John Churchman, The Magnetic Atlas Map, (1790)
Known also by it’s more lengthy title: “An explanation of the magnetic atlas, or variation chart, hereunto annexed: projected on a plan entirely new, by which the magnetic variation on any part of the globe may be precisely determined for any time, past, present, or future: and the variation and latitude being accurately known, the longitude is of consequence truly determined.”
This map was drawn by John Churchman (1753-1805) and was originally printed in Philadelphia by James and Johnson in 1790. It is dedicated to George Washington, President of the United States at the time.
Churchman, an American, was devoted to the study, and his own theories, of magnetism. He believed that two bodies revolved around the Earth in circles parallel to the equator: one near the North Pole and one near the South Pole. These two bodies were magnetic and magnetic needles would always ‘rest in the plane of the circle.’ His theories and ideas were met with criticism from the learned world due to his status level as a commoner. However, men like George Washington and Thomas Jefferson supported his theories of magnetism. While on a voyage back to America from a scientific group in Europe, Churchman fell ill and died during the passage.
From the J. Welles Henderson Archives & Library at the Independence Seaport Museum. Follow us on Tumblr!