The steam engine as a means of propulsion was not to be allowed to remain unchallenged, but the only attempt at rivalry to merit serious consideration was that associated with the _Waterwitch_, in 1866, and Mr. Ruthven’s system of hydraulic propulsion. Although the first patent was taken out in 1839 and another followed in 1849, and a small boat fitted with the Ruthven machinery was placed on the Thames and a working model was shown at the Exhibition of 1851, engineers did not take kindly to it. The objections, apparently insuperable, were that the water had to overcome the resistance of a very large rubbing surface, and that the perforated bottom of the ship was liable to be choked in shallow water, and it was also contended that the cost of increasing the power beyond a certain rate was prohibitive. The advantages of the system, and they were undeniable, were that the ship could be propelled either end foremost, or turned, or brought to a stop and restarted without stopping or reversing the engines. A vessel was built, partly at the expense of the Prussian Government, and fitted with engines of this type, and was said some years afterwards to be still running on the Oder. In 1863, Mr. Murray, Chief Engineer of Portsmouth Dockyard, reported, on the application by Mr. Ruthven, of Greenock, for an extension of his father’s patent, that he saw no reason why the speed attained with the Ruthven propeller should not equal that obtained with the paddle or screw, and that he had been on official duty for the Admiralty to Belgium to inspect and report upon a vessel built by the Cockerill firm and called the _Seraing_, which was equipped with the Ruthven propeller. He recommended the Admiralty to give the principle serious attention. [Illustration: RUSSIAN CIRCULAR MONITOR “NOVGOROD.” _From a Contemporary Wood Engraving._] [Illustration: THE FRENCH IRON-PLATED SHIP “MAGENTA.” _From “The Illustrated Times.”_]