Quenya 

naltalma

noun. heliograph

A word for a “heliograph” appearing in notes from around 1968, an elaboration of Q. nalta “glittering reflection” (NM/353). Tolkien described it as “an Eldarin device for signalling from afar, like a heliograph, though it is said to have been also usable in a clear moon. Its form and the manner of manipulating it are not recorded, but it must have contained a bright surface.”