The listing, VINTAGE REPLICA OF COMPASS used on Lewis and Clark expedition has ended.
I don't know to what degree of accuracy but it definitely works. It's about 3x3 and built into a latching wood case. I like it because it's a pretty look into the history of technology (and of course history).
LEWIS AND CLARK - FROM WIKIPEDIA
The Lewis and Clark Expedition (1804–1806) was the first United States expedition to the Pacific Coast. Commissioned by President Thomas Jefferson and led by two Virginia-born veterans of Indian wars in the Ohio Valley, Meriwether Lewis and William Clark, the expedition had several goals. Their objects were both scientific and commercial – to study the area's plants, animal life, and geography, and to discover how the region could be exploited economically. According to Jefferson himself, one goal was to find a "direct & practicable water communication across this continent, for the purposes of commerce with Asia" (the Northwest Passage). Jefferson also placed special importance on declaring U.S. sovereignty over the Native American tribes along the Missouri River, and getting an accurate sense of the resources in the recently-completed Louisiana Purchase.They were accompanied by a fifteen-year-old Shoshone Indian woman, Sacagawea, the wife of a French-Canadian fur trader. After crossing the Rocky Mountains, the expedition reached the Pacific Ocean in the area of present-day Oregon (which lay beyond the nation's new boundaries) in November 1805. They returned in 1806, bringing with them an immense amount of information about the region as well as numerous plant and animal specimens...Although Lewis and Clark failed to find a commercial route to Asia ... their journey helped to strengthen the idea that United States territory was destined to reach all the way to the Pacific. Although the expedition did make notable achievements in science,[scientific research itself was not the main goal behind the mission.