====================+========================+====================== | _Arethusa._ | _Bristol._ --------------------+------------------------+---------------------- Displacement (tons) | 3520 | 4800 Armament | 2--6in. | 2--6in. | 6--4in. | 10--4in. | 4 above water t. tubes | 2 submerged t. tubes Side protection | 2½″ | _nil._ H.P. | 30,000 | 22,000 Speed (est.) kts. | 30 | 25 ====================+========================+====================== Fuel supply has never been given out officially, but it may be stated that, roughly, by making use of oil fuel in the _Arethusa_, a radius equal to that of the _Bristols_ was secured with a considerable saving in weight. Incidentally, this is one of the most interesting examples of how the progress of invention makes possible to-day the impossibility of yesterday. When the _Bristols_ were designed they were the “best possible” of 1908. Four years later oil fuel had opened out an entirely novel vista. In the 1913–14 Estimates another eight of similar cruisers were provided for, with, however, 250 tons odd added to the displacement and an extra 6-inch gun forward allowed for; though this, however, was altered afterwards, as this batch of cruisers, the _Calliope_, _Caroline_, _Carysfort_, _Champion_, _Cleopatra_, _Comus_, _Conquest_, _Cordelia_, do not carry any 6-inch guns forward like the _Arethusa_, but mount a couple, one abaft the other aft--a wise arrangement, as a heavy weight forward does not make for sea-worthiness. The _Arethusas_ and the “C” class, therefore, compare as follows:-- ==============+==========+============+=================== | Forward. | Amidships. | Aft. --------------+----------+------------+------------------- _Arethusas_ | One 6in. | Four 4in. | One 6in., two 4in. “_C_” _class_ | Two 4in. | Six 4in. | Two 6in. ==============+==========+============+=================== which indicates a couple of 4-inch guns gained for the extra 250 tons. In the 1914–15 Estimates four similar vessels were provided for, but no details whatever have been published concerning them. _DESTROYERS IN THE DREADNOUGHT ERA._ The Dreadnought era, while simplifying types of big ships, was the early institution of two distinct types of destroyers, plus an experimental vessel which was not duplicated. The original staple idea of Dreadnought era destroyers was to build very fast ocean-going destroyers for fleet work, and smaller craft, “coastals,” for local duties. A considerable flourish of trumpets accompanied the announcement of this decision, which, however, was in no way really novel. It merely reproduced in destroyers the long exploded idea of sea-going and coast-defence ironclads.