heliograph

We bivouacked at Granaatz Plaatz farm that night, whence the heliograph winked the news of our engagement to our camp.

Instantly, the ship shone like the polished mirror of a heliograph.

The Hussars left behind a Colt-Maxim and a heliograph for our usage.

Very often these heliograph stations are located on mountain tops in the midst of extremely inaccessible country.

Of course it is all prearranged who should be notified in case a fire is reported to the heliograph man.