Marker Logo HMdb.org THE HISTORICAL
MARKER DATABASE
“Bite-Size Bits of Local, National, and Global History”
“Bite-Size Bits of Local, National, and Global History”
Flagstaff in Coconino County, Arizona — The American Mountains (Southwest)
 

42-Inch Reflecting Telescope

 
 
42-Inch Reflecting Telescope Marker image. Click for full size.
By Cosmos Mariner, May 31, 2015
1. 42-Inch Reflecting Telescope Marker
Inscription.  This 11-ton telescope, built by the Alvan Clark & Sons Telescope Manufacturing Company of Cambridgeport, Massachusetts, was installed at Lowell Observatory in 1909. It came with four secondary mirror combinations so that it could be operated at four different focal lengths. One secondary mirror was for the Newtonian focus, the shortest, giving a focal length of 18.3 feet (5.6 meters). Three other secondary mirrors were used with a modified classical Cassegrain focus of 53, 80, and 150 feet (16, 24, and 46 meters) respectively. Dr. Vesto Melvin Slipher used the 80 foot (24m) focus for spectroscopic studies for approximately 2 years. Earl C. Slipher used the 150 foot (46m) focus for Kodachrome pictures of the planets.

From 1909 until 1950, staff astronomer Dr. C. O. Lampland was the principal observer with this telescope. During these years he made over 10,000 photographs of galaxies, diffuse nebulae, star clusters, and star fields. These images were used for studying any changes and motions within these objects and throughout the star fields. In 1922 Dr. Lampland and Dr. W. W. Coblentz, of the National Bureau of Standards, used this telescope
Marker detail: 42-Inch Reflecting Telescope image. Click for full size.
2. Marker detail: 42-Inch Reflecting Telescope
Click or scan to see
this page online
to measure the surface temperatures of Mars, Venus and the other planets. After the discovery of Pluto on February 18, 1930, Dr. Lampland used this telescope to derive accurate positions for the determination of its orbit.

Beginning in 1948, part of the observing time was allotted to the solar variations program, an investigation to determine the constancy of the light from solar-type stars. In 1969, a new 42-inch mirror made of low expansion glass was completed, and the decision was made to use a modern telescope mounting. The new telescope was placed at Lowell Observatory's dark sky site on Anderson Mesa 12 miles (19 km) southeast of Flagstaff.

This old telescope, although maintained in place in its dome, was not used much after 1970. In November 1999 it was removed from its original dome, and it was placed on display here in May 2001.
 
Topics. This historical marker is listed in these topic lists: Air & SpaceScience & Medicine. A significant historical year for this entry is 1909.
 
Location. 35° 12.139′ N, 111° 39.887′ W. Marker is in Flagstaff, Arizona, in Coconino County. Marker can be reached from West Mars Hill Road 0.6 miles west of West Santa Fe Avenue. Marker is located on the Lowell Observatory campus. It is along the walkway just north of the Steele Visitor Center. Touch for map. Marker is at or near this postal address: 1400 West Mars Hill Road, Flagstaff AZ 86001, United States of America. Touch for directions.
 
Other nearby markers. At least 8
Marker detail: 42-inch Mirror Prior to Installation image. Click for full size.
3. Marker detail: 42-inch Mirror Prior to Installation
other markers are within walking distance of this marker. Clark Dome Weather Station (within shouting distance of this marker); Lowell Observatory (within shouting distance of this marker); Henry Lee Giclas (about 400 feet away, measured in a direct line); The Lawrence Lowell Telescope (about 700 feet away); Methodist Episcopal Church (approx. 0.7 miles away); The Old Tractor (approx. 0.7 miles away); Flagstaff Flag - Raising (approx. 0.7 miles away); The Navajo Code Talkers (approx. ¾ mile away). Touch for a list and map of all markers in Flagstaff.
 
Related markers. Click here for a list of markers that are related to this marker. Lowell Observatory
 
Marker detail: Dome for the 42-inch Telescope image. Click for full size.
4. Marker detail: Dome for the 42-inch Telescope
Marker detail: Construction of the 42-inch Telescope image. Click for full size.
5. Marker detail: Construction of the 42-inch Telescope
Eli Giclas, father of Lowell Observatory astronomer Henry Giclas, is seen standing.
42-Inch Reflecting Telescope & Marker image. Click for full size.
By Cosmos Mariner, May 31, 2015
6. 42-Inch Reflecting Telescope & Marker
42-Inch Reflecting Telescope image. Click for full size.
By Cosmos Mariner, May 31, 2015
7. 42-Inch Reflecting Telescope
 
 
Credits. This page was last revised on May 8, 2020. It was originally submitted on May 6, 2020, by Cosmos Mariner of Cape Canaveral, Florida. This page has been viewed 65 times since then and 7 times this year. Photos:   1. submitted on May 7, 2020, by Cosmos Mariner of Cape Canaveral, Florida.   2, 3, 4, 5, 6, 7. submitted on May 8, 2020, by Cosmos Mariner of Cape Canaveral, Florida.

Share This Page.  
Share on Tumblr
m=149451

Paid Advertisement
Apr. 15, 2021