Among the more important performances of the allied fleet in the Baltic was the severe injury inflicted on the fortress of Sveaborg, one of the strongest belonging to Russia to keep her neighbours in awe in that part of the world. The fortress of Sveaborg is built on a granite island about a mile in advance of Helsingfors, the Russian capital of Finland. There are eight island rocks connected by strong fortifications, and in the centre is situated the fort in which the Russian flotilla was congregated. It was looked upon as the Gibraltar of the North, and had been considerably strengthened since the commencement of the war. The citadel of this water-surrounded fortress is called Wargon. The allied fleet, consisting of seventeen British men-of-war, fifteen gunboats, and sixteen mortar-vessels, with two French men-of-war, six gunboats, and five mortar-vessels, left Nargen on the 6th of August, and anchored the same night among the islands about five miles from Sveaborg. During the night and next day, some batteries were thrown up on the neighbouring islands; and early on the morning of the 9th, the squadron having taken up their positions,--several behind the islands, where the enemy's guns could not reach them,--the bombardment commenced. The showers of shot and shell told with terrific effect on the devoted fortress; powder magazines and stores of projectiles one after the other blew up, and fires broke out in various directions, which all the efforts of the garrison could not extinguish, and in a short time the whole of the arsenal was reduced to ashes. Still the mortars continued to play, to prevent the fires which were blazing up around from being extinguished. Very few men were wounded, and none were killed during the whole of the operations. Although the naval and military stores were destroyed, the fortress still remained intact. The Russians, however, had been taught the lesson that it would be better for them in future not to make aggressions on their neighbours, or to venture hastily into war. Captains Yelverton and Vansittart had already shown them how little they could rely on their boasted fortifications, by destroying all between Viborg and Helsingfors, Fredericksham, Kotka, and Swartholme. THE WHITE SEA SQUADRON. A small squadron, consisting of the _Eurydice_, twenty-six guns, _Miranda_, fifteen, and _Brisk_, fourteen, had been sent in July 1854 into the White Sea, to destroy the Russian shipping and forts on the coasts of Russian Lapland. On the 23rd of July the town of Novitska was attacked and burned by the _Miranda_ and _Brisk_.