94 Through the Lutzu Country to Men-kong 
but they are likely to be far less changed than the Lutzu of 
T‘sam-p‘u-t‘ong. The former we may call ‘black’ Lutzu, 
not entirely with a detergent significance, to distinguish 
them from their more refined relatives to the south. 
My tent was pitched on the flat roof of one of the 
houses. The rain had ceased, and a warm breeze blew up 
the valley; a few stars shone out through rifts in the clouds, 
and tired as I was after eleven hours climbing in the rain, 
I turned in and slept like the dead. The sun was high in 
the heavens when I awoke and heard below me the river 
rattling over the end of the shingle bank. 
For the remainder of our journey up the Salween valley 
the weather was glorious, yet trying. About mid-day a 
scorching wind began to blow, increasing in violence till 
the middle of the afternoon, and gradually dying out after 
sunset. The deep U-shaped valley became a V-shaped 
gorge like that of the Mekong, the cliffs became more and 
more bare, the dryness of the atmosphere steadily increased 
till it became intolerable, and day after day the sun glared 
in the ribbon of blue sky which faithfully followed the 
windings of the deep valley. But on the mountains east 
and west poured the everlasting rain. It was an exact 
repetition of the Yang-tze and Mekong, and further, in the 
case of the Salween and Mekong at least, the arid regions 
begin in exactly the same latitude. 
The jungles of the Salween, as we have seen, give 
place abruptly to the arid gorges above T'‘sam-p‘u-t‘ong, 
and it would be possible to pass in a day from a region 
where it rains practically every day for six months in the 
year (it is useless to hazard what the rainfall might be) to 
a strip of country about two miles wide where the annual 
rainfall certainly does not exceed ten inches, and may be 
substantially less. 
The Salween-Irrawaddy divide stretching north and 
south with its high snow-clad peaks above T‘sam-p‘u-t‘ong 
checks the rain-bearing winds from the south-west, thus 
acting as an efficient rain-screen to the valley further north. 
Any clouds which succeed in crossing this range throw 
down their moisture, not in the deep and narrow valley, 
but on the now greatly elevated Mekong-Salween water- 
shed, which, from an average altitude of 15,000-17,000 
