the australians from "hobart" with their hotchkiss gun arrived at dawn on 10 august but the gun had to be dismantled for loading, which reduced its rate of fire to once every five minutes, while its 32 he rounds and 32 solid shot lasted. on 11 august, the italians bombarded then attacked the west end of the assa hills at punjab ridge with a brigade of infantry, pushed back the defending company of the 3rd battalion, 15th punjab regiment, then repulsed a counter-attack; attacks on mill and knobbly hills failed. on 12 august, all of the british positions were attacked simultaneously and by the evening mill hill, the least fortified position, had been captured after a determined resistance by troops of the northern rhodesian regiment. two of the east african light battery [[howitzer]]s were lost and the italians had established themselves in the assa hills, dominating the southern side of the gap. on 13 august, the defenders of knobbly hill defeated another attack but the italians infiltrated down mirgo pass past the defended localities and ambushed a convoy carrying water and ammunition, which managed to fight its way through to castle hill. next day, castle hill and observation hill were bombed and bombarded by artillery but an attack on observation hill failed. mussolini signalled to aosta,