Photo courtesy of Wisconsin Historical Society William A. Burt’s solar compass

EAGLE HARBOR — In 1834, while surveying and subdividing the layout of 13 townships in land that would one day become northern Wisconsin, says the Wisconsin Historical Society, government surveyor William Austin Burt of Michigan came to a key realization. High levels of iron ore in the region were disturbing Burt’s magnetic compass and garbling readings from the earth’s magnetic field, making it difficult to determine north-south survey lines.

After a year of experimentation, Burt devised a solution to this problem by inventing a solar compass that did not depend on magnetic readings.

The Keweenaw County Historical Society is hosting a presentation tonight titled “Adventures in History: How the Sun Compass was Critical to U.P. Mining.”

“Among the KCHS collections is an unassuming surveying instrument in a wooden box called a solar compass,” the announcement states. “Who was its inventor, William Burt, and how did he come to invent an instrument used to fulfill Thomas Jefferson’s dream of westward expansion? Learn how the solar compass relates to U.P. history. Join Mark Montgomery as he shares insights from his paper presented to the North American Sundial Society in December 2023.”

Burt was a United States government deputy surveyor whose work took him into wilderness areas largely unknown even to the fur trappers, according to Michigan State University. For more than 20 years he was one of a small group of men who ran the lines that divided the two peninsulas of Michigan into a checkerboard 0f townships and sections as prescribed by the Ordinance of 1785. Today almost all land titles and conveyances begin with the surveyors’ designations as to range and township.

The Detroit Historical Society says The solar compass became popular because it was a precise instrument that helped solve many issues that surveyors encountered while using magnetic compasses. The new invention earned Burt respect and national fame as a top surveyor. The compass was used in the Michigan Survey, to resurvey the boundary between Wisconsin and Michigan after a dispute arose regarding the border, and to survey the Upper Peninsula.

The Historical Society’s presentation will be held at 7 p.m. tonight at the Eagle Harbor Community Center. It open to the public and there is a $5 admission.