“My efforts to make a ship safe, from an engineer’s point of view, lie in the method of propulsion. My plans are to apply all the engine-power of the ship to pumps for propulsion, and which can be used for pumping out leakage and propelling at the same time. In the largest pump I have made, 800 indicated horse-power discharged 350 tons of water a minute, and propelled the vessel faster than her sister ships with twin screws. The hydraulic propeller is of greatest value for the highest speeds, and has the greatest power of control. As the hydraulic is capable of subdivision to a great degree, the greatest amount of safety is possible. After an experience of sixty years of hydraulic propulsion, I am still of opinion that it is the means by which greater safety can be obtained at sea, and by which the highest speeds can be obtained with safety and economy.”[97] [97] _Institute of Marine Engineers’ Transactions_, vol. ix. This, however, was said before such phenomenal speeds were obtained with turbines and combined turbine and reciprocating engines. A number of lifeboats fitted with jet-propelling machinery have been built by, among others, Messrs. Thornycroft, and have given every satisfaction. Whatever be the advantages of the system, and they are many, the drawbacks are very great, and the hydraulic method has been generally condemned because of the friction engendered by the pumping of such large quantities of water, and the probability of the inlet orifices becoming choked by sand, mud, or floating matter. Notwithstanding its evident advantages, the screw propeller, whether single or double, had many enemies. It was asserted to be the cause of premature decay in both wood and iron vessels, and stringent orders were even given to ship captains to use canvas except in extreme cases when steam was absolutely necessary. “Our screw navy is, therefore,” said a paper of that period, “more of a sailing than a steam navy.” The twin-screw arranged by Messrs. Dudgeon was claimed to have developed the principle in such a way as to leave no doubt of its superiority over the single propeller. Twin-screws were no new thing at this time. Captain Smith, known as “Target Smith” because of his movable target in use on the _Excellent_, had experimented with some with a considerable measure of success, but it was Messrs. Dudgeon who solved the problem of twin-screw propellers for ocean-going steamers. They demonstrated that as good results could be got from two small propellers as from one large one. The first application of twin-screws on the modern principle was made by Messrs. J. and W. Dudgeon in the _Flora_ in November 1862.