Finally, That ample subsidies be granted to lines of steamers built in American yards, to the end that competition with powerful foreign organizations may be successfully inaugurated and sustained. The Chamber ordered the resolutions engrossed, accompanied by a memorial forwarded to Congress. These resolutions, in our opinion, embody the solution of the question under consideration, and we trust they may be speedily and favorably acted upon by Congress. * * * * * Young men out of employment can easily obtain enough subscribers for the SCIENTIFIC AMERICAN to receive a cash prize of sufficient magnitude to insure them a good salary for six weeks' work. Send for prospectus and circulars. * * * * * CORRESPONDENCE. _The Editors are not responsible for the Opinions expressed by their Correspondents_. * * * * * Aerial Navigation--A Suggestion. Messrs. Editors:--As a constant reader of your invaluable paper, many subjects of deep interest come under my observation, and doubtless no journal throughout the land contains more instructive reading--that which tends to accelerate the progress of scientific investigation, and promote the general interest of the people--than the SCIENTIFIC AMERICAN. The series of articles under the head of "Aerial Navigation," commenced on page 309, volume XXI., has, perhaps, been read with as much pleasure and interest as anything published in your valuable journal. I say with pleasure--because it is really gratifying to mark the advancing steps which inventors are making in this branch of science; and with interest--because every new idea set forth, calculated to further the success of aerial navigation, should be, and no doubt will be, regarded as of great importance by every one. And, as the more suggestions placed before the minds of those working for the improvement of any invention, the greater number will they have from which to choose or experiment upon, I would like to make one suggestion here, which may be of some importance in the construction and operation of the "Aeroport," under the supervision of Mr. Porter, of your city, a description of which is given on pages 346-7, volume XXI., of your paper.