David Tucker’s post below reminded me to bring Jason Emerson’s book, "Lincoln the Inventor" to your attention. Emerson’s essay is only about 50 pages, and then he reprints Lincoln’s patent for floating grounded riverboats (the only president to have a patent), and then his Two Lectures on Discoveries and Inventions (which are hardly ever referenced). The First Lecture (April 6, 1858) begins: "All creation is a mine, and every man, a miner." I always liked that. And then a few lines later, "Man is not the only animal who labors; but he is the only one who improves his workmanship."
It is in the Second Lecture (Feb 11, 1859) in which he famously talks about language and writing and printing (the "greatest invention of the world" that allowed men to "rise to the level of equality"). There is a lot more here, as Julie knows, for I have talked with her about this over the years (and she has done good work on it, which I have been using, stealing really, for a good while). It is probable, by the way, that the two lectures are really one, but because of the way they were discovered, were made into two, so that’s the way refer to them now. Lincoln gave the lecture six time between April 1858 and April 1860. It is also true that generally speaking, everyone thought it was a failure. Anyway, Emerson’s is a nice little book.