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MINUTES OE PROCEEDINGS OE 
square feet, and tlie total number of shot which struck the granite was 65, 
whilst the total number which struck the shield was 22; it therefore follows 
that the blows delivered on iron were as 1 to 5 square feet of surface, 
whereas they were only as 1 to 7*9 square feet of granite. In point of 
value they were at the rate of 520 foot tons per square foot of surface on 
iron, and of only 302 foot tons per square foot of granite, so that, whether 
considered in regard to the number or the force of the blows, the iron shield 
received a much more severe battering than the granite wall. The firing 
at the former, moreover, was almost entirely with steel shot, whilst at the 
granite cast-iron was almost exclusively used. 
18. The superiority of iron does not, however, rest merely upon its 
shot-resisting power, for, as the Committee have already observed, the 
destruction of the lower tier of casemates in a granite structure involves the 
abandonment of the upper and barbette batteries, whilst it is probable that, 
owing to the enormous strength which must be given to an iron battery to 
give it sufficient shot-resisting power, there will, even after such an attack as 
might have rendered the lower casemates untenable, remain more than suffi¬ 
cient strength for the support of the general structure. Finally, the Committee 
would observe, this experiment has proved that whilst the attack of a 
properly constructed iron-built battery would be hopeless, except with steel 
or hardened shot, at a range not much exceeding 600 yards, the destruction of 
a granite fort may readily be effected with cast-iron shot at 1000 yards. 
It is proper to add, that considered as a granite fort with iron shields, the 
One now reported upon appears not to have been as strong as such a 
structure might be made with those improvements which the result of the 
present costly experiment will doubtless suggest to the Department of 
Works, if any more such works are to be designed* But the Committee 
have for the foregoing reasons no hesitation in recording their opinion, that 
granite shotild if possible not be used in exposed parts of the structure of 
forts liable to be regularly engaged by heavily armed iron-clads. That 
tvhen unavoidably used, it should not be combined in the piers with brick¬ 
work or any other inferior material in the manner in which it was combined 
in this structure, and that it would be far preferable to provide forts in 
such situations with external defences entirely of iron. 
The iron-faced flanks have not yet been attacked, and the Committee 
must wait for a further supply of steel shot before proceeding to do so. 
This will also afford time for clearing away the rubbish and examining the 
rest of the structure more minutely. 
