Boyden perfected the process for making patent leather, created malleable iron, invented a nail-making machine, and built his own steamboat.

Then he built a double-skinned oak door and studded it with fat-headed iron nails from the nearby, long defunct Presteigne nail-making machine.

This all works out fine for O'Rourke and me and whoever is running the nail-making machine in China; he or she is presumably better off doing that than being a peasant farmer or an unemployed urbanite.