from its shallowness, would, in a heavy sea, be in a great measure out of water, there is a contrivance by which a moveable or false rudder is attached to the lower part of the true or fixed rudder, and which descends to the same depth as the two false keels, and, like them, can be raised or lowered at pleasure.
The main or true rudder was composed of wood, but the lower or false rudder was made of iron, and was so constructed as to grasp the lower part of the upper or fixed one, firmly on either side, but was bolted through in such a way as to be moveable, as if it were fastened by a hinge, so that, by means of a chain run up to the taffrail from its outer edge, it could be hauled up to any height required.
The next striking peculiarity in the construction of the Nemesis was, that the entire vessel was divided into seven water-tight compartments, by means of iron bulkheads; so that, in fact, it somewhat resembled a number of iron tanks, cased over, so as to assume the external form of one connected vessel. By this means, the occurrence of any accident, such as striking on a rock, or shot-holes, &c., which might occasion a dangerous leak in one compartment, would have no effect upon any other part of the vessel.
The advantages of this arrangement were often tested, during her three years' hard service; and, indeed, within a few days after her first departure from Liverpool, as will be presently related, this contrivance sufficed to save her from the almost certain destruction which would otherwise have awaited her.
The last peculiarity which it seems necessary here to mention, was the provision of some kind of instrument for counteracting the effect of the local attraction of so large a mass of iron upon the compasses, and for correcting the errors occasioned thereby. This difficulty had been seriously felt by Colonel Chesney, on board the small iron steamers which he had under his orders, during his expedition to the Euphrates; although he was of opinion, that the placing of the compasses at a certain height above the vessel, so as to be further removed from the sphere of the local attraction of the iron, was sufficient to reduce their errors materially.
Without entering into the merits of Barlow's counteracting plates, or Professor Airy's interesting discoveries, it will be sufficient here to mention, that the Nemesis was fitted with correctors, very much according to the system of Professor Airy, but not under his own superintendence; that the experiments were conducted at Liverpool under every disadvantage, and that the result was never perfectly satisfactory. Indeed, the accident which shortly befel her, has been attributed, upon strong grounds, principally to the imperfection of her compasses. It is right, however, to mention, that other vessels, such as the Phlegethon and Pluto, which have been fitted with Airy's correctors, tested according to the most approved principles, and after experiments conducted with great attention, have been totally relieved from this source of danger and anxiety, and have been navigated with perfect accuracy and confidence.
We may now come to the interesting moment of the departure of the Nemesis from Liverpool, where she was built. Everything seemed at first to prosper; the weather was favourable, and the machinery perfect in all its parts. She had cleared the narrowest part of the Irish Channel, had passed the coast of Wales, and crossed the entrance to the Bristol Channel; and the course she had been steering would have taken her well clear of the Land's End.
It was now the second day since her departure. About two o'clock in the morning, the weather being still hazy and the night dark, she struck heavily on a rock.
Of course the engines were instantly stopped, but the way she already had on her appeared sufficient to carry her over the reef; and, indeed, the actual rocks themselves could be seen outside of her, so that she had evidently passed between them and the land, and had merely struck the edge of the reef.
Finding that the vessel did not hang upon the reef, and was therefore still afloat, her head was turned to seaward, and the engines kept working slowly, while the dawn was anxiously expected. It was now discovered, that the rocks upon which she had struck were aptly enough called "The Stones," lying at the entrance to the bay of St. Ives, in Cornwall, and not very far distant from the Land's End. It was soon evident, also, that the accident had occasioned a very serious leak, in one of the foremost compartments of the vessel. It was with difficulty that the water could be kept lower in it than the level of the sea outside, with the hand-pump; and, in fact, if the vessel had not been divided into these water-tight compartments, it is difficult to imagine that the accident would not have been fatal to her.
However, she was carried, without much difficulty, round the Land's End, into Mount's Bay, where she anchored about three miles from Penzance, off St. Michael's Mount. The object here was to procure an additional pump, in the hope of being able, by that means, to empty the tank or compartment, so as to be able to stop the leak from the inside. Fortunately, one perfectly adapted for the purpose was obtained from a small coasting-vessel which was at anchor in the bay. It was an iron one, and has been preserved on board ever since, and, on many occasions, has been found of the greatest utility. Indeed, every vessel of this description should be provided with an extra pump of this kind, to be worked by hand, and at all times ready to be placed into any compartment, as an additional means of pumping it out, and also as a security against fire, for the purpose of pumping water into the vessel in case of necessity.
With the assistance of this additional pump, the water in the compartment was completely emptied, and, then it was discovered that a hole had been cut completely through her bottom by the rock, but could now be easily stopped from the inside.
This being speedily effected, the vessel pursued her voyage without the least difficulty, and came to anchor on the following evening in Yarmouth Roads, inside the Isle of Wight.
It should here be mentioned, that every compartment of the vessel was provided with a small pipe and cock, by means of which, the water could be let out of one compartment into another, and so passed on, from one to the other, into the engine-room, where it could be pumped out by the machinery. But, as this appeared a rather clumsy mode of doing it, namely, by floating nearly half the ship unnecessarily, it was not resorted to. But, in vessels more recently constructed, a great improvement has been introduced in this respect. From each of the compartments, a pipe leads directly into the engine-room itself, without communicating with any other part; so that, by means of a cock, the water can at once be pumped out by the engine, or else can be confined to the compartment itself, and pumped out by hand, when it is not desirable to let it flow into the engine-room.
As little time as possible was lost in completing the necessary repairs, and in rendering her in all respects fit to undertake the long and unknown voyage she was about to perform. At length she was cleared out for the Russian port of Odessa, much to the astonishment of every one; but those who gave themselves time to reflect hardly believed it possible that such could be her real destination.
She was armed with two 32-pounder guns, mounted on pivot, or traversing carriages, for the purpose of throwing either shot or shell, one being placed forward and the other aft, as in all armed steamers.[1]
On leaving England she had on board about sixty men and officers; but, during the operations in China, she usually had about ninety men and officers.[2] Her daily consumption of fuel was about eleven tons.
She had no paddle-boats; but in other respects, she was well found in boats, while in China. She had two cutters, pinnace, gig, jolly-boat, dingy, and always a large Chinese boat. A large platform was also built between the paddle-boxes, instead of the small bridge which is usually constructed there. This platform covered the whole space between the paddle-boxes, and was found particularly convenient, when troops were on board, as it was always occupied by the officers, while the decks were crowded with the soldiers. There was also a 6-pounder brass pivot gun, mounted upon the bridge, which was very useful for trying the range. A rocket tube and a supply of rockets were always kept in
