Mount Wilson (California)

Mount Wilson
The north slope of Mount Wilson as seen from Angeles Crest Highway
Elevation	5,712 ft (1,741 m) NAVD 88[1]
Prominence	150 ft (46 m)
Location
Location	Los Angeles County, California, USA
Range	San Gabriel Mountains
Coordinates	34°13′25.53″N 118°03′41.92″W / 34.2237583°N 118.0616444°W / 34.2237583; -118.0616444Coordinates: 34°13′25.53″N 118°03′41.92″W / 34.2237583°N 118.0616444°W / 34.2237583; -118.0616444[1]
Topo map	USGS Mount Wilson
Climbing
Easiest route	Drive

Map showing the location of Mount Wilson

Mount Wilson is one of the better known peaks in the San Gabriel Mountains, part of the Angeles National Forest in Los Angeles County, California. It is the location of the Mount Wilson Observatory and has become the astronomical center of Southern California with 60-inch (1,524 mm) and 100-inch (2,540 mm) telescopes, and 60-foot (18.3 m) and 150-foot (45.7 m) tall solar towers. The summit is at 5,710 feet (1,740 m). Some surrounding peaks are slightly higher. Due to its elevation, snow can sometimes interrupt astronomical activities on the mountain.

Mount Wilson is also referred to as a metro-media center^{[citation needed]} for its relay broadcasting of radio and television for the Greater Los Angeles Area.

History

The native inhabitants of the San Gabriels probably belonged to various tribes of the Tongva people who lived in the low-lying valleys. Granite outcroppings along the Angeles Crest show signs of meal preparations with metate pots ground into rock surfaces.

The first recorded exploration of the mountain was performed by Benjamin Davis Wilson also known as "Don Benito". Wilson, who was the grandfather of George S. Patton, Jr., was the owner of Rancho San Pascual in about 1852 and ran a winery at his home, "Lake Vineyard", which was in the area of today's San Marino. Wilson hoped to find a suitable wood for his casks but was disappointed by the poor quality of trees on the mountain. He built a trail, following an established Indian route, which became known as the Mount Wilson Trail. In turn Wilson's trail became the predecessor of the Mount Wilson Toll Road. He was surprised to find line shacks at the summit, probably left by Spaniards who were known to track down destructive grizzly bears. He built a three-room cabin along the trail called "Halfway House." Despite Wilson's inability to find adequate wood, the hike became a popular pastime for locals who would make a weekend trip to the summit. These hikers built signal fires on the summit to let people below know that the party had arrived safely.

Astronomy

In 1889 Professor William Pickering of Harvard University along with Alvan P. Clark, famous lens grinder, prepared an experiment with a 4-and-13-inch (102 and 330 mm) telescopes at Mount Wilson. University students would operate the telescopes for nighttime viewing, but more often than not they would log in "bad weather, no visibility" and head to town to relieve their boredom. The small observatory was abandoned with plans to build a larger one at a later date.^[2]

In 1891 Prof. Thaddeus S. C. Lowe incorporated the Pasadena & Mount Wilson Railroad with the plan of building a scenic mountain railroad to the summit of Mt. Wilson. At the same time land and easement disputes between camp owners Steils and Strain were going on over the public and private use of the Mount Wilson Trail. The courts ruled that the trail was a public thoroughfare and that any blockading would be illegal. At the foot of the mountain, a local contractor Thomas Banbury built a 10-mile (15 km) roadway to be named "The New Mount Wilson Trail," aka "The Mount Wilson Toll Road." Passage fare was 25¢ round trip for hikers and 50¢ for horseback.^[2]

In 1892 Prof. Charles William Eliot, president of Harvard University, planned to have two 40-inch (102 cm) lenses shipped from Alvin Clark and Sons in Corning, New York to the newly named Mount Harvard, directly adjacent to Mt. Wilson. The money was to be put up by Mr. Spence of the University of Southern California. Walter Raymond, of Raymond & Whitcomb Travel Agency, Boston, and owner of the Raymond Hotel, Pasadena, offered to pay for rail from New York. Lowe offered to take the lenses up via his yet-to-be-built Mt. Wilson Railway. Spence died suddenly and left no word of the money for the project. The lenses ended up at Yerkes Observatory in Wisconsin, and Lowe's railway ended up going to Oak Mountain (Mount Lowe).^[2]

By 1901 The Mount Wilson Toll Road Co. had purchased Henninger Flats, Strain's Camp, Martin's Camp, and 640 acres (2.6 km²) of the summit.^[2]

In 1903 George Ellery Hale visited Mt. Wilson only to become so enthused by the perfect conditions for which to set up an observatory, which would become the Mount Wilson Observatory. In 1905 40 acres (160,000 m²) were leased for 99 years by the Carnegie Institute for telescopes, and construction began on a new Mt. Wilson Hotel. In 1908 a 60-inch (1524 mm) telescope was installed at the summit, and in 1910 the 150-foot (46 m) tall Solar Tower was erected. In 1913 the hotel burned down and was replaced by a second hotel that lasted until its demolition in 1966. The Toll Road opened to automobiles in 1912 and lasted until 1936.^[2]

In 1917 the 100" Hooker Telescope became operational and would be the world's largest telescope until the opening of the 200" Palomar Hale Telescope in 1948.^[2]

In 1919, American astronomer Edwin Hubble arrived at Mt. Wilson and, throughout the 1920s, made many astronomical discoveries using the Hooker Telescope. Among his contributions are the observational proof that many nebulous objects are actually galaxies beyond our own Milky Way galaxy, the classification of galaxies according to the Hubble sequence, and the development of Hubble's Law relating a galaxy's observed red shift to its distance away. These contributions led to an understanding that the universe is not static, but expanding.

In 1926 Albert Abraham Michelson made what was the most precise calculation of the speed of light at the time by measuring the round-trip travel time of light between Mount Wilson and Mount San Antonio 22 miles (35 km) away.^[2]

Mount Wilson Electronics Reservation

Antennas on Mount Wilson, covered in ice after heavy snowfall

The first antenna on Mount Wilson was installed in 1948. The mountain became so popular as a site for transmiters that, in 1963, the Metromedia company bought 720 acres (2.9 km²) from the Mount Wilson Hotel Company. Metromedia built Skyline Park which consisted of a pavilion, a children's zoo and landscaped walks.^[3] The park closed in 1976 after operating at a loss for almost a decade. The property is now the home of numerous transmitters serving the Los Angeles metropolitan area and includes radio, television and microwave relay facilities. The tallest of which, according to the FCC database, is the guyed mast, formerly home of KCBS-TV, now operated by Richland Towers, which stands at a height of 972 feet (296.3 m),^[4][5] built in 1986.

Observatory salvaged

In 1984 the Carnegie Institute began the process of shutting down the observatories on Mount Wilson, opting to concentrate on newer sites in Chile. In 1986 the Mt. Wilson Institute was formed and plans to reopen the observatories were made so that by 2000 all the telescopes were back in operation.^{[citation needed]}

Construction began in 1996 for six 1-meter telescopes by the Center for High Angular Resolution Astronomy at Georgia State University. This is the largest optical interferometric array ever built. Ground was broken for the telescopes in 1999 and the facility became operational in 2001.^[6]

On the evening of August 30, 2009, the Station Fire threatened the tower cluster and the Observatory, along with nearby Mount Harvard.^[7]

The view of Los Angeles from Mount Wilson.

See also

• Angeles Crest Highway
• Sierra Madre, California
• Mount Wilson Toll Road
• San Gabriel Mountains
• Angeles National Forest
• Mount Wilson Observatory

References

1. ^ ^{a b} "Wilson Peak". NGS data sheet. U.S. National Geodetic Survey. http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=EW1864. Retrieved 2009-08-17. 
2. ^ ^{a b c d e f g} "History of Mt. Wilson". oldradio.com. http://www.oldradio.com/archives/stations/LA/mtwilson1.htm. Retrieved 2010-12-04. 
3. ^ "The Story of Mt. Wilson, California Part 3 – Broadcasters Invade". oldradio.com. http://www.oldradio.com/archives/stations/LA/mtwilson3.htm. Retrieved 2010-12-04. 
4. ^ "Antenna Structure Registration 1012836". fccinfo.com. http://www.fccinfo.com/CMDProASRLookup.php?tabSearchType=ASR+Search&sASR=1012836. Retrieved 2010-12-04. 
5. ^ "Antenna Structure Registration Search Results Within 15 Kilometers of 34-13-55.0 and 118-04-18.0". fccinfo.com. http://www.fccinfo.com/CMDProASRLookup.php?sKilometers=15&sLatitude=34-13-55.0&sLongitude=118-04-18.0&tabSearchType=ASR+W&order=7%7CA%7CN. Retrieved 2010-12-04. 
6. ^ Center for High Angular Resolution Astronomy Web site (http://www.chara.gsu.edu/CHARA/), Retrieved 8-4-2011.
7. ^ "Station fire likely to hit historic Mt. Wilson observatory, fire officials say". L.A. Now (The Los Angeles Times). August 30, 2009. http://latimesblogs.latimes.com/lanow/2009/08/station-fire-approaching-historic-mt-wilson-observatory-fire-officials-say.html. Retrieved 2010-12-04. 

External links and sources

• List of Mount Wilson broadcasters
• Photos from Mount Wilson
• Webcam at Mount Wilson Observatory
• Hikers