Instantly, the ship shone like the polished mirror of a heliograph.
He had also been corroborated by a man who had seen the man who took it down from the heliograph.
The heliograph would be useless in stormy weather or in fog.
The Hussars left behind a Colt-Maxim and a heliograph for our usage.
If there is no sun I cannot heliograph and I have a host of signals to look up ...