Harold Spencer Jones

Harold Spencer Jones


Date of Birth
March 29, 1890
Date of Death
November 3, 1960

A mathematical prodigy, Harold Spencer Jones won scholarshipts that led him to the University of Cambridge, where he received his master's degree in 1913. After that, he was successively astronomical assistant at the Royal Observatory, Greenwich, His Majesty’'s Astronomer at the Cape of Good Hope, and, from 1933 to 1955, director of the Royal Observatory and Astronomer Royal. His work was devoted to fundamental positional astronomy. At the Cape he worked on proper motions and parallaxes and the publication of catalogues, as well as a thorough study of the changing spectra of a nova. He also led a program of determination of stellar distances by determining parallaxes from photographs. Later he showed that small residuals in the apparent motions of the planets are due to the irregular rotation of the earth. He led the worldwide effort to determine the distance to the sun by triangulating the distance of the asteroid Eros when it passed near the earth in 1930-31: he photographed Eros more than 1200 times and reduced the data from other observers. He worked on all aspects of timekeeping and showed that the Earth’s rotation period was no longer adequate as a precise clock. After World War II he supervised the move of the Royal Observatory to Herstmonceux, where it was renamed the Royal Greenwich Observatory. Note: Some sources list his surname as Jones. He preferred Spencer Jones.

Presentation of Bruce medal

Bowen, Ira S., PASP 61, 61 (1949).

Other awards

Royal Astronomical Society, Gold medal, 1943, presented by S. Chapman, MNRAS 103, 116-17 (1943).
Royal Society of London, Royal medal, 1943.

Some offices held

International Astronomical Union, President, 1943-48.
Royal Astronomical Society, President, 1937-39.
United Kingdom, Astronomer Royal, 1933-55.

Biographical materials

Anonymous, “Sir Harold Spencer Jones,” Popular Astronomy 53, 503-06 (1945).
Cambridge University Libraries, Biography accompanying papers.
Jackson, J., “Sir Harold Spencer Jones, K.B.E.,” Observatory 76, 15-16 (1956) [on his retirement].
Kopal, Zdenek, Dictionary of Scientific Biography 12, 573-74.
Oxbury, H.F., Great Britons: Twentieth-Century Lives (Oxford Univ. Press, Oxford, UK, 1955)
Ronan, Colin A., Their Majesties’ Astronomers (Bodley Head, London, 1967).
Snedegar, Keith, Biographical Encyclopedia of Astronomers, 2nd ed. (Springer, NY, 2014), pp. 2036-38.
Wooley, R.v.d.R., Biographical Memoirs of the Royal Society 7, 136-45 (1961).


Anonymous, Monthly Notes of the Astron. Soc. Southern Africa 19, 146-149 (1960).
Jackson, J., Observatory75, 15-16 (1956).
Sadler, D.H., QJRAS 4, 113-25
Smart, W.M., JRASC 55, 117-19 (1961).


Caltech Archives
Christmas Island postage stamp
Encyclopedia Brittanica

Named after him

Lunar crater Spencer Jones
Martian crater Jones
Minor planet #3282 Spencer Jones
The Spencer Jones Group of Meridian Instruments at Herstmonceux (now closed)


Papers, etc.

Papers are in the Royal Greenwich Observatory Archives at the Cambridge University Library.

Other References: Historical

Broughton, R.P., “The Speeches of Spencer Jones,” Observatory 104, 273-74 (1984) [Letter to the editor].

Forbes, Eric G., A.J. Meadows, &Derek Howse, Greenwich Observatory: The Royal Observatory at Geenwich and Herstmonceux, 1675-1975 (Taylor &Francis, London, 1975).

Howse, Derek, “The Astronomers Royal and the Problem of Longitude,” Antiquarian Horology 21, 43-51 (Autumn 1993).

Hoyle, Fred, Home is Where the Wind Blows: Chapters from a Cosmologist’s Life (University Science Books, 1994).

Johnson, Peter Jeffrey, The History of the Royal Observatory and Royal Greenwich Observatory (Royal Greenwich Observatory, Herstmonceux, 1987).

Lovell, Sir Bernard, “The Royal Society, the Royal Greenwich Observatory and the Astronomer Royal,” Royal Society of London Notes and Records 48, 283-297 (1994).

Meadows, A.J., Greenwich Observatory: The Royal Observatory at Greenwich and Herstmonceux, 1675-1975, vol. 2: Recent History (1936-1975) (Taylor &Francis, London, 1975).

Parker, Chas, “Castle in the Sky — The Story of the Royal Greenwich Observatory at Herstmonceux”

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Other References: Scientific

Spencer Jones, Harold, “Determination of the Elements of the Moon’s Orbit, the Parallactic Inequality and the Moon's Semidiameter from Occultations of Stars by the Moon Observed at the Royal Observatory, Cape of Good Hope, in the years 1880 to 1922,” Annals of the Cape Observatory 8, 8.1-8.47 (1909).

Jones, H.S., “Note on the Reduction of Latitude Variation Observations,” MNRAS 80, 157-62 (1919).

Jones, H.Spencer, “The Moon’s Mean Longitude, Longitudes of Perigee and Node, Semidiameter and Parallactic Inequality Derived from Occultations of Stars Observed at the Royal Observatory, Cape of Good Hope, 1880-1922,” MNRAS 85, 11-35 (1924).

Spencer Jones, H., “Determination of the Solar Parallax from Observations of Mars Secured by the Royal Observatory, Cape of Good Hope, near the Opposition of 1924. I. Photographic Observations. MNRAS 85, 832-44 (1925). II. Heliometer Observations,” MNRAS 85, 845-53 (1925).

Spencer Jones, Harold, Proper Motions of Stars Contained in the Cape Fundamental Catalogues of 1846 Stars for the Equinox 1900 (H. M. Stationery Off., London, 1925).

Spencer Jones, H., “Note on the Secular Motion of the Pole,” MNRAS 86, 338-41 (1926).

Spencer Jones, H., “The Rotation of the Earth,” MNRAS 87, 4-31 (1926).

Spencer Jones, Harold, Catalogue of 4569 Stars from Observations with the Reversible Transit Circle Made at the Royal Observatory (H. M. Stationery Off., London, 1928).

Spencer Jones, H. & J.W. Jackson, “Observations of Eros at the Opposition 1930-31,” MNRAS 90, 190-98 (1929).

Spencer Jones, H., “Observations of (433) Eros at the Opposition 1930-31,” Astronomical Journal 40, 117-19 (1930).

Spencer Jones, Harold, “Discussion of Observations of Occultations of Stars by the Moon, 1672-1908, Being a Revision of Newcomb’s “Researches on the Motion of the Moon, part II”,” Annals of the Cape Observatory 13, pt. 3 (H.M. Stationery Off., London, 1932).

Spencer Jones, H., “The Mean Motions of the Lunar Perigee and Node and the Figure of the Moon” MNRAS 97, 406-09 (1937).

Spencer Jones, H., “The Determination of the Constant of Nutation from the Greenwich Latitude Variation Observations” MNRAS 98, 440-47 (1938) and 99, 211 (1939).

Spencer Jones, Harold, The Earth as a Clock, Being the Halley Lecture Delivered on 5 June 1939 (Clarendon Press, Oxford, UK, 1939).Spencer Jones, H., “The Rotation of the Earth, and the Secular Accelerations of the Sun, Moon and Planets,” MNRAS 99, 541-58 (1939).

Spencer Jones, H. & J. Jackson, Catalogue of 20554 Faint Stars in the Cape Astrographic Zone –40 deg. to –52 deg. For the Equinox of 1900.0 Giving Positions, Precessions, Proper Motions and Photographic Magnitudes (Her Majesty's Stationary Office, London, 1939).

Spencer Jones, Harold, Discussion of Observations of Occultations of Stars by the Moon, 1672-1908, Being a Revision of Newcomb’s “Researches on the Motion of the Moon, part II” (H. M. Stationery Off., London, 1932).

Spencer Jones, Harold, Stellar Parallaxes (1st series) Determined in the Years 1926-1930, (H. M. Stationery Off., London, 1935).

Spencer Jones, Harold, “The Solar Parallax and the Mass of the Moon from Observations of Eros at the Opposition of 1931,” Memoirs Royal Astron. Soc. 76, pt. 2, 11-66 (1941).

Spencer Jones, Harold, “The Solar Parallax: A Coordinated International Measure of a Fundamental Constant,” Observatory 64, 99-104 (1941) [reprinted in Shapley, Harlow, ed., Source Book in Astronomy 1900-1950 (Harvard Univ. Press, Cambridge, MA, 1960), 88-92.

Spencer Jones, Harold, “Dimensions and Rotation,” in Gerald P. Kuiper, ed., The Earth as a Planet (University of Chicago Press, Chicago, 1954), 1-41.

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Other Works: Popularizations, Fiction, Texts, etc.

Spencer Jones, H., General Astronomy (E. Arnold &Co., London, 1922, 1934, 1951).

Spencer Jones, H., Worlds without End (English Universities Press, London; Macmillan, NY, 1935).

Spencer Jones, Sir Harold, The Royal Observatory Greenwich (Longman Green &Co., London, 1943, 1944, 1946).

Spencer Jones, Harold, “Greenwich Sets the World’s Time, ” Popular Astronomy 52, 399-402 (1944).

Barlow, Crossley William Crosby, George Hartley Bryan, & Harold Spencer Jones, Elementary Mathematical Astronomy (University Tutorial Press Ltd., London, 1944).

“Isaac Newton Observatory: Memoranda Addressed to the President and Council of the Royal Society” MNRAS 107, 11-19 (1947).

Spencer Jones, H. John Couch Adams and the Discovery of Neptune (Cambridge Univ. Press, Cambridge, UK, 1947).

Spencer Jones, Harold, “The Development of Navigation,” Pop. Astr. 56, 263-66 (1948).

Spencer Jones, Harold, “The New Royal Greenwich Observatory at Herstmonceux,” Pop. Astr. 58, 479-82 (1950).