THE “PACIFIC” (1853).
From a Painting in the Victoria and Albert Museum.
Turning our attention away from the North Atlantic for a while, we shall be able to see that steamships on other routes were now fast passing from the olden types, when designers and builders were working with only a minimum of data on which to base their achievements. We have already referred to the highly important knowledge which was gradually being obtained concerning the relations between the hull of a ship and the water in which she is floated. One of the greatest authorities on this subject about the middle of the last century was John Scott Russell, who worked out a theory regarding the resistance of the ship passing through the water. He it was who contended that the hull should only move the water out of the way sufficiently to allow the widest section of the ship to pass through, and to do this in such a manner as should cause the least amount of friction and disturbance of the water, so that, when the ship was gone by, the particles of water should be restored to their original quietude. It is important to bear in mind that the design of a ship must be made with regard to the speed which it is intended to get out of her. Thus, it is now a well-known principle that to give a ship highly powerful engines so that she is forced beyond her proper speed only makes the waves diverge from the sides and waste themselves instead of travelling with the vessel and giving it a forward impetus.
The model of the hull in [the illustration facing page 134] represents the steamship Victoria, which was built in 1852 of iron, and designed by those two great geniuses Brunel and Scott Russell for the Australian Royal Mail Steam Navigation Company. Even the least practised eye on looking at her lines can see that she possessed speed, and it was this ship that gained the £500 prize offered by the Colonies for the fastest voyage to Australia, her time from Gravesend to Adelaide being sixty days, including two days’ delay at St. Vincent. The Victoria was designed as embodying the wave-line theory and for a speed of ten knots. It is not necessary to examine this model many moments before one realises how unmistakably the clumsy, ponderous hulls so characteristic of earlier years were now being replaced by sweet, graceful, non-resisting features. The hull of the Victoria was separated into a dozen water-tight compartments and displaced 3,000 tons, her length being 261 feet, with a breadth of 38 feet, or approximately seven beams to the length. She had a two-bladed screw, and when this was not in use, and the Victoria proceeded under sail-power alone, the propeller was fixed vertically. Thus arranged, the ship could sail 5½ knots, but it is interesting to remark that when the screw was allowed to revolve freely the speed of the ship was increased another couple of knots.
MAUDSLAY’S OSCILLATING ENGINE.
From the Original in the Victoria and Albert Museum.
ENGINES OF THE “CANDIA.”