History of the telescope
The earliest known telescope appeared in 1608 in the Netherlands when an eyeglass maker named Hans Lippershey tried to obtain a patent on one. Although Lippershey did not receive his patent, news of the new invention soon spread across Europe. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo improved on this design the following year and applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens and by 1655 astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces.
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.