A lot of mechanical aids to calculation and measurement had been constructed for astronomical and navigation use. The planisphere was a star chart invented by Abū Rayhān al-Bīrūnī from the early 11th century.[eight] The astrolabe was invented while in the Hellenistic globe in possibly the 1st or 2nd hundreds of https://f-r97642.blogripley.com/26686255/main-options