erfully render to him far more than this, even their unfeigned
admiration.

_Military Bridges:_ With Suggestions of New Expedients and
Constructions for crossing Streams and Chasms; including, also,
Designs for Trestle and Truss Bridges for Military Railroads.
Adapted especially to the Wants of the Service in the United
States. By HERMANN HAUPT, late Chief of Bureau in Charge of the
Construction and Operation of United States Military Railways,
etc. New York: D. Van Nostrand. 8vo. pp. 310.

There is in the War Department at Washington a series of splendid
photographs, illustrative of scenes along the line of march of our
armies in Virginia, and depicting minutely the great pioneer labor of
transporting troops and ammunition, giving evidence of the greatest
engineering genius, and the illimitable resource that has been evoked by
this dreadful War of Rebellion.

The book before us is the result of these operations reduced to form.
The author's name has for the last twenty-five years been associated
with most of the great works of internal improvement in this country,
and is familiar to every Massachusetts man as connected with the great
railroad-enterprise of the State,--the Hoosac Tunnel.

The professional reputation of the author of "The General Theory of
Bridge-Construction" would of itself be a sufficient guaranty that a new
work from the same source would be entitled to consideration. General
Haupt does not often appear before the public as an author: his works
are few, but of rare merit. The first which appeared, "The General
Theory of Bridge-Construction," was the fruit of many years of
experiment, observation, and calculation, and at once established his
reputation in Europe and America, as unequalled in the specialty of
Bridges. This work was not only the first, but up to the present time is
the only publication in which the action of the parts in a complicated
system is explained, and the direction and intensity of each and every
strain brought within the reach of mathematical formulas, and rendered
accurately determinable. Before the appearance of this book it is
probable that not another engineer in the world could be found able to
calculate the strain upon every sort of bridge-truss, but only on
certain simple forms and combinations. Now, such calculations can be
made by any student in any institution where civil engineering is taught
thoroughly, and where "Haupt on Br