The Glaciers of the Alps Part 13

While waiting for this permission I employed myself in various ways. On the 2nd of September I ascended the Brevent, from which Mont Blanc is seen to great advantage. From Chamouni its vast slopes are so foreshortened that one gets a very imperfect idea of the extent to be traversed to reach the summit. What, however, struck me most on the Brevent was the changed relation of the Aiguille du Dru and the Aiguille Verte. From Montanvert the former appears a most imposing ma.s.s, while the peak of the latter appears rather dwarfed behind it; but from the Brevent the Aiguille du Dru is a mere pinnacle stuck in the breast of the grander pyramid of the Aiguille Verte.

[Sidenote: THE "SeRACS" REVISITED. 1858.]

On the 4th I rose early, and, strapping on my telescope, ascended to the Montanvert, where I engaged a youth to accompany me up the glacier. The heavens were clear and beautiful:--blue over the Aiguille du Dru, blue over the Jora.s.se and Mont Mallet, deep blue over the pinnacles of Charmoz, and the same splendid tint stretched grandly over the Col du Geant and its Aiguille. No trace of condensation appeared till towards eleven o'clock, when a little black balloon of cloud swung itself over the Aiguilles Rouges. At one o'clock there were two large ma.s.ses and a little one between them; while higher up a white veil, almost too thin to be visible, spread over a part of the heavens. At the zenith, however, and south, north, and west, the blue seemed to deepen as the day advanced. I visited the ice-wall at the Tacul, which seemed lower than it was last year; the cascade of le Geant appeared also far less imposing. Only in the early part of summer do we see the ice in its true grandeur: its edges and surfaces are then sharp and clear, but afterwards its n.o.bler ma.s.ses shrink under the influence of sun and air.

The _seracs_ now appeared wasted and dirty, and not the sharp angular ice-castles which rose so grandly when I first saw them. Thirteen men had crossed the Col du Geant on the day previous, and left an ample trace behind them. This I followed nearly to the summit of the fall. The condition of the glacier was totally different from that of the opposite side on the previous year. The ice was riven, burrowed, and honeycombed, but the track amid all was easy: a vigorous English maiden might have ascended the fall without much difficulty. My object now was to examine the structure of the fall; but the ice was not in a good condition for such an examination: it was too much broken. Still a definite structure was in many places to be traced, and some of them apparently showed structure and bedding at a high angle to each other, but I could not be certain of it. I paused at every commanding point of view and examined the ice through my opera-gla.s.s; but the result was inconclusive. I observed that the terraces which compose the fall do not front the middle of the glacier, but turn their foreheads rather towards its eastern side, and the consequence is that the protuberances lower down, which are the remains of these terraces, are highest at the same side.

Standing at the base of the Aiguille Noire, and looking downwards where the Glacier des Periades pushes itself against the Geant, a series of fine crumples is formed on the former, cut across by creva.s.ses, on the walls of which a forward and backward dipping of the blue veins is exhibited. Huge crumples are also formed by the Glacier du Geant, which are well seen from a point nearly opposite the lowest lateral moraine of the Glacier des Periades. In some cases the upper portions of the crumples had scaled off so as to form arches of ice--a consequence doubtless of the pressure.

[Sidenote: THERMOMETER AT THE JARDIN. 1858.]

The beauty of some Alpine skies is treacherous; in fact the deepest blue often indicates an atmosphere charged almost to saturation with aqueous vapour. This was the case on the present occasion. Soon after reaching Chamouni in the evening, rain commenced and continued with scarcely any intermission until the afternoon of the 8th. I had given up all hopes of being able to ascend Mont Blanc; and hence resolved to place the thermometers in some more accessible position. On the 9th accordingly, accompanied by Mr. Wills, Balmat, and some other friends, I ascended to the summit of the Jardin, where we placed two thermometers: one in the ice, at a depth of three feet below the surface; another on a ledge of the highest rock.[B] The boiling point of water at this place was 194.6 Fahr.

Deep snow was upon the Talefre, and the surrounding precipices were also heavily laden. Avalanches thundered incessantly from the Aiguille Verte and the other mountains. Scarcely five minutes on an average intervened between every two successive peals; and after the direct shock of each avalanche had died away the air of the basin continued to be shaken by the echoes reflected from its bounding walls.

[Sidenote: EVENING RED. 1858.]

The day was far spent before we had completed our work. All through the weather had been fine, and towards evening augmented to magnificence. As we descended the glacier from the Couvercle the sun was just disappearing, and the western heaven glowed with crimson, which crept gradually up the sky until finally it reached the zenith itself. Such intensity of colouring is exceedingly rare in the Alps; and this fact, together with the known variations in the intensity of the firmamental blue, justify the conclusion that the colouring must, in a great measure, be due to some _variable const.i.tuent_ of the atmosphere. If _the air_ were competent to produce these magnificent effects they would be the rule instead of the exception.

[Sidenote: FINISHED WORK. 1858.]

No sooner had the thermometers been thus disposed of than the weather appeared to undergo a permanent change. On the 10th it was perfectly fine--not the slightest mist upon Mont Blanc; on the 11th this was also the case. Balmat still had the old thermometer to which I have already referred; it might not do to show the minimum temperature of the air, but it might show the temperature at a certain depth below the surface.

I find in my own case that the finis.h.i.+ng of work has a great moral value: work completed is a safe fulcrum for the performance of other work; and even though in the course of our labours experience should show us a better means of accomplis.h.i.+ng a given end, it is often far preferable to reach the end, even by defective means, than to swerve from our course. The habits which this conviction had superinduced no doubt influenced me when I decided on placing Balmat's thermometer on the summit of Mont Blanc.

FOOTNOTES:

[A] I find with pleasure that my friend Mr. John Ball is now exerting himself in this direction.

[B] The minimum temperature of the subsequent winter, as shown by this thermometer, was -6 Fahr., or 38 below the freezing point. The instrument placed in the ice was broken.

SECOND ASCENT OF MONT BLANC, 1858.

(25.)

[Sidenote: SHADOWS OF THE AIGUILLES. 1858.]

On the 12th of September, at 5-1/2 A.M. the sunbeams had already fallen upon the mountain; but though the sky above him, and over the entire range of the Aiguilles, was without a cloud, the atmosphere presented an appearance of turbidity resembling that produced by the dust and thin smoke mechanically suspended in a London atmosphere on a dry summer's day. At 20 minutes past 7 we quitted Chamouni, bearing with us the good wishes of a portion of its inhabitants.

[Sidenote: INTERFERENCE-SPECTRA. 1858.]

A lady accompanied us on horseback to the point where the path to the Grands Mulets deviates from that to the Plan des Aiguilles; here she turned to the left, and we proceeded slowly upwards, through woods of pine, hung with fantastic lichens: escaping from the gloom of these, we emerged upon slopes of bosky underwood, green hazel, and green larch, with the red berries of the mountain-ash s.h.i.+ning brightly between them.

Through the air above us, like gnomons of a vast sundial, the Aiguilles cast their fanlike shadows, which moved round as the day advanced.

Slopes of rhododendrons with withered flowers next succeeded, but the colouring of the bilberry-leaves was scarcely less exquisite than the freshest bloom of the Alpine rose. For a long time we were in the cool shadow of the mountain, catching, at intervals, through the twigs in front of us, glimpses of the sun surrounded by coloured spectra. On one occasion a brow rose in front of me; behind it was a l.u.s.trous s.p.a.ce of heaven, adjacent to the sun, which, however, was hidden behind the brow; against this s.p.a.ce the twigs and weeds upon the summit of the brow shone as if they were self-luminous, while some bits of thistle-down floating in the air appeared, where they crossed this portion of the heavens, like fragments of the sun himself. Once the orb appeared behind a rounded ma.s.s of snow which lay near the summit of the Aiguille du Midi.

Looked at with the naked eyes, it seemed to possess a billowy motion, the light darting from it in dazzling curves,--a subjective effect produced by the abnormal action of the intense light upon the eye. As the sun's disk came more into view, its rays however still grazing the summit of the mountain, interference-spectra darted from it on all sides, and surrounded it with a glory of richly-coloured bars. Mingling however with the grandeur of nature, we had the anger and obstinacy of man. With a view to subsequent legal proceedings, the Guide Chef sent a spy after us, who, having satisfied himself of our delinquency, took his unpleasant presence from the splendid scene.

Strange to say, though the luminous appearance of bodies projected against the sky adjacent to the rising sun is a most striking and beautiful phenomenon, it is hardly ever seen by either guides or travellers; probably because they avoid looking towards a sky the brightness of which is painful to the eyes. In 1859 Auguste Balmat had never seen the effect; and the only written description of it which we possess is one furnished by Professor Necker, in a letter to Sir David Brewster, which is so interesting that I do not hesitate to reproduce it here:--

[Sidenote: PROFESSOR NECKER'S LETTER. 1858.]

"I now come to the point," writes M. Necker, "which you particularly wished me to describe to you; I mean the luminous appearance of trees, shrubs, and birds, when seen from the foot of a mountain a little before sunrise. The wish I had to see again the phenomenon before attempting to describe it made me detain this letter a few days, till I had a fine day to go to see it at the Mont Saleve; so yesterday I went there, and studied the fact, and in elucidation of it I made a little drawing, of which I give you here a copy: it will, with the explanation and the annexed diagram (Fig. 9), impart to you, I hope, a correct idea of the phenomenon. You must conceive the observer placed at the foot of a hill interposed between him and the place where the sun is rising, and thus entirely in the shade; the upper margin of the mountain is covered with woods or detached trees and shrubs, which are projected as dark objects on a very bright and clear sky, except at the very place where the sun is just going to rise, for there all the trees and shrubs bordering the margin are entirely,--branches, leaves, stem and all,--of a pure and brilliant white, appearing extremely bright and luminous, although projected on a most brilliant and luminous sky, as that part of it which surrounds the sun always is. All the minutest details, leaves, twigs, &c., are most delicately preserved, and you would fancy you saw these trees and forests made of the purest silver, with all the skill of the most expert workman. The swallows and other birds flying in those particular spots appear like sparks of the most brilliant white.

Unfortunately, all these details, which add so much to the beauty of this splendid phenomenon, cannot be represented in such small sketches.

[Ill.u.s.tration: Fig. 9. Luminous Trees projected against the sky at sunrise.]

"Neither the hour of the day nor the angle which the object makes with the observer appears to have any effect; for on some occasions I have seen the phenomenon take place at a very early hour in the morning.

Yesterday it was 10 A.M., when I saw it as represented in Fig. 10. I saw it again on the same day at 5 P.M., at a different place of the same mountain, for which the sun was just setting. At one time the angle of elevation of the lighted white shrubs above the horizon of the spectator was about 20, while at another place it was only 15. But the extent of the field of illumination is variable, according to the distance at which the spectator is placed from it. When the object behind which the sun is just going to rise, or has just been setting, is very near, no such effect takes place. In the case represented in Fig. 9 the distance was about 194 metres, or 636 English feet, from the spectator in a direct line, the height above his level being 60 metres, or 197 English feet, and the horizontal line drawn from him to the horizontal projection of these points on the plane of his horizon being 160 metres, or 525 English feet, as will be seen in the following diagram, Fig. 10.

[Sidenote: SILVER TREES AT SUNRISE. 1858.]

[Ill.u.s.tration: Fig. 10. Luminous Trees projected against the sky at sunrise.]

[Sidenote: BIRDS AS SPARKS OR STARS. 1858.]

"In this case only small shrubs and the lower half of the stem of a tree are illuminated white, and the horizontal extent of this effect is also comparatively small; while at other places when I was near the edge behind which the sun was going to rise no such effect took place. But on the contrary, when I have witnessed the phenomenon at a greater distance and at a greater height, as I have seen it other times on the same and on other mountains of the Alps, large tracts of forests and immense spruce-firs were illuminated white throughout their whole length, as I have attempted to represent in Fig. 11, and the corresponding diagram, Fig. 12. Nothing can be finer than these silver-looking spruce-forests.

At the same time, though at a distance of more than a thousand metres, a vast number of large swallows or swifts (_Cypselus alpinus_), which inhabit these high rocks, were seen as small brilliant stars or sparks moving rapidly in the air. From these facts it appears to me obvious that the extent of the illuminated spots varies in a direct ratio of their distance; but at the same time that there must be a constant angular s.p.a.ce, corresponding probably to the zone, a few minutes of a degree wide, around the sun's disk, which is a limit to the occurrence of the appearance. This would explain how the real extent which it occupies on the earth's surface varies with the relative distance of the spot from the eye of the observer, and accounts also for the phenomenon being never seen in the low country, where I have often looked for it in vain. Now that you are acquainted with the circ.u.mstances of the fact, I have no doubt you will easily observe it in some part or other of your Scotch hills; it may be some long heather or furze will play the part of our Alpine forests, and I would advise you to try and place a bee-hive in the required position, and it would perfectly represent our swallows, sparks, and stars."

[Ill.u.s.tration: Fig. 11. Luminous Trees projected against the sky at sunrise.]

[Ill.u.s.tration: Fig. 12. Luminous Trees projected against the sky at sunrise.]

[Sidenote: THE LADDER CONDEMNED. 1858.]

Our porters, with one exception, reached the Pierre a l'Ech.e.l.le as soon as ourselves; and here having refreshed themselves, and the due exchange of loads having been made, we advanced upon the glacier, which we crossed, until we came nearly opposite to the base of the Grands Mulets.

The existence of one wide creva.s.se, which was deemed impa.s.sable, had this year introduced the practice of a.s.sailing the rocks at their base, and climbing them to the cabin, an operation which Balmat wished to avoid. At Chamouni, therefore, he had made inquiries regarding the width of the chasm, and acting on his advice I had had a ladder constructed in two pieces, which, united together by iron attachments, was supposed to be of sufficient length to span the fissure. On reaching the latter, the pieces were united, and the ladder thrown across, but the bridge was so frail and shaky at the place of junction, and the chasm so deep, that Balmat p.r.o.nounced the pa.s.sage impracticable.

[Sidenote: CROSSING CREVa.s.sES. 1858.]

The porters were all grouped beside the creva.s.se when this announcement was made, and, like hounds in search of the scent, the group instantly broke up, seeking in all directions for a means of pa.s.sage. The talk was incessant and animating; attention was now called in one direction, anon in another, the men meanwhile throwing themselves into the most picturesque groups and att.i.tudes. All eyes at length were directed upon a fissure which was spanned at one point by an arch of snow, certainly under two feet deep at the crown. A stout rope was tied round the waist of one of our porters, and he was sent forward to test the bridge. He approached it cautiously, treading down the snow to give it compactness, and thus make his footing sure as he advanced; bringing regelation into play, he gave the ma.s.s the necessary continuity, and crossed in safety.

The rope was subsequently stretched over the _pont_, and each of us causing his right hand to slide along it, followed without accident.

Soon afterwards, however, we met with a second and very formidable creva.s.se, to cross which we had but half of our ladder, which was applied as follows:--The side of the fissure on which we stood was lower than the opposite one; over the edge of the latter projected a cornice of snow, and a ledge of the same material jutted from the wall of the creva.s.se, a little below us. The ladder was placed from ledge to cornice, both of its ends being supported by snow. I could hardly believe that so frail a bearing could possibly support a man's weight; but a porter was tied as before, and sent up the ladder, while we followed protected by the rope. We were afterwards tied together, and thus advanced in an orderly line to the Grands Mulets.

[Sidenote: GORGEOUS SUNSET. 1858.]

The cabin was wet and disagreeable, but the sunbeams fell upon the brown rocks outside, and thither Mr. Wills and myself repaired to watch the changes of the atmosphere. I took possession of the flat summit of a prism of rock, where, lying upon my back, I watched the clouds forming, and melting, and ma.s.sing themselves together, and tearing themselves like wool asunder in the air above. It was nature's language addressed to the intellect; these clouds were visible symbols which enabled us to understand what was going on in the invisible air. Here unseen currents met, possessing different temperatures, mixing their contents both of humidity and motion, producing a mean temperature unable to hold their moisture in a state of vapour. The water-particles, obeying their mutual attractions, closed up, and a visible cloud suddenly shook itself out, where a moment before we had the pure blue of heaven. Some of the clouds were wafted by the air towards atmospheric regions already saturated with moisture, and along their frontal borders new cloudlets ever piled themselves, while the hinder portions, invaded by a drier or a warmer air, were dissipated; thus the cloud advanced, with gain in front and loss behind, its permanence depending on the balance between them. The day waned, and the sunbeams began to a.s.sume the colouring due to their pa.s.sage through the horizontal air. The glorious light, ever deepening in colour, was poured bounteously over crags, and snows, and clouds, and suffused with gold and crimson the atmosphere itself. I had never seen anything grander than the sunset on that day. Clouds with their central portions densely black, denying all pa.s.sage to the beams which smote them, floated westward, while the fiery fringes which bordered them were rendered doubly vivid by contrast with the adjacent gloom. The smaller and more attenuated clouds were intensely illuminated throughout. Across other inky ma.s.ses were drawn zigzag bars of radiance which resembled streaks of lightning. The firmament between the clouds faded from a blood-red through orange and daffodil into an exquisite green, which spread like a sea of glory through which those magnificent argosies slowly sailed. Some of the clouds were drawn in straight chords across the arch of heaven, these being doubtless the sections of layers of cloud whose horizontal dimensions were hidden from us. The c.u.muli around and near the sun himself could not be gazed upon, until, as the day declined, they gradually lost their effulgence and became tolerable to the eyes. All was calm--but there was a wildness in the sky like that of anger, which boded evil pa.s.sions on the part of the atmosphere. The sun at length sank behind the hills, but for some time afterwards carmine clouds swung themselves on high, and cast their ruddy hues upon the mountain snows. Duskier and colder waxed the west, colder and sharper the breeze of evening upon the Grands Mulets, and as twilight deepened towards night, and the stars commenced to twinkle through the chilled air, we retired from the scene.

[Sidenote: STORM ON THE GRANDS MULETS. 1858.]

The antic.i.p.ated storm at length gave notice of its coming. The sea-waves, as observed by Aristotle, sometimes reach the sh.o.r.e before the wind which produces them is felt; and here the tempest sent out its precursors, which broke in detached shocks upon the cabin before the real storm arrived. Billows of air, in ever quicker succession, rolled over us with a long surging sound, rising and falling as crest succeeded trough and trough succeeded crest. And as the pulses of a vibrating body, when their succession is quick enough, blend to a continuous note, so these fitful gusts linked themselves finally to a storm which made its own wild music among the crags. Grandly it swelled, carrying the imagination out of doors, to the clouds and darkness, to the loosened avalanches and whirling snow upon the mountain heads. Moored to the rock on two sides, the cabin stood firm, and its manifest security allowed the mind the undisturbed enjoyment of the atmospheric war. We were powerfully shaken, but had no fear of being uprooted; and a certain grandeur of the heart rose responsive to the grandeur of the storm.

Mounting higher and higher, it at length reached its maximum strength, from which it lowered fitfully, until at length, with a melancholy wail, it bade our rock farewell.

A little before half-past one we issued from the cabin. The night being without a moon, we carried three lanterns. The heavens were crowded with stars, among which, however, angry ma.s.ses of cloud here and there still wandered. The storm, too, had left a rear-guard behind it; and strong gusts rolled down upon us at intervals, at one time, indeed, so violent as to cause Balmat to express doubts of our being able to reach the summit. With a thick handkerchief bound around my hat and ears I enjoyed the onset of the wind. Once, turning my head to the left, I saw what appeared to me to be a huge ma.s.s of stratus cloud, at a great distance, with the stars s.h.i.+ning over it. In another instant a precipice of _neve_ loomed upon us; we were close to its base, and along its front the annual layers were separated from each other by broad dark bands.

Through the gloom it appeared like a cloud, the lines of bedding giving to it the stratus character.

[Sidenote: A COMET DISCOVERED. 1858.]

Immediately before lying down on the previous evening I had opened the little window of the cabin to admit some air. In the sky in front of me shone a curious nodule of misty light with a pale train attached to it.