The French, who had formed somewhat more favourable opinions of iron armour than we had, had, after Sinope, already commenced the construction of five floating batteries which were to carry armour. They were wooden ships of 1,400 tons displacement, with four-inch armour over their hulls. They carried eighteen fifty-pounder guns and a crew of 320. As originally designed they were intended to sail, although they were fitted with slight auxiliary steam power. When completed they were found unable to sail, so pole masts were fitted to them. Artificial ventilation was also supplied and their funnels were made telescopic. The designs of these vessels were sent to the British Admiralty, who, after considerable delay, built four copies, the _Glatton_, _Meteor_, _Thunder_, and _Trusty_. These, however, were not completed in time to take any part in the war. So soon as the French armoured batteries were ready they were sent out to the Crimea, where they joined a large fleet which had been prepared to attack Kinburn, which was bombarded in October, 1855. In a very short while the forts were totally destroyed, and with very small loss to the armoured batteries. The effect created by this was so great that four more armoured batteries were ordered in England, the _Etna_, _Erebus_, _Terror_, and _Thunderbolt_. In the Baltic, to which a British fleet, under Admiral Napier, had been sent, the Russians kept behind the fortifications at Kronstadt, and nothing was accomplished beyond the bombardment of Sveaborg, and the destruction of the town and dockyard. Some small bombardments also took place in the White Sea and on the Siberian coast, where Petropavlovsk was attacked and the attack was defeated, and such other actions as took place were generally unsuccessful. It had become abundantly clear that against fortifications wooden ships had very small chance of success. Incidental items of naval interest are that in this particular war Captain Cowper Coles mounted a sixty-eight-pounder gun upon a raft named the _Lady Nancy_. This attracted so much attention from the small target, light draft and steady platform, that Coles was sent home to develop his ideas. In this war, also, mines appeared, the Russians dropping a good many off Kronstadt. Those used by the Russians were filled with seventy pounds of powder, and exploded on contact by the familiar means of a glass tube of sulphuric acid being broken and the acid falling into chlorate of potash. No material damage was done to ships by this means, but a considerable number of those who had picked them up and investigated them were injured.