At the Pah Took we turned west and ascended 90 feet to the Pah Too Pah (Stone Gate)—a gap 200 feet broad, in the line of limestone cliffs that fringe the eastern edge of the summit of the plateau. The cliffs on either side of the gap rose like the wall of a fortress to a height of 300 feet, and the ground at the gap was 1941 feet above the level of the sea. Continuing along the eastern edge of the plateau, which sloped from north to south, we reached the base of Loi Pah Heeng. Leaving Loi Pah Heeng trending away to the south-west, we descended the eastern slope of the plateau—the same that we had previously mounted from the Meh Lah—and after marching a mile, reached the head of the Meh Lah Noi valley. The crest of the spur at this point is 1564 feet above the sea, and I have assumed that elevation as the height that the railway would have to cross between the valleys of the Meh Wung and the Meh Ngow; but it is evident that a considerably lower pass might be found between the spur and the coronet-topped hill which still loomed above it in the distance. Continuing our descent, we shortly afterwards came to the source of the Meh Mau, and skirting its channel until we found water in its bed, halted for breakfast and for the night—being hungry, thirsty, and weary with our long march. My long-legged male elephant had kept me in perpetual torment by plunging at every step, and nearly breaking my back. The voices of deer were heard in the vicinity of the camp after dark. These inquisitive animals were most likely attracted by the light of our fires. Next morning we crossed the Meh Mau, and soon afterwards left it at the point where it turns south to enter the Meh Chang, which empties into the Meh Wung—seven and a half hours’ journey to the south of Lakon. During the first three miles from the camp, we gradually ascended 171 feet to the source of the Huay Kyoo Lie, and then followed that brook down-stream for two miles to where its beautiful glen merges into the great plain of the Meh Wung. After marching across the plain for three hours, we entered the rice-fields and suburbs of Ban Sa-det, and passing through the village, put up at the _sala_, or rest-house, which is situated on the banks of the Meh Wung. During the morning we met a party of Burmese Shans, accompanying 102 oxen laden with salt, which they were bartering for cotton to take back with them to Kiang Tung. Ban Sa-det is 60½ miles from Zimmé and 823 feet above the level of the sea.