The most important points of the main line of defence were:  1st.  The Flag-staff Bastion. 2d.  The Central Bastion. 3d.  The Malakoff. 4th.  The Redan. 5th.  The little Redan.  The command of the first was about fifteen feet, its ditch thirty feet wide and from twelve to fifteen feet deep.  A portion of the scarp was provided with palisades some ten feet high.  The construction of the Central Bastion was similar to that of the Flag-staff, but weaker in profile.  The relief of the other works was still less.  The command of the Malakoff was about fourteen feet, its ditch eighteen feet wide and twelve feet deep.  The thickness of parapet in these works was generally about eighteen feet, and the bombproofs were covered with timber eighteen inches thick and six feet of earth.  The loop-holed walls connecting these works were covered by a rampart and parapet, or entirely replaced by a simple parapet.  Many of the embrasures were revetted with the common boiler iron ships’ water-tanks filled with earth.  The same material was sometimes used for traverses.  Rope mantelets were used to protect the artillerists at the pieces from rifle balls and small grape.  Great attention was given to the construction of bombproofs to cover the men from vertical firing.  These were sometimes under the rampart and the second line of defence (where there was one), often under special traverses, or entirely under ground, and occasionally excavated in the solid rock.  Some had fireplaces and chimneys, and were well ventilated.  Interior slopes were revetted with gabions, crowned by fascines and sand bags.  Gabions were also employed to repair the damage caused by the enemy’s artillery.  Abattis, military pits, caltrops and spikes, stuck through planks, and explosive machines were employed in front of different parts of the defences.  Mines were resorted to in front of the Flag-staff Bastion to retard the French approaches.  They were made in rocky soil with craters from twelve to fifteen feet deep.  The Russian counter-approaches generally consisted of fleches, united by a simple trench.

Captain McClelland, one of our officers sent to the Crimea, from whose valuable Report most of the foregoing details are gathered, adds the following remarks upon these works of defence:—­

“From the preceding hasty and imperfect account of the defences of Sebastopol, it will appear how little foundation there was for the generally-received accounts of the stupendous dimensions of the works, and of new systems of fortifications brought into play.  The plain truth is, that these defences were simple temporary fortifications of rather greater dimensions than usual, and that not a single new principle of engineering was developed.  It is true, that there were several novel minor details, such as the rope mantelets, the use of iron tanks, etc., but the whole merit consisted in the admirable adaptation of well-known principles to the peculiar locality and circumstances of the