Cheung Mai is one of the five northern Laos provinces belonging to Siam. This northern Laos country is bounded on the north (lat. 20° 20′ N.) by the Shan states, tributary to Independent Burmah; on the north-east by some independent Shan states lying between Laos and Tonquin; on the east by Anam; on the south by Siam. The western boundary is the river Salween, separating the Laos country from British Burmah and Karenee. The extreme distance from north to south is two hundred and twenty miles; from east to west, about four hundred and twenty miles. The entire population of the five Laos provinces tributary to Siam is estimated at about two millions. These two millions are composed of about ten tribes; all of them, however, excepting the remnants of three or four aboriginal tribes inhabiting the mountains, are branches of a common stock, the Lou. Each of these five Lou provinces is a kingdom, the ruler of which is always a native prince, who can, however, exercise authority only after receiving investiture from the king of Siam. Cheung Mai, reckoning all the territory over which the king of Cheung Mai exercises jurisdiction, is the largest and most populous of the Laos provinces. A recent census of the houses throughout the province of Cheung Mai gave the number of ninety-seven thousand, and the census was not at that time complete; the population of the entire province is not under six hundred thousand. The city of Cheung Mai (written Zimme on English maps) is the capital, and is reached from Bangkok by boat; the distance is approximately five hundred and fifty miles, and the time required to make the journey in native boats, propelled by men, is usually fifty days. The isolation of Cheung Mai, the long, tedious and expensive journey required to reach it, and the unwholesome climate, are considered by some sufficient arguments against retaining it as a mission-station. But there are other considerations worthy of attention, which I wish to present.