DEAR SIR: In reply to the inquiries which you have done me the honor to make, in asking my opinion “of the propriety of establishing a system of telegraphs for the United States,” I would say, in regard to the general question, that I believe there can scarcely be two opinions, in such a community as ours, in regard to the advantage which would result, both to the Government and the public generally, from the establishment of a system of communication by which the most speedy intercourse may be had between the most distant parts of the country. The _mail system_, it seems to me, is founded on the universally admitted principle, that the greater the speed with which intelligence can be transmitted from point to point, the greater is the benefit derived to the whole community. The only question that remains, therefore, is, what system is best calculated, from its completeness and cheapness, to effect this desirable end? With regard to telegraphs constructed on the ordinary principles, however perfected within the limits in which they are necessarily confined, the most perfect of them are liable to one insurmountable objection—_they are useless the greater part of the time_. In foggy weather, and ordinarily during the night no intelligence can be transmitted. Even when they can transmit, much time is consumed in communicating but little, and that little not always precise. Having invented an entirely new mode of telegraphic communication, which, so far as experiments have yet been made with it, promises results of almost marvellous character, I beg leave to present to the Department a brief account of its chief characteristics.