History of the telescope a wider field of view than a classic Cassegrain. During the period 1850–1900, reflectors suffered from problems with speculum metal mirrors, and a considerable number of "Great Refractors" were built from 60 cm to 1 metre aperture, culminating in the Yerkes Observatory refractor in 1897; however, starting from the early 1900s a series of ever-larger reflectors with glass mirrors were built, including the Mount Wilson 60-inch (1.5 metre), the 100-inch (2.5 metre) Hooker Telescope (1917) and the 200-inch (5 metre) Hale telescope (1948); essentially all major research telescopes since 1900 have been reflectors. A number of 4-metre class (160 inch)
Harlan J. Smith Telescope of Texas discovered the star HIP 56948 in 2007 using the Harlan J. Smith telescope at McDonald Observatory. Four largest telescopes 1968: Harlan J. Smith Telescope The Harlan J. Smith Telescope is a telescope located at the McDonald Observatory, in Texas, in the United States. This telescope is one of several research telescopes that are part of the University of Texas at Austin observatory perched on Mount Locke in the Davis Mountains of west Texas. The telescope was completed in 1968 with substantial NASA assistance, and is named after Harlan James Smith, the first Texas director of McDonald Observatory. Smith