 Complete the following phrase:  The heyday of the heliograph was probably the Second Boer War in South Africa, where it was much used by both the British and the Boers. The terrain and climate, as well as the nature of the campaign, made heliography a logical choice. For night communications, the British used some large Aldis lamps, brought inland on railroad cars, and equipped with leaf-type shutters for keying a beam of light into dots and dashes. During the early stages of the war, the British garrisons were besieged in Kimberley, Ladysmith, and 