Finally, after 18 failed attempts, the lens was finished, transported safely across country, and on December 31, 1887, was carefully installed in the telescope tube. One of the huge glass disks broke during shipping, and making a replacement was delayed. He gave the contract for casting the high quality optical glass blanks, of a size never before attempted, to the firm of Charles Feil in Paris. The famous large telescope maker Alvan Clark was in charge of the optical design. The fabrication of the two-element achromatic objective lens, the largest lens ever made at the time, caused years of delay. It is 60 feet (18 m) in diameter, and can be raised or lowered through a distance of 16 + 1⁄ 2 feet (5.0 m), its purpose being to bring the observer within convenient reach of the eye end of the telescope.Ī drawing of the telescope from an astronomy book The movable floor in the dome is the first of the kind to be constructed. This system receives its supply from the winter rains falling on the roofs the water being pumped to the reservoirs on the higher peak by means of windmills. Another peak seven-eighths of a mile to the east is the summit of Mount Hamilton it is 180 feet higher than the Observatory, and supports the reservoirs supplying power for moving the dome, raising the movable floor, and winding the driving clock of the great telescope. A spring about 350 feet below and one mile to the northeast of the Observatory supplies excellent water. On a closely connected peak half a mile to the east of the Observatory, and 50 feet higher, are the reservoirs from which water for household and photographic purposes is distributed. The height of the marble floor of the main building above mean sea level is 4209 feet. Here are some excerpts from an 1894 book describing the telescope: James Lick is entombed below the floor of the observing room of the telescope. The original hydraulic arrangement still operates today, with the exception that the original wind-powered pumps that once filled the reservoirs have been replaced with electric pumps. The instrument is housed inside a dome that is powered by hydraulic systems that raise and lower the floor, rotate the dome and drive the clock mechanism to track the Earth's rotation. The telescope is located at the University of California's Lick Observatory atop Mount Hamilton at an elevation of 4,209 feet (1,283 m) above sea level. Also called the "Great Lick Refractor" or simply "Lick Refractor", it was the largest refracting telescope in the world until 1897 and now ranks third, after the 40-inch refractor at the Yerkes Observatory and the Swedish 1-m Solar Telescope.
The instrument remains in operation and public viewing is allowed on a limited basis. It has a lens 36 inches (91 cm) in diameter-a major achievement in its day. The James Lick Telescope is a refracting telescope built in 1888. The James Lick Telescope, shown here in an 1889 drawing
0 kommentar(er)
