 Based only on uncertain descriptions of the first practical telescope which Hans Lippershey tried to patent in the Netherlands in 1608 , Galileo , in the following year , made a telescope with about 3x magnification . He later made improved versions with up to about <unk> magnification . With a Galilean telescope , the observer could see magnified , upright images on the earth — it was what is commonly known as a terrestrial telescope or a spyglass . He could also use it to observe the sky ; for a time he was one of those who could construct telescopes good enough for that purpose . On 25 August 1609 , he demonstrated one of his early telescopes , with a magnification of about 8 or 9 , to Venetian lawmakers . His telescopes were also a profitable sideline for Galileo , who sold them to merchants who found them useful both at sea and as items of trade . He published his initial telescopic astronomical observations in March 1610 in a brief treatise entitled Sidereus Nuncius ( Starry Messenger ) . 
