Dark-field micrometer,19th century. This device was designed and built by British-Australian astronomer Robert Lewis John Ellery (1827-1908) for the equatorial telescope of the Melbourne Observatory. It was described in a paper published in 1884. Micrometers are precision measuring instruments used to help measure the position of stars and other objects observed through a telescope or recorded on a photographic record of a telescope observation | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Royal Astronomical Society |
Bildgröße: | 4315 px × 4085 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |