Chapter Twenty Seven.
The Snow-Line.
“In three days the cart was finished. We had no difficulty in constructing one, as the principal part—that is, the wheels—was already made. We had two pair of them, of course, in our old wagon; and the larger ones, which happened to be in very good order, served our purpose exactly. Cudjo soon attached a body and shafts to them, and Pompo’s harness was put into thorough repair.
“We had not long to wait for a fine day. Every day was fine in the clear, pure climate of our valley; so that, as soon as the cart was ready, we had a day to our liking.
“We set out shortly after sunrise, with our hearts full of anticipated pleasure. Of course we all went—Mary, the children, Cudjo, Pompo, dogs, and all. The house was again left to take care of itself. Mary and the two little ones rode in the cart, upon a soft seat made of palmetto leaves and Spanish moss. Pompo, who appeared to partake of the general happiness, whisked the vehicle along as if there had been nobody in it, and he was only drawing it for his own amusement. Cudjo cracked his great wagon-whip, and every now and then uttered a loud ‘wo-ha;’ while Castor and Pollux galloped gaily from side to side, running their noses into every bush that grew near the path.
“We soon made our way through the valley, and climbed up to the plain. We looked once more upon the Desert that stretched away on all sides; but its dreary aspect no longer filled us with fear. We did not regard it now, and the sight inspired us with feelings of curiosity and novelty rather than of terror. Away to the southward the sun was glancing upon the broad expanse of white sand; and several tall objects, like vast dun-coloured towers, were moving over the plain. They were whirlwinds carrying the dust upward to the blue sky, and spinning it from point to point. Sometimes one glided away alone, until it was lost on the distant horizon. Here two of them were moving in the same direction, keeping a regular distance from each other, and seemingly running a race. There several came together; and, after a short gusty contest, the whole set would break up into shapeless masses of yellowish clouds, and then float onward with the wind, and downward to the earth again. It was an interesting sight to view those huge pillars towering up to the heavens, and whirling like unearthly objects over the wide plain. It was indeed an interesting sight, and we remained for many minutes observing their motions.
“At length we turned our faces toward the mountain, and continued our journey along the edge of the cliffs. The high peak glistened before us, and the sun’s rays falling upon it caused it to appear of a beautiful colour—a mixture of gold and red, as though a shower of roses had fallen upon the snow! We noticed that there was now more snow upon the mountain than when we had first seen it, and that it came farther down its sides. This attracted the attention of all of us; and Frank at once called for an explanation, which his mother volunteered to give, for she very well understood the phenomenon.
“‘In the first place,’ said she, ‘as you ascend upwards in the atmosphere, it becomes thinner and colder. Beyond a certain point it is so cold, that neither men nor any other animals can exist. This can be proved in several ways; and the experience of those who have climbed mountains, only three miles high, confirms it. Some of these adventurous men have been nearly frozen to death. This is a fact, then, in regard to the atmosphere over all parts of the earth; but we may also observe, that under the Equator you may go higher without reaching this extreme cold, than in the countries which lie nearer to the Poles. Another fact, which you will easily believe, is, that in summer you can climb higher before you reach the cold region than in winter. Bear these facts in mind. Now, then, if it be so cold at a certain height that men would be frozen to death, of course at that height snow will not melt. What is the natural inference? Why—that mountains whose tops pierce up into this cold region will most certainly be covered with perpetual snow. It is not likely that anything but snow ever falls upon their summits,—for when it rains upon the plains around them, it is snowing upon the high peaks above. Indeed, it is probable that most of the rain which descends upon the earth has been crystals of snow when it commenced its descent; and, afterwards melting in the lower and warmer regions of the atmosphere, takes the shape of water globules, and thus falls to the ground. These globules, no doubt, are very small when they first emerge from the snow region; but, as they pass slowly downward through clouds of vapour, they gather together and attract others (by a law which I have not time to explain); and, descending faster and faster, at length plash down to the earth in large drops. Whenever it rains, then, at any particular place, you may be almost certain that it is snowing at the same time over that place—only at a point in the atmosphere far above it. I have been convinced of this fact, by observing that immediately after every occasion when it has rained in the valley, there appeared a greater quantity of snow upon the mountain. Had the mountain not been there, this snow would have continued on, and become rain, like that which fell upon the plains, and into the valley.’
“‘Then, mamma,’ interrupted Frank, ‘this mountain must be of great height, since the snow lies upon it all the year.’
“‘Does that follow?’