Variation of the compass, 1773


Date: 1773 | Size: 1 item(s), 1 item, 7 p.


Written by William Alexander at Basking Ridge, New Jersey, March 27, 1773, this essay appeals to the American Philosophical Society to collect and publish astronomical observations. It was sent to the American Philosophical Society, where it was duly read in May 1773.

Background note

Earl of Stirling, William Alexander, was a prominent politician in colonial New Jersey who served as a general in the Continental Army. Alexander was born in New York City in 1726. He was the sole heir to the earldom of Stirling. He was born into wealth and further secured his standing amongst the elite of New York by marrying into the Livingston family.

He worked as a merchant for much of the colonial period. He provided supplies to William Shirley's Canadian offensive during the Seven Years' War. As a result, he received some of the blame for Shirley's failure. In 1757, he traveled to London, in part to clear his name.

He returned to the colonies in 1761 and served in a variety of political positions in New York and New Jersey. But with the outbreak of the Revolutionary War, he resigned all British appointments and served in a number of revolutionary organizations in New Jersey. He was put in charge of the New Jersey militia and eventually became a brigadier general in the Continental Army, serving under Washington, with whom he began a close friendship.

Collection Information

Physical description

1 manuscript item, 7 p.


Received, 1773 (47040). Provenance unknown.

Early American History Note

This slender volume is an essay by William Alexander, a prominent figure in New Jersey politics and business. Alexander wrote this essay with the hope that it would spur the American Philosophical Society to support the study of variations in compasses. Alexander's interest in this subject likely had to do with his background as a merchant. He realized compass variations created inefficiencies and risks for captains and the merchants that relied on them. Alexander appeals specifically to the APS's mission by stating that such a study would be "useful to mankind." Alexander's essays shows that he is conversant in many of the current theories about variations. He also proposed a plan for the APS to facilitate a systematic study of compass variations that he believed would produce a clear general law for variations in compasses.

Indexing Terms

Corporate Name(s)

  • American Philosophical Society


  • Scientific Correspondence
  • Scientific Data


  • Astronomy -- 18th century
  • Compass.
  • Learned institutions and societies.
  • Science and technology
  • Surveying and Maps
  • Trade