Gildwiller1918 Posted June 12, 2020 Share Posted June 12, 2020 Here is something not seen much anymore, a pre-WW1 U.S. Signal Corps Lantern. The device was produced by J.B. Colt and patented in 1902. This model was powered by the use of a acetylene generator, which was in a cylinder that was attached to the lantern. The lantern itself is very well made, heavy as its mainly brass. According the the 1916 signal corps manual, this device could produce 1900 candlepower, which is an obsolete form of measurement, however today the candlepower equals roughly 1 per 13 lumens. These devices were primarily used for night signaling and the range was about 30 miles. I have only been lucky enough to find the main unit, I am still looking for the tripod and the generator. However the item I have in in very good shape, with no real damage and seems to function as normal, the Morse key also functions. Except from the 1916 signal corps manual in which it discusses the device. Image from the internet showing the heliograph and generator. 3 Quote Link to comment Share on other sites More sharing options...
Gildwiller1918 Posted June 12, 2020 Author Share Posted June 12, 2020 Here is an image from the internet showing the device in use. 3 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 27, 2020 Share Posted November 27, 2020 Nice! But this is not a heliograph, this is a signal lantern - most specifically, a United States Signal Corps field signaling lantern. The heliograph used mirrors and sunlight for daylight signaling, and the signal lantern acetylene for night signaling. Here are links to the photographs of each in the 1910 Manual of Visual Signaling of the U.S. Signal Corps: Heliograph, Signal_Lantern . That manual also has extensive descriptions of both. In the 1905 manual, this lantern was called the "field lantern", to distinguish it from the larger "station lantern" - illustrations linked here: Field Lantern ; Station Lantern. Here are period outdoor images at the Library of Congress: Field Lantern, heliograph , and 1908 postcards: Night Signals with Lantern , Heliographing . The National Museum of the Marine Corps in Virginia has both field lantern and heliograph on display, side by side, and the museum at Fort Huachuca in Arizona had a field lantern on display when I was there, many years ago. Regarding candlepower - 1 (old) candlepower is 0.981 candelas, so 1900 candlepower is 1864 candela. A candela is a lumen per steradian (the lumen is the total amount of luminous power, and the candela the intensity). 1 lumen will provide a uniform intensity of 1/(4*pi) = 0.0796 candela in all directions if radiating uniformly in all directions (a lightbulb comes close to this), but a 1 lumen laser pointer would be 16 million candela (assuming a 1 milliradian uniform beam) in the beam (and 0 candela outside of the beam). 4 Quote Link to comment Share on other sites More sharing options...
Gildwiller1918 Posted November 27, 2020 Author Share Posted November 27, 2020 Awesome, thanks for the information. Maybe one day I will complete the kit, but the individual parts and tripod are proving hard to find. 3 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 28, 2020 Share Posted November 28, 2020 > Awesome, thanks for the information. You're welcome! > Maybe one day I will complete the kit, but the individual parts and tripod are proving hard to find. Yes, the signal lantern bits seem amazingly rare - here are a few that came up for sale in the past: https://www.worthpoint.com/worthopedia/colt-brass-carbide-acetylene-field-307701130https://www.worthpoint.com/worthopedia/colt-acetylene-field-signal-lantern-1946438985https://www.worthpoint.com/worthopedia/19th-c-colt-field-acetylene-signal-corps-lantern I've attached some photos I took of the U.S. Signal Corps Colt Field Signal Lantern on display at the museum at Fort Huachuca, in Arizona. I've uploaded them in fairly high resolution, so if you click on them, you should get a larger image (but it may take a while). The top of the canister is stamped: "J.B. Colt Company New York U.S.A. Patent July 5 1904" (note that the patent could be for some aspect of that component, vs. the lamp). 4 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 28, 2020 Share Posted November 28, 2020 Here's a crop of the photo at the Library of Congress: Signal_Corps_USA_Night_Work cropped to just show the signal lantern on tripod just right of center. Note the transport box at bottom left - compare to photos above. The tripod looks to be the same tripod used for the heliograph - the British army similarly used the same tripod for heliograph and signal lamp. Double-click on the image for a higher resolution. 4 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 28, 2020 Share Posted November 28, 2020 Here, from the TuckDB database of Tuck Postcards at tuckdbpostcards.org, is the May 20, 1908 issued postcard, Night_Signals_with_Lantern, part of the six card set titled U.S._Army_Signal_Corps . Since my focus is heliographs, I've only collected the heliograph one, but it is a nice set, and tuckdbpostcards.org has gone to a lot of work to make the images available to all. 4 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 28, 2020 Share Posted November 28, 2020 Hmmm ... while that 1908 signal lantern postcard above credits "Photo by Chaplain Dickson U.S.A.", it bears a remarkable resemblence to the photo below I found in "Acetylene as Used by the Army Signal Corps", an article in Acetylene Journal, V9N2, March 1907, p. 354. which says it is based on extracts from an article in Leslie's Weekly by Mrs. C.R. Miller, who they also credit with the photo. I poked about a bit to see if I could find the Leslie's article, but no luck so far. 4 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 28, 2020 Share Posted November 28, 2020 (edited) I tracked down the patent alluded to by the stamping on top of the canister on display at Fort Huachaca above ("J.B. Colt Company New York U.S.A. Patent July 5 1904"). As I suspected, that patent is for that component, not the lantern as a whole. The patent is US_Patent_764,048, "Acetylene-gas generator", inventor Nelson Goodyear, assignee J.B. Colt Company, filed 9/21/1903, issued July 5, 1904. I've attached a side-by-side comparison of the canister cross-section Figure_20 from Manual of visual signaling of U.S. Signal Corps, 1905, Page 114, and a figure from the patent, and there are certainly lots of similarities. I expect that reading the patent might help quite a bit in understanding how that part of it works. I've attached the patent as a .pdf - on my browser, it looks like a black rectangle below the figure, but if you hover your mouse over it, it says what it is, and if you click on it, you should be able to download it. US764048.pdf Edited November 28, 2020 by heliographer Explain how to download the .pdf 4 Quote Link to comment Share on other sites More sharing options...
heliographer Posted November 28, 2020 Share Posted November 28, 2020 !? This very nice example (pretty much what you have, but with the carrying box, too) was on offer just earlier this month! Nice photos of the box - worth studying, here: https://picclick.co.uk/Rare-Colt-Field-Acetylene-Signal-Lantern-pre-WW1-224151396250.html 4 Quote Link to comment Share on other sites More sharing options...
Gildwiller1918 Posted November 28, 2020 Author Share Posted November 28, 2020 Thanks for all the information! I will keep an eye out for these in the future. But like all collectibles, my eye tends to wander to other areas, lol. I really liked the image with the troops in the M1902 uniforms, that is another area of interest for me as well. 3 Quote Link to comment Share on other sites More sharing options...
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