By Sylvanus P. Thomson.
"What one fool can learn, another can."- Old Simian Proverb
The very best of the old-school mathematics textbooks....in less than 200 pages, in a book that (in some editions) can be put into a coat pocket, you have the equivalent of an expensive thousand-page American three-semester calculus textbook. Taught in inimitably English public school style, it relates most examples to practical experience, with some humor, and in a section called "To Deliver You From Preliminary Horrors" explains thoroughly all of the intriguing symbols used in what you will ever after refer to as "the calculus".
Some have said it doesn't have enough theory. Actually it does have some...and unless you're going to stick around to learn analysis, there's more than enough to get you by almost any engineering course in the country.
Also, there is rumored to be a very Victorian sex joke in it. I remember catching it, then forgetting where it was, after my orgasm, and subsequent nap. Readers be warned.
A new edition is annotated by Martin Gardner. Addison-Wesley...again, be warned!