlantic. Tiffany & Company of New York purchased the cable remaining on board the USS Niagara after the successful completion of the cable and sold 4-inch sections as souvenirs. Each section of cable was banded at the ends with brass ferrules and had a brass plaque that read “ATLANTIC TELEGRAPH CABLE/GUARANTEED BY/TIFFANY & CO./ BROADWAY • NEW YORK • 1858.” The cable souvenirs originally sold for 50 cents and came with a reproduced letter of authenticity from Cyrus W. Field, the pioneer of the transatlantic cable system. The jubilation turned to jeers when the cable failed a few weeks later, and Tiffany never sold its supply of cable. In 1974 Lanello Reserves began reselling the transatlantic cable, and donated this object to the Smithsonian.
Charles Wheatstone and William Cooke's 5-needle telegraph unit. Wooden case with five pointers along the middle row. Thirteen of the original twenty letters remain on the unit. The pointers indicate which letter of the alphabet is being transmitted. Reference: W. James King, "Development of Electrical Technology in the 19th Century 2: the Telegraph and the Telephone," Bulletin of the United States National Museum (Washington, DC, 1966), 289-291.
This has an ebony frame, a reinforced brass index arm, an ivory scale that is graduated every 20' from -2° to +107° and read by vernier with tangent screw to 30" of arc. The inscription reads "Spencer Browning & Co London. Made for D. McGregor & Co Glasgow & Greenock." Spencer Browning & Co. were in business from 1840 to 1870.
Western Union transferred this sextant to the Smithsonian in 1972.
