Visual Documentation of Mount Wilson Observatory:
Installation of the Snow Solar Telescope in 1904-05
A remarkable album of original early photographs of Mount Wilson Observatory and environs, made the year of its founding, including panoramic views of the San Gabriel Mountains, views of the transport and installation of the Snow Solar Telescope, which arrived at Mount Wilson in 1904-05. This device was used in pioneering work to clarify the nature of sunspots. Also an indoor view of scientific instruments at the observatory, group portraits of founding staff and visitors at the observatory and related images.
The first 17 photographs in the album are 8 x 10 views relating to the Mount Wilson Observatory. Included here are exterior and interior views, panoramic views, close-ups of telescopes, and a group portrait of George Ellery Hale (the first director) with the founding staff and prominent visitors at the observatory. Many of the remaining photographs, which are mostly in the smaller 6 x 8 inch format, are signed in the negative "E.B. Gray." These show landscape scenes, a yucca plant, and scenes of men around a campfire.
E.B. Gray was a prolific photographer who did photographic work for the Mount Wilson Observatory and would eventually maintain a darkroom on site. He had a great love of hiking and much of his photographic work focused on the San Gabriel Mountains and Mount Wilson. According to John W. Robinson, "In 1899 Gray and his family moved west [from Ohio] to Pasadena, where he opened a small photographic studio... From 1907 until he moved to Idyllwild in 1930, Gray booked literally thousands of photographs of Mount Wilson and its observatory, mountain camps throughout the range, portraits of mountain visitors, and novelty scenes such as children on burroback and costumed burros."
While many of Gray's negatives were converted into postcards for the tourist trade in Pasadena, the present photographs are clearly early productions from Gray's photographic career large format original prints and clearly intended as a luxury photographic production, likely custom-made for one of the scientists who worked at the Observatory.
Selected images include:
- Outdoor group portrait of George Ellery Hale with the founding staff at Mount Wilson Observatory. Posing behind the Monastery, left to right: H. L. Miller (construction superintendent), Charles Greely Abbott (Smithsonian Institution), George Ellery Hale (first director), Leonard Ross Ingersoll (Abbot’s assistant), Ferdinand Ellerman, Walter Sydney Adams (second director) Edward E. Barnard (visiting from Yerkes to make wide-angle photographs of the Milky Way), and Charles Backus (general assistant).
- Six 8 x 10 inch views of the Snow solar telescope as installed at Mount Wilson, interior and exterior views and close-ups of the telescope itself.
- Several views of Mt. Wilson, access trails, burros and horses, including transport of Snow Telescope components up the narrow mountain trail with specially designed carriages towed by horses
- Three different panoramic views looking toward the San Gabriel Valley from Mount Wilson, including a night view.
- Waterfall. Signed in negative: "Photo by E.B. Gray"
- A Mount Wilson Yucca. Copyright 1905 by E.B. Gray.
- Group of 7 young men shaving and washing up in a creek. "Photo by E.B. Gray"
- Same group of men at a campfire. "Photo by E.B. Gray"
- Scene of pack horses and burros ascending the mountain. "Photo by E.B. Gray"
- "Above the clouds, Photo by E.B. Gray."
- Yucca tree.
- A view of the moon.
- Unidentified interior view of a Bible missionary display, which prominently shows a massive double hemisphere world map indicating religions and missionary stations.
- Large group portrait of men and women. Photographer's name in negative: "Boland"
Snow Telescope
The Snow Solar Telescope at Mount Wilson Observatory in California, originally called the Snow Horizontal Telescope, was a pioneering solar instrument designed by George Ellery Hale and made possible through a 1903 donation by Helen E. Snow of Chicago in memory of her father, George W. Snow. Assembled first at Yerkes Observatory and later relocated to Mount Wilson in 1905, it employed a 30-inch coelostat to direct sunlight into a stationary horizontal observing shed. This configuration enabled precise, laboratory-style study of the Sun, including spectroheliographic imaging. The Snow Telescope was the first major research instrument at Mount Wilson and played a critical role in early 20th-century solar physics, including the landmark discoveries that sunspots are cooler than the surrounding solar photosphere and are associated with magnetic fields. Though later eclipsed by larger tower telescopes, the Snow continued to contribute to solar observation for decades, including studies of solar vortices, flocculi, and the infrared spectrum. Its innovative design and findings helped lay the groundwork for modern solar astronomy.
Mount Wilson
The Mount Wilson Observatory, located in the San Gabriel Mountains northeast of Los Angeles, was founded in 1904 by George Ellery Hale, one of the most influential astronomers of the early 20th century. Its creation marked a turning point in American observational astronomy, driven by Hale’s vision to establish a state-of-the-art facility equipped with the world’s most powerful telescopes.
The site was chosen for its high elevation (approximately 5,700 feet) and relatively stable atmospheric conditions, which provided clear and steady views of the night sky—ideal for astronomical observation. Initial development was supported by the Carnegie Institute, which agreed to fund Hale’s proposal for a solar observatory. A small 12-inch refractor and a 60-foot solar tower telescope were among the first instruments installed, enabling groundbreaking solar research.
By 1908, the observatory saw the installation of the 60-inch reflector telescope, then the largest in the world. Constructed with funding from Andrew Carnegie, it represented a major leap forward in optical astronomy. Hale’s ambitions did not stop there. In 1917, the 100-inch Hooker telescope—named after donor John D. Hooker—was completed and became the most powerful telescope on Earth for several decades. This instrument enabled Edwin Hubble’s landmark discoveries in the 1920s, including the observation of galaxies beyond the Milky Way and the formulation of the law of cosmic expansion.
Throughout the first half of the 20th century, Mount Wilson remained at the forefront of astronomical discovery. Its telescopes were instrumental in reshaping humanity’s understanding of the universe, particularly in extragalactic astronomy and cosmology. Though later eclipsed by newer facilities, Mount Wilson remains an iconic site in the history of science.
Ernest Benjamin Gray (1874–1940) was a prolific Southern California photographer known for his striking and wide-ranging images of the San Gabriel Mountains. Based in Pasadena, Gray captured thousands of photographs of Mount Wilson and its iconic observatory, helping to shape the visual identity of the region in the early 20th century. His work was not limited to landscapes; he built a successful business photographing guests at remote mountain resorts and camps, developing the prints in his own darkroom atop Mount Wilson. These souvenir photographs were cherished by visitors and became part of the cultural memory of mountain recreation in Southern California.
Gray’s interests extended beyond photography. He was deeply involved in gymnastics and physical culture, and during World War I, he served as the official photographer for Camp Kearney in San Diego. There, and later at the naval training camp in Balboa Park, Gray documented military life, creating an important visual archive of California’s wartime mobilization efforts. His legacy lies not only in the sheer volume of his work but also in the breadth of subject matter he pursued—from the rugged serenity of alpine trails to the regimented discipline of wartime camps—offering a uniquely Southern Californian blend of natural beauty and civic documentation.