Hevelius observing with a woodentubed refracting telescope some 30 feet 9.144m. The blockandtackle and rope mounting was not inconvenient. From Selenographia by Johannes Hevelius Gedani, Gdansk. Danzig, 1647. Engraving. Editorial Stock Photo - Afloimages
Hevelius observing with a wooden-tubed refracting telescope some 30 feet (9.144m). The block-and-tackle and rope mounting was not inconvenient. From 'Selenographia' by Johannes Hevelius (Gedani, Gdansk. Danzig, 1647). Engraving.