And now it was that, being on some occasion made ashamed of my ignorance in figures, which I had twice failed in learning when at school, I took Cocker’s book of Arithmetic, and went through the whole by myself with great ease. I also read Seller’s and Shermy’s books of Navigation, and became acquainted with the little geometry they contain; but never proceeded far in that science. And I read about this time Locke On Human Understanding, and the Art of Thinking, by Messrs. du Port Royal.