These changes made the use of a cylindrical boiler necessary, as the form best able to withstand the increased pressure. The old box-like shape has disappeared; and if the shade of Oliver Evans is ever able to visit us, it must be with an intense feeling of satisfaction to find his ideas of eighty years since now accepted by all the world.
The date 1870 marks the advent of a new type of ship, in those of the Oceanic Company, better known as the White Star line, built of iron by Harland & Wolff, of Belfast—engined with compound engines, and of extreme length as compared with their breadth. They established a new form, style, and interior arrangement, which has largely been followed by other lines, though the extreme disproportion of length and beam is now disappearing. The Britannic and Germanic, the two largest of the earlier of this line, are 468 feet in length and 45 feet 3 inches in beam, carrying 220 cabin passengers and 1,100 in the steerage, besides 150 crew. They develop 5,000 indicated horse-power, and make their passage, with remarkable regularity, in about 8 days 10 hours to Queenstown. The earlier ships of this line, when first built, had a means of dropping their propeller-shaft so as to immerse more deeply the screw; so many inconveniences, however, were associated with this that it was given up. Their general arrangement was a most marked advance upon that of their predecessors—an excellent move was placing the saloon forward instead of in the stern, a change almost universally followed.
In the same year with the Britannic came out the City of Berlin, of the Inman line, for some years the largest steamer afloat (after the Great Eastern), being 520 feet in length by 44 feet beam, of 5,000 indicated power, and in every way a magnificent ship.
The Bothnia and Scythia were also built in 1874, by the Cunard company, as representatives of the new type, but were smaller than the ships of the same period built by the Inman and White Star lines. They were of 6,080 tons displacement and 2,780 indicated horse-power, with a speed of 13 knots. The pressure carried was 60 pounds. These ships had by far the largest cargo-carrying capacity (3,000 tons measurement) and passenger accommodation (340 first-cabin) of any yet built by the company. With the addition of this great number of steamers, change was not to be expected for some years; and it was not until 1879, when the Guion company put afloat the Arizona, that a beginning was made of the tremendous rivalry which has resulted in putting upon the seas, not only the wonderful ships which are now running upon the Atlantic, but in extending greatly the size and speed of those employed in other service.
