The construction of this ship calls for more space than we can here devote thereto, but some of the important features may be enumerated. She was of great strength longitudinally, and from the keel to the water-line her hull was double. The longitudinal bulkheads extended to the topmost deck, and materially added to her strength, while the inner skin just mentioned not merely gave added strength, but was an extension of the double-bottom idea, and so increased her chances in case of collision. Furthermore, the space between the two skins was available for water ballast, so as to preserve the trim of the ship as she neared the end of her voyage, and her coal bunkers were becoming lightened. Transversely, also, the ship was divided by iron bulkheads into water-tight compartments in addition to the longitudinal ones. The iron plates out of which the ship’s skin was made varied from a half to three-quarters of an inch thick. The _Great Eastern_ was able to give the world a very convincing proof of the utility of the double bottom, for she had the bad luck to run on a rock, and although more than a hundred feet of her outer hull was afterwards found to be damaged, yet she was able to complete her voyage without the water getting through into her hull proper. For steering so large a vessel as the _Great Eastern_ the usual type of steering-wheel would clearly have entailed the expenditure of very considerable physical effort; so, for the first time, was introduced in this ship a steam steering gear, an example that is nowadays followed by almost all steamers of any size, including even excursion boats. This arrangement necessitates the use of a miniature steam engine, the two cylinders working cranks, and the shaft causing the drum containing the steering chain to revolve. Any movement of the steering wheel admits steam, and as soon as the steersman ceases to turn his wheel so quickly does the little engine cease to work. We have no desire to try the patience of the reader by presenting a mass of statistics, but those who delight in comparisons may be interested to learn how the _Great Eastern_ would appear if put alongside the _Mauretania_. The latter displaces 40,000 tons, the _Great Eastern_ displaced 32,000. The big Cunarder is 790 feet long, between perpendiculars, while the _Great Eastern_ was 680 feet. The latter possessed a combined horse-power--paddle and screw engines--of 11,600, while the Cunarder has 70,000. And so we could continue. But now that we have seen to what unheard-of limits the steamship had shown herself capable of reaching by the end of the sixth decade in the nineteenth century--how she had, step by step, grown from moderation to exaggeration--let us now examine her progress during the next twenty years, in which she passed through her transition period. CHAPTER V THE LINER IN HER TRANSITION STATE