Background

Chandler was born on September 16, 1846, in Boston, Massachusetts, the son of Seth Carlo and Mary (née Cheever) Chandler.

Education

Chandler was educated at the English High School in Boston, graduating in 1861. During his last year in high school he performed mathematical computations for Benjamin Peirce, of the Harvard College Observatory.

Career

After graduation, in 1861, Chandler became private assistant to Benjamin Apthorp Gould and involved with the U.S. Coast Survey, which he joined in 1864. Rather than accompany Gould to Argentina, Chandler worked for many years as an actuary and did not resume his scientific activities until 1881. He then became associated with the Harvard College observatory, evolving with Ritchie the Science Observer Code (1881), a system for transmitting by telegraph information about newly discovered comets.

Chandler published many papers on comets and variable stars and compiled several useful catalogs of the latter objects. His most important contribution to science was the discovery of the variation of latitude. Soon after arriving at Harvard, Chandler devised the almucantar, an instrument by means of which one relates positions of stars not to the meridian but to a small circle centered at the zenith. In his discussion (1891) of observations made with this instrument during 1884-1885 he concluded that the latitude varied with amplitude 073 in a period of fourteen months. Observations made about the same time in Berlin by Kustner had shown a similar variation. From an exhaustive re-discussion of observations made as far back as Bradley’s time, Chandler was able to verify the fourteen-month period and to show that there was in addition a variation having a period of twelve months. His announcements met with considerable opposition, initially because Euler had shown that any variation would have a period often months; but as Newcomb pointed out, since the earth is not completely rigid, the period would be longer.

Chandler was editor of the Astronomical Journal from 1896 to 1909 and subsequently an associate editor.

Achievements

• Chandler best known for his discovery (1885) of the Chandler Wobble, a movement in Earth’s axis of rotation that causes latitude to vary with a period of about 433 days. His research on this spanned nearly three decades.
  
  He received the Watson Medal of the National Academy of Sciences (1895), and the Gold Medal of the Royal Astronomical Society (1896). The crater Chandler on the Moon is named after him.

Works

More photos

• book

  • The Science Observer Code

    (Excerpt from The Science Observer Code The principal uses...)

  • A Comparative Atlas And Graphical History Of American Life Insurance
  • Catalogue of Variable Stars

Connections

Father:

Seth Carlo

Mother:

Mary Cheever

colleague:

Benjamin Peirce

References

• Dictionary of Scientific Biography Volume 3
  1971
• The Biographical Encyclopedia of Astronomers This book is a unique and valuable resource for historians and astronomers alike. The two volumes include approximately 1550 biographical sketches on astronomers from antiquity to modern times.
  2009