Bible Encyclopedias
Heliography
The Nuttall Encyclopedia
A method of signalling from distant points by means of the sun's rays flashed from mirrors; messages can in this manner be transmitted a distance of 190 m.; it has been found of great practical value in military operations.
Copyright Statement
Public Domain.
Bibliography Information
Wood, James, ed. Entry for 'Heliography'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/h/heliography.html. Frederick Warne & Co Ltd. London. 1900.