The second-class protected cruiser _Bristol_, launched at Messrs. John Brown and Co.’s Clydebank establishment in February last, is of special interest as she embodies the introduction of yet another method of propulsion. When it became known that an experiment was to be made there was some speculation as to whether the gas system was to be tried, as the experiments in the gunboat _Rattler_ are understood to have been successful, and it is well known that more than one engineering firm has been giving attention to the subject. The _Rattler_ experiments did not prove that the requisite power could be developed by the method, and the _Bristol_ experiment is an installation of the “Brown-Curtis” turbine, this vessel being the first of recent years for the British Navy in which Parsons turbines have not been placed. She is of 4850 tons displacement and is to have a speed of 25 knots. Four sister ships, also building, are fitted with Parsons turbines. The _Bristol_ will have twelve Yarrow water-tube boilers, and the furnaces will use either coal or oil. Two other British warships, one an improved _Bristol_, are to be fitted with Curtis turbines, besides vessels for other Powers, and another experiment which will be watched with considerable interest is the combination of Parsons and Curtis turbines proposed to be placed in the 32-knot destroyers under construction for the Argentine Government by Cammell, Laird and Co. Foreign Governments, the French especially, have made many experiments in warship building and designing, for the attempts to develop fixed types have failed in this country as elsewhere, as the type has been generally superseded almost before the specimen vessel has been completed. This was particularly the case with the turrets when first introduced. The barbette system has descended from it, and in turn has been subjected to numerous changes. The amount of sail carried by modern gunboats and cruisers, if any, is reduced to the smallest quantity, the masts being little else than signalling poles; while in the big battleships and cruisers the masts, which were at one time of the “military” pattern and were used as hoists for ammunition, being made hollow and of large diameter for the purpose, have in their turn given way to skeleton masts and tripods, and combinations of the two, of a strictly utilitarian character. The bringing down of a mast, fitted for wireless telegraphy, at the first round in some firing practice recently, showed that naval architects have not yet reached the last word in the development, or diminution, of the masts. Some exceedingly powerful battleships have been built in this country for foreign nations, among the latest being the _Minas Geraes_, by Armstrongs on the Tyne, for Brazil, which represents all that is most modern in the construction of a warship, this vessel and her sister being two of the most powerful battleships ever designed. They show, too, what private yards can accomplish.