Heliograph
/ˈhiː.li.ə.ɡræf/noun
A device for signaling by flashes of sunlight, or a photographic image made by sunlight.
Did you know?The word comes from Greek roots for “sun” and “write,” and the same writing-root also appears in words like “graph,” “telegram,” and “autograph” — language has been turning light into message for centuries.
Etymological Timeline
Ancient Greek
grc
hḗlios
“the sun”
Ancient Greek
grc
gráphein
“to write, inscribe”
19th Century
English
heliograph
“a device for sending signals by reflected sunlight”
19th Century
English
heliograph
“a photograph made by sunlight”
Modern English
English
heliograph
“a sun-signaling device or sun-made image”