KACHO, KECHIO, or BACKHING, the capital of the kingdom of Tonquin, in Asia, situated on the west side of the river Songkoi, about eighty miles from the sea. It is of great extent, and has neither walls nor fortifications, being merely surrounded by a bamboo hedge. The principal streets are wide and airy, and for the most part are paved with bricks and small stones; intermediate spaces being, however, left for the passage of elephants and other beasts of burden. The other streets are narrow and ill paved. Many of the houses are built with brick, though the larger proportion are constructed of mud and timber, and thatched with leaves, straw, or reeds, which exposes them to the danger of fires; and they are not above one story in height. The magazines and warehouses belonging to foreigners are the only edifices built of brick; and these, though plain, yet, by reason of their height and more elegant structure, make a considerable show among the rows of wooden huts. The public edifices are very spacious, but particularly the royal palace, which is several miles in circuit, and is surrounded by high walls. It contains many buildings within its precincts, which are devoted to different purposes, and embellished with a variety of carvings and gildings after the Indian manner, all finely varnished. In the outer court are sumptuous stables for the king's horses and elephants. It was extremely difficult to procure access to the inner courts during the residence of the sovereigns of Tonquin, who have for some years past transferred their abode to a city in Cochin China. Besides this palace there are to be seen the ruins of one still more magnificent, which is said to have been six miles in circumference. Cachao is a great commercial resort, and its trade is facilitated by the river, which is always crowded with vessels. The imports are long cloths, chintz, arms, pepper, and other articles, in exchange for which gold is given; and manufactured goods, namely, beautiful silks, and lacquered ware, which is generally reckoned superior to any in the East. The English factory, which stood on the banks of the river, north of the city, and that of the Dutch, south of it, have long been withdrawn. On the opposite side of the Songkoi is the Campez, a town of the Chinese. Cachao, built chiefly of wooden and brick houses, is peculiarly liable to fires; and to prevent these, or to extinguish them after they have broken out, the city is governed by a very rigid police, and is divided into wards, each subjected to a certain jurisdiction. Fires for domestic use are only permitted some hours during the day. About the middle of the eighteenth century the city was nearly burnt to the ground by a conflagration, which was the work of incendiaries, who discharged fire-arrows during the night against the straw-covered roofs, and the whole was in a moment in a blaze. The accounts of the population vary extremely. By some of the missionaries it is reckoned equal to that of Paris. Later authors compute it at 40,000. Long. 105. 15. E. Lat. 22. 36. N.