Charles XII., having struck this terrific blow, left the tzar to recover as best he could, and turned his attention to Poland, resolved to hurl Augustus from the throne. Peter himself hurried to Poland to encourage Augustus to the most vigorous prosecution of the war, promising to send him speedily twenty thousand troops. In the midst of these disasters and turmoil, the tzar continued to prosecute his plans for the internal improvement of his empire, and commenced the vast enterprise of digging a canal which should unite the waters of the Baltic with the Caspian, first, by connecting the Don with the Volga, and then by connecting the Don with the Dwina, which empties into the Baltic near Riga. War continued to rage very fiercely for many months between the Swedes on one side, and Russia and Poland on the other, Charles XII. gaining almost constant victories. The Swedes so signally proved their superiority in these conflicts, that when, on one occasion, eight thousand Russians repulsed four thousand Swedes, the tzar said, "Well, we have at last beaten the Swedes, when we were two to one against them. We shall by and by be able to face them man to man." In these conflicts, it was the constant aim of Peter to get a foothold upon the shores of the Baltic, that he might open to his empire the advantages of commerce. He launched a large fleet upon Lake Ladoga, a large inland sea, which, by the river Neva, connects with the Gulf of Finland. The fleets of Sweden penetrated these remote waters, and for months their solitudes resounded with the roar of naval conflicts. We can not refrain from recording the heroic conduct of Colonel Schlippenbuch, the Swedish commander of the town of Notteburg, on this lake. The town was invested by a large Russian army. For a month the Russians battered the town night and day, until it presented the aspect of a pile of ruins, and the garrison was reduced to one hundred men. Yet, so indomitable was this little band, that, standing in the breaches, they extorted honorable terms of capitulation from their conqueror. They would not surrender but on condition of being allowed to send for two Swedish officers, who should examine their remaining means of defense, and inform their master, Charles XII., that it was impossible for them any longer to preserve the town.