What does the word heliograph mean?

Usage examples for heliograph

  1. The burghers were constantly on the alert when they were on the veld, whether they were merely wandering about, leaving for home, or returning to the laager, and as soon as they secured any information which they believed was valuable they dashed away to the nearest telegraph or heliograph station, and reported it to their general or commandant. – With the Boer Forces by Howard C. Hillegas
  2. Far across the plains I saw a flashing light, as of a heliograph. – Neighbours by Robert Stead
  3. Lieutenant Magill took possession of the heliograph outfit without the loss or injury of a man. – Our War with Spain for Cuba's Freedom by Trumbull White