When we left the following day we passed dozens of caravans and groups of men and women carrying great disks of salt.  Each piece was stamped in red with the official mark for salt is a government monopoly and only licensed merchants are allowed to deal in it; moreover, the importation of salt from foreign countries is forbidden.  For the purposes of administration, China is divided into seven or eight main circuits, each of which has its own sources of production and the salt obtained in one district may not be sold in another.

In Yuen-nan the salt of the province is supplied from three regions.  The water from the wells is boiled in great caldrons for several days, and the resulting deposit is earth impregnated with salt.  This is crushed, mixed with water, and boiled again until only pure salt remains.  After passing a village of considerable size called Pei-ping, we began the ascent of an exceedingly steep mountain range twelve thousand feet high.  All the afternoon we toiled upward in the rain and camped late in the evening at a pine grove on a little plateau two-thirds of the way to the summit.  During the night it snowed heavily and we awoke to find ourselves in a transformed world.

Every tree and bush was dressed in garments of purest white and between the branches we could look westward across the valley toward the Mekong and the purple mountain wall of the Burma border.  There were still one thousand feet of climbing between us and the summit of the pass.  The trail was almost blocked, but by slow work we forced our way through the drifts.  Some of the mules were already weak from exposure and underfeeding, and two of them had to be relieved of their loads; they died the next day.  Our mafus did not appear to suffer greatly although their legs were bare from the knees down and their feet had no covering except straw sandals.  Indeed when we discovered, on the summit of the pass, a tiny hut in which a fire was burning, they waited only a few moments to warm themselves.

We met two other caravans fighting their way up the mountain from the other side, and by following the trail which they had broken through the drifts we made fairly good time on the descent.  There had been no snow on the broad, flat plain which we reached in the late afternoon and we found that its ponds and fields were alive with ducks, geese, and cranes.  The birds were wild but we had good shooting when we broke camp in the morning and killed enough to last us several days.

On December 31, our weary days of crossing range after range of tremendous mountains were ended, and we stood on the last pass looking down upon the great Chien-chuan plain.  Outside the grim walls of the old city, which lies on the main A-tun-tzu—­Ta-li Fu road, are two large marshy ponds and, away to the south, is an extensive lake.  We camped just without the courtyard of a fine temple, and at four o’clock Yvette and I went over to the water which was swarming with ducks and geese.