A chain of mountains, of which the highest peak is 6274 English feet above the level of the sea, extends to the S.W., joins the ranges of Chantaboun, Pursak, and Thung Yai, which are from 4000 to 5000 feet high, and reaches nearly to Komput and Hatienne; while to the north another small chain, joining the greater one of Korat, runs eastward, throws some ramifications into the provinces of Battambong and Ongcor Borege, which is 40 miles farther north, and bears the name of the mountains of Somrai.
Not being in direct communication with the Archæological Society, I wish to call your attention to the marvellous remains at Ongcor of the civilization of a great people.
The country is rich in woods and mines, and although thinly populated, produces enough cotton for the use of Cochin China, while the great lake, which abounds in fish, furnishes an immense quantity of this article also to China. Iron of a superior quality is also abundant, and the Kouis, an ancient tribe of a primitive race, living east of the Mekon, who speak the same language as the Stiêns, work it very industriously. There are also many other mines, rich in gold, lead, and copper, in the chains to the east and west; that of Pursak produces the beautiful cardamom, which, when transplanted, gives fine stems but no fruit.
Unluckily most of these mountains are frightfully unhealthy, and no one but those who have lived there from infancy can remain long among them with impunity.
In the island of Phu-Quor or Koh Trou, which belongs to Cochin China, and which is very near to Komput, there are rich mines of cannel coal. I was not able to get there, the war having rendered the people hostile and cruel to all white men; but my attention having been drawn to it by some ornaments worked in this mineral by the islanders, I procured two specimens, which I send you.
There are several extinct volcanoes in Pechaburi, four of which I have ascertained to form part of the numerous detached and conical hills which are probably all ancient craters belonging to the great chain Khao Deng, which occupies all the northern part of the centre of the Malayan peninsula, and is inhabited by the Kariens, a primitive and independent people, who, like the Stiêns and other tribes, have doubtless been driven back to the mountains by the encroachments of the Siamese, and where the inclemency of the climate protects them against all attacks from their neighbours. The mountains are known in the country as the Na-Khou, Khao, Panom Knot, Khao Tamonne, and Khao Samroum. The last two are 1700 and 1900 feet above the level of the sea, and only a few leagues distant from each other. All these craters appear to have been originally upheaved (“craters of elevation” M. de Buch styles them) from the bottom of the water, at a period when all this part of the country, as far as the great chain, which I have not yet been able to visit, was under the sea.
Besides an immense volcanic cone, in part fallen in, and where the ground resounds under one’s feet, each of the mounts has several lateral mouths and a number of fissures and chimneys, or passages, which bear evident traces of subterranean fires. They are entirely composed of trachytic rocks, scoria, lava, felspar, &c.
The Siamese have made temples of the largest of these caverns, which are of great depth and breadth, and extremely picturesque. One of the caverns of Samroum is quite inaccessible. Having descended to the depth of 20 feet by a chimney 2 feet wide at its mouth, and shut in between rocks, I found myself at the entrance of a deep cavern, but there all my efforts to proceed farther were defeated; a few steps from the entrance my torch suddenly went out, my breathing was checked, and I in vain fired my gun several times in order to disperse the foul air.