The Lewis & Clark air gun ... and a dangerous demonstration

As Meriwether Lewis prepared for his early 19th century trip with William Clark to explore what is today is the American Northwest, he bought an air gun – a rifle that used compressed air, stored in its stock, to shoot a large, .46 caliber lead ball about as well as any other gun of the day. Each air gun held about 22 of these balls in a magazine attached to the gun, which could be much more rapidly fired (the entire magazine in about a minute) than any muzzle-loader. The downside is that it took about 1,500 strokes of a small air pump, similar to today’s bicycle pump, to fully pressurize the gun at 600 to 800 pounds per square inch. Also, the effectiveness of the gun dropped as pressure was lost with each shot.


The Girandoni air gun.
(Photo courtesy of the U.S. Army)

Lewis enjoyed demonstrating the gun, and one of the first entries in his account of the expedition mentions an incident that could have been an ominous beginning for the trip. After Lewis demonstrated the gun to some “gentlemen” on August 30, 1830, he allowed them to inspect it. It discharged, with the ball from it striking a woman bystander, as told in Lewis’ own words (and with his own punctuation and spelling):

“Left Pittsburgh this day at 11ock with a party of 11 hands 7 of which are soldiers, a pilot and three young men on trial they having proposed to go with me throughout the voyage.  Arrived at Bruno's Island 3 miles below halted a few minutes.   went on shore and being invited on by some of the gentlemen present to try my airgun which I had purchased brought it on shore charged it and fired myself seven times fifty five yards with pretty good success; after which a Mr. Blaze Cenas being unacquainted with the management of the gun suffered her [referring to the gun] to discharge herself [again, referring to the gun] accedentaly  the ball passed through the hat of a woman about 40 yards distanc cuting her temple about the fourth of the diameter of the ball; shee fell instantly and the blood gusing from her temple  we were all in the greatest consternation  supposed she was dead by [but] in a minute she revived to our enespressable satisfaction, and by examination we found the wound by no means mortal or even dangerous; …”  

During the rest of the expedition to the West Coast, when Lewis and Clark encountered new groups of Indians, they reported demonstrating the rapid fire of the air gun. Many people who have studied the Lewis and Clark expedition believe that these demonstrations of firepower suggested that the expedition was more formidable that it was, helping ensure its continued well-being as it traveled through lands occupied only by Indians.

Based on a written description of the gun by a “gentleman” who saw it demonstrated by Lewis a few days after the unfortunate shooting of the bystander described by Lewis above, it was almost certainly a design developed earlier by G.C. Girandoni in Europe, and adopted for use in the Austrian army from the late 1700s until the early 1800s.