heliograph

英 ['hiːliəɡrɑːf] 美 ['hiːliəɡræf]

• v. 照相制版；太阳摄影机；日光仪

英英释义

Noun:

1. an apparatus for sending telegraphic messages by using a mirror to turn the sun's rays off and on

Verb:

1. signal by means of a mirror and the using the sun's rays