nd the impression that
the most gigantic benefits may be so abused as to tempt us into an
occasional wish that they had never existed.

One reason of this general ignorance has been the absence of any
text-book or manual on the subject, giving a clear and thorough
exposition of its mysteries. The present is the first American work
which takes the subject in hand from the beginning and carries it
through the entire process which leads to the results we have spoken of.
Its author brings to his work the best possible qualification,--a
long familiarity with the subject in the every-day details of its
development. His Introduction informs the reader that he has been
engaged for thirteen years in the business of practical telegraphing.
He is thus sure of his ground, from the best of sources, personal
experience.

We shall not criticize the work in detail, but shall rest satisfied with
saying that the author has succeeded in his design of making the whole
subject clear to any reader who will follow his lucid and systematic
exposition. The plan of the work is simple, and the arrangement orderly
and proper. A concise statement is given of the fundamental principles
of electricity, and of the means of its artificial propagation. This
includes, of course, a description of the various batteries used in
telegraphing. Then follows a chapter upon electro-magnetism and its
application to the telegraph. This prepares the way for a statement
of the physical conditions under which the electrical current may be
conveyed. The author then describes the instruments necessary for the
transmission and recording of intelligible signs, under which general
head of "Electric Telegraph Apparatus" the various telegraphic systems
are made the subject of careful description. A chapter is given to the
history of each system,--the Morse, the Needle, the House, the Bain, the
Hughes, the Combination, and others of less note. These chapters are
very complete and very interesting, embodying, as they do, the history
of each instrument, the details of its use, and a statement of its
capabilities. The system most used in America is the Combination
system, the printing instrument of which is the result of an ingenious
combination of the most desirable qualities of the House and Hughes
systems. Of this fine instrument a full-page engraving is given, which,
with Mr. Prescott's careful explanation, renders the recording process
very clear.

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