To write of any completed phase of the expedition at this stage, when I have carried my readers only as far as Tuna, is a lapse in continuity that requires an apology. My excuse is that to all transport officers, and everyone who was in touch with them, the Tuna and Phari plains will be remembered as the very backbone of resistance, the most implacable barriers to our advance.
The expedition was essentially a transport 'show.' It is true that the Tibetans proved themselves brave enemies, but their acquired military resources are insignificant when compared with the obstacles Nature has planted in the path of their enemies. The difficulty of the passes, the severity of the climate, the sterility of the mountains and tablelands, make the interior of the country almost inaccessible to an invading army. That we went through these obstacles and reached Lhasa itself was a matter of surprise not only to the Tibetans, but to many members of the expeditionary force.
To appreciate the difficulties the mission force had to contend with, one must first realize the extraordinary changes of climate that are experienced in the journey from Siliguri to Tuna. Choose the coldest day in the year at Kew Gardens, expose yourself freely to the wind, and then spend five minutes in the tropical house, and you may gather some idea of the sensation of sleeping in the Rungpo Valley the night after crossing the Jelapla.
When I first made the journey in early January, even the Rungpo Valley was chilly, and the vicissitudes were not so marked; but I felt the change very keenly in March, when I made a hurried rush into Darjeeling for equipment and supplies. Our camp at Lingmathang was in the pine-forest at an elevation of 10,500 feet. It was warm and sunny in the daytime, in places where there was shelter from the wind. Leaf-buds were beginning to open, frozen waterfalls to thaw, migratory duck were coming up the valley in twos and threes from the plains of India--even a few vultures had arrived to fatten on the carcasses of the dead transport animals. The morning after leaving Lingmathang I left the pine-forest at 13,000 feet, and entered a treeless waste of shale and rock. When I crossed the Jelapla half a hurricane was blowing. The path was a sheet of ice, and I had to use hands and knees, and take advantage of every protuberance in the rock to prevent myself from being blown over the _khud_. The road was impassable for mules and ponies. The cold was numbing. The next evening, in a valley 13,000 feet beneath, I was suffering from the extreme of heat. The change in scenery and vegetation is equally striking--from glaciers and moraines to tropical forests brilliant with the scarlet cotton-flower and purple Baleria. In Tibet I had not seen an insect of any kind for two months, but in the Sikkim valleys the most gorgeous butterflies were abundant, and the rest-house at Rungpo was invested by a plague of flies. In the hot weather the climate of the Sikkim valleys is more trying than that of most stations in the plains of India. The valleys are close and shut in, and the heat is intensified by the radiation from the rocks, cliffs, and boulders. In the rains the climate is relaxing and malarious. The Supply and Transport Corps, who were left behind at stages like Rungpo through the hot weather, had, to my mind, a much harder time on the whole than the half-frozen troops at the front, and they were left out of all the fun.