Overview of the Collection
Scope and Content Note
Overview of the Collection
Title: Milton La Salle Humason Papers
Dates (inclusive): 1930-1952
Collection Number: mssHumason papers
Humason, Milton L. (Milton La
Approximately 2,100 items in 5 boxes.
The Huntington Library, Art Collections, and Botanical Gardens.
1151 Oxford Road
San Marino, California 91108
Phone: (626) 405-2129
Abstract: This collection consists primarily of the correspondence, dated 1948 to 1952, of Milton La Salle Humason (1891-1972),
a staff astronomer for the Mount Wilson [& Palomar] Observatories,
known chiefly for his collaboration with Edwin P. Hubble in the field of observational cosmology. There are occasional personal
letters but these are few compared to the correspondence with the public, received and answered by Humason in his capacity
as Secretary of the Observatory.
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.
There is no evidence that Humason passed on his literary rights to anyone. The Carnegie
Observatories, as part of the 1987 letter of agreement, have given the Huntington Library
the right to provide permission to publish from the papers.
[Identification of item]. Milton La Salle Humason Papers, The Huntington Library, San
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 Huntington Library.
Cataloging of the papers was completed in 1989 prior to their transfer to the Huntington.
Milton La Salle (his middle name has also been cited as Lasell) Humason was a staff
astronomer for the Mount Wilson [& Palomar] Observatories throughout his entire
astronomical career. Humason is remembered chiefly for his collaboration with Edwin P.
Hubble in the field of observational cosmology. Perhaps his most notable accomplishment,
however, was his rise from mule-driver and janitor at Mt. Wilson to the position of
astronomer with the lack of a high-school education.
Humason was born on August 19, 1891, in Dodge Center, Minnesota. His family moved to
California, and in the summer of 1905 he was taken to a summer camp on Mt. Wilson. At this
time, the Mt. Wilson Observatory was not yet a year old, and there was a good deal of
activity by the solar astronomers on the mountain top. Humason involved himself in this
activity by quickly dropping out of high school in the fall of 1905 and within a few years
becoming a mule driver. He would lead mule-powered wagons up the Mt. Wilson Toll Road
carrying timber, iron, and other supplies for the construction of the telescopes and support
buildings at the Observatory. It was as a mule driver that Humason met Helen Dowd, daughter
of the Observatory's engineer, Merritt C. "Jerry" Dowd, in 1910. They
married one year later.
In 1910, Humason left mountain work and got a job as a foreman on a relative's ranch in La
Verne, California. In 1917, however, Jerry Dowd told Humason that a janitor's job would be
opening soon at Mt. Wilson Observatory. Knowing that the janitor's position at the
Observatory could eventually involve duties such as relief night assistant on the
telescopes, Humason took the offer. With the new 100-inch Hooker Telescope going into
operation at the Observatory in 1919 and the need for more night assistants, Humason soon
got to work with the telescopes. At about the same time, Hugo Benioff, a volunteer assistant
at Mt. Wilson from Pomona College, showed Humason how to take photographic plates with the
10-inch astrographic camera on the mountain. Humason became so adept at this that Benioff
soon recommended that Humason carry on the former's work in the fall. As Humason gained
experience he also started taking plates for Harlow Shapley's observing program. And Humason
used the 10-inch to look for W. H. Pickering's proposed Planet X in 1919. When Pluto was
discovered in 1930, Seth Nicholson and Nicholas Mayall examined Humason's early plates and
found that Pluto had been recorded on the photographs. Unfortunately for Humason, Pluto was
so near the edge of the plates, and the images there were of such bad quality, that it is
not surprising that Pluto was not discovered then. Humason's abilities with the telescopes
on Mt. Wilson were so admired that by 1920 he was promoted from janitor to the staff of the
Observatory's Stellar and Nebular Division. Humason continued his work with the 10-inch,
observing clusters like M22 and also watching the Andromeda Nebula (M31) for novae. As Edwin
Hubble's work on the spiral nebulae showed them to be distant galaxies, he initiated in the
late 1920s a program of systematic observation of nebular redshifts. Obtaining usable
spectra of the extragalactic nebulae, with their low surface brightness, would require the
utmost expertise in observing skill. For this reason, it is not surprising that Humason was
chosen to be Hubble's colleague. Humason developed and refined the techniques required to
take exposures of up to forty hours (over several nights) with the 100-inch telescope. From
the beginning of the redshift program until his retirement in 1957, Humason photographed
spectra of approximately 600 galaxies. He used the 100-inch telescope to obtain these until
the 200-inch Hale Telescope became available in 1949. During this time, Humason also applied
his observing skill to projects on supernovae, old novae, and faint blue stars.
On October 1, 1948, Humason was appointed Secretary of the Observatory upon Alfred H. Joy's
retirement. The duties of the Secretary involved handling the Observatory's public
relations. This meant reading and often answering the various letters from the general
public. The letters ranged from questions from high school students to requests for
photographs to oddball theories of the universe. A colleague of
Humason's, Robert S. Richardson, described the job: "It was not an easy job by any means. One
of his most onerous duties was answering the numerous phone calls and crank letters that
came into the observatory. You have no idea of the number of people who seem to have nothing
better to do than worry about whether the moon is in its orbit, or in denouncing such
impostors as Newton and Einstein, and their wholly erroneous theories of gravitation (in
contrast to their own entirely new rational theory). If you answer a letter of this kind,
trying to explain the fallacy in their reasoning, you immediately get another one back
demanding more information. Humason's policy was to answer every such letter once, but a
second time --no. If you conscientiously answered them all, you would soon find that instead
of working for the observatory in Pasadena, California, you were spending most of your time
working for some victim of delusional insanity in Pasadena, Newfoundland." Humason remained as Secretary
until his retirement in 1957.
Humason never earned a degree until, in 1950, an honorary doctorate was conferred on him by
the University of Lund in Sweden. He retired on July 1, 1957, and soon moved to Mendocino,
California. While in retirement he was occasionally consulted by the astronomers at the
Observatory on questions dealing with the telescopes, especially the 100-inch. He died at
his home on June 18, 1972.
Scope and Content Note
This collection consists primarily of the correspondence of Milton La Salle Humason, a staff astronomer for the Mount Wilson
[& Palomar] Observatories.
There are occasional personal and scientific
letters but these are very few compared to the letters from the public. The correspondence covers the years 1930-1952 (bulk
1948-1952). It contains both
incoming and carbons of outgoing correspondence. The collections also includes a few press
releases, newsletters, one manuscript in German, some ephemera, several black-and-white
photographs and two black-and-white slides.
Notable participants include: Ansel Adams,
Robert Aitken, Loyal Aldrich, Lawrence Aller, C. T. Elvey, G. F. Fassett, George Gamow,
Cecilia Gaposchkin, Warren K. Green, John C. Hogg, Edwin Powell Hubble, Wilhelminia
Iwanowska, Martin Johnson, H. Spencer Jones, Egbert A. Kreiken, Wasley Krogdahl, Oliver
Justin Lee, J. H. Moore, Thornton Page, Upton Sinclair, William T. Skilling, Harold C. Urey,
H. L. Vanderlinden, Edwin Wald, Fletcher G. Watson, Frederick Weiss, Astronomy charted,
Boston Museum of Science, California Institute of Technology, Carnegie Institution of
Washington, Drake University, Grolier Society, Harvard College Observatory, Jet Propulsion
Laboratory, Los Angeles Astronomical Society, Physics today, Popular astronomy, Popular
mechanics, Science illustrated, and Scientific American (this is only a partial list).
The Humason papers have been arranged, with only minor changes, according to the manner in
which they had been found in the attic of the Carnegie Observatories. They are broken into
six chronological groups, arranged in the boxes as follows:
- Box 1: 1930-1947, 1948
- Box 2: 1949
- Box 3: 1950
- Box 4: 1951
- Box 5: 1952
Within each chronological group, the correspondence is arranged in alphabetical order by
Humason, Milton L. (Milton La
Jones, H. Spencer (Harold
Mount Wilson and Palomar
Observatories -- History -- Sources.
Mount Wilson Observatory --
History -- Sources.
Astronomers -- Correspondence.
Astronomical observatories -- California --
Wilson, Mount (Mountain)
Astronomy -- 20th century.
Black-and-white photographs -- 20th
Black-and-white slides -- United States --
Ephemera -- United States -- 20th
Letters (correspondence) -- United States --
Manuscripts -- Germany -- 20th
Newsletters -- United States -- 20th
Press releases -- United States -- 20th
Adams, Ansel, 1902-1984.
Aitken, Robert Grant, 1864-1951.
Aldrich, Loyal Blaine, 1884-1965.
Aller, Lawrence H. (Lawrence Hugh),
Elvey, C. T. (Christian Thomas),
Fassett, F. G. (Frederick Gardiner),
Gamow, George, 1904-1968.
Green, Warren K. (Warren Kimball),
Hogg, John C.
Hubble, Edwin, 1889-1953.
Iwanowska, Wilhelminia, 1905-1999.
Johnson, Martin, 1896-1983.
Kreiken, Egbert A.
Krogdahl, Wasley Sven, 1919-2009.
Lee, Oliver Justin, 1881-1964.
Moore, J. H. (Joseph Haines),
Sinclair, Upton, 1878-1968.
Skilling, William T. (William Thompson),
Urey, Harold Clayton, 1893-1981.
Vanderlinden, H. L. (Henri Louis),
Watson, Fletcher G. (Fletcher
Weiss, Frederick U.
Boston Museum of Science.
California Institute of Technology.
Carnegie Institution of Washington.
Harvard College Observatory.
Jet Propulsion Laboratory (U.S.)
Los Angeles Astronomical Society.
Popular Mechanics Press.
Scientific American, inc.