McCormick Observatory

Leander McCormick Observatory
Leander McCormick Observatory in 2010
Organization	Department of Astronomy, University of Virginia
Code	780
Location	Charlottesville, Virginia, United States
Coordinates	38°01′57.73″N 78°31′20.61″W / 38.0327028°N 78.5223917°W / 38.0327028; -78.5223917Coordinates: 38°01′57.73″N 78°31′20.61″W / 38.0327028°N 78.5223917°W / 38.0327028; -78.5223917
Altitude	264 meters (866 ft)
Established	1884
Website McCormick Observatory
Telescopes McCormick Telescope 26-inch refractor

Leander McCormick Observatory in 1890

The McCormick Observatory is one of the astronomical observatories operated by the Department of Astronomy^[1] of the University of Virginia and is situated just outside of Charlottesville, Virginia (USA) in Albemarle County on the summit of Mount Jefferson (also known as Observatory Hill). It is named for Leander J. McCormick (1819–1900), who provided the funds for the telescope and observatory. Leander was the son of Robert McCormick (1780–1846), the inventor of a mechanical reaper, and brother of Cyrus H. McCormick, who patented it, and undertook the large scale manufacture and marketing of the invention. The McCormick family's homestead of Walnut Grove was located near Raphine, Virginia, although they moved to Chicago to manufacture of the reaper on a large scale in 1848. In Chicago Cyrus, Leander and their brother William founded what became the McCormick Harvesting Machine Company and eventually International Harvester. In 1870 Leander decided to donate the largest telescope in the world to his home state of Virginia. However, the financial impact of the American Civil War on Virginia as well as the impact of the Great Chicago Fire on his own finances, delayed his efforts, and the telescope was the second largest refractor in the world when completed.

It was largely through the efforts of Charles Scott Venable (aide-de-camp to Gen. Robert E. Lee from 1862 to 1865 and professor of mathematics at the University of Virginia from 1865 to 1896) that McCormick finally (in 1877) decided to make his gift to the University of Virginia. For years he was also considering Washington College (later Washington and Lee University) in Lexington, Virginia, since it was located much closer to the family homestead. In 1870, Robert E. Lee, who was then president of Washington College, sent a letter of introduction to Joseph Henry, secretary of the Smithsonian Institution, making known McCormick's wishes to establish an astronomical observatory in the state. However, in 1878, the University officially received McCormick's donation of the telescope. This was followed in 1881 by a donation of $18,000 for the observatory itself, contingent on the University's raising the funds to endow the professorship.^[2][3]

The telescope and building were completed in 1884 and dedicated on Thomas Jefferson's birthday, April 13, 1885. At the time it was the equal largest telescope in the United States. The telescope was made by Alvan Clark & Sons of Cambridgeport, Massachusetts, who were regarded as the finest telescope makers of the age. The dome, at 45 feet, was the largest in the world when completed; it was designed by Warner and Swasey with a unique three shutter design.

It was nearly a twin of the earlier 26-inch refractor at the U.S. Naval Observatory in Washington. However, the Clarks made some adjustments to the lens to improve the image quality over that of the Naval Observatory refractor. In 1877 while the McCormick Refractor was still in Cambridgeport, Alvan Clark used it to verify the discovery of the moons of Mars the night after the discovery observations were made by Asaph Hall with the Naval Observatory refractor.

Under the first director, Ormond Stone, a program to measure the positions of southern stars was carried out (an extension on the Durchmusterung star catalogue to -23 degrees). In addition, the orbits of southern double stars were measured and southern nebulae were observed. The first published observations to be carried out at the Observatory, before the telescope was even complete, was of the Transit of Venus on December 6, 1882. Observations were made at the site of the observatory as well as at the Rotunda of the University of Virginia.

Starting in 1914 the second director, Samuel Alfred Mitchell, began a program to measure the distances to nearby stars (stellar parallax) using photography. This program continued under the next two directors, Harold Alden and Laurence Fredrick; over the course of more than 80 years, the distances to thousands of stars have been determined with the McCormick Refractor. Peter van de Kamp, Alexander N. Vyssotsky, Emma T. R. Williams and Dirk Reuyl also carried out research on the number and types of stars seen in different directions, and from this deduced information about the size and shape of the Milky Way.

Since the 1880s, daily weather observations have been taken at McCormick Observatory, and it has been part of the National Weather Service's Cooperative Observer Program (COOP) since the programs inception in 1890.

The telescope is the largest Alvan Clark refractor still mounted on its original Alvan Clark mount. The Observatory is now used primarily for teaching and public outreach, and contains a museum of the history of astronomy at the University of Virginia. The observational research of the Astronomy Department is carried out at Fan Mountain Observatory, and at other observatories.

References

1. ^ University of Virginia Department of Astronomy
2. ^ Bruce, Philip Alexander (1921). History of the University of Virginia, 1819-1919: The Lengthening Shadow of One Man. III. New York: Macmillan. pp. 375–376. http://books.google.com/books?id=rbYVAAAAIAAJ&pg=PA375&vq=mccormick+observatory&dq=editions:LCCN20022846&client=firefox-a&source=gbs_search_s. 
3. ^ Board of Visitors Minutes. 1881-06-27. pp. 93–94,97–99. http://repo.lib.virginia.edu:18080/fedora/get/uva-lib:245667/uva-lib-bdef:100/getFullView. 

• Warner, Deborah Jean; Robert B. Ariail (1995). Alvan Clark & Sons, Artists in Optics. ISBN 0943396468. 
• Letter to the Hon. R. W. Thompson, Secretary of the Navy, Announcing the Discovery of the Satellites of Mars, in Monthly Notices of the Royal Astronomical Society, 1877, vol 37, page 443-445, by John Rodgers
• History of McCormick Observatory [1]
• Lyons, Norbert (1955). The McCormick reaper legend; the true story of a great invention. New York: Exposition Press. 

See also

• List of observatories
• List of largest optical refracting telescopes

External links

• McCormick Observatory home page
• Leander McCormick Observatory Clear Sky Clock Forecasts of observing conditions.