term Roche de l’azur may have been used loosely for blue-stone, i.e. carbonate of copper, which would assume a green colour through moisture.  He adds:  “Nero, according to Pliny, actually used chrysocolla, the siliceous carbonate of copper, in powder, for strewing the circus, to give the course the colour of his favourite faction, the prasine (or green).  There may be some analogy between this device and that of Kublai Khan.”  This parallel is a very happy one.

[Illustration:  Mei Shan]

NOTE 13.—­Friar Odoric gives a description, short, but closely agreeing in substance with that in the Text, of the Palace, the Park, the Lake, and the Green Mount.

A green mount, answering to the description, and about 160 feet in height, stands immediately in rear of the palace buildings.  It is called by the Chinese King-Shan, “Court Mountain,” Wan-su-Shan, “Ten Thousand Year Mount,” and Mei-Shan, “Coal Mount,” the last from the material of which it is traditionally said to be composed (as a provision of fuel in case of siege).[1] Whether this is Kublai’s Green Mount does not seem to be quite certain.  Dr. Lockhart tells me that, according to the information he collected when living at Peking, it is not so, but was formed by the Ming Emperors from the excavation of the existing lake on the site which the Mongol Palace had occupied.  There is another mount, he adds, adjoining the east shore of the lake, which must be of older date even than Kublai, for a Dagoba standing on it is ascribed to the Kin.

[The “Green Mount” was an island called K’iung-hua at the time of the Kin; in 1271 it received the name of Wan-sui shan; it is about 100 feet in height, and is the only hill mentioned by Chinese writers of the Mongol time who refer to the palace grounds.  It is not the present King-shan, north of the palace, called also Wan-sui-shan under the Ming, and now the Mei-shan, of more recent formation.  “I have no doubt,” says Bretschneider (Peking, l.c. 35), “that Marco Polo’s handsome palace on the top of the Green Mount is the same as the Kuang-han tien” of the Ch’ue keng lu.  It was a hall in which there was a jar of black jade, big enough to hold more than 30 piculs of wine; this jade had white veins, and in accordance with these veins, fish and animals have been carved on the jar. (Ibid. 35.) “The Ku kung i lu, in describing the Wan-sui-shan, praises the beautiful shady green of the vegetation there.” (Ibid. 37.) —­H.  C.]

["Near the eastern end of the bridge (Kin-ao yue-tung which crosses the lake) the visitor sees a circular wall, which is called yuean ch’eng (round wall).  It is about 350 paces in circuit.  Within it is an imperial building Ch’eng-kuang tien, dating from the Mongol time.  From this circular enclosure, another long and beautifully executed marble bridge leads northwards, to a charming hill, covered with shady trees, and capped by a magnificent white suburga.” (Bretschneider, p. 22.)—­H.  C.]