Yet she is only 60 feet shorter than the mammoth _Great Eastern_, and measures 620 feet in length, 65 feet 3 inches in breadth, and 43 feet in depth from the upper deck. Her tonnage is 12,000, while that of the _Great Eastern_ was 18,000; but then her horse-power is 30,000 as against the _Great Eastern's_ 7650! This enormous development of engine-power is perhaps the most remarkable feature about these two new vessels. Each of them is fitted with two sets of the most powerful triple-expansion engines ever put together. A visit to the engine-room is a liberal education in the mechanical arts, and even to the eye of the uninitiated there is the predominant impression of perfect order in the bewildering arrangement of pipes, rods, cranks, levers, wheels, and cylinders. The two sets of engines are placed in two separate rooms on each side of a centre-line bulkhead fitted with water-tight doors for intercommunication. Each set has five inverted cylinders which have exactly the same stroke, and work on three cranks. Two of the cylinders are high-pressure, one is intermediate, and two are low-pressure. Besides the main engines, there are engines for reversing, for driving the centrifugal pumps for the condensers, for the electric light, for the refrigerating chambers, and for a number of other purposes--all perfect in appointment and finish. In fact, in these vast engine-rooms one is best able to realise not only the immense size and power of the vessel, but also the perfection to which human ingenuity has attained after generations of ceaseless toil--and yet it is only half a century since the _Britannia_ began the transatlantic race. Each of the various engines has its own steam-supplier. The main engines are fed by twelve double-ended boilers, arranged in rows of six on each side of a water-tight bulkhead. The boilers are heated by ninety-six furnaces, and each set of six boilers has a funnel with the diameter of an ordinary railway tunnel. In the construction of these boilers some eight hundred tons of steel were required, the plates weighing four tons each, with a thickness of an inch and a half. From these mighty machines will be developed a power equal to that of 30,000 horses! Compare this with the _Great Eastern's_ 7650 horse-power, or even with the later 'greyhounds.' The greatest power developed by the two previous additions to the Cunard fleet, the _Etruria_ and _Umbria_, is about 14,000 horses, which is the utmost recorded by any single-screw engines. The _City of Paris_ has a power of 18,500, and the _Teutonic_ a power of 18,000 by twin-screw engines. The _Campania_, therefore, is upwards of half as much again more powerful than the largest, swiftest, and most powerful of her predecessors.