On the 24th of May, the travellers, accompanied by Madame de Baluseck, departed from Kaigan and crossed the Great Wall. This colossal defensive work consists of double crenelated ramparts, locked together, at intervals of about 100 yards, by towers and other fortifications. The ramparts are built of brickwork and ash-tar cemented with lime; measure twenty feet in height, and twenty-five to thirty feet in thickness; but do not at all points preserve this solidity. In the province of Kansou, there is but one line of rampart. The total length of this great barrier, called Wan-ti-chang (or "myriad-mile wall") by the Chinese, is 1,250 miles. It was built about 220 B.C., as a protection against the Tartar marauders, and extends from 3 deg. 30' E. to 15 deg. W. of Pekin, surmounting the highest hills, descending into the deepest valleys, and bridging the most formidable rivers. Our travelers entered Bourgaltai in the evening, simultaneously with the caravan of camels, which had started a fortnight before, and were lodged in a squalid and filthy inn. Nothing, however, could disturb the cheerful temperament of Madame de Bourboulon, who rose superior to every inconvenience or vexation, and this _bonhommie_ is the chief charm of her book. Thus, speaking of the first evening in this dirty Mongolian inn, she says:--"There was nothing to be done but to be content with some cold provisions, and our camping-out beds. It was the birthday of Queen Victoria, and as our landlord was able to put his hand upon two bottles of champagne, we drank, along with Sir Frederick Bruce and Mr. Wade, her Majesty's health. Afterwards we played a rubber at whist (for we had found some cards). Surely, never before was whist played in the Mongolian deserts!" * * * * * Before accompanying our travellers into these deserts, it may be convenient that we should note the _personnel_ of their following, and the organization of their expedition. In addition to Monsieur and Madame de Bourboulon, the French caravan consisted of six persons:--Captain Bouvier, of the Engineers; a sergeant and a private of the same branch of the service; an artillerist; a steward (_intendant_); and a young Christian, a native of Pekin, whom M. de Bourboulon was taking with him to France. Madame de Baluseck's suite consisted of a Russian physician; a French waiting maid; a Lama interpreter, named Gomboi; and a Cossack (as escort). A small carriage, well hung on two wheels, was provided for the two ladies. The other travellers journeyed on horseback or in Chinese carts. These small carts, with hoods of blue cloth, carry only one passenger; they are not hung upon springs, but are solidly constructed. [Illustration: HONG KONG.] At Zayau-Tologoi, the Chinese drivers were replaced by Mongolian postillions, and the Chinese mandarins gave up the responsibility of escort to Mongolian officials.