- a device for signaling by means of a movable mirror that reflects beams of light, especially sunlight, to a distance.
- photoheliograph.
- an instrument for recording the duration and intensity of sunshine.
- an early type of photoengraving made on a metal plate coated with sensitized asphalt.
- to communicate by heliograph.
- 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
