Just before the first rapid, which occurs at 113½ miles, a great rock pierced by two flat-arched caverns juts up from the bed of the stream; and a little farther a spur, Loi Hin Poon, ends in a bluff 60 feet high, which has its face riddled with caves and adorned with stalactites.
After passing the second rapid the scenery becomes bold, and great precipices of mural limestone, with their red and black mottled faces beautified by lichens, mosses, and stalactites, occasionally are seen on either side. A mile farther the defile may be said to commence, the hills coming to the bank on either side, and on the west rising sheer from the river’s edge in precipices 1000 feet high; similar cliffs soon afterwards skirt the river on the east.
Beyond Loi Panya Lawa, the hill of the Lawa chief, is a bold bluff with a face strongly resembling a gigantic sphinx. This cliff lies on the west of the river, and its face for some distance has been scooped out at the foot for 15 and 20 feet in width by the action of the strong current. The precipice on the opposite bank resembles a gigantic Norman castle with rounded towers jutting out from its face. The strata in these cliffs are pitched up vertically, as though they had been bodily turned over on their side.
Beyond the castle-cliff the precipice on the west bank changes its aspect, and looks as though it had been punched up or telescoped from below, one precipice rising above another, and another above it, with a slope at the foot of each, appearing as if before the subsidence of the tiers the slopes had been continuous.
There can be no doubt that the great ravine has been caused by sinkage into caverns and underground passages worn out by water, the hills subsiding into them during a period of violent earth-action. An earthquake-belt extends right up the Malay Peninsula through Burmah and Siam into Yunnan and Szechuen. The whole region is still in a period of unrest, as is evidenced by the numerous hot springs passed by travellers, and the earthquakes which frequently occur in this region.
We halted for the night at the hamlet of Ban Kau, which is situated 123 miles from Zimmé, in a small valley which is drained by the Huay Kau. The precipice facing the village was grotto-worked by the action of the lime-water, the grottoes overhanging in great masses giving the cliffs a honeycombed appearance.
At Ban Kau the river makes a westerly bend for 4 miles, and then continues nearly due south for 19 miles, until it is joined by the Meh Teun.
The next morning we passed six rapids before we reached Ban Sa-lee-am, the last Ping Shan village on the river. Below it the river-banks are under the direct control of Siam.
Soon after leaving the village we halted for breakfast at a barrier of rocks 6 feet high, through which a passage had been made for boat traffic. Here I noticed slate and shale outcropping from the bank and forming the base of the mural limestone, which was much veined with quartz. The cliff on the east of the river below the barrier rises about 600 feet, and is known as Loi Pa May-yow, the Cliff of the Cat. Its name is derived from the great mottled patches of lichen on its face representing figures of cats, tigers, and other animals to people with a fertile imagination.
Between the barrier and Loi Chang Hong, three rapids are passed. Down the last, boat after boat was let down by a rope, the crews of my boats and of that belonging to the enterprising Chinese smuggler who had attached himself to our party in the hope of escaping the custom-houses on the river, tugging at the rope to check the speed of the boat.