A manual for three different sizes of heliograph used to communicate with others via Morse code.

Introduction --Packing specification, instructions for setting up, and description of the heliographs -- How to start and operate the heliographs -- Operations at the transmitting station -- Points to be noted in the practical working of the heliographs -- Adjustment of the heliographs -- Cleaning and repairs -- Weights of the heliographs in travelling order -- Morse signals.