THIS work is offered as a valuable Book of Reference for Mechanics and Manufacturers, trusting they will find information therein that will well repay them.

It is the intention of the Author to produce the most disirable information in the most intelligible form for practical application.

The mechanic who has studied mathematics but little, will find that by studying some of the brief rules herein, he will get a clear comprehension of things that would otherwise be unintelligible to him.

The Author acknowledges his indebtedness to numerous English and American authors for valuable material for tables, etc B. F. V.