Rivers of Ice by Robert Michael Ballantyne (the rosie project .txt) 📕

the particular pint that puzzles you, ma'am?"

Emma laughed aloud at this, and coughed a little to conceal the fact. She was rather easily taken by surprise with passing touches of the ludicrous, and had not yet acquired the habit of effectually suppressing little explosions of undertoned mirth.

"The thing that puzzles me," said Mrs Stoutley, "is, that glaciers should _flow_, as I am told they do, and yet that they should be as hard and brittle as glass."

"Ah, well, yes, just so, h'm!" said the Captain, looking very wise; "that is exactly the pint that I want to know myself; for no man who looks at the great tongue of that glacier day Bossung--"

"Des Bossons," said the Professor, with a bland smile.

"Day Bossong," repeated the Captain, "can deny that it is marked with all the lines, and waves, an eddies of a rollin' river, an' yet as little can they deny that it seems as hard-and-fast as the rock of Gibraltar."

The Professor nodded approvingly.

"You are right, Captain Whipper--"

"Wopper," said the Captain, with a grave nod.

"Wopper," repeated the Professor, "the glacier des Bossons, like all the other glaciers, seems to remain immovable, though in reality it flows-- ever flows--downward; but its motion is so slow, that it is not perceptible to the naked eye. Similarly, the hour-hand of a watch is to appearance motionless. Do you want proof? Mark it just now; look again in quarter of an hour, and you see that it has moved. You are convinced. It is so with the glacier. Mark him to-day, go back to-morrow--the mark has changed. Some glaciers flow at the rate of two and three feet in the twenty-four hours."

"Yes, but _how_ do they flow, being so brittle?" demanded Mrs Stoutley.

"Ay, that's the pint, Professor," said the Captain, nodding, "_how_ do they flow, bein' made of hard and brittle ice?"

"Why, by rolling higgledy-piggledy over itself of course," said Lewis, flippantly, as he came up and sat down on the end of the sofa, being out of humour with himself and everybody in consequence of having utterly failed to gain the attention of Nita Horetzki, although he had made unusually earnest efforts to join in conversation with her father. Owing to somewhat similar feelings, the artist had flung himself into a chair, and sat glaring at the black fireplace with a degree of concentration that ought to have lighted the firewood therein.

"The cause of a glacier flowing," said the Professor, "has long been a disputed point. Some men of science have held that it is the pressure of ice and snow behind it which causes it to flow. They do not think that it flows like water, but say it is forced from behind, and crushed through gorges and down valleys, as it were, unwillingly. They say that, if left alone, as they now are, without additions, from this time forward, glaciers would no longer move; they would rest, and slowly melt away; that their motion is due to the fact that there are miles and miles of snow-fields, thousands of feet deep, on the mountain-tops and in the gorges, to which fresh snows are added every winter, so that the weight of what is behind, slipping off the slopes and falling from the cliffs, crushes down and forward that which is below; thus glaciers cannot choose but advance."

"Ay, ay," said the Captain, "no doubt no doubt that may be so; but why is it that, bein' as brittle as glass, a glacier don't come rumblin' and clatterin' down the valleys in small hard bits, like ten thousand millions of smashed-up chandeliers?"

"Ay, there's the rub," exclaimed Lewis; "what say you to that?"

"Ha!" exclaimed the Professor, again smiling blandly, "there you have touched what once was, and, to some philosophers it seems, still is, the great difficulty. By some great men it has been held that glacier ice is always in a partially soft, viscid, or semi-fluid condition, somewhat like pitch, so that, although _apparently_ a solid, brittle, and rigid body, it flows sluggishly in reality. Other philosophers have denied this theory, insisting that the ice of glaciers is _not_ like pitch, but like glass, and that it cannot be squeezed without being broken, nor drawn without being cracked. These philosophers have discovered that when ice is subjected to great pressure it melts, and that, when the pressure is removed, the part so melted immediately freezes again--hence the name regelation, or re-freezing, is given to the process. Thus a glacier, they say, is in many places being continually melted and continually and instantaneously re-frozen, so that it is made to pass through narrow gorges, and to open out again when the enormous pressure has been removed. But this theory of regelation, although unquestionably true, and although it exercises _some_ influence on glacier motion, does not, in my opinion, alone account for it. The opinion which seems to be most in favour among learned men--and that which I myself hold firmly--is, the theory of the Scottish Professor Forbes, namely, that a glacier is a semi-fluid body, it is largely impregnated throughout its extent with water, its particles move round and past each other--in other words, it flows in precisely the same manner as water, the only difference being that it is not quite so fluid; it is sluggish in its flow, but it certainly models itself to the ground over which it is forced by its own gravity, and it is only rent or broken into fragments when it is compelled to turn sharp angles, or to pass over steep convex slopes. Forbes, by his careful measurements and investigations, proved incontestably that in some glaciers the central portion travelled down its valley at double or treble the rate of its sides, without the continuity of the mass being broken. In small masses, indeed, glacier-ice is to all appearance rigid, but on a large scale it is unquestionably ductile."

"Has the theory of regelation been put to the proof?" asked Lewis, with a degree of interest in glaciers which he had never before felt.

"It has," answered the Professor. "An experimentalist once cut a bar of solid ice, like to a bar of soap in form and size, from a glacier. To this an iron weight of several pounds was suspended by means of a very fine wire, which was tied round the bar. The pressure of the wire melted the ice under it; as the water escaped it instantly re-froze above the wire; thus the wire went on cutting its way through the bar, and the water went on freezing, until at last the weight fell to the ground, and left the bar as solid and entire as if it had never been cut."

"Well, now," said Captain Wopper, bringing his hand down on his thigh with a slap that did more to arouse Mrs Stoutley out of her languor than the Professor's lecture on glacier ice, "I've sailed round the world, I have, an' seen many a strange sight, and what I've got to say is that I'll believe that when I _see_ it."

"You shall see it soon then, I hope," said the Professor, more blandly than ever, "for I intend to verify this experiment along with several others. I go to the Mer de Glace, perhaps as far as the Jardin, to-morrow. Will you come?"

"What may the Jardang be?" asked the Captain.

"Hallo! monkey, what's wrong?" said Lewis to Emma, referring to one of the undertoned safety-valves before mentioned.

"Nothing," replied Emma, pursing her little lips till they resembled a cherry.

"The Jardin, or garden," said the Professor, "is a little spot of exquisite beauty in the midst of the glaciers, where a knoll of green grass and flowers peeps up in the surrounding sterility. It is one of the regular excursions from Chamouni."

"Can ladies go?" asked Lewis.

"Young and active ladies can," said the Professor, with his blandest possible smile, as he bowed to Emma.

"Then, we'll all go together," cried Lewis, with energy.

"Not all," said Mrs Stoutley, with a sigh, "I am neither young nor active."

"Nonsense, mother, you're quite young yet, you know, and as active as a kitten when you've a mind to be. Come, we'll have a couple of porters and a chair to have you carried when you knock up."

Notwithstanding the glowing prospects of ease and felicity thus opened up to her, Mrs Stoutley resolutely refused to go on this excursion, but she generously allowed Emma to go if so disposed. Emma, being disposed, it was finally arranged that, on the following day, she, the Captain, Lewis, and Lawrence, with Gillie White as her page, should proceed up the sides of Mont Blanc with the man of science, and over the Mer de Glace to the Jardin.


CHAPTER NINE.


A SOLID STREAM.

There is a river of ice in Switzerland, which, taking its rise on the hoary summit of Mont Blanc, flows through a sinuous mountain-channel, and terminates its grand career by liquefaction in the vale of Chamouni. A mighty river it is in all respects, and a wonderful one--full of interest and mystery and apparent contradiction. It has a grand volume and sweep, varying from one to four miles in width, and is about twelve miles long, with a depth of many hundreds of feet. It is motionless to the eye, yet it descends into the plain continually. It is hard and unyielding in its nature, yet it flows as really and steadily, if not with as lithe a motion, as a liquid river. It is _not_ a half solid mass like mud, which might roll slowly down an incline; it is solid, clear, transparent, brittle ice, which refuses to bend, and cracks sharply under a strain; nevertheless, it has its waves and rapids, cross-currents, eddies, and cascades, which, seen from a moderate distance, display all the grace and beauty of flowing water--as if a grand river in all its varied parts, calm and turbulent, had been actually and suddenly arrested in its course and frozen to the bottom.

It is being melted perpetually too. The fierce sun of summer sends millions of tiny streamlets down into its interior, which collect, augment, cut channels for themselves through the ice, and finally gush into the plain from its lower end in the form of a muddy river. Even in winter this process goes on, yet the ice-river never melts entirely away, but holds on its cold, stately, solemn course from year to year-- has done so for unknown ages, and will probably do so to the end of time. It is picturesque in its surroundings, majestic in its motion, tremendous in its action, awful in its sterility, and, altogether, one of the most impressive and sublime works of God.

This gigantic glacier, or stream of ice, springing, as it does, from the giant-mountain of Europe, is appropriately hemmed in, and its mighty force restrained, by a group of Titans, whose sharp aiguilles, or needle-like peaks, shoot upward to a height little short of their rounded and white-headed superior, and from whose wild gorges and riven sides tributary ice-rivers flow, and avalanches thunder incessantly. Leaving its cradle on the top of Mont Blanc, the great river sweeps round the Aiguille du Geant; and, after receiving its first name of Glacier du Geant from that mighty obelisk of rock, which rises 13,156 feet above the sea, it passes onward to welcome two grand tributaries, the Glacier de Lechaud,