Ibrahim bin Jandab was an astronomer, astrologer and and an inventor who invented the astrolabe. He was a great thinker and through his knowledge he invented a kind of telescope so he could use it not only to view distant objects but also find the distance. He called it "astrolabe".
In 776 A.D. Ibrahim invented this instrument-the astrolabe while Galellio (1564-1642 AD), an italian scientist modified the original design and made several changes to it, made the telescope.Many people claim that Galellio was the inverntor of the telescope although it had been invented long time earlier by a muslim scientist Ibrahim bin Jandab.
Astrolabe was made of two hollow pipes. One remained stationary, while the other one could be moved upwards, downwards, left and right. Both these tubes were placed on a stand. hulu