Ottoman Army heliograph

Ottoman Army signallers use a heliograph (far left) to relay messages to troops in advanced positions at Huj in Palestine. 

The heliograph was a wireless solar telegraph instrument that relayed Morse code using flashes of sunlight reflected by a mirror. The flashes were produced by pivoting the mirror or interrupting the beam of sunlight with a shutter. Heliographs were used by both British and Ottoman forces during the Sinai and Palestine campaigns, where they were effective over distances of more than 50 km.

Just to the right of the heliograph in the image is another signalling instument, probably a blinkgerat.  These were powered by acetylene gas and therefore could be used when there was no sun. (See a higher resolution copy of this image here).

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Richard A. Fowell

Posted: 29 Aug 2012

Definitely seems to be German heliograph + signal lamp + telescope. Here are two photographs on Flickr of WWI German signal crews with the same equipment set:
Note that the first of these is available under an attribution/noncommercial/sharealike license, allowing adaptation, so you could extract closeups of the instruments there for comparison here. The full resolution version is here, showing all the fiddly bits below the signal lamp in great detail:


Posted: 14 Jul 2012

Hi John. Thanks very much for your post. From the information on this page:
and a close up of the image:
- it looks like the Heliograph is the far left instrument. You have to see the hi-res version to see the mirror properly. The Blinkgerat is next to it, so presumably this was used at night.
I'll update our caption once I've done some more research.
Regards, Jamie Mackay


Posted: 08 Jul 2012

This photograph does not show a heliograph but a German-made signalling lamp called a Blinkgerat. I think that is was powered by acetylene gas produced form calcium carbide and if you look closely under the lamp you will see the water supply necessary for its operation.