1874.

Entered according to act of Congress, in the year 1874, by
A. WILLIAMS & CO.,
in the office of the Librarian of Congress, at Washington, D.C.




PREFACE.


This little treatise was written for the purpose of supplying a want
felt by the author while giving instruction upon the subject. It was
intended for an aid to the young Engineer, and is not to be considered
as a complete substitute for the more elaborate works on the subject.

The first portion of this work mentions the various strains to which
beams are subjected, and gives the formulæ used in determining the
amount of those strains, together with a few examples to illustrate
their application, and also the method of calculating a simple truss.

The second portion names and explains the various members of a Bridge
Truss, and, by means of examples, shows the method of calculating the
strains upon the various timbers, bolts, etc., as well as their proper
dimensions; and gives, in addition, several useful tables.

The explanatory plates, which are referred to freely throughout the
work, are believed to be amply sufficient for the purpose intended.