■ CASTING 100-TON G TJN, 
(36*1 ft.), having a maximum diameter at bottom of 1‘23 metre (4 ft.), 
and a minimum diameter at top of 0 # 87 metre (2*85 ft.), so that the 
breech of the gun was downwards. The core had a maximum dia¬ 
meter at bottom of 40 cm (1*3 ft.), and a minimum above of 34 cm (1*1 ft.) 
To fill such an enormous cavity and its siphons there was required a 
mass of some 66 tons of cast-iron. This would have involved no great 
difficulty if reverberatory furnaces capable of containing the full charge 
had been built round the pit; but no such appliances existed, nor was 
it deemed advisable for a mere first experiment to spend a large sum of 
money in building new furnaces. Thus the foundry, confined to exist¬ 
ing constructions, was compelled to face the exigencies of the casting 
with four large reverberatory furnaces standing round the pit capable 
of holding a charge of 40 tons, and six small reverberatory furnaces 
capable of holding a charge of 27 tons, but situated in a neighbouring 
building at a distance of from 80 to 100 yds. from the pit. The metal 
to replace casual loss, and to feed the deadhead on the shrinking of 
the casting, was to be furnished from old guns run down in a small 
furnace. 
The transport of the metal from the smaller reverberatory furnaces 
to the pit was effected by three ladles capable of containing 9 tons 
each. They were manoeuvred by the foundry hydraulic crane. 
The operation of casting was brilliantly successful. The transport of 
the molten metal in successive trips took 35 minutes; the metal of the 
ladles, mixed with that of the reverberatory furnaces, passing through 
the channels, poured down the siphons and filled the mould in 19 
minutes * after which the water was- turned on to circulate in the core, 
to initiate the cooling. The feeding of the deadhead was carried on 
for 4 hours, requiring a little more than 5 'tons of metal. 
Judging from the regular and precise way in which the casting was 
effected, it may be taken as highly probable that the block will be 
perfect. 
The transport of such an enormous amount of molten metal, com¬ 
bined with the necessity of a rapid and uniform flow of the whole mass 
properly mixed, constitute without doubt an operation of unusual 
difficulty ; and the excellent result is a proof that every arrangement 
necessary thereto had been properly made. The' success redounds to 
the credit of the General who proposed the gun, of the intelligent 
direction of Colonel Giovanetti, and of the co-operation of the hard¬ 
working establishment of the Turin foundry, among whom the 
foreman, Mr. Daguino, deserves especial mention. 
In a few days the work on the casting will be commenced, and we 
may reasonably hope that it will be completed in a year. 
