- 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. 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