We may turn now from some of the more technical problems incurred by the steamship to a consideration of some of those which are of a more practical nature. It is just because the ship has in modern times taken on a dual character--become something else besides a sea-craft--that the possibilities of any accident occurring to her have increased tremendously. It is obvious that so long as you retain simplicity, there is not much chance offered for accident; but as soon as you begin to make the ship a mass of complications, then instantly there arise on every side facilities for mishap of some sort or another. Fractured shafts are happily of rare occurrence, but when they happen at all they are naturally far worse for the single-screw ship than the vessel having two or more propellers. When a connecting rod or piston-rod breaks the matter is serious, for it is not advisable to attempt repairing the same at sea, since unless the thing is done quite effectively, there is danger of the rod giving way again, and if the piston were to be disconnected suddenly from the crank, it would smash the engine. The first time that a tail-shaft was ever repaired at sea was in October of 1900, when the chief engineer of the s.s. _Athena_ successfully brought about so interesting an achievement, and a similar feat was performed about five years later on the s.s. _Milton_, so that the ship was able to steam at the rate of a hundred miles per day. But a far more difficult and rarer task was that of the chief engineer of the s.s. _Matoppo_, who for the first time on record actually renewed the blades of the propeller at sea. This would be no mean performance in the case of fair weather, but, as it happened, there was a high sea running at the time, and the work was rendered both difficult and dangerous. One of the most tiresome accidents occurs when the steamship loses her rudder, or it becomes so much damaged as to be unserviceable. In the case of a twin-screw ship, as we have already intimated, the consequences are not necessarily serious, and ships have succeeded in making long passages steering by means of their two propellers. But in the case of a single-screw ship the carrying away of the rudder is of greater consequence, and it becomes necessary to rig up a jury rudder as well as possible. This consists in towing astern a spar which is attached to either quarter of the ship by means of hawsers.