Blow Up!

Animation by BOBfx Digital Imaging
Production by David E. Nelson

By the time of the Lewis and Clark Expedition the flintlock firearm had been evolving over a period of 300 years. It was still literally manu-factured—hand made—and it was the most intricate mechanism an average person was apt to encounter during his lifetime, other than a clock. One more step remained—the interchangeability of parts.

The Parts of the Lock

The parts of a muzzle loader lock exploded with labels

In France in 1786 Thomas Jefferson saw that step being applied to the manufacture of locks for muskets. The "inventor," said Jefferson, "presented me the parts of 50 locks, taken to pieces, and arranged in compartments. I put several together, taking the pieces at hazard as they came to hand, and found them fit interchangeably in the most perfect manner."1

It seems certain that Lewis saw to it, in person, that this very principle was applied to the manufacture of the thirty locks he ordered at Harpers Ferry, for on March 20, 1806, he noted:

The guns of Drewyer and Sergt. Pryor were both out of order. the first was repared with a new lock, the old one having become unfit for uce; the second had the cock screw broken which was replaced by a duplicate which had been prepared for the lock at Harpers ferry where she was manufactured. but for the precaution taken in bring on those extra locks, and parts of locks, in addition to the ingenuity of John Shields, most of our guns would at this moment been untirely unfit for use; but fortunately for us I have it in my power here to record that they are all in good order.2

The principle of uniformity in firearm manufacture was officially adopted by the U.S. Government in 1815, but wasn't broadly applied until the 1840's.

1. Julian P. Boyd, ed., The Papers of Thomas Jefferson (9 vols., Princeton, New Jersey: Princeton University Press, 1954), Vol. 9, p. 214.

2. Elliott Coues substituted the words "broken tumbler" for Lewis's "cock screw broken." Coues may have surmised that the cock screw broke off at the face of the tumbler, which would have necessitated the replacement of the tumbler. See Elliott Coues, ed., The History of the Lewis and Clark Expedition . . . (4 vols, New York: Harper, 1893; Reprint, 3 vols, New York: Dover), 3:817.

Funded in part by a grant from the National Park Service Challenge Cost Share Program