The fortress howitzers were not mounted in accordance with the authorized armament table, though the character of the ground rendered them essential. The 6-inch howitzers were of little use, having only a short range; for this reason General Smirnoff ordered eight 9-inch coast howitzers to be mounted in two batteries on the land side. They were taken from the coast batteries, where they had been quite idle, and were mounted in rear of the first line, from which position they did excellent work against the enemy's siege batteries, approaches, and places of concentration. They were of the greatest use up to the end of the siege. For the twenty 6-inch (43 cwt.) guns (latest pattern) which arrived in the Fortress in March and the twenty-one carriages (1877 pattern) new batteries were built. The carriages had to be adapted to the guns, but it was a very difficult operation and not successful, and they were continually under repair. On the land front new batteries were being constructed right up to the end of the siege, to take either fresh guns from the fleet or repaired Chinese guns, and whenever the plan of defence was changed the guns again had to be moved. Most of the heights round Port Arthur on which the forts and batteries settled on by the Committee (which had drawn out the scheme for the armament of the Fortress) were placed were sloping on the outer side, while on the inner they ran sharply down into deep ravines. It was, therefore, almost impossible to site these batteries to shoot well and yet to keep them concealed. If they were placed near the top, there was very little ground in rear of the guns, and they were visible; if they were placed further back and down the rear slope, all idea of shelling the approaches up the front slope would have to be given up. This was the reason why permanent batteries and fortifications were placed on open ground where they were visible to the enemy, and why guns were mounted in the open on the permanent forts. The reserve of guns was originally intended to be organized by units of artillery, but in April it had to be broken up to arm new points. Later on another reserve was formed of guns from the unattacked left flank of the western front and from the central wall.