Don't deceive yourself with the idea that what you get out of this will be merely book learning. What is said in this will be plain, unvarnished, practical facts. It is not the author's intention to use any scientific terms, but plain everyday field talk. There will be a number of things you will not find in this book, but nothing will be left out that would be of practical value to you. You will not find any geometrical figures made up of circles, curves, angles, letters and figures in a vain effort to make you understand the principle of an eccentric. While it is all very nice to know these things, it is not necessary, and the putting of them in this book would defeat the very object for which it was intended. Be content with being a good, practical, everyday engineer, and all these things will come in time.