_From the Drawing in the Victoria and Albert Museum._] It was in this ship that a type of engine was fitted to which, so far, we have not referred. This was the oscillating kind, and was destined to become pretty well universal in paddle-ships, though not without serious opposition at one time. This type had been patented as far back as 1827, by Joseph Maudslay, and in the _Aaron Manby_, already mentioned, the machinery was of an oscillating nature, for which Manby had obtained a patent in 1821, but even farther back still--in 1785--William Murdoch had proposed the use of oscillating cylinders. It is only fair to Maudslay to say that he had independently worked out this arrangement, and so afforded yet another instance of the possibility, which I have enunciated before, of different inventors working at the same set of problems and bringing about a similar method of solution. In the accompanying illustration is shown Maudslay’s original oscillating engine. In this type the cylinders, instead of being fixed, oscillate, and the necessity of the connecting rod is dispensed with, for the cylinder is placed immediately underneath the crank shaft, as a reference to the illustration will show. Each cylinder is mounted on trunnions in the same manner as a cannon, being placed at a point about the middle of the cylinder’s length, so that it can swing, or oscillate, in such a way as to correspond with the arc which the crank makes in its movement. Thus there are both weight and valuable space saved. In the instance before us the condenser is placed between the two cylinders; the central trunnions communicate with the condenser, and the outside trunnions with the steam pipe. But Maudslay’s engines did not at that time find the appreciation which had been hoped for, and it was not until 1838, when they were re-introduced by John Penn, that they received their full favour. We shall return to the oscillating type when we come to consider the _Great Eastern_. But we may remark that the interesting steamship illustrated opposite page 130 was also provided with the oscillating pattern. This is the packet steamer _Pacific_, which was built in 1853 for the Mediterranean service, and is another example of a vessel constructed on the wave-line system. She was built of iron, and had nine water-tight compartments.