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Mount Wilson Observatory Optical Shop Papers: Finding Aid
mssMount Wilson optical shop
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Title: Mount Wilson Observatory Optical Shop
Papers
Dates (inclusive): 1911-1966
Bulk dates: 1930-1947
Collection Number: mssMount Wilson optical shop
Creator:
Mount Wilson Observatory
Optical Shop.
Extent:
931 items in 8 boxes
Repository:
The Huntington Library, Art Collections, and Botanical Gardens.
Manuscripts Department
1151 Oxford Road
San Marino, California 91108
Phone: (626) 405-2129
Email: reference@huntington.org
URL: http://www.huntington.org
Abstract: This collection contains records of the Mount Wilson Observatory Optical Shop, relating to the operation of the department
from 1911 to 1963 (bulk 1930-1947).
The department was responsible for repairing and maintaining the Observatory's telescopes, as well as for observatories around
the United States. The materials
include research and procedural notes,
correspondence, inventories and requisition slips, and job lists and employee time
sheets.
Language:
English.
Open to qualified researchers by prior application through the Reader Services
Department. For more information, contact Reader Services.
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 responsibility for identifying the copyright holder, if there is
one, and obtaining necessary permissions rests with the researcher.
[Identification of item]. Mount Wilson Observatory Optical Shop Papers, The
Huntington Library, San Marino, California.
Deposit, Observatories of the Carnegie Institution of Washington Collection,
1988. Approximately fifty additional separate collections form the Mount Wilson Papers of
the Observatories of the Carnegie Institution of Washington and are available for
research in the Manuscripts Department of the Huntington Library.
Founded in December 1904 by George Ellery Hale and funded by the Carnegie
Institution, the Mount Wilson Observatory quickly became one of the 20th century’s
major astronomical research centers. Located just north of Los Angeles high atop the
San Gabriel Mountains, the observatory took full advantage of Southern California’s
clear nights and uniquely steady air. The observatory’s 60’’ telescope completed in
1908 was the largest then in existence. In 1917, another Mount Wilson telescope,
100’’ in diameter, claimed that title. The Optical Shop was the department
responsible for repairing and maintaining these telescopes. Optical Shop workers
ground and polished mirrors, lenses, and prisms: tasks requiring meticulous
precision and technique. In addition to serving Mount Wilson, the Optical Shop
produced optical instruments for observatories across the country.
During the Second World War, the Mount Wilson Observatory Optical Shop played an
important role in U.S. war effort. Shop technicians produced roof prisms for
military optics on a large scale, eventually publishing an instruction manual for
other optical workshops. Experiments with newly-invented Schmidt cameras helped
develop the field of aerial photography. New camera shutters and film sweep
mechanisms were invented. Procedures for measuring lens resolution were tested.
The Mount Wilson Observatory Optical Shop Papers comprise 8 boxes of material
relating to the operation of the department from 1911 to 1963 (bulk 1930-1947). This
material is divided into four general categories: research and procedural notes,
correspondence, inventories and requisition slips, and job lists and employee time
sheets. Each group is arranged chronologically. Various scientific manuals,
brochures, and unidentified notes have been gathered into a folder of ephemera.
Shop notebooks form the bulk of the research material. These notebooks outline
various procedures for grinding and polishing mirrors, drilling glass, and
configuring lenses. Several notebooks track the construction of the observatory’s
100’’ Hooker telescope as well as the 200’’ Hale telescope housed at the California
Institute of Technology’s Palomar Observatory. Declassified research on aerial
photography for the National Defense Research Committee is included in several
progress reports.
The majority of correspondence is between Optical Shop technicians and astronomers
both at Mount Wilson and elsewhere around the country. These letters are generally
technical in nature with the various interlocutors trying to solve specific optical
problems. Several manufacturing firms solicit the Optical Shop personnel about their
products. Walter S. Adams and Don O. Hendrix participate in the bulk of the
correspondence. Included is Hendrix’s signed “Pledge of Secrecy” and commission from
the Office of Scientific Research and Development. Inventory notebooks detail the
supplies used in the Optical Shop: everything from towels and paper goods to slabs
of optical glass and chemical solvents. Lists of lenses, mirrors, and prisms record
material in stock and material lent out to other institutions. Requisition slips and
shipping invoices illustrate the broad network of suppliers the shop needed for
their highly specialized work.
A number of notebooks chart the myriad jobs the Optical Shop performed for both the
Mount Wilson Observatory and other institutions. These notebooks assign each job a
number, outline the work, and list the employees working on it. Separate employee
time charts are also included with address and contact information for each.
Notable participants include: Walter S. Adams, who succeeded Hale as director of the
observatory, Don O. Hendrix, the Shop's chief optician and Ira Sprague Bowen,
Bannevar Bush, Robert E. Hopkins, Brian O'Brien, Frank E. Ross, and Jet Propulsion
Laboratory.
Note: Two inventory notebooks have been treated for mold and are held separate from the main collection. Please contact Reader
Services for access to these notebooks.
Arranged in 8 boxes in the following order:
- Boxes 1-2: Research and Procedure Notes
- Box 3: Correspondence
- Boxes 4-6: Shop Inventories, Invoices, and Requisition Slips
- Boxes 7-8: Job Lists and Time Charts and Ephemera
Adams, Walter S. (Walter Sydney), 1876-1956.
- Addressee of Frank E. (Frank Elmore) Ross, 1874-1960 letter (1936, May 30). Box 3 (1).
- Addressee of B.H. Witherspoon letters (1941, July-1941, Aug.). Box 3 (5). Addressee of Benjamin Liebowitz letter (1945, Dec. 10). Box 3 (29).
Bowen, Ira Sprague, 1898-1973.
- Addressee of Jet Propulsion Laboratory (U.S.) letter (1949, Nov. 22). Box 3 (40).
The following terms have been used to index the description of this collection in the
Huntington Library's Online Catalog.
Carnegie Institution of
Washington.
Mount Wilson and
Palomar Observatories.
Mount Wilson
Observatory -- History -- Sources.
Mount Wilson
Observatory Optical Shop.
Office of Scientific
Research and Development.
Astronomers -- United States --
Correspondence.
Astronomical observatories --
California -- Wilson, Mount (Mountain)
Astronomical photography -- Equipment
and supplies.
Astronomy -- United States -- History
-- 20th century -- Sources.
Astrophysics -- History -- 20th century
-- Sources.
Telescopes -- Design and construction
-- History -- Sources.
Inventories -- California -- 20th
century.
Letters (correspondence) -- United
States -- 20th century.
Notebooks -- California -- 20th
century.
Time sheets -- California -- 20th
century.
Adams, Walter S. (Walter Sydney),
1876-1956.
Bowen, Ira Sprague, 1898-1973,
recipient.
Bush, Vannevar, 1890-1974.
Hendrix, Don O.
Hopkins, Robert E. (Robert Earl)
O'Brien, Brian, 1898-1992.
Ross, Frank E. (Frank Elmore),
1874-1960.
Jet Propulsion Laboratory (U.S.)
Mount Wilson Observatory.