The "Polyphemus", which has just been ordered form Malta to join the flag, is a "twin screw special torpedo vessel (protected ram)", and this description practically sets forth the purposes to which the Polyphemus would be put in war.  She is the only vessel of her kind in our Fleet, and, speaking generally, may be said to represent the views of certain extremists among Naval officers of twenty years ago, who at that time were loudly proclaiming the advantages of the ram as an almost resistless means of offence.  

The idea of the ram of course goes back to the times of the old galleys of Greece and Rome, whose principal weapon it was.  In the days of the old sailing men-of-war  with which England won the mastery of the seas, broadside to broadside fighting was the accepted method of warfare, and there was no place for the ram.  It dropped out of memory, indeed, until early in the sixties of the present century, when, on the advent of the steam propelled iron-clad, the ram reappeared as a weapon of special potentialities, owing to the fact that the most vulnerable part of the modern iron ship is below the water-line, where the side armour ceases to afford protection.  All our early iron-clads from the "Warrior" onwards have been fitted with the ram, which soon showed it's value under the new conditions, first in the American Civil War, and then at the battle of Lissa, where the Italian flag-ship was sunk by one blow from the ram of an Austrian iron-clad.  Both England and France after this paid attention to the construction of vessels specially built for ramming, of which our own present "Rupert" and "Hotspur" are existing specimens.  In them a big gun equipment is placed in a single turret in the fore part of the ship for use in end on fighting, with the idea of helping to clear the way for the onset of the attacking ship by an attack with heavy projectiles.  The advocates of the ram after that put pressure on the Admiralty in England to build a vessel specially for ramming and without heavy guns at all.  The result was the present "Polyphemus", begun in 1878 and completed in 1882.  There was reason in building her, for the guns of the day were slow-firers and the ships of the day slow movers, while the "Whitehead" torpedo was still a comparatively unknown quantity.

The leading features of the "Polyphemus'" design, as our photographs show, are a low hull, exposing only a small mark for an enemy's fire, the portion of the ship above water being also turtle-back shaped and covered with thin armour to project light gun projectiles that may strike.  A high rate of speed was given the ship from the first, between 17 and 18 knots, with a powerful ram-prow and a torpedo equipment of five submerged tubes.  These are her special means of offence, the ship's defensive armament being confined to a few light guns for repelling boat or torpedo attacks, mounted on the superstructure above the hull, where the ship's boats are carried and whence the ship is worked at sea.  The "Polythemus" is a vessel of 2640 tons displacement, with length 240ft, beam 40 ft and mean draught 20ft.  She cost originally (according to Brassey's Annual) £174,450, and has cost since then, owing to alterations and reconstructions, probably a good deal more over again.