486 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



a report to the French Admiralty. In view of the deficien- 

 cies of most of the materials hitherto employed by steam 

 users for the above purpose, the claims of cork to such em- 

 inent practical utility may be worth an examination. La 

 MetaUurgie. 



THE NEW MONSTER CANNON OF ENGLAND. 



When the English had cast their cannon, the " Woolwich 

 Infant," of 35 tons, it was supposed that the limit attain- 

 able by engineers had been reached, and would not soon be 

 surpassed. But the success of the first infant seems to 

 have been only an incentive, and now the world is aston- 

 ished by the appearance of a new monstrous cannon of 81 

 tons, destined to form a part of the armament of the iron- 

 clad Inflexible. It is . well understood, even by those not 

 professional engineers, that the perfection of metallurgical 

 processes has enabled the art of defense to keep pace with 

 that of attack. The old cannon of 25 tons, and its projectile 

 of 700 pounds, were no sooner eclipsed by the production of 

 heavier iron-clads, than the cannon of 35 tons was made in 

 order to overcome the new resistance. No sooner was the 

 latter ordnance finished than the Russians constructed an 

 iron defense of 20 inches' thickness, on which the 35-ton can- 

 non had no effect, as shown by the experiments at Shoebury- 

 ness and Woolwich. It became then urgent to construct a 

 new type of cannon more powerful than its predecessors, 

 which should be able to cope with the defenses of the Rus- 

 sian monitors. An 81 -ton monster is accordingly now near- 

 ly finished. It is constructed according to the method of 

 Frazer, which differs from that of Armstrong in that the 

 fibres of the hoops around the breech which inclose the 

 steel tube, instead of being placed lengthwise of the cannon, 

 are disposed transversely to its axis, which gives the metal 

 greater resistance to the shock of explosion. The whole is 

 formed of seven pieces : five hoops of forged iron, one tube 

 of steel, and the solid breech end. Its total length is 27 

 feet; its calibre, when finished, will be 16 inches, but the 

 first series of trials will be made with a calibre of 15 inches, 

 after which the gun will be still further bored out. Its 

 trial will take place in July at Shoeburyness, the charge 

 being over 300 pounds of powder, and the weight of the 



