In 1866 the French Government determined on despatching an expedition to explore the upper valley of the great Cambodian river, and placed it in charge of M. de Lagrée, a captain in the French navy. M. Thorel, a surgeon, was attached to it as botanist; M. Delaporte, as artist; Dr. Joubert, as physician and geologist; and among the other members were Lieutenant Garnier, to whose record of the expedition we are about to be indebted, and M. de Carné. After a visit to Ongcor, the capital of the ancient kingdom of the Khmers, with those vast memorials of antiquity described so graphically by M. Mouhot, the expedition proceeded to ascend the great river, passing the busy villages of Compong Luong and Pnom Penh--the latter the residence of the king of Cambodia. Here they abandoned the gun-brigs which had brought them from Saigon, and embarked themselves and their stores on board boats better fitted for river navigation. ~BOATING ON THE MEKONG.~ These boats or canoes are manned, according to their size, by a crew of six to ten men. Each is armed with a long bamboo, one end of which terminates with an iron hook, the other with a small fork. The men take up their station on a small platform in the fore part of the boat, plant their bamboos against some projection on the river-bank, tree or stone, and then march towards the stern; returning afterwards on the opposite side to repeat the process. This strange kind of circular motion suffices to impel the boat at the rate of a man walking at full speed, when the boatmen are skilful at their work, and the river-bank is straight and well defined. The master’s attention is wholly occupied, meanwhile, in keeping the bow of the canoe in the direction of the current, or rather slightly headed towards the shore. It is obvious that such a mode of navigation is liable to many interruptions, and cannot be commended on the score of swiftness or convenience. [Illustration: SCENE ON THE MEKONG] ~FORMIDABLE RAPIDS.~ On the 13th of July the canoes took their departure from Cratieh, and soon afterwards arrived at Sombor. They then effected the passage of the rapids of Sombor-Sombor--no great difficulty being experienced, owing to the rise of the waters. Beyond this point the broad bed of the great river was encumbered with a multitude of islands, low and green, while the banks were covered with magnificent forests. The voyagers noticed here some trees of great value--the yao; the ban-courg, the wood of which makes capital oars; and the lam-xe, which should be highly prized by the European cabinet-makers. ~A WEARY VOYAGE.~