when a few passengers were accommodated in the aftercastle, or the poop, where the captain and the navigating officers had their quarters, the place of honor on the ship. Here they stayed even when steam power supplanted the force of the wind, but only as long as side-propeller wheels were used.

The introduction of the screw-propeller made this part of the ship the most uncomfortable, because of the noise and vibration. It was then that the cabin was moved towards the centre of the ship, immediately in front of the steam engine. Gradually, the accommodation for passengers encroached more and more upon the cargo-carrying capacity of the vessel. This evolution worked along two separate lines. In the first place, passenger cabins were built in the space where formerly cargo could have been carried, although this tendency was counteracted as much as possible by building deck superstructures, higher and higher with every successive type, until to-day a maximum number of ten decks has been reached. But the adaptation of the ship's construction to passenger service, which requires greater speed, meant an even more serious curtailment of the cargocarrying capacity. Increased speed means more fuel; more fuel means more bunker space, which is available only at the expense of cargo space. But, beyond a certain point, increase of speed cannot, economically, be attained by the increased use of fuel; it necessitates a considerable reduction of the block coefficient of the hull. Thus, ships of 17 or 18 knots should hardly exceed 70 percent, and an increase of the speed over and above 23 knots means a further loss of from 10 to 13 percent, unless the economical side of speed production is to be disregarded.

Load-index affects profitableness. One of the most important considerations regarding the profitableness of

installing passenger accommodations in freight vessels, has been the load index. As we have seen in Chapter II, the cargo movements from one country to another are often badly balanced. This is particularly true on the all-important North Atlantic route. The exports from North America to Europe by far exceed the imports from Europe, in point of weight and volume. Here steerage passengers offer to the trans-Atlantic steamship companies a welcome solution of a difficult problem. Human freight, going west, balances the excess cargo going east. It is a serious question whether, without these favorable circumstances, steerage capacity would have been offered in as large dimensions, or whether steerage rates would have been as low as they have been. The increase of income, due to the better utilization of tonnage space, thus achieved, could be used to defray the greater cost of higher speed and more slender build of the passenger steamers. Only on this basis could the combination vessel enter into competition against the tramp and cargo liner, which were operated on a much lower cost basis.

Evolution of the express steamer.-Parallel to this evolution of the combination steamer, grew up another type of passenger vessel, namely, the pure passenger express steamer. Its paying value is based upon the earnings from transporting the most exacting travelling public of the earth-American tourists-coupled with the income from enormously increased steerage capacity. Only a few vessels of this type can exist side-by-side and pay for their investment and operating cost.

The competition of this highest type in turn reacted upon the combination vessel, which had to increase its speed more and more if all cabin passengers were not to be lost to the express steamer. The result was that the speed of the combination liner gradually increased from 12 to 14 knots to 17

or 18 knots. The prevailing speed of express steamers varies from 21 to 23 knots, while only rare exceptions develop a speed of from 24 to 25 knots.

Different policies pursued by different companies.— It is interesting to study how the different steamship companies have arrived at different conclusions in trying to solve this problem of the relative speed, size, passenger and cargo accommodations, cabin and steerage accommodations, etc. Contenting ourselves with a rough characterization of the most important steamship companies serving the North Atlantic route, one may say that the Cunard Line has emphasized speed; and the White Star Line comfort and luxury. In their latest bids for the leadership in North Atlantic travel, the Hamburg-American Line tried to combine the speed of the Cunarder with the comfort and luxury of the White Star Line, without at the same time sacrificing the chance of earning a fair sum from the transportation of cargo. The chart given on page 272 has given the cargocarrying capacity of the Bismarck as 15,000 tons, the capacity of a very large freighter.

Different considerations determine the policy regarding passenger accommodation on different routes. Thus, the almost extravagant display of luxury which marks the latest products of the marine architect, created for the North Atlantic route, might prove a doubtful asset to a company catering to the Australian or South African traveling public. It is an interesting speculation whether, in the future, the North Atlantic route will hold first rank as regards luxury and display. Reports are current that passenger ships are to ply between Pacific ports of the United States and Hawaii, whose luxury and comfort will outdo anything previously offered. Among the ships which the HamburgAmerican Line had to surrender under the terms of the