The slips of the shipyards at Alt-Hofen (Hungary) belonging to the Imperial and Royal Navigation Company of the Danube are so arranged that the vessels belonging to its fleet can be hauled up high and dry or be launched sidewise. They comprise three distinct groups, which are adapted, according to needs, for the construction or repair of steamers, twenty of which can be put into the yard at a time. The operation, which is facilitated by the current of the Danube, consists in receiving the ships upon frames beneath the water and at the extremity of inclined planes running at right angles with them. After the ship has been made secure by means of wedges, the frame is drawn up by chains that wind round fixed windlasses. These apparatus are established upon a horizontal surface 25.5 feet above low-water mark so as to give the necessary slope, and at which terminate the tracks. They may, moreover, be removed after the ships have been taken off, and be put down again for launching. For 136 feet of their length the lower part of the sliding ways is permanent, and fixed first upon rubble masonry and then upon the earth. Fig. 1 gives a general view of the arrangement. The eight sliding ways of the central part are usually reserved for the largest vessels. The two extreme ones comprise, one of them 7, and the other 6, tracks only, and are maneuvered by means of the same windlasses as the others. A track, FF, is laid parallel with the river, in order to facilitate, through lorries, the loading and unloading of the traction chains. These latter are 3/4 inch in diameter, while those that pass around the hulls are 1 inch. The motive power is furnished by a 10 H.P. steam engine, which serves at the same time for actuating the machine tools employed in construction or repairs. The shaft is situated at the head of the ways, and sets in motion four double-gear windlasses of the type shown in Fig. 2. The ratio of the wheels is as 9 to 1. The speed at which the ships move forward is from 10 to 13 feet per minute. Traction is effected continuously and without shock. After the cables have been passed around the hull, and fastened, they are attached to four pairs of blocks each comprising three pulleys. The lower one of these is carried by rollers that run over a special track laid for this purpose on the inclined plane. [Illustration: FIG. 1.--WAYS OF LAUNCHING VESSELS SIDEWISE.]