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.
Anglo-Australian Telescope
The telescope was commissioned in 1974 with a view to allowing high quality observations of the sky from the southern hemisphere. At the time, most major telescopes were located in the northern hemisphere, leaving the southern skies poorly observed. It was the largest telescope in the Southern hemisphere from 1974-1976, then a close second to the Victor M. Blanco Telescope from 1976 until 1998, when the first ESO Very Large Telescope (VLT) was opened. The AAT was credited with stimulating a resurgence in British optical astronomy. It was built by the United Kingdom in partnership with Australia but has been entirely funded by Australia since 2010. Observing time is available to astronomers worldwide.