The idea of transmitting intelligence to a distance by means of electrical action, has been suggested by various persons, from the time of Franklin to the present; but, until the last few years, or since the principal discoveries in electro-magnetism, all attempts to reduce it to practice were, necessarily, unsuccessful. The mere suggestion however, of a scheme of this kind is a matter for which little credit can be claimed, since it is one which would naturally arise in the mind of almost any person familiar with the phenomena of electricity; but the bringing it forward at the proper moment, when the developments of science are able to furnish the means of certain success, and the devising a plan for carrying it into practical operation, are the grounds of a just claim to scientific reputation, as well as to public patronage. About the same time with yourself Professor Wheatstone, of London, and Dr. Steinheil, of Germany, proposed plans of the electro-magnetic telegraph, but these differ as much from yours as the nature of the common principle would well permit; and, unless some essential improvements have lately been made in these European plans, _I should 'prefer the one invented by yourself_. With my best wishes for your success I remain, with much esteem Yours truly JOSEPH HENRY. I consider this one of the most important bits of contemporary evidence that has come down to us. Professor Henry, perfectly conversant with, all the minutiae of science and invention, practically gives to Morse all the credit which the inventor himself at any time claimed. He dismisses the claims of those who merely suggested a telegraph, or even made unsuccessful attempts to reduce one to practice, unsuccessful because the time was not yet ripe; and he awards Morse scientific as well as popular reputation. Furthermore Professor Henry, with the clear vision of a trained mind, points out that advances in discovery and invention are necessarily slow and dependent upon the labors of many in the same field. His cordial endorsement of the invention, in this letter and later, so pleased and encouraged Morse that he refers to it several times in his correspondence. To Mr. Smith, on July 16, 1842, he writes:--