This poster produced by the US Army Corps of Engineers describes a fascinating and once-mysterious piece of American history: the Lewis & Clark Air Rifle. Known as "A Great Curiosity," this weapon was a high-tech marvel of the early 19th century and played a crucial role in the success of the Corps of Discovery.

The "Great Medicine" Gun

The air rifle was one of Meriwether Lewis’s most prized possessions. He used it as a diplomatic tool, demonstrating it to nearly every Native American tribe they encountered. Because it could fire multiple shots rapidly without smoke, fire, or loud noise, many tribes found it "perfectly incomprehensible" and referred to it as "Great Medicine." This display of advanced technology often served as a deterrent against potential conflict.

Key Technical Specifications

The rifle was far more advanced than the standard flintlocks of the time:

* Action: A repeating air rifle capable of firing 22 shots in under a minute.

* Caliber: It fired .46 caliber lead balls.

* Power Source: A detachable, leather-wrapped iron buttstock served as the air reservoir, pressurized to approximately 800 psi.

* The Pump: Recharging the reservoir was labor-intensive, requiring roughly 1,500 strokes of a hand pump (about 15-20 minutes of work).

* Velocity: It could propel a ball at about 600 feet per second, enough to take down a deer or penetrate a one-inch pine board at 100 yards.

The Historical Mystery: Lukens vs. Girardoni

For over 150 years, historians debated which specific rifle Lewis carried.

* The Lukens Theory: For a long time, it was believed to be a custom rifle made by Philadelphia clockmaker Isaiah Lukens. An inventory of Lukens' estate in 1847 even listed "one large air gun made for and used by Messrs. Lewis and Clark."

* The Girardoni Discovery: Modern scholarship (pioneered by Dr. Robert Beeman and Michael Carrick) has concluded the rifle was actually a Girardoni-style repeating air rifle. The deciding evidence came from eyewitness accounts (like those of Thomas Rodney) describing a 22-shot repeater—a feature the Lukens single-shot models lacked.

Measures 24” x 36”.

The poster is printed on heavy stock glossy paper. It will be rolled and mailed in a tube.