Sidereus Nuncius
The first telescopes appeared in the Netherlands in 1608 when Middelburg spectacle-maker Hans Lippershey tried to obtain a patent on one. By 1609 Galileo had heard about it and built his own improved version. He probably was not the first person to aim the new invention at the night sky but his was the first systematic (and published) study of celestial bodies using one. One of Galileo's first telescopes had 8x to 10x linear magnification and was made out of lenses that he had ground himself. This was increased to 20x linear magnification in the improved telescope he used to make the observations in "Sidereus Nuncius".
Portobello, Dublin
Thomas Grubb (1800–1878), a notable optician, developed his first telescope in a small house between Portobello Bridge and Charlemont Bridge and erected a public observatory at No. 1 Upper Charlemont Street. He founded the Grubb Telescope Company. One of his earliest instruments – the telescope for Markree Observatory in County Sligo – was, for several years, the largest telescope in the world. They provided the telescopes for many observatories worldwide, including Melbourne, Vienna and Aldershot Observatory in 1891. The company was acquired in 1925 by Charles Algernon Parsons and renamed Sir Howard Grubb, Parsons and Co. Ltd.