How to construct a mounting for a refracting telescope so that the Sun's image could be projected onto a screen and sunspots safely studied. A second screen at R blocked out indirect sunlight and made it possible to use the instrument without a camera obscura. From Rosa Ursina by Christoph Scheiner (Bracciano,1630). Engraving | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / UIG / Universal History Archive |
Bildgröße: | 2880 px × 3044 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |