Mount Wilson Observatory Photographs and Audiovisual Materials photCL
COPC
Suzanne Oatey
The Huntington Library
December 2021
1151 Oxford Road
San Marino, California 91108
Business Number: (626) 405-2191
reference@huntington.org
Contributing Institution:
The Huntington Library Photo Archives
Title: Mount Wilson Observatory photographs and audiovisual materials
Creator:
Carnegie Institution of Washington
Identifier/Call Number: photCL COPC
Physical Description:
35.55 Linear Feet
(87 boxes, 5 volumes)
Date (inclusive): approximately 1890s-2004
Date (bulk): 1925-1975
Abstract: A collection of photographs and
audiovisual materials chiefly related to Mount Wilson Observatory, Los Angeles County,
California, and 20th-century astronomical research.
Language of Material: Materials are in
English.
Conditions Governing Access
Open for use by qualified researchers and by appointment. Please contact Reader Services at
the Huntington Library for more information.
Restrictions apply to: Boxes 23-79: Glass plate negatives not available for paging due to
fragility and availability of digital reproductions in the
Huntington Digital Library.
Conditions Governing Use
The Huntington Library does not require that researchers request permission to quote from
or publish images of this material, nor does it charge fees for such activities. The
Huntington Library owns the copyright for these materials; copyright was transferred by the
Observatories of the Carnegie Institution of Washington.
Preferred Citation
[Identification of item]. Mount Wilson Observatory photographs and audiovisual materials,
The Huntington Library, San Marino, California.
Immediate Source of Acquisition
Placed on deposit in the Huntington Library by the Observatories of the Carnegie
Institution of Washington, 1988.
Biographical / Historical
Mount Wilson Observatory was founded in 1904 by George Ellery Hale under the auspices of
the Carnegie Institution of Washington. Built on the summit of Mount Wilson, above Pasadena
in Los Angeles County, California, it was called the Mount Wilson Solar Observatory until
1919, when "Solar" was dropped from the name.
Scope and Contents
This is a collection of over 8,000 photographs and a few audiovisual materials chiefly
related to Mount Wilson Observatory, located in the San Gabriel Mountains above Pasadena, in
Los Angeles County, California. The materials date from 1890 to 2004, with the bulk of
material dated 1925 to 1975. Subjects include the building of the observatory and its
development, various telescopes, structures, and scientific instruments, as well as numerous
astronomers, scientists, and related workers. Images depict the construction of Mount Wilson
Toll Road, transportation of items to the observatory, night views of city lights seen from
Mount Wilson, and brush fires around Mount Wilson. Scientists are seen working at the Mount
Wilson Observatory administrative buildings and workshops on Santa Barbara Street in
Pasadena, and taking part in various eclipse expeditions. Other subjects are: the Hale Solar
Laboratory, Palomar Observatory, Yerkes Observatory, astronomical photographs, and many
images of notable scientists and astronomers, including George Ellery Hale, Edwin Powell
Hubble, Albert Einstein, Walter Sydney Adams, and Ferdinand Ellerman. Also included are
audio recordings and motion picture films related to Mount Wilson Observatory.
Processing Information
In 1988 and 1989, Ronald Brashear, the Huntington's first History of Science curator,
organized the collection and wrote photograph descriptions. From 1999 to 2001, 2,219 images
were scanned by the Huntington Library and added to the Huntington Digital Library. In 2018
and 2019, Laura Rips re-housed some materials and wrote descriptions of the albums. In 2021,
Suzanne Oatey completed processing and created a finding aid.
Arrangement
Organized in six series:
- Series 1. Photograph albums, 1891-1936
- Series 2. Photographic prints, approximately 1890s-1987
- Series 3. Glass plate negatives, approximately 1890s-1920s
- Series 4. Film negatives, approximately 1920s-1970s
- Series 5. Audiovisual materials, 1930-2004
- Series 6. Photocopies and subject index, approximately 1989
Existence and Location of Copies
Physical Characteristics and Technical Requirements
Boxes 18-22: Film negatives and audiovisual materials housed in cold storage; extended
retrieval and delivery time required.
Related Materials
Subjects and Indexing Terms
Astronomers -- United States -- 20th century
Astronomical observatories
Astronomical observatories -- California -- Wilson, Mount
(Mountain)
Astronomical photography -- Equipment and supplies
Astronomy -- United States -- History -- 20th century --
Sources
Astronomy -- Photographs
Telescopes -- Design and construction -- History -- Sources
Mount Wilson (Calif.)
Pasadena (Calif.) -- Buildings, structures, etc.
San Gabriel Mountains (Calif.) -- Photographs
Photograph albums
Photographs
Glass plate negatives
Film negatives
Negatives (photographs)
Audiocassettes
Videocassettes
Motion pictures (visual works)
Wire recordings
Carnegie Institution of Washington
Mount Wilson and Palomar Observatories.
Mount Wilson Observatory
Mount Wilson Solar Observatory
Adams, Walter S. (Walter Sydney), 1876-1956
Einstein, Albert, 1879-1955 -- Photographs.
Ellerman, Ferdinand, 1869-1940
Hale, George Ellery,
1868-1938
Hubble, Edwin, 1889-1953
Yerkes Observatory
Photograph albums Series 1
1891-1936
Physical Description: 11.34 Linear
Feet (8 albums in 8 boxes)
Scope and Contents
These albums contain primarily professional photographs of the construction and early
development of Mount Wilson Observatory, with one album of photographs of Yerkes
Observatory, Williams Bay, Wisconsin.
Arrangement
Arranged by subject, then chronologically.
Existence and Location of Copies
The majority of the photographs in these albums have corresponding negatives that were
digitized and can be found in the
Huntington Digital Library.
Box 10
Mount Wilson Observatory photograph album Album 1
approximately 1904-1911
Physical Description: 79
Photographic Prints
Scope and Contents
This album begins with images of the construction of the 60-foot and 150-foot towers
at Mount Wilson. Next are images of staff and researchers at Mount Wilson, including
George Ellery Hale, Charles G. Abbot, and E. E. Barnard, among others. There is also a
group portrait of members of the International Union for Co-Operation in Solar
Research, 1910. Other images depict views of Mount Wilson, construction, buildings and
equipment, and the interiors of the original physical laboratory in Pasadena.
Box 11
Mount Wilson Observatory photograph album Album 2
approximately 1904-1916
Physical Description: 106
Photographic Prints
Scope and Contents
The first group of photographs are numbered 1 to 71, and most relate to construction
and the transportation of material to Mount Wilson for the observatory. The second
group is numbered 1 to 35 and contains photographs of other structures on Mount
Wilson, and interiors of rooms with equipment and machines. There are some photographs
of scientists' rooms, referred to as "the monastery."
Box 12
Mount Wilson Observatory photograph album Album 3
approximately 1904-1914
Physical Description: 104
Photographic Prints
Scope and Contents
The first set of photographs is numbered 1 to 74 and includes images of the
construction of the Snow Telescope building, and interior images showing the coelostat
and other equipment. Some photographs show what appear to be sleeping quarters for the
workers. The second set is numbered 1 to 31, and mostly depict construction of the
60-inch dome; assembly of the telescope and related equipment; and a technical
drawing. Some of the photographs of the 60-inch telescope were taken in the erecting
house at Mount Wilson Observatory's Pasadena workshop.
Existence and Location of Copies
A few photographs at the beginning of the album are not available in digital
form.
Box 13
Mount Wilson Observatory photograph album Album 4
approximately 1909-1924
Physical Description: 91
Photographic Prints
Scope and Contents
The first four photographs are exterior and interior shots of the observatory's
Pasadena offices, laboratory, and shop exterior, including equipment and instruments.
The next 12 photographs are views of the Mount Wilson Observatory, including the
60-foot dome and telescope, the 60-foot and 150-foot tower telescopes, and the Hooker
Telescope. The next group of 59 photographs are celestial images taken from Mount
Wilson Observatory. They include images of stars, comets, the sun, sunspots, solar
coronas, typical spectrograph, nebulae, Mars, Jupiter, and the moon. Most photographs
have captions.
Box 14
Mount Wilson Observatory photograph album Album 5
approximately 1911-1915
Physical Description: 103
Photographic Prints
Scope and Contents
This album contains photographs related to the 100-inch telescope on Mount Wilson.
Photographs include the building site, construction of the dome, installation of the
telescope parts and related equipment, instruments and machinery. There are also a few
photographs of technical drawings.
Box 15
A Photographic History of the Construction of the Two-Hundred-Inch Reflecting
Telescope for the California Institute of Technology, Pasadena, California (Copy
1)
approximately 1935-1936
Physical Description: 1
Volume (351 photographs in one
album)
Scope and Contents
This album of photographs is related to the 200-inch Hale Telescope at Palomar
Observatory in San Diego County, California. The front of the album has a label noting
the album was prepared for George Ellery Hale by Ferdinand Ellerman. Many of the
photographs have captions. The first part of the album includes photographs of the
astrophysical lab, machine shop and optical shop at the California Institute of
Technology, as well as the arrival and uncrating of the 120-inch glass test blank at
Caltech. There are numerous photographs of a grinding machine and tools, plus other
equipment and instruments including a coelostat and Schmidt telescope. Lab workers are
shown in many photographs, and a few are identified in captions. Twenty photographs
show the 200-inch disk at Corning Glass Works. A small group of images show the
aluminizing chamber for the 60-inch mirror. The second part of the album includes the
transportation and arrival of the 200-inch mirror blank at Caltech, models of the
telescope, views of the Hale telescope site in the Palomar mountains, cottages and
other surrounding buildings and infrastructure, and photographs of the early
construction of the 200-inch dome.
Existence and Location of Copies
Many of these photographs do not have digital surrogates and are not available in the
Huntington Digital Library.
Box 16
A Photographic History of the Construction of the Two-Hundred-Inch Reflecting
Telescope for the California Institute of Technology, Pasadena, California (Copy
2)
approximately 1935-1936
Physical Description: 1
Volume (358 photographs in 1
album)
Scope and Contents
This album is almost a duplicate of Copy 1, but it does not include the front label
noting that it was prepared for George Ellery Hale by Ferdinand Ellerman. There are a
few additional photographs, most of which are variant views or reproductions.
Box 17
Yerkes Observatory photograph album
approximately 1891-1922; bulk
1895-1899
Physical Description: 93
Photographic Prints
Scope and Contents
This album contains early images of Yerkes Observatory in Williams Bay, Wisconsin.
Included are photographs of the construction of the observatory, construction workers,
exterior and interior views of the observatory, surrounding structures, and views of
Lake Geneva. Many photographs show machinery and instruments, including the 40-inch
refracting telescope, the Kenwood 12-inch refracting telescope, a heliostat and
spectrohelioscope, and equipment for grinding and polishing. There is also a
photograph of the exterior of the Kenwood Astrophysical Observatory in Chicago,
Illinois, plus an office interior at Kenwood. Group portraits include attendees of the
Yerkes Observatory dedication and first conference of astronomers and astrophysicists
in October 1897, and members of the National Academy of Science in 1903. Notable
people include George Ellery Hale, George Willis Ritchey, John Alfred Brashear,
Ferdinand Ellerman, E. E. Barnard, and other prominent astronomers and instrument
makers.
Existence and Location of Copies
Photographic prints Series 2
approximately 1890s to 1987
Physical Description: 6.67 Linear
Feet (9 boxes)
Scope and Contents
Over 3,000 photographs primarily related to the history of Mount Wilson Observatory,
and 14 panoramic photographs. Also includes images of related observatories,
astronomical equipment and telescopes, astronomers, scientists and other workers. The
photographs are in envelopes with sequential numbers, but have no subject information on
the envelopes. Some have identifications or dates written on the back. Many of these
photographs have corresponding glass or film negatives elsewhere in the collection. See
the Huntington Digital Library for subject searching of the digital versions.
Existence and Location of Copies
Many of these prints have corresponding negatives that were digitized, though some
prints were digitized if negatives were unavailable. Digital reproductions can be seen
in the
Huntington Digital Library.
The digital image records contain detailed captions, names, dates, and other
information that is searchable.
Arrangement
Arranged in sequential numbers assigned by Huntington Library staff. Numbers not
inclusive; missing numbers are images in glass and/or film negative format.
Box 1
Photographs COPC 00001-00671
Box 2
Photographs COPC 00672-01490
Box 3
Photographs COPC 01491-02160
Box 4
Photographs COPC 02161-02750
Box 5
Photographs COPC 02751-03300
Box 6
Photographs COPC 03301-03355
Box 7
Photographs
Scope and Contents
Approximately 200 unnumbered photographs, in folders by subject: Ancient astronomers;
Carnegie Institution exhibits; celestial images, including eclipses, approximately
1900s to 1943; Edison Pettit's 6-inch telescope, 1939; George Ellery Hale Elementary
School, Pasadena; Hale Solar Lab magnetograph; Kitt Peak Observatory construction;
Dominion Observatory; Lick Observatory; McDonald Observatory; Paul Merrill and
classmates, 1906 to 1913; Mount Wilson Observatory 100-inch Telescope Landmark
Ceremony, June 20, 1981; Charles G. Abbott; Mount Wilson Observatory laboratory and
optical shop in Pasadena.
Box 8
Photographs
Scope and Contents
Approximately 300 photographs, unnumbered, of miscellaneous subjects: National Bureau
of Standards aerial photos, Washington D.C.?; various observatories and astronomers;
spectrograms; telescopes and machinery; Bernhard Schmidt at Hamburg Observatory,
Germany, 1934 to 1935; "Sun Among the Stars" conference, Riverside, California, 1966;
U.S. Naval Air Missile Test Center, 1957; Yerkes Observatory.
Box 9
Panoramic photographs
approximately 1921-1957
Scope and Contents
Fourteen panoramic photographs, rolled. Nine are of the aluminizing tank in the
100-inch dome at Mount Wilson Observatory. There are two copies of a group portrait of
President Warren G. Harding, Albert Einstein, and members of the National Academy of
Sciences at the White House, April 25, 1921. Others are group portraits of
astronomical societies or unidentified people.
Glass plate negatives Series 3
approximately 1890s-1920s
Physical Description: 12.12 Linear
Feet (58 boxes)
Conditions Governing Access
RESTRICTED: Glass plate negatives not available for paging due to fragility and availability of
digital reproductions in the Huntington Digital Library.
Existence and Location of Copies
The digital image records contain detailed captions, names, dates, and other
information that is searchable.
Scope and Contents
This series contains glass plate negatives (photographs) made by unidentified
photographers, most likely working for the Carnegie Institute in Washington. Many of
these images are duplicated in print copies or film copy negatives elsewhere in the
collection.
Arrangement
Arranged in sequential numbers assigned by Huntington Library staff. Numbers not
inclusive; missing numbers are images in film negative or print format.
Box 23
Glass plate negatives COPC 69-257
Physical Description: 4 x 5 inches
Box 24
Glass plate negatives COPC 260-453
Physical Description: 4 x 5 inches
Box 25
Glass plate negatives COPC 454-666
Physical Description: 4 x 5 inches
Box 26
Glass plate negatives COPC 667-884
Physical Description: 4 x 5 inches
Box 27
Glass plate negatives COPC 885-904
Physical Description: 4 x 5 inches
Box 28
Glass plate negatives COPC 905-1080
Physical Description: 4 x 5 inches
Box 29
Glass plate negatives COPC 1081-1120
Physical Description: 4 x 5 inches
Box 30
Glass plate negatives COPC 1121-1216
Physical Description: 4 x 5 inches
Box 31
Glass plate negatives COPC 1217-1227
Physical Description: 4 x 5 inches
Box 32
Glass plate negatives COPC 1228-1243
Physical Description: 4 x 5 inches
Box 33
Glass plate negatives COPC 1244-1270
Physical Description: 4 x 5 inches
Box 34
Glass plate negatives COPC 1271-1290
Physical Description: 4 x 5 inches
Box 35
Glass plate negatives COPC 1298-1386
Physical Description: 4 x 5 inches
Box 36
Glass plate negatives COPC 1387-1539
Physical Description: 4 x 5 inches
Box 37
Glass plate negatives COPC 1540-1768
Physical Description: 4 x 5 inches
Box 38
Glass plate negatives COPC 1769-1815
Physical Description: 4 x 5 inches
Box 39
Glass plate negatives COPC 2333-2785
Physical Description: 4 x 5 inches
Box 40
Glass plate negatives COPC 2786-2807
Physical Description: 4 x 5 inches
Box 41
Glass plate negatives COPC 2895-3266
Physical Description: 4 x 5 inches
Box 42
Glass plate negatives COPC 16-1065
Physical Description: 5 x 7 inches
Box 43
Glass plate negatives COPC 1065-1376
Physical Description: 5 x 7 inches
Box 44
Glass plate negatives COPC 1584-3256
Physical Description: 5 x 7 inches
Box 45
Glass plate negatives COPC 1-16
Physical Description: 8 x 10 inches
Box 46
Glass plate negatives COPC 17-42
Physical Description: 8 x 10 inches
Box 47
Glass plate negatives COPC 43-63
Physical Description: 8 x 10 inches
Box 48
Glass plate negatives COPC 64-79
Physical Description: 8 x 10 inches
Box 49
Glass plate negatives COPC 80-96
Physical Description: 8 x 10 inches
Box 50
Glass plate negatives COPC 97-121
Physical Description: 8 x 10 inches
Box 51
Glass plate negatives COPC 122-221
Physical Description: 8 x 10 inches
Box 52
Glass plate negatives COPC 222-249
Physical Description: 8 x 10 inches
Box 53
Glass plate negatives COPC 250-292
Physical Description: 8 x 10 inches
Box 54
Glass plate negatives COPC 293-365
Physical Description: 8 x 10 inches
Box 55
Glass plate negatives COPC 366-443
Physical Description: 8 x 10 inches
Box 56
Glass plate negatives COPC 443-476
Physical Description: 8 x 10 inches
Box 57
Glass plate negatives COPC 478-510
Physical Description: 8 x 10 inches
Box 58
Glass plate negatives COPC 511-544
Physical Description: 8 x 10 inches
Box 59
Glass plate negatives COPC 545-588
Physical Description: 8 x 10 inches
Box 60
Glass plate negatives COPC 589-679
Physical Description: 8 x 10 inches
Box 61
Glass plate negatives COPC 682-762
Physical Description: 8 x 10 inches
Box 62
Glass plate negatives COPC 763-838
Physical Description: 8 x 10 inches
Box 63
Glass plate negatives COPC 844-909
Physical Description: 8 x 10 inches
Box 64
Glass plate negatives COPC 910-988
Physical Description: 8 x 10 inches
Box 65
Glass plate negatives COPC 989-1023
Physical Description: 8 x 10 inches
Box 66
Glass plate negatives COPC 1024-1073
Physical Description: 8 x 10 inches
Box 67
Glass plate negatives COPC 1074-1156
Physical Description: 8 x 10 inches
Box 68
Glass plate negatives COPC 1156-1293
Physical Description: 8 x 10 inches
Box 69
Glass plate negatives COPC 1294-1330
Physical Description: 8 x 10 inches
Box 70
Glass plate negatives COPC 1331-1355
Physical Description: 8 x 10 inches
Box 71
Glass plate negatives COPC 1356-1405
Physical Description: 8 x 10 inches
Box 72
Glass plate negatives COPC 1405-1455
Physical Description: 8 x 10 inches
Box 73
Glass plate negatives COPC 1455-1524
Physical Description: 8 x 10 inches
Box 74
Glass plate negatives COPC 1524-1618
Physical Description: 8 x 10 inches
Box 75
Glass plate negatives COPC 1619-1752
Physical Description: 8 x 10 inches
Box 76
Glass plate negatives COPC 1753-2052
Physical Description: 8 x 10 inches
Box 77
Glass plate negatives COPC 2052-2884
Physical Description: 8 x 10 inches
Box 78
Glass plate negatives COPC 2887-3089
Physical Description: 8 x 10 inches
Box 79
Glass plate negatives COPC 3089-3263
Physical Description: 8 x 10 inches
Box 80
Glass plate negatives
Physical Description: 8 x 10 inches or
smaller
Scope and Contents
Unnumbered; miscellaneous subjects.
Film negatives Series 4
approximately 1920s-1970s
Physical Description: 4 Linear
Feet (4 boxes)
Scope and Contents
Film negatives are in envelopes with numbers only. There are three different sizes, and
negatives are numbered in sequence within each of the three sizes. Many images are also
in print form (Series 2).
Existence and Location of Copies
The digital image records contain detailed captions, names, dates, and other
information that is searchable.
Arrangement
Arranged by size, and then in sequential numbers assigned by Huntington Library staff.
Numbers not inclusive; missing numbers are images in glass negative or print format.
Box 18
Film negatives COPC 1-2545
Physical Description: 8 x 10 inches
Box 19
Film negatives COPC 2546-3355 (8 x 10); COPC 727-2299 (5 x 7)
Physical Description: 8 x 10 and 5 x 7
inches
Box 20
Film negatives COPC 2300-3247 (5 x 7); COPC 135-2215 (4 x 5)
Physical Description: 5 x 7 and 4 x 5 inches
Box 21
Film negatives COPC 2216-3293
Physical Description: 4 x 5 inches or
smaller
Box 22, Folder 1-5
Film negatives
Scope and Contents
A small group of negatives without numbers, of miscellaneous subjects: Lick
Observatory; J. Pier and G. Avery passport photographs; Mount Wilson Observatory;
Edison Pettit's 6-inch telescope; "Sun Among the Stars" conference at Riverside,
California, May, 1966, attendees and speakers; Yerkes Observatory.
Audiovisual materials Series 5
1930-2004
Physical Description: 0.42 Linear
Feet (1 box)
Existence and Location of Copies
Six films and one audio recording were digitized and digital reproductions are
available. See links in listings below.
Scope and Contents
This series contains motion picture films made of Mount Wilson Observatory in 1930, and
a videocassette film made in 2004 about Albert Einstein's teaching years at Caltech in
Pasadena in the 1930s. There is also a sound recording, in two formats, of the
dedication of the 200-inch Hale Telescope at Palomar Observatory in 1948.
Box 22, Folder 6
Motion picture films of Mount Wilson Observatory
1930
Physical Description: 6
Reels(35mm film)
Existence and Location of Copies
Scope and Contents
Includes various scenes at Mount Wilson Observatory and scientists at the Observatory
offices in Pasadena, as well as a solar eclipse expedition to Honey Lake in Northern
California. Individuals who appear include: Walter S. Adams, Seth B. Nicholson, Edison
R. Hoge, Sinclair Smith, Roscoe F. Sanford, Robert S. Richardson, Frederick H. Seares,
Olin C. Wilson, Adriaan van Maanen, Edwin P. Hubble, Arthur S. King, Ferdinand
Ellerman, Donald O. Hendrix, Francis G. Pease, Oscar Swanson, and M. C. Hurlbut.
Reel 6 is a Hearst Metrotone News newsreel titled "Behind the scenes with star
hunters -- How the men of science seek and find new worlds at famous Mt. Wilson."
Box 22, Folder 7
Audiocassette recording of dedication of the 200-inch Hale Telescope at
Palomar Observatory
1948 June 3
Physical Description: 2
Cassettes(one master and one duplicate
copy)
Scope and Contents
Recording is approximately 32 minutes. James R. Page presides over the ceremony.
Speakers in order of appearance: Lee Alvin DuBridge, president of the California
Institute of Technology, followed by Vannevar Bush, president of the Carnegie
Institute of Washington, and Ira S. Bowen, director of the Carnegie Observatories.
Existence and Location of Copies
Box 22, Folder 8
Wire recording of dedication of the 200-inch Hale Telescope at Palomar
Observatory
1948 June 3
Physical Description: 1
Items(wire recording)
Scope and Contents
Same audio as cassette version (Folder 7).
Box 22, Folder 9
Videocassette recording: When Einstein Lived in Pasadena
2004 September 1
Physical Description: 1
Items(VHS videocassette: 45 minutes, 30
seconds)
Scope and Contents
A 45-minute film by producer and writer Michael Kardos. The film details the three
winters in the early 1930s when Albert Einstein and his wife, Elsa, lived in Pasadena,
during his visiting professorships at Caltech.
Photocopies and subject index Series 6
approximately 1989
Physical Description: 1 Linear
Feet (5 volumes)
Scope and Contents
Four binders of photocopies of photographs in the collection, arranged by sequential
numbers. Also, a binder containing a subject index to the photographs, created by
Huntington Library staff approximately late 1980s. There are 40 subjects, and then lists
of corresponding images, with captions and image numbers.
Volume 1
Photocopies of photographs
Physical Description: 1 Volume
Volume 2
Photocopies of photographs
Physical Description: 1
Volume
Volume 3
Photocopies of photographs
Physical Description: 1
Volume
Volume 4
Photocopies of photographs
Physical Description: 1
Volume
Volume 5
Subject index to photographs
Physical Description: 1
Volume
Scope and Contents
An index of 40 subjects and corresponding photographs in the collection. Photographs
are listed by number, description and date. The index was created by Huntington
Library staff shortly after the collection was received. Subjects include: various
sizes of telescopes, various buildings on Mount Wilson, clouds, eclipse expeditions,
scientific exhibits, brush fires around Mount Wilson, Mount Wilson Hotel and cottages,
scientific instruments, speed of light experiments, astronomers' residences on Mount
Wilson, Mount Wilson trail and toll road, and water reservoirs on Mount Wilson.
