Being now fairly behind most of the great snow and rain-collecting mountains, I experienced a considerable change in the climate, which characterises all these rearward lofty valleys, where very little rain falls, and that chiefly drizzle; but this is so constant that the weather feels chilly, raw, and comfortless, and I never returned dry from botanising. The early mornings were bright with views northwards of blue sky and Kinchinjhow, while to the south the lofty peak of Tukcham, though much nearer, was seldom seen, and black cumuli and nimbi rolled up the steep valley of the Lachen to be dissipated in mist over Tallum. The sun's rays were, however, powerful at intervals during the forenoon, whence the mean maximum temperature of July occurred at about 10 a.m. The temperature of the river was always high, varying with the heat of the day from 47 degrees to 52 degrees; the mean being 50 degrees. These streams do not partake of the diurnal rise and fall, so characteristic of the Swiss rivers and those of the western Himalaya, where a powerful sun melts the glaciers by day, and their head-streams are frozen by night. Here the clouds alike prevent solar and nocturnal radiation, the temperature is more uniform, and the corroding power of the damp southerly wind that blows strongly throughout the day is the great melting agent. One morning I saw a vivid and very beautiful halo 20 degrees distant from the sun's disc; it was no doubt caused by snow in the higher regions of the atmosphere, as a sharp shower of rain fell immediately afterwards: these are rare phenomena in mountainous countries.