And indeed, had the prisoners but known it, the Allies were hard at work preparing to take the fortress and town. To do so from the north was, as has already been said, impossible, for the harbour was far too broad to allow of an effective bombardment, and, moreover, its northern shore was commanded by heavy batteries. Therefore, as we have seen, the Allies marched to the Chersonese heights, the British left resting upon Balaclava, while the French lay to our right. Opposite them was the southern face of Sebastopol, up till then undefended by very formidable works, though the plan of defences had long ago been sketched and partially executed. But no sooner was the object of the allied army discovered than hordes of Russians quickly transformed this side of the fortress, throwing up powerful earthworks, and arming them with guns drawn from the inexhaustible arsenals at the dockyard. And while they slaved, the British and French planned their own earthworks, and set fatigue-parties to work. By October 16th they were completed, and after a council of war, in which naval as well as military officers took part, it was decided that the bombardment should commence on the morrow, the batteries on the Chersonese heights doing their utmost to reduce the works in front of them, while the ships engaged the forts on the sea-face to distract attention. The cannonade was to be followed by a general assault. A moment's reflection will show the reader that nothing could have been wiser than a preliminary battering with cannon-shot, followed by an assault; but how the ships could have aided in one or the other it is difficult to understand. As the forts were placed on elevated plateaux, and in some cases on the cliffs, an assault by means of landing-parties was out of the question. Therefore the Russian commander would not, and did not, trouble to garrison them with infantry, but merely assured their having a sufficiency of gunners to replace possible casualties. Then again, compared with a heavily-armed stone fort, what is a wooden ship? It was a hopeless and a foolish undertaking, and it is not surprising that the allied fleet retired, having done little damage, although they had suffered severely themselves. On shore things were perhaps a little more satisfactory. Three star shells fired from Mount Rudolph, the French battery, gave the signal for the bombardment at an early hour on October 17th, and from that moment for four awful hours the Allies' combined 126 heavy guns poured a hail of shell into the Russian defences. These consisted of outworks and of various forts of formidable power known as the Flagstaff Bastion, the Malakoff, and the Redan, the whole armed with 118 guns, not to mention a thousand and more of lighter casting to be used in case of assault.