- a device for signaling by means of a movable mirror that reflects beams of light, especially sunlight, to a distance.
- Astronomy. photoheliograph.
- Meteorology. an instrument for recording the duration and intensity of sunshine.
- Photography, Printing. an early type of photoengraving made on a metal plate coated with sensitized asphalt.
- to communicate by heliograph.
Origin of heliograph
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for heliograph
Instantly, the ship shone like the polished mirror of a heliograph.Islands of Space
John W Campbell
He had also been corroborated by a man who had seen the man who took it down from the heliograph.A Yeoman's Letters</p>
P. T. Ross
The heliograph would be useless in stormy weather or in fog.El Diablo
The Hussars left behind a Colt-Maxim and a heliograph for our usage.My Reminiscences of the Anglo-Boer War
If there is no sun I cannot heliograph and I have a host of signals to look up and get ready.The Pillar of Light
- an instrument with mirrors and a shutter used for sending messages in Morse code by reflecting the sun's rays
- a device used to photograph the sun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for heliograph
Online Etymology Dictionary, © 2010 Douglas Harper