On the whole the Mid-European glaciers are a legacy from a distant past.

Their former size and extent corresponded to general meteorological conditions which have long ceased to exist.

They might—and no doubt did—alternately increase and decrease within historical times. They nevertheless must be viewed as a bequest, a kind of heirloom coming from a prehistoric ancestry. They are the survival of a phenomenon which, in its former compass and intensity, is no longer compatible with the meteorological rÉgime of Central Europe.

The temperature most suitable for the formation of ice in nature is the temperature which remains the most steadily around the freezing-point of water. Extremes of temperature are not favourable to the formation of snow, which is the form in which water generally passes into glacier ice.

It stands to reason that the oftener the atmosphere can be saturated with moisture in circumstances which allow a frequent discharge in the shape of snow falling upon surfaces that are iced—or such as will retain the snow, assuring the transformation of some of it, ultimately, into ice—the more will the thermometer readings show a temperature rising and falling only moderately above and below the freezing-point of natural water. There is no use in further emphasising this obvious truth.

Everybody will understand that moisture formed in hot tracts of the atmosphere has little chance of being converted into snow, and that, while a warm atmosphere may generate water—destructive of ice and snow surfaces—a very cold atmosphere cannot assist in glacier formation—on high land, at any rate—for want of vapours to condensate and precipitate, and for want of water masses to consolidate.

It follows that, within historical times, the Alpine glaciers have undergone variations according to changes in the quantity of moisture contained in the atmosphere, theirs being such altitudes and such climatic conditions as might allow the Centigrade thermometer to swing pretty steadily between 20 degrees above zero and 20 degrees under, all the year round and in the course of a day.

These conditions existed more fully in periods when the Alps were well wooded. Such a period pre-existed the first historical epoch of Switzerland. Under the Romans, say from 50 B.C. to 500 A.D., this first historical epoch was marked by the wholesale destruction of forests—the usual price to be paid for civilisation—and the glacier world retreated in a ratio commensurate with the process of denudation.

Then came the Early Middle Ages, which for about six or seven hundred years show a distinct retrogression in Swiss civilisation. The glaciers now regained some of the ground they had lost, because the wooded surface, which is the most favourable to the condensation of moisture, underwent a considerable increase.

In modern times the forest area has again undergone such shrinkage that it has reached the minimum when artificial means have to be devised for its preservation. Glaciers have gone back again.

We may therefore define glaciers as ice and snow reservoirs formed under prehistoric conditions which no longer exist. They are kept alive on a reduced scale, in a direct ratio to the moisture yielded by the atmosphere as often as it is conveniently a little above and a little below the freezing-point of natural water.

Our knowledge of the glacier world in its formative processes is as yet extremely deficient. What proportion of the year’s snowfall—within the glacier region—is actually converted into ice? What proportion melts away on the surface and passes directly into water, to be carried away, carrying along with itself some of the ice? What proportion is, by sublimation and evaporation, returned to the atmosphere, to become again the toy of winds, in the shape of snow or rain-clouds, never feeding the glacier at all on which it first fell?

On the other hand, who can tell how much ice is formed on the glacier surface by the direct absorption of the air moisture collecting upon such a condensator? And would it be alien to our subject to ask what effect may have on the present glaciers the loss of pressure consequent upon the enormous reduction in bulk and height which they have undergone? Is the glacier ice formed under the present rate of pressure capable of offering anything like the same resistance to disintegration as its prehistoric congener? What are its powers of self-preservation under the vastly inferior pressure which it experiences in the very places in which ice was once packed to a height and in a bulk we should not like to express in figures, even if we possessed competent data?

The broad fact seems to be that as much snow as falls on the glaciers throughout the year is taken back into the atmosphere, and that the snow congealed and fixed in the upper basins is as nothing compared with the quantity of water that evaporates or runs away at the nether end of the mass every summer. What is the capacity of the ice-forming firn of the Aletsch basin compared to the extent of its melting surface? And how much snow does the firn receive every year from the atmosphere? And how much of that snow is incorporated?

There are now so many approaches to the glacier world of Switzerland that it should be easy to determine, at the outlet of a few typical glaciers, the amount of water thaw conveys to the valleys below. According to the season, it is quite easy to distinguish between rain-water, water from springs, and glacier water. Such observations would lead to results reciprocally verificatory.

My provisional conclusions are that:—

1. The snow falling on the Swiss glaciers is a mere fraction of the quantity wanted to assure their stability.

2. The average snowfall of any year returns to the atmosphere.

3. The source and means of congealation are not proportionate to the exigencies of ice-formation, even for the maintenance of the status quo.

4. The glaciers, regressing as they are now doing, are not being replenished to any appreciable extent from the so-called everlasting snow storage, and certainly not at all in proportion to their wastage.

In other words:—

1. In a number of years X the whole glacier mass of Switzerland is dissolved and reconstituted in proportions that are less than in the preceding X period.

2. The snow fallen during the period X—if present conditions are accepted—is pumped back by the atmosphere during the same period.

3. The quantity of water flowing from those glaciers in the time is greater than the means of glacier recuperation.

4. Yet the glaciers do recuperate in some proportion to their former size.

5. Consequently the condensation and congealing of atmospheric moisture must be much more effective an agent than hitherto suspected, for there is no reason why, upwards of 9,000 feet, snow should be less liable to thaw on ice than on rock surfaces. Rock and ice areas are conterminous.

Glaciers may be classed, according to their physical conformation, under the following headings:—

1. Circular Schema.—They are then enclosed in a basin more or less irregular in shape. The enclosed mass of ice remains concave as long as it is lower than the rim of the basin. But it becomes convex in the centre when it rises above the horizontal line joining the opposite rims of the basin.

2. Longitudinal Schema.—A. On the flat, or approximately, those glaciers show convex surfaces.

B. When resting on a slope they are concave in the upper basin, which feeds them and become convex as they reach lower and wider channels.

This second type is the normal glacier type.

A diagram or section of the convex portion of the glacier—an ideal diagram of course—would show the mechanical and static forces at work in a fan-shaped formation radiating from a point on the not geometrical, but mechanical, centre line of the glacier, this point being situated on its bed, where the side-pressures converge and annihilate each other’s progress.

From this point the bottom ice works its way up to the melting-surface—but obliquely, being the whole time carried down by the slope—and throws up side moraines and one or several spinal moraines in the process. The spinal moraines always rest on pure ice. The ice seams have been thrown up from the inside.

Crevasses may occur in an outward, open, surface-formation, as in sÉracs when they are grouped together, or else they are the result of accidental deflections or temporary oppositions in mechanical and static forces at work in the ice.

We said a while ago that there was no reason why, at the height of 9,000 feet and upwards, snow accumulations should be more stable and constant on ice surfaces than on rock. The cause for this is simply that rock and ice are too near to each other and at altitudes too closely alike for serious differences in temperature.

Let us now pass to the matter of avalanches. If snow is utterly unstable on rock, so it is on ice. Rock and ice constitute an avalanche area, which in winter extends down so as to include all steepnesses on which snow may lodge and whence it may be dislodged by the forces of Nature.

Avalanches may be periodic or accidental.

A periodic avalanche is the kind that comes down regularly at a known spot, each time sufficient cause is brought into play. Maps of the Alps exist on which those periodic avalanches are noted. Almost every Alpine village has a periodic avalanche on its territory. The peasants know when and where to expect it. It is called the avalanche of so and so, and your business is to find out, each time you propose going out on an expedition, whether it has come down or not, and all about it.

An accidental avalanche arises from general causes taking effect fortuitously.

The general causes are:—

1. A quick rise in the temperature.

2. A sudden fall of the barometer.

3. A change of wind.

4. A fresh fall of snow.

5. Slopes of a certain angle and conformation.

6. Differences of density, moisture, and consistency in superposed layers of snow.

A study of the statics of snow is the royal road to the understanding of avalanches.

On a slope snow is in a state of more or less pronounced instability.

A first fall of dry winter snow upon dry slopes is extremely avalanchy, provided it be heavy enough. If it be a fall of wet snow on a porous surface—that is, neither frozen ground nor hard rock—the snow will as it were flop together in a slithering mass, but is not likely to form itself into a dangerous compact floe.

As soon as a second fall of snow comes to adhere to what is left of the first, it may happen that the second layer does not get properly welded to the first. The thoroughness of the attachment depends on the adhesiveness of the snow and on weather conditions. A foundation is therefore laid for the slipping of the new snow upon the surface of the old.

In the course of the winter the snow gets consolidated in one mass, but the process takes each time from two to three days, during which caution is necessary. A homogeneous layer of snow, hardened from the outside by wind pressure, or freezing over after a slight thaw, may then break up into slabs which slide down on the older snow, should one with ski, or in any other fashion, cut that snow away—at any point—from its support.

A stratum of snow on a steep open slope is like a piece of cardboard balanced on your finger. There is a limit to the inclination of the cardboard beyond which it will slip off its pivot. So it is with snow.

Newly fallen snow soon ceases to be an amorphous mealy mass. Its bottom layer models itself on the surface on which it lies and, if turned over, would show that surface en relief. The next stratum adheres to the first more or less, and finds points of support for itself, such as rocks protruding through the first stratum, trees, shrubs, fences, dykes, &c. Every ensuing layer is less shored up than the one beneath. Should there be a rise in the temperature, an increase of moisture brought on by a change in the wind, the snow becomes heavier and may start down; as a dry sponge on an inclined board, gradually absorbing water, must slide down when the inclination of the board and the quantity of water reach the critical point.

Our illustration from the cardboard balanced on a finger-tip, and from the sponge on an inclined plane, makes it clear that it is impossible to state at what definite angle the equipoise of a snow stratum must be lost or is sure to be kept. That angle depends on the finger-tip, on the weight and size of the cardboard, on the sponginess of the sponge, on the slipperiness of the plank, on your holding your breath, or mischievously blowing upon the suspended object, &c. When about to capsize, the cardboard may meet some external point of support, such as your raised hand, which, in the case of the snow stratum, would be a pre-existing prop and maintain an otherwise impossible stability.

A fall in the barometer almost always means an increase of moisture which is unfavourable to the steadiness of old snow. A dry, hot wind—such as foehn—is worse, because its heat penetrates the snow to the very bottom and sets it moving throughout its thickness.

New snow is dangerous till it has had time to set—that is, for two or three days.

Runners are generally agreed to call steep the slopes on which avalanches may occur.

Steep slopes are either concave, convex, or straight.

They are concave when the slopes converge towards a central dividing line lying deeper, to the eye, than their sides; these are scooped out of the hill.

Concave slopes are:—

1. Funnel-shaped, when the funnel may be either upright or upside down.

If it is upright, the wide opening is at the top. If the slope affect the shape of a reversed funnel, it opens out at the bottom, but it may also be choked up in the middle, opening up again above, like an hour-glass.

Concave slopes are quite safe if strewn with rocks, overgrown with shrubs, or wooded. They are untrustworthy if the sides have been planed down, as it were, by what we may call natural wear and tear.

The reader sees here how the indications of nature may be properly interpreted. It is quite clear that a gorge which is a natural shrubbery, for instance, has not been visited by avalanches for a time at least as long as the plants took to grow to their visible size.

The trouble here is that Londoners, for example, having to deal with a gorge which they have not seen free from snow, cannot be expected to tell whether it is safe or not. The local man alone—a permanent eye-witness—possesses the information required, and failing actual acquaintance with the place, a practised mountaineer alone can form an opinion.

Slopes are convex when the centre line, to the eye, rises above their sides. These stand out from the hill, diverging from its top.

Convex slopes should be ascended and descended along the dividing-line. This line, as a dominating centre, will always be sought out by the good High Alp runner. It is both the shortest and surest path from point to point, and great is the delight to see at one’s feet the avalanche runs. If the coping is occupied by rocks, the runner will keep to the snow near to the rocks, but he has no business there at all if the rock ridge is considerable enough to harbour avalanche snow. A practised eye sees at a glance whether snow in excess of the capacity of the gullies is still suspended above the runner’s head, or whether it lies in cakes and balls at his feet.

Here again the native will know. It would help you but little to say that you have found him out to be an unconventional runner, that he is slow and not at all the handy man you expected. However much you may be entitled to fancy yourself or your skill as a conventional runner, he is the better mountaineer, and should your conventional style leave you in the lurch, he is the fellow to do the right thing for you. It is then just as well to remember, when one writes in a home magazine, that, on the spot, one was the incompetent person of the party. “He of the ice-axe,” your guide, would do that second job, too, far better than you, if the use of the pen in that periodical was not inconsistent with his inferior social standing and extremely imperfect education.

The straight slope is the slope on which every point is on the same plane as another. These slopes are safe when they abut on to ground which obviously is locally viewed as not exposed to avalanches: vineyards, potato-fields, woods, hay-lofts, &c.

They are unsafe when undermined by a trickle of water—springs, for instance—and when the layer of snow next to the ground has melted away without affecting the upper layers; or when the slope rests upon a protruding ledge over which it bulges out; or when it is cut by longitudinal ribs of blown-out snow which you may break open unawares, letting out the mealy contents upon yourself.

All slopes may be traversed—that is, you may run across them obliquely.

When about to traverse, look to the foot of the slope, and then look to the head of the slope. If all is right, sound the snow with your stick and glance into the conic hole made by it. In time you will acquire an ability to tell by the feel whether the snow is mealy, or set, or damp, and how many layers your stick breaks through before coming to a standstill upon frozen ground, or against rock, or before sinking into the hollow space that may exist between the nethermost layer of snow and the soil.

Of course, all this you cannot do with a short, light bamboo, conveniently fitted with an osier disk within three inches of the point! To go forth so simply equipped means that you are leaving your brains at home on that day—a thing I often do myself—but, I assure you, only when out for mere play!

A stick that cannot be used on an emergency either as an anchor or as a sounding-line to take castings with, is a poor friend. It is instructive to look curiously into the hole made by one’s stick. What would be the use of a sport practised simply as an opportunity for being scatter-brained with impunity, so long as luck lasts?

On the hill-side, slopes—concave, convex, and straight—are joined to one another by linking surfaces varying in shape and inclination, but of too limited a development and too irregular a build to offer to avalanches any opportunity of spreading over them; or else slopes are separated from one another by breaks in the ski-ing surface, such as ravines. In these, masses of snow gather most conveniently. The longitudinal gaps opened up by landslips, torrent beds, or even only the slides made by wood-cutters through forest and pasture land to launch felled trees into the valley, are very distinctly avalanche runs. Efforts are now being made to bar such runs by artificial plantations, fencings, or walls.

The centre of military ski-running in Switzerland is in the environment of the permanent Alpine forts which defend the St. Gothard knot of trans-Alpine and sub-Alpine (railway tunnels) lines of communication from Italy into Switzerland, betwixt the sources of the Reuss, Ticino, Rhine, and RhÔne. Another centre is situated in the RhÔne Valley, at the point where a natural defile bars the line of communication between the upper RhÔne Valley, at St. Maurice, and the Lake of Geneva, commanding to some extent the roads converging upon that point from Northern Savoy and leading to it from Italy over the St. Bernard pass or through the Simplon tunnel.

The opening of the Loetschberg tunnel on the new short railway route between Berne and Milan will, however, make it advisable to erect some kind of additional works about Brigue.

The Gothard and St. Maurice guards use ski, and ski-ing detachments are about to be attached to the brigades of mountain infantry located all along the range of the Alps.

Many junior Swiss officers have made themselves proficient in the new mountaineering by joining military ski courses. Military patrol competitions meet with much favour at the large ski gatherings.

For all that, the adaptability of ski to military purposes is not very great in the High Alps. Still they are called upon to become quite a consideration in border defence or attack. Small troops of skiers could pass easily from one side to another of the Alps, occupying flying posts of observation, and even raiding places where the defence would have preferred to put its own outposts, had it not allowed itself to be forestalled. The Alpine Club huts afford sufficient shelter for summarily equipped detachments numbering from twenty to forty men.

Bodies of troops crossing the Alps in winter by the passes available for considerable military transport would enjoy a distinct advantage if the outlet of the passes had been previously occupied by half or quarter companies of bold ski-ing infantry pouncing, as it were, from the skies upon small snow-bound places with summer hotels ready for occupation and better stocked with means of subsistence than one would at first be led to expect. In some Swiss Alpine villages particularly, large supplies are often accumulated for the next summer season, and in others much merchandise is stored up to accommodate the Italian smugglers whose “exports” from Switzerland are all the year round a source of profit to their purveyors.

Swiss ski-runners, by expeditions like my own, have proved that the glaciers may be used, within strict limits, as highways for rapid and unexpected military movements. Till now it was assumed that crevasses, iced rocks, and piles upon piles of corniced snow would offer insuperable obstacles to any military action. But the crevasses—as the reader now knows—are most hermetically sealed. To the expert and wary runner the snow opposes no greater barrier than to the pedestrian in summer. Does not history teach how foot-soldiers have en masse, with artillery and baggage, been moved to and fro across the Alps? Henceforth, military runners may be trusted to scour the ranges, undetected, cutting communications one day at the St. Bernard hospice and opening fire three days later upon the Simplon hospice, hanging alternately on the only two military roads joining Switzerland and Italy between the St. Gothard forts and French Savoy.

Those raiding parties could be followed by considerable parties of transport men, carrying fresh ammunition and supplies.

Such places as Bourg St. Pierre, Fionnay, Arolla, Zinal, Zermatt, Saas, would be, from the Italian point of view, worth seizing and manning at the outset of a winter campaign. From the point of view of a Swiss advance aiming at laying hold of the southern outlets of the military roads before the enemy could move up its advanced columns, those places would be valuable bases for the auxiliary services waiting upon the raiding detachments.

Hitherto forces crossing the Alps in winter could expect to be safe from attack on their flanks. Henceforth there might be a very different story to relate. The few experiments hitherto made show that an attack by skirmishing ski-runners upon columns on the march could not be met by dispatching against them rifle-men on foot. Across country a man on foot will take about an hour—on flat ground—to cover a distance which an average runner on 2 feet of snow will overtake in one-quarter of the time. Uphill, the advantage of the ski-man is still more marked, and he may continue much longer. Moreover, he disposes of the whole hill-side, and may take cover exactly as he pleases, by crossing snows over which the pedestrian can make no progress at all, and becomes a most convenient mark. The ski-runner may force his pursuer into any ground he chooses. For a force developed across an expanse of snow, it is extraordinarily difficult to carry out an attack upon ski-runners firing from behind shelter. They occupy probably the higher position, and their field of vision is absolutely uninterrupted. Rushes from point to point across the zone of fire are quite out of the question in the absence of any screen whatsoever.

As for the rifle-men or sharpshooters on foot in charge of a village, sallying forth to dislodge a party of runners firing into their position and then withdrawing out of the reach of adversaries firing from opened-up tracks, spaces, or houses, the idea is not plausible. A dismounted horse-soldier might just as well advance sword in hand against marksmen manning rifle-pits, or an infantry man, short of ammunition, might just as well trust his bayonet to reach a horseman galloping away out of sight.

Ski-ing patrols of mountain infantry with portable machine-guns could defend such passes as the Furka or the Grimsel against forces pushed forward in vastly superior numbers.