The commanders of the Swedish army were very ingenious in expedients, as well as bold and energetic in action, and they often gained an advantage over their enemy by their wit as well as by their bravery. One instance of this was their contrivance for rendering their prisoners helpless on their march homeward after the battle of Narva, by cutting their clothes in such a manner as to compel the men to keep both hands employed, as they walked along the roads, in holding them together. On another occasion, when they had to cross a river in the face of the Russian troops posted on the other side, they invented a peculiar kind of boat, which was of great service in enabling them to accomplish the transit in safety. These boats were flat-bottomed and square; the foremost end of each of them was guarded by a sort of bulwark, formed of plank, and made very high. This bulwark was fixed on hinges at the lower end, so that it could be raised up and down. It was, of course, kept up during the passage across the river, and so served to defend the men in the boat from the shots of the enemy. But when the boat reached the shore it was let down, and then it formed a platform or bridge by which the men could all rush out together to the shore. At the same time, while they were getting these boats ready, and placing the men in them, the Swedes, having observed that the wind blew across from their side of the river to the other, made great fires on the bank, and covered them with wet straw, so as to cause them to throw out a prodigious quantity of smoke. The smoke was blown over to the other side of the river, where it so filled the air as to prevent the Russians from seeing what was going on. [Illustration: Stratagems of the Swedes.] It was about a year after the first breaking out of the war that the tide of fortune began to turn, in some measure, in favor of the Russians. About that time the Czar gained possession of a considerable portion of the Baltic shore; and as soon as he had done so, he conceived the design of laying the foundation of a new city there, with the view of making it the naval and commercial capital of his kingdom. This plan was carried most successfully into effect in the building of the great city of St. Petersburg. The founding of this city was one of the most important transactions in Peter's reign. Indeed, it was probably by far the most important, and Peter owes, perhaps, more of his great fame to this memorable enterprise than to any thing else that he did. The situation of St. Petersburg will be seen by the map in the preceding chapter. At a little distance from the shore is a large lake, called the Lake of Ladoga. The outlet of the Lake of Ladoga is a small river called the Neva. The Lake of Ladoga is supplied with water by many rivers, which flow into it from the higher lands lying to the northward and eastward of it; and it is by the Neva that the surplus of these waters is carried off to the sea.