THE AMERICAN TURTLE. "The body, when standing upright, in the position in which it is navigated, has the nearest resemblance to the two upper shells of the tortoise, joined together. It is seven and a half feet long, and six feet high. The person who navigates it enters at the top. It has a brass top or cover which receives the person's head, as he sits on a seat, and is fastened on the inside by screws. "On this brass head are fixed eight glasses, viz: two before, two on each side, one behind, and one to look out upwards. On the same brass head are fixed two brass tubes to admit fresh air when requisite, and a ventilator at the side, to free the machine from the air rendered unfit for respiration. "On the inside is fixed a barometer, by which he can tell the depth he is under water; a compass by which he knows the course he steers. In the barometer, and on the needles of the compass, is fixed fox-fire--that is, wood that gives light in the dark. His ballast consists of about nine hundred-weight of lead, which he carries at the bottom and on the outside of the machine, part of which is so fixed as he can let run down to the bottom, and serves as an anchor by which he can ride _ad libitum_. "He has a sounding lead fixed at the bow, by which he can take the depth of water under him, and a forcing-pump by which he can free the machine at pleasure, and can rise above water, and again immerge, as occasion requires. "In the bow he has a pair of oars fixed like the two opposite arms of a windmill, with which he can row forward, and, turning them the opposite way, row the machine backward; another pair, fixed upon the same model, with which he can row the machine round, either to the right or left; and a third by which he can row the machine either up or down; all of which are turned by foot, like a spinning wheel. The rudder by which he steers he manages by hand, within-board. "All these shafts which pass through the machine are so curiously fixed as not to admit any water. "The magazine for the powder is carried on the hinder part of the machine, without-board, and so contrived that, when he comes under the side of a ship, he rubs down the side until he comes to the keel, and a hook so fixed as that when it touches the keel it raises a spring which frees the magazine from the machine, and fastens it to the side of the ship; at the same time it draws a pin, which sets the watch-work a-going, which, at a given time, springs the lock, and an explosion ensues." Thus wrote Dr. Benjamin Gale to Silas Deane, member of Congress at Philadelphia. His letter bears the date November 9, 1775, and, after describing the wonderful machine, he adds: