 Well, what's fascinating is that Whitney, who is iconically associated with the practical application of interchangeable parts, didn't talk about them until he was in trouble. In fact, he didn't mention interchangeable parts when he got his contract, but 10 months into the contract, Treasury Secretary Oliver Wolcott Jr. sent him a, quote, foreign pamphlet on arms manufacturing techniques, and after that, he started talking about interchangeability.