The transportation begins with the train loads of ore that run from the mines to the lake shore and out upon the wharves built to receive them. These wharves are enormous structures, sometimes half a mile in length, built up to about the height of the masts of ore boats. On the sides and in the centres of these towering structures are huge bins for holding the ore, these bins communicating directly with the holds of the ore steamers tied up alongside. Four tracks are frequently laid on the top of the wharves, and are so arranged that trains four abreast can dump the ore into the bins, or waiting ships, at the same time. If the bins are empty and boats waiting to receive a cargo, the ore is discharged by long chutes into the holds from the cars. Otherwise the bins are filled, the trains returning to the mines as quickly as possible for fresh loads. The boats for receiving this cargo are of special design, many of them differing very greatly in appearance from ordinary ocean liners of corresponding size. This is particularly true of the "whale-backs" which have little in common in appearance with ordinary steamers except in the matter of funnels; and even these are misplaced sternwards to a distance quite out of drawing with the length of the hull. Their shape is that of the ordinary type of submarine boat--that is, cigar-shaped--this effect being obtained by a curved deck completely covering the place ordinarily occupied by a flat deck. A wheel-house, like a battle-ship's conning-tower, is placed well forward, supported on steel beams some distance above the curved deck for observation purposes; and engines, boilers, and coal bunkers occupy a small space in the stern. The boat, therefore, is mostly hold. But the "whale-backs" form only a small portion of the ore-fleet. The ordinary type of boat conforms more nearly to the shape of ocean boats, except that the bridge, wheel-house, and engines are located as in the whale-backs. The bows of these boats are blunt, the desideratum in such craft being hull-capacity rather than speed. For sea-worthiness they are equal to any ocean boats, as the battering waves of Lake Superior are quite as powerful and even more treacherous than those of the Atlantic or Pacific. Some of these boats are five hundred feet long, equal to all but the largest ocean vessels. Their coal-carrying capacity is relatively small, since coaling stations are numerous at various points on the journey, and every available inch of space is utilized for the precious iron ore. In order to facilitate loading, the decks are literally honey-combed with hatches, some boats having fifteen or sixteen openings extending the width of the deck. By this arrangement the time of loading is reduced to a matter of a few hours, as a dozen chutes, each discharging several tons of ore per minute, soon fill the yawning compartments with the necessary six, eight, or nine thousand tons, that make up the cargo.