Sunday, April 14, 2013
Sorry For The Delay
It's taking me a while to get to the next research post. That's because I picked up a pair of assignments from Military History Quarterly - one on the "Heliograph" (think of it as a "sun telegraph" using mirrors to flash the sun's rays - see below) and the other on "Operations Research" (a rather esoteric discipline that looks to improve how systems work). I'm pretty much done with the first, and should be able to get to the post about Historical Societies before starting the second. Thank you for your patience.
The photo shows an early U.S. Army heliograph. On the right is the mirror system that reflects the sun's rays. On the left is a shutter used to send Morse Code dots and dashes by blocking the flash from the mirror. The range on these instruments could be over 100 miles (on a sunny day). They were invented c. 1869, and in use by armies around the world until after World War I.
Subscribe to:
Post Comments (Atom)
Richard,
ReplyDeleteMany thanks for the information and the links. And you answered one of my questions about how long any of the services used the device. I've only got 2000 words to play with, and there is, sadly, not much room for many details. The piece starts off with the performance of the heliograph during the Jowaki-Afridis Expedition in 1877, and ends, basically, with a description of General Nelson's network in the pursuit of Geronimo. With more space I would expand the narrative on how the U.S. Forestry service employed the mirrors to report wild fires. Thanks again for commenting. How how many instruments in your collection?
I sent you my email address as a Facebook message - if you reply with yours, I can send you .pdfs and photos as attachments.
ReplyDeleteTwo thousand words doesn't seem like a lot - is there any room for pictures?
From the time period you mention, there are the heliograph illustrations from the Mance and Grugan patents, and the Cairo photo. I could also provide a photo of a Roorkee heliograph from ~1880.
I have about 13 heliographs, but only one (the Roorkee model) is from the 1877-1886 era, and the only American military model I have is the rather modern one in the photograph at the head of your article.
For the era you are focusing on (1877-1886), the best contemporary summary is: http://books.google.com/books?id=nLCgAAAAMAAJ&pg=PA91
A good scholarly summary of the Geronimo campaign is Rulak's article:
http://huachuca-www.army.mil/pages/history/Rolak.html
A thorough summary of the American heliograph history of 1875-1886 is this article online:
http://www.flickr.com/photos/signalmirror/sets/72157631040759962/
which is a lot denser than it appears - each section of blue text directly hyperlinks to the section of the reference that the online sentence summarizes (if only we could do this in your article!). There is also a lot of good material in the associated photoset and their comments.
I sent you some photos via Facebook message, by the way. Some photos of American heliographs from the Spanish-American war and later are on Flickr here:
ReplyDeletehttp://www.flickr.com/photos/signalmirror/galleries/72157630246445306/
> With more space I would expand the narrative on how the U.S. Forestry service employed the mirrors to report wild fires.
That could easily be an article in itself.
When President Roosevelt visited the Mt. Hood National Forest on Sept. 28, 1937:
"Another committee arranged to have lookout on duty on twelve of the lookout points which were visible from the entrance of the Hotel and make the necessary arrangements for the display of heliograph flashes from these lookouts during the ceremony."
See also:
books.google.com/books?id=E03ZAvwxhswC&pg=PA47&lpg=PA46&dq=heliograph
www.google.com/books?id=CI5OAAAAMAAJ&dq=heliograph&pg=160