Nasmyth was a titan of 19th century British engineering, and his autobiography is outstanding. Any study of the great engineers of history would be remiss without this book.
However, this particular edition is not the one to buy. Although the text is complete (as far as I can tell), this book is missing all the drawings and figures present in the original text. If you're considering this book, don't buy this edition. Find yourself a copy of the original, complete work.