John Lewis Tiarks

John Lewis Tiarks, FRS (born Johann Ludwig Tiarks, 10 May 1789 – 1 May 1837), Johann Ludwig Tiarks, was a German mathematician who became the British astronomer to the North American Boundary Line Commission.

Early life He was born in Waddewarden, Wangerland, Friesland, Lower Saxony on 10 May 1789. His father was Reverend Johann Gerhard Tiarks and his mother was Christine Dorothea Ehrentraut. In 1825 Tiarks was elected a Fellow of the Royal Society as "a person well versed in mathematics and nautical astronomy".

Second visit to North America

He returned to North America in 1825 to determine the northwestermost point of the Lake of the Woods, from which the boundary was supposed to run due west to the Mississippi River.

From 1826 to 1830 he worked on matters of concern to the boundary commission. He was called to The Hague to explain certain points to William II of the Netherlands, who had been asked to arbitrate the boundary question. Tiarks returned to Jeven.

Personal life In 1822 he married Auguste Antoinette Sophie Toel of Jever. They had several children, but only one daughter survived to adulthood.

Final years and death He long wished to be a professor in a German university, but no position ever became available. In March 1837 he suffered from a stroke from which he never recovered.

The Webster–Ashburton Treaty, which settled the boundary disputes in question, was signed in 1842.