"T. Whitney PHILADA"
4 inches square
This small compass was made by Thomas Whitney in Philadelphia, and owned by Capt. William Clark, one of the leaders of Corps of Discovery that set out from St. Louis in 1804 to explore the northwestern lands of the United States. It has a mahogany box, a brass rim that is graduated to degrees and numbered in quadrants from north and south, a paper dial, two small brass sight vanes, and a leather carrying case.