QUICK-FIRING GUNS IN HARBOUR DEFENCE. 
299 
considerable fraction of the length of deck in the line of fire, for the 
decks of modern ships present many objects that will keep a shot 
from glancing. Besides the gun is laid by the. sights for elevation as 
well as direction, so that less elevation is really given to it as the ship 
comes closer. Thus we may fairly say that the ship is likely to be hit 
by rounds fired at the same tangent-scale elevation whilst she changes 
her range by 150 yards, or, taking the extreme case of a speed of 22 
miles an hour, during at least half-a-minute. Thus even with the 
6-inch gun we might expect to get off three rounds by rapid fire at 
each elevation at which ranging rounds are fired, or six with the 6-pr. 
at the least. 
From this it would seem that Avith a rapidly moving target, using 
G-inch or 4‘7-inch guns, the first system (a) proposed would be most 
suitable, and with these guns a range-finder Avould probably be pro¬ 
vided ; while with the 0-prs. no range-finder would be required under 
any conditions, so use (#). 
In the attack of torpedo-boats, Avhose movement is so extremely 
rapid while presenting such a small target, it Avould be advisable to 
fire at the nearest boat until disabled or out of range or training. 
From the shortness of a torpedo-boat, added to its speed, it follows 
that deflection must be given in the direction of its movement, or the 
shots will fall behind it. 
As the guns in a “ dispersed ” group, say of three guns, as above Propose^ 
described, might be as much as 40 yards apart, it folloAvs that, in corre?ti^ g 
shooting at a target moving on a flank, such as a ship advancing up mission • 
the line of coast towards the group, the gun on the flank furthest of the e^ns. 
away from the target would be nearly 80 yards further away from the 
objective than the gun on the nearer flank, and the centre one 40 
yards. It must be decided whether to take this into account and 
endeavour to reduce to a minimum the disadvantages of laying guns, 
whose ranges really differ as much as is shown above, as if they were 
all at the same distance from the objective; or Avhether to disregard it 
altogether. The disadvantages must be considerable, and I would 
propose a way of surmounting them, though this introduces fresh 
complications in the laying, and causes parallelism of fire. This latter 
would not in this case have the disadvantages attending it when using 
position-finders with heavy guns, as it would not be a question of 
knocking armour to pieces by blows planted close together, but of 
attacking unarmoured spaces with man-killing projectiles; and there 
the parallelism would only mean distribution of the fire, rather an advan¬ 
tage than otherwise, if only the increased difficulties of the laying can 
be got over. We are taught that the guns must be laid on some 
prominent and unmistakeable part of the ship, such as the bow, centre 
funnel, stern, &c., to give the layers some well-marked aiming point, 
and to ensure uniformity ; the Fort Commander directing his fire on 
particular portions, if necessary, by giving deflection. Still keeping 
to this principle I would propose, in the group of quick-firing guns 
described above, that the Nos. 1 of the guns should be instructed to 
lay each on a different prominent point of the ship, on the order “ Dis¬ 
tribute the fire.” The No. 1 of the gun on the farther flank would 
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