LEWIS AND CLARKE EXPEDITION. The two men selected to conduct the expedition across the continent, Meriwether Lewis and William Clarke, were especially fitted for their arduous task. Both were officers in the army, holding the rank of captain. Lewis had been private secretary to the President, and Clarke was brother to the heroic George Rogers Clarke, whose services were of peculiar value in the Revolutionary struggle. Before they could complete the preparations for their long and dangerous journey, the territory to be traversed had been transferred to the United States, and the expedition at once assumed a significance and importance little dreamed of when Jefferson first conceived it. The original design had been a favorite one with Mr. Jefferson for many years. When he resided at Paris as our minister, before the Federal Government was organized, he encouraged a similar expedition, to be fitted out in Kamtchatka, to sail to our western coast, and thence to come eastward across the continent. This design was to be executed by the somewhat noted John Ledyard, a roving and adventurous man from Connecticut, who had accompanied Captain Cook on his famous voyage to the Pacific, and whom Jefferson afterwards met in Paris. The necessary authority was obtained from the Russian Government; but, after Ledyard had reached the borders of Kamtchatka, he was suddenly recalled, driven with speed day and night in a closed carriage, on a return journey of several thousand miles, and set down in Poland, penniless, and utterly broken in health. This strange action was the offspring of jealousy on the part of the Empress Catharine, who feared that the energy of the young and vigorous government of the United States would absorb the north-west coast of America, upon which the Russian Government had already set its ambition.