Definition of "heliograph"

It was a lieutenant and a couple of privates of the 8th Hussars, with a stand like a theodolite, which the artilleryman told me was a heliograph.

1895–1897, H[erbert] G[eorge] Wells, “What I Saw of the Destruction of Weybridge and Shepperton”, in The War of the Worlds, London: William Heinemann, published 1898, book I (The Coming of the Martians), page 91

And Love had made him very sage, as Nature made her fair; / So Cupid and Apollo linked, per heliograph, the pair.

1919, Rudyard Kipling, “A Code of Morals”, in Departmental Ditties and Ballads and Barrack-Room Ballads

when we stood up at nightfall we saw, in the sunset, the sparkle of the heliograph above cities, on the far side of the horizon.

1979, Alasdair Gray, “Five Letters From an Eastern Empire”, in Every Short Story 1951-2012, Canongate, published 2012, page 93

With damnatory dot and dash he heliographed his wife / Some interesting details of the General's private life.

1919, Rudyard Kipling, “A Code of Morals”, in Departmental Ditties and Ballads and Barrack-Room Ballads