The size of the train will vary, depending on grade, curvature, and speed. TRANSPORTATION OF ARTILLERY-HORSES BY SEA. Transports for horses should be especially prepared for the purpose; as a rule, the larger the vessel the better is she adapted for the conveyance of horses. Ventilation is of primary importance, the safety and condition of the horses mainly depending upon their having plenty of fresh air; large air-ports or scuttles are indispensable, and wind-sails down every hatch to each deck should be insisted upon. If time permits, fixed air-shafts should be provided for each deck. The ventilation of steamers may be assisted by using the donkey-engines for this purpose. The stalls are preferably between-decks, never, if it can be avoided, in the hold; should horses be put on the spar-deck, nothing will be stowed on the stall-sheds. Stalls should be about 6½ feet long, 28 inches wide; tail-boards fastened to the rear posts, and padded as low as the hock; breast-boards and side-boards fitted in grooves about 4 feet from the floor, the first padded on the inner side and upper edge, the latter on both sides; the floors of the stalls set on blocks that the water may pass under them; four slats across each floor to give the horses foothold. Troughs should be made to hang with hooks, so as to be easily removed. Before embarkation the side-boards are removed, and replaced as each horse is placed in his stall. Horses, in all cases, should stand athwart-ship; in this position they better accommodate themselves to the motion of the vessel. When on the upper deck, they should face inward; this for the reason that the spray will not strike them in their faces, and, besides, when facing each other in this manner they will suffer less from fright and nervous excitement. All stalls, hitching-bars, or whatever other arrangement for securing horses, must be strong beyond any possibility of giving way. The living force exerted by a row of horses, as they swing with the motion of a ship in a heavy sea, is very great, and it is better to have no securing arrangements whatever than to have those that, by giving way, will wound and injure the animals in the wreck. If the transport is to be used in very inclement weather, the spar-deck, over the horses, should be covered. Canvas stretched over a secure frame is better than boards, as the latter in a severe storm might be carried away, and its wreck would cause disaster among the horses.