This book was commenced with the intention of making it a purely Elementary Treatise. As he proceeded with his work, however, the Author became convinced that, in our language, the want is much more felt of such books as Schellen's, Dub's, Moi gno's, Blavier's, and others, than of such as he had proposed to make his. He has therefore endea voured to make it sufficiently elementary to come within the comprehension of every educated man, and, at the same time, sufficiently technical to be useful to electricians. The work is divided into Two Parts: the First being confined to a short history of the Electric Telegraph, and descriptions of many of the past and existing methods and apparatus; the Second Part being confined exclusively to the more scientific matter relating especially to Cable York. N 0 new theories are started, nor has anything been introduced which expe rience has not confirmed as having merits to recommend it.