The first thing I ever learned in the way of book knowledge was while working in this salt-furnace. Each salt-packer had his barrels marked with a certain number. The number allotted to my stepfather was "18." At the close of the day's work the boss of the packers would come around and put "18" on each of our barrels, and I soon learned to recognize that figure wherever I saw it, and after a while got to the point where I could make that figure, though I knew nothing about any other figures or letters.