1. Most heliographs of the 19th and 20th century were completely manual. 2. The first digitally controlled heliograph was designed and built in 2015. 3. Communications with the mainland was originally done by a signal lamp or heliograph . 4. Ni�pce had experimented further with other chemicals, to improve contrast in his heliographs . 5. They requested Dugenne to send a heliograph message back to Hanoi to seek instructions. 6. The Mance, Grugam and Pursell heliographs used two tripods, and the others one. 7. The heliograph had some great advantages. 8. The Canadian Army was the last major army to have the heliograph as an issue item. 9. In 1961, the US Air Force was working on a space heliograph to signal between satellites 10. The Ni�pce heliograph was not included in the sale, but shortly afterward Gernsheim donated it. 
Mobile