It is very difficult, I know, for a little boy like you to understand how ice, and much more how soft snow, should have such strength that it can grind this little stone, much more such strength as to grind whole mountains into plains. You have never seen ice and snow do harm. You cannot even recollect the Crimean Winter, as it was called then; and well for you you cannot, considering all the misery it brought at home and abroad. You cannot, I say, recollect the Crimean Winter, when the Thames was frozen over above the bridges, and the ice piled in little bergs ten to fifteen feet high, which lay, some of them, stranded on the shores, about London itself, and did not melt, if I recollect, until the end of May. You never stood, as I stood, in the great winter of 1837-8 on Battersea Bridge, to see the ice break up with the tide, and saw the great slabs and blocks leaping and piling upon each other's backs, and felt the bridge tremble with their shocks, and listened to their horrible grind and roar, till one got some little picture in one's mind of what must be the breaking up of an ice-floe in the Arctic regions, and what must be the danger of a ship nipped in the ice and lifted up on high, like those in the pictures of Arctic voyages which you are so fond of looking through. You cannot recollect how that winter even in our little Blackwater Brook the alder stems were all peeled white, and scarred, as if they had been gnawed by hares and deer, simply by the rushing and scraping of the ice,--a sight which gave me again a little picture of the destruction which the ice makes of quays, and stages, and houses along the shore upon the coasts of North America, when suddenly setting in with wind and tide, it jams and piles up high inland, as you may read for yourself some day in a delightful book called Frost and Fire. You recollect none of these things. Ice and snow are to you mere playthings; and you long for winter, that you may make snowballs and play hockey and skate upon the ponds, and eat ice like a foolish boy till you make your stomach ache. And I dare say you have said, like many another boy, on a bright cheery ringing frosty day, "Oh, that it would be always winter!" You little knew for what you asked. You little thought what the earth would soon be like, if it were always winter,--if one sheet of ice on the pond glued itself on to the bottom of the last sheet, till the whole pond was a solid mass,--if one snow-fall lay upon the top of another snow-fall till the moor was covered many feet deep and the snow began sliding slowly down the glen from Coombs's, burying the green fields, tearing the trees up by their roots, burying gradually house, church, and village, and ****** this place for a few thousand years what it was many thousand years ago. Good-bye then, after a very few winters, to bees, and butterflies, and singing-birds, and flowers; and good-bye to all vegetables, and fruit, and bread; good-bye to cotton and woollen clothes. You would have, if you were left alive, to dress in skins, and eat fish and seals, if any came near enough to be caught. You would have to live in a word, if you could live at all, as Esquimaux live now in Arctic regions, and as people had to live in England ages since, in the times when it was always winter, and icebergs floated between here and Finchampstead. Oh no, my child: thank Heaven that it is not always winter; and remember that winter ice and snow, though it is a very good tool with which to make the land, must leave the land year by year if that land is to be fit to live in.
I said that if the snow piled high enough upon the moor, it would come down the glen in a few years through Coombs's Wood; and I said then you would have a small glacier here--such a glacier (to compare small things with great) as now comes down so many valleys in the Alps, or has come down all the valleys of Greenland and Spitzbergen till they reach the sea, and there end as cliffs of ice, from which great icebergs snap off continually, and fall and float away, wandering southward into the Atlantic for many a hundred miles. You have seen drawings of such glaciers in Captain Cook's Voyages; and you may see photographs of Swiss glaciers in any good London print-shop; and therefore you have seen almost as much about them as I have seen, and may judge for yourself how you would like to live where it is always winter.
Now you must not ask me to tell you what a glacier is like, for I have never seen one; at least, those which I have seen were more than fifty miles away, looking like white clouds hanging on the gray mountain sides. And it would be an impertinence--that means a meddling with things which I have no business--to picture to you glaciers which have been pictured so well and often by gentlemen who escape every year from their hard work in town to find among the glaciers of the Alps health and refreshment, and sound knowledge, and that most wholesome and strengthening of all medicines, toil.
So you must read of them in such books as Peaks, Passes, and Glaciers, and Mr. Willes's Wanderings in the High Alps, and Professor Tyndall's different works; or you must look at them (as I just now said) in photographs or in pictures. But when you do that, or when you see a glacier for yourself, you must bear in mind what a glacier means--that it is a river of ice, fed by a lake of snow. The lake from which it springs is the eternal snow- field which stretches for miles and miles along the mountain tops, fed continually by fresh snow-storms falling from the sky. That snow slides off into the valleys hour by hour, and as it rushes down is ground and pounded, and thawed and frozen again into a sticky paste of ice, which flows slowly but surely till it reaches the warm valley at the mountain foot, and there melts bit by bit.