15 knots, say, does not convey any correct idea as to whether the speed is high or not for the ship, unless it is coupled with the size or length of the ship. Fifteen knots would be a high speed for a vessel 150 ft. long, but quite a moderate speed for a vessel 500 ft. long. A measure of speed is obtained by comparing it with the

V

square root of the length. When this ratio is above unity we

have a speed which is high for the ship, and which requires a very large expenditure of horse-power to obtain. It is interesting to note that, in the Atlantic liners, as speeds have gone up, so lengths

have increased, keeping the ratio

V

nearly constant. Thus we

When, however, we come to cruisers, we find that we have speeds which are much higher, relative to the size of ships. Thus we have

As regards economy of propulsion alone it would doubtless be better to increase the length of cruisers, but it is not desirable to make them longer than absolutely necessary, as the longer ship requires heavier scantlings and more protection, and affords a larger target than the shorter ship, besides being less handy in turning. The gain in propulsion obtained by the longer ship would be more than lost in other directions.

"In some quarters, whatever length is decided upon, it is pronounced to be 50 ft. too short, as a rule, without any investigation of what such an addition would involve. Where criticisms have been associated with alternative proposals -and such cases are few-it has been the writer's task to investigate them. In no single case so treated has it appeared that the proposals made would have given the gains in propulsion anticipated, in association with other supposed advantages. As a rule, the proposals made have been proved to be incompatible with a due provision of stability."1

Comparison between "Juno" and "Hyacinth."-A comparison between these two ships is interesting, because they have the same dimensions and displacement, but the weight is disposed differently, giving very different qualities.

Thus the Hyacinth got considerably more both in speed and armament than the Juno on the same displacement. The reason of the difference is found in the different types of machinery. The Juno had cylindrical boilers of 155-lb. pressure, with engines of 39-in. stroke and 140 revolutions. The Hyacinth had watertube boilers of 300-lb. pressure, with engines of 30-in. stroke and 180 revolutions.

The machinery of the latter ship, developing 25 per cent. more power at natural draught, was obtained on rather less weight than in the Juno on account of the watertube boilers, higher pressure and quicker running engines. The smaller height of the engines also made it possible to get them beneath the protective deck, and so the armour protection to the cylinders, necessary in the Juno, was saved in the Hyacinth. The weight thus made available was used to replace the 6 4:7-in. guns of the Juno by 6 6-in. guns in the Hyacinth, and thus a ship of much greater power as a fighting machine was obtained.

Comparison between "Topaze" and " and "Sentinel."-An example of two recent designs having nearly the same displacement,

1 Sir William White, K.C.B., Cassier's Magazine, August, 1897.

but of different qualities, is seen in the third class cruiser Topaze and the scout Sentinel. The following table shows the main features of these vessels:

In the latter case it is seen that the ship has only a slight armament of 12-pounder and smaller guns, with only 150 tons of coal at the designed draught. The machinery is 17,000 I.H.P. for the 25 knots desired. Thus the ship is only able to carry herself and her machinery with a comparatively small load, in order to reach the high speed of 25 knots. In the former case the ship is able to carry an armament of 4-in. guns, with a large amount of coal, but this increase of load carried can only be obtained by having the lower speed of 213 knots. It is seen that an increase of speed from 213 to 25 knots, or an increase of 15 per cent., means an increase of nearly 75 per cent. on the power.

CHAPTER XXIV.

NOTES ON THE LOSS OF H.M.S. “VICTORIA" (June 22, 1893).

CIRCUMSTANCES leading up to the collision:

The fleet was proceeding in two lines, the Victoria leading the starboard column, the Camperdown leading the port column. The ships were proceeding at a speed of 8.8 knots, the two lines being 1200 yards apart. At the time of the signal to turn, the helm of Victoria went "hard-a-starboard" 35° (corresponding to a tactical diameter of 600 yards). The helm of Camperdown was put at 28° (corresponding to a tactical diameter of 800 yards). When the ships had turned through eight points, it was recognized that collision was inevitable, and the port engines of Victoria and the starboard engines of Camperdown were reversed, but this had little effect, as the collision took place one minute later. The speed of the ships at the time of the collision was from 5 to 6 knots.

The Camperdown struck the Victoria nearly at right angles, about 65 ft. abaft the stem. The blow was just before important transverse bulkheads (Fig. 208). Both the ships turning rapidly at the time of the collision caused the sterns to swing together, and this considerably widened the breach in the side of the Victoria. This, together with the hole caused by the original blow, destroyed the connections of the bulkheads above-mentioned with the side of the ship. The value of these bulkheads was thus completely destroyed, and the compartments on either side were thrown open to the sea.

For the first minute after the collision the two vessels were locked, and during this time the Victoria heeled slightly to starboard and settled a little by the bow. After the Camperdown had cleared, the Victoria continued to settle by the bow and to increase her heel to starboard. These movements proceeded gradually for

See also end of Chapter VI. regarding the question of watertight doors.

about ten minutes, when a sudden lurch to starboard took place. The ship turned bottom up and finally sank by the head.

It will be desirable to briefly describe the main features of the Victoria in so far as they bear on this question. The ship was built to carry two 111-ton guns in a turret forward, and

the great weight of this armament and the armour necessitated a somewhat low freeboard forward, viz. about 11 ft. Abaft the turret was a battery with fronts inclined abaft the beam, as shown, to give a large arc of training to the heavy guns. These fronts had armour doors in them, and the sides of the battery

T

W.L.