In Chapter 2, p. 56, 'D. M. Smith's Bank Lock,' there is reference to Smith's patent as 'footnote #27.' In the Notes section, on p. 347, however, the patent citation is found in 'footnote #26' as US6878 issued to 3 April 1849. That patent number, however, is not for a lock but rather for an 'ox-yoke.' Assuming that the given publication date was correct I did locate the Smith patent as US6272. How 6272 became 6878 is a puzzle as it can hardly be attributed to mistyping as the numbers involved on the typical QWERTY keyboard are quite separate. It & the misnumbered footnote appear to be just the inevitable products of sloppy proofreading while this book was being finalized for publication.

In a bit of serendipity I happened upon another bank lock patent issued on the same date: US6252 to Ritchie. This patent is mentioned in "American Genius' on page 68 as 'footnote 48' (p. 347) but with the inventor's name misspelled as 'Ritchey.'

Jack