Heliograph
/ˈhiliəɡræf/noun
A signalling device that flashes messages by tilting a mirror to reflect sunlight.
The Greek roots
Literally: “sun writing”
The story of the word
Two inventions claimed the name. Niépce called his process héliographie, sun-writing, and the view from his window at Le Gras, made around 1826, is the oldest surviving photograph. The military heliograph was a mirror on a tripod that sent Morse by flashes, standard issue in the British army in India and worked hard across the Boer War, with ranges of fifty kilometres on a clear day. Helium is the same sun, named in 1868 from a yellow line in the solar spectrum, twenty-seven years before anyone found the gas on Earth.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
In a sentence
A heliograph on the ridge blinked twice and the column halted.
The museum keeps a folding heliograph in its case of colonial signalling gear.