Stephen Alexander (September 1, 1806 – June 25, 1883) was an American

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

and educator.

Early years

He was born in

Schenectady, New York Schenectady ( ) is a City (New York), city in Schenectady County, New York, United States, of which it is the county seat. As of the United States Census 2020, 2020 census, the city's population of 67,047 made it the state's ninth-most populo ...

, on September 1, 1806. He was the brother-in-law of

Joseph Henry Joseph Henry (December 17, 1797– May 13, 1878) was an American physicist and inventor who served as the first secretary of the Smithsonian Institution. He was the secretary for the National Institute for the Promotion of Science, a precursor ...

, the first secretary of the Smithsonian, and worked closely with him. His education was obtained at

Union College Union College is a Private university, private liberal arts college in Schenectady, New York, United States. Founded in 1795, it was the first institution of higher learning chartered by the New York State Board of Regents, and second in the s ...

, where he graduated in 1824, and at

Princeton Theological Seminary Princeton Theological Seminary (PTSem), officially The Theological Seminary of the Presbyterian Church, is a Private university, private seminary, school of theology in Princeton, New Jersey, Princeton, in the U.S. state of New Jersey. Establish ...

, where he graduated in 1832.

Career

He became a tutor in mathematics at

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

in 1832; he would later become professor of astronomy and mathematics and advocate for the construction of Princeton's first observatory. Alexander relied on the assistance of a free African American man named Alfred Scudder, who worked for him at Princeton during the 1850s. Because of his role as Alexander's assistant on campus, Scudder received the nickname "Assistant Professor of Natural Philosophy" from students. Alexander was elected a member of the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

in 1839 and an Associate Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

in 1850. In 1860, he was the head of an expedition to the coast of

Labrador Labrador () is a geographic and cultural region within the Canadian province of Newfoundland and Labrador. It is the primarily continental portion of the province and constitutes 71% of the province's area but is home to only 6% of its populatio ...

to observe the

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season i ...

which occurred July 18 of that year, and later to observe the one of 1869. He was one of the original members of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

in 1862, and a member of the

, and the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsib ...

. He also served as the president of this last organization in 1859. His principal writings are "Physical Phenomena attendant upon Solar Eclipses", read before the American Philosophical Society in 1848; a paper on the "Fundamental Principles of Mathematics," read before the American Association for the Advancement of Science in 1848; another on the "Origin of the Forms and the Present Condition of some of the Clusters of Stars and several of the Nebulae", read before the American Association in 1850; others on the "Form and Equatorial Diameter of the Asteroid Planets" and "Harmonies in the Arrangement of the Solar System which seem to be Confirmatory of the Nebular Hypothesis of Laplace", presented to the National Academy of Science; and a "Statement and Exposition of Certain Harmonies of the Solar System", which was published by the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...

in 1875.

Works

Among many noteworthy astronomical papers he published: * ''Fundamental Principles of Mathematics'' * ''Statement and Exposition of Certain Harmonies of the Solar System''

References

Citations

Sources

* * * * * * **

External links

National Academy of Sciences Biographical MemoirPrinceton Faculty Biography
{{DEFAULTSORT:Alexander, Stephen (astronomer) 1806 births 1883 deaths 19th-century American astronomers Fellows of the American Academy of Arts and Sciences Scientists from Schenectady, New York Princeton University faculty Union College (New York) alumni Members of the United States National Academy of Sciences Smithsonian Institution people Members of the American Philosophical Society Presidents of the American Association for the Advancement of Science