electrograph
/ɪˈlɛktrə(ʊ)ɡrɑːf/ /ɪˈlɛktrəʊɡraf/noun
1 Meteorology. An instrument for producing a graphical record of variations in the electrical potential gradient in the atmosphere.
2An apparatus for transmitting an image telegraphically; an image so transmitted (also figurative ). Now historical.
Origin
Mid 19th century (in an earlier sense). From electro- + -graph.