Chapter IX: Mountaineering on Ski (1)

BY ARNOLD LUNN

Winter mountaineering may be said to date from Mr. Moore’s crossing of the Strahlegg and Finsteraarjoch Passes in January 1865. The first big peak to be climbed in winter was the Wetterhorn, which was ascended in 1874 by the Rev. W. A. B. Coolidge and Miss Brevort; a few days later this party climbed the Jungfrau. These brilliant expeditions set a fashion which was, however, only followed by a select company of mountaineers, among whom a place of honour must be given to Mrs. Le Blonde. It was not until Paulcke crossed the Oberland at the end of 1897 on the ski that winter mountaineering began to be a popular sport. To wade up a big peak in deep snow on snow-shoes or on foot only appealed to a minority, but the number of those who were attracted by the chance of combining mountaineering with ski-ing steadily increased.

The English were slow to follow the new fashion; the number of British ski-runners who have a long list of glacier ski tours to their credit is still small, but abroad hundreds of experienced mountaineers have explored the High Alps on ski, and abroad the advisability of using the ski in the High Alps has passed beyond the limits of discussion.

The time is coming when most alpine huts will be provided with ski. A steadily increasing number of mountaineers realize that such peaks as Monte Rosa or the Zermatt Breithorn provide excellent ski-ing at all months of the year, and that the trouble of dragging a light pair of summer ski to the summit is well repaid by a magnificent run down to the hut.

There is no month in the year in which the writer has not enjoyed first-class ski-ing, and there is no season in the whole alpine calendar in which ski cannot be used on the loftier snow peaks in the Alps. Ski have come to stay as an indispensable adjunct to mountaineering. To the rock climber the ski are perhaps mainly useful in bad seasons; if the weather in summer were uniformly good the enthusiastic rock climber would have little use for the ski. But long spells of bad weather are not unknown, and many a climber who has engaged a guide or a couple of guides for a month has spent a week, a fortnight, or in some cases even longer without climbing a peak. I venture to assert that if he took himself and his ski to a club hut he would at least have the satisfaction of making good use even of an afternoon’s fine weather. I remember once finding myself at the Egon von Steiger hut during bad weather. It snowed all day and all night, and cleared at ten o’clock the next morning. Two parties on foot attempted the easy Ebnefluh. Both were driven back after a very brief struggle with deep soft snow. Myself and a friend reached the summit on ski in more or less normal time, and enjoyed a wonderful run back to the hut, where the disgruntled foot-sloggers had spent the day.

Let the rock climber learn to ski, and when the big rock peaks are deep in snow he will be able to snatch a Monte Rosa or Breithorn from the first fine day. In bad seasons individual fine days are often sandwiched between two or three days of bad weather. Such isolated days are useless to the foot-climber but invaluable to the ski-runner.

[Sidenote: Technique.]

I cannot spare the space to explain the technique of ski-ing.[18] Here I need only attempt to dispel a lingering belief, that dies hard, to the effect that there is one technique for ordinary ski-runners and another for mountaineers. This curious superstition is the last relic of an exploded system of ski-ing taught by an Austrian called Zdarsky, the main effect of which was to encourage timid, slow and clumsy ski-ing. The ‘Lillienfeld’ ski were short, and made straight running very difficult and turning very easy. The Lillienfeld system taught people to ski very quickly by dodging all difficulties and encouraged a free use of the stick. It was a bad system, and is now quite discredited; but there still lingers a curious belief that the Norwegian style may be all very well for small mountains but is too dashing and insecure for the High Alps. As a rule, glacier ski-ing is far easier than ski-ing among the lower mountains; the most difficult of all ski-ing country is wooded country, such as extends for miles round Christiania, the home of the ‘Norwegian style.’ Let me therefore urge the reader to master the free Norwegian style, to make all his turns and swings without the aid of the stick, and to acquire a free and dashing style. The mountaineer even more than the low-level ski-runner should have complete control of his ski, and complete control is impossible unless you have learned to control your ski not by means of the stick, but by means of the ski themselves.

There are a few occasions on which the use of the stick is permissible on tour; but it is so dangerous to begin by using the stick as a brake, that I would advise the beginner NEVER to use the stick until he has at least passed the ‘THIRD-CLASS TEST’ which is held from time to time in all ski-ing centres patronized by British runners.

Furthermore, though of course it is absurd to take risks in the High Alps, occasions often arise where speed means safety. With bad weather or night approaching, the man who can run fast stands more chance than the man who can not, and, consequently, the higher your speed consistent with safety the better your chances. Now, a high speed consistent with safety can only be maintained by those who have lost no chance on small expeditions of raising the speed at which they feel comfortable, and this, again, can only be achieved by running just a little faster than is quite comfortable.

In the High Alps a reckless runner, who is always falling, is a danger to his companions and himself, but a man who is quite incapable of a fair speed is always a nuisance on tour, and may sometimes prove a danger. Steadiness is the first requisite in the High Alps, but speed is by no means unimportant. Any man with average balance and nerve, if he is properly taught, can learn to run steadily and to make slow turns on average snow at the end of a fortnight. To become a really expert ski-runner is, of course, another matter, but some of the finest ski-turns in the High Alps have been carried through with success by men who were not even third-class runners. Let the mountaineer learn to ski and take such chances as a snowy summer may afford. In a few hours he will begin to enjoy ski-ing, and his enjoyment will steadily increase with his experience. It is easy to become a third-class ski-runner, and very well worth while taking sufficient trouble to become a second-class runner. First-class ski-ing is, of course, not within the reach of all.

In order to make much that follows comprehensible to the reader, who, though a mountaineer, has yet to become a ski-runner, a short definition of the ski-ing turns and swings is necessary.

The object of every ski-runner is to approximate as nearly as possible in his course to a straight line between the point of departure and the goal. Obviously this ideal is impossible of attainment save on comparatively short open slopes, which can be taken straight. Hence the regrettable necessity of turns and swings which, unlike skating turns and swings, are not an end in themselves, and are only incidentally beautiful and graceful to execute and to watch.

There are three principal turns or swings: the _Stemming turn_, the _Telemark_, the _Christiania_.

Each of these turns can be used either as a stop turn (i.e. in order to stop more or less suddenly), or as a means of linking one tack to another. For instance, a slope may be too steep to take straight; in this case the good runner descends in a series of linked curves.

According to the condition of the snow, he will make these linked curves either by means of the Stemming, the Telemark, or the Christiania turns.

The Stemming turn is the easiest and slowest turn. It is the key to alpine ski-ing, and can be employed on snow on which a Telemark or linked Christiania would be either difficult or impossible. The beginner should try to combine Stemming with Christianias, to begin his turn as a Stem and to finish with a Christiania. This swing, which is sometimes called a Stem-Christiania or a ‘Closed Christiania’ (as opposed to ‘Open Christianias’), or by a natural abbreviation a ‘Closti,’ is the most generally useful of ski-ing swings.

The Lillienfeld system placed exclusive reliance on the Stemming turn and dismissed the other two as fancy tricks. This was absurd, for in many kinds of snow the Telemark or Christiania is much the more useful manœuvre. Either of these latter turns can be executed at a very high speed, whereas the Stemming turn cannot be done at a high speed.

The Telemark is mainly useful in deep soft snow or in soft breakable crust; in either of which the Stemming turn and the linked Christiania is difficult or impossible.

The Christiania, as a stop turn, is the safest method of stopping at high speed. Linked open Christianias are not easy to master, but are very satisfactory when mastered. Wherever a linked series of Christianias can be executed, linked Stem-Christianias are easier, and safer. The power to make a series of continuous non-stop turns with the Christiania marks out the expert; nothing is more beautiful than fast descent on glacier snow, film crust or crust slightly softened by means of a series of swift-running Christianias.

For the High Alps I consider that the Stemming turn and the Christiania should always be used in preference to the Telemark, excepting in very deep soft snow--rare in the High Alps--or in soft breakable crust.

The Telemark is a one-foot turn; all the weight is on the leading foot; consequently the Telemark is less powerful and less sure than the Christiania, which is a two-foot turn. Furthermore, the falls resulting from a Telemark which has gone wrong are more dangerous than from any other turn. From a faulty Christiania or Stemming turn one is usually thrown backwards or sideways against the slope; from a faulty Telemark one is often thrown on to one’s head or outwards from the slope. Further, the ski have a nasty habit of crossing behind in a badly timed Telemark.

To sum up: Use the stick as little as possible. Make all your linked turns by Stem-Christianias, except in deep soft snow or breakable crust, where the Telemark should be used. For a sudden stop use the Christiania in preference to the Telemark.

[Sidenote: Equipment.]

In addition to the ordinary mountaineer’s equipment, the ski-runner must have ski, sealskins, ski-sticks and repair outfit for ski.

I have no space to advise on the choice of ski, but I might warn the reader against the common illusion that ski for mountaineering should be markedly shorter than ski for short tours. They should be a couple of inches shorter, but very short ski should not be used save in the summer. I have used the longest size obtainable (2·36 in.) for quite long tours, and the next longest size (2·31 in.) in the High Alps.

Sealskin are detachable, and are fixed on to the ski to prevent the ski side-slipping while climbing a steep slope. Ski-ing boots are bigger than mountaineering boots. They should be nailed--lightly nailed, of course, but on no account entirely nailless. The nailless ski-ing boot is a superstition imported from Norway, where the hills are milder in gradient than in the Alps.

For all glacier tours crampons, or, to use another word, ‘ice-claws,’ should be taken. Eight-pointers are best, though good work can be done with six-pointers. The small four pointers are most insecure and uncomfortable.

For all further details as to equipment the reader may consult my book _Cross Country Ski-ing_.

THE ALPINE CALENDAR

The first winter snows usually fall in October: excellent ski-ing is often obtained at the ordinary winter sports centres in October. Glacier tours should certainly not be attempted before December, as the danger from crevasses is at its maximum in October and November. January and February are the best months for ski tours up to about ten thousand feet. The winter proper is NOT the best season for glacier ski tours, though most of the classic ski tours in the High Alps have been carried out between December and the end of February. Good ski-ing can be obtained at low levels well on to the end of April, and sometimes even later. As a rule, the snow lies down to about five thousand feet on north slopes well on into the middle of May.

MAY AND JUNE ARE THE BEST MONTHS FOR GLACIER SKI-ING, though excellent ski-ing may be obtained throughout the summer. There is no month in the year in which the High Alps do not yield good snow, but the best all-round months for mountaineering on ski are undoubtedly May and June.

SNOW CRAFT

The expert cross-country ski-runner must not only be a fast and safe runner on all kinds of snow and ground, but he must also possess a thorough knowledge of snow craft. Unfortunately, there are nine ski-runners whose Telemarks are perfect for one whose knowledge of snow is even adequate, and the number of those whose understanding of snow in all seasons of the year is really expert is indeed small.

Snow craft in winter and in spring is even more complex than in summer, and requires a special study of its own. Even the most expert guides whose knowledge of summer snow leaves nothing to be desired require considerable winter experience before they are thoroughly competent to lead a party among the High Alps in winter. The same is true of spring; each season, in fact, requires a separate study.

The ski-runner needs to possess a more exact knowledge of snow than that which the foot-mountaineer requires. A mountaineer on foot is mainly interesting to discover whether the snow is hard enough to walk uphill without sinking in, and whether the snow is likely to avalanche. Hard snow, soft snow and avalanche snow are the three main categories in which the foot-mountaineer divides snow. He need not bother with all the delicate gradations of value that distinguish snow which is so hard that it will not take a Stemming turn, and snow which, though hard enough to bear a foot, will yet take a Christiania or even a Telemark.

The ski-runner who neglects snow craft is severely punished for his carelessness. He runs into fast and sticky snow and pitches heavily on his face, or from soft snow on to hard snow and falls heavily backwards. Even the least observant ski-runner soon realizes that an elementary knowledge of snow is essential to his comfort and his safety. His knowledge of snow needs to be instinctive. On foot a man has time to probe and to examine, but on ski he has to diagnose the snow while travelling at a high speed. He has to possess an accurate sense of direction so that he can foretell the changes of snow that occur when travelling from, say, a north-east slope on to an eastern slope, or an eastern slope on to a south-eastern slope.

Quite as many bad ski-ing falls are caused by deficient snow craft as by deficient balance.

Precisely because even the most casual ski-runner is bound to learn from the past experience of nasty falls, ski-ing inevitably teaches even the most unobservant some knowledge of snow craft. A ski-runner cannot hand over the whole strategy of the day’s campaign to a guide. He must think for himself and study for himself. In summer the real business of climbing usually begins when the glacier or the summer snowline is reached, but in winter a ski-runner can kill himself in an avalanche within an hour of the hotel. Snow craft begins in winter at the hotel door.

The careful study of snow is a fascinating branch of nature study. More can be learned from books than the reader might imagine. Once a ski-runner has grasped how snow is affected by altitude, orientation, wind and sun, he is in a better position to profit by his knowledge in practice than if he was forced painfully to unravel the laws of snow by personal observation. In the early days of ski-ing in the Alps the guides themselves were completely ignorant of the main laws of snow in winter. They are still, for the most part, ignorant of the subtleties of spring ski-ing, which is much more difficult to understand than winter ski-ing. In winter, if a snow slope holds good snow in the morning it will probably hold good snow throughout the day, but in spring the same slope goes through a regular cycle of changes. It may be unskiable at dawn, yield perfect ski-ing at midday, prove absolutely unsafe at three in the afternoon, and yield good running again in the evening.

To time a descent accurately, to forecast from a knowledge of the orientation and altitude of a given mountain that it will yield perfect ski-ing at a given hour, is to know one of the most satisfactory intellectual pleasures that the mountains afford.

WINTER SNOW

There are certain forms of snow which are characteristic of certain seasons. ‘_Powder snow_,’ for instance, is normal in winter and uncommon in the late spring; none the less powder snow is often found even in summer, just as certain forms of snow which are characteristic of spring or early summer are occasionally found even in midwinter. ‘Winter snow’ must then be taken to mean the kind of snow which is common and characteristic of, but not limited to, winter.

[Sidenote: Powder snow.]

In winter a normal snowfall is accompanied by a temperature below freezing; snow that falls with the temperature just above freezing usually descends in the form of sleet. Fortunately, such conditions are not common.

Snow will even fall when the temperature registers a degree or two of thaw. I have known dry snow fall with a temperature of two degrees above zero--centigrade, at a height of 5500 feet above the sea. Similarly, as icemakers know, water will freeze on a rink even when the temperature is above freezing-point.

The explanation for this anomaly may be sought in the well-known law that pressure lowers the freezing-point.[19] It seems a natural deduction that diminished pressure will _raise_ the freezing-point. 0° centigrade is the freezing-point of water at sea-level. Under a pressure greater than that of the air at sea-level, the freezing-point is lowered so that the bottom of a glacier will be in a condition of liquefaction at a temperature below freezing. It should follow that an air pressure _less_ than that of the air at sea-level should raise the freezing-point; or, in other words, that at any point above sea-level the freezing-point should be higher than zero. From my own observations I believe that water will freeze and rain turn to snow when the temperature is 2 degrees centigrade above zero at a height of 5000 feet.

Fortunately, the normal snowfall is accompanied by a temperature below freezing, for if the snow is on the point of turning to rain, it forms a crust when the temperature falls. A normal dry snowfall takes the form of small hexagonal crystals. Newly fallen snow is not compact, and contains a great deal of air, which slowly escapes as the snow settles, so that after a day or two the new snow has lost nearly a half of its apparent depth.

New snow is very soft and slow, but gives good running on steep slopes; though, of course, long steep slopes are liable to avalanche. Good running is also often obtained during a snowfall by choosing south slopes, previously covered by a hard crust; for there is nothing pleasanter than two or three inches of snow on hard crust, and during a gentle snowfall it is possible to enjoy quite good sport on such slopes. In general, expeditions--even quite short ones--are impossible till the snow stops, and unsafe for a day or two after a heavy fall. Newly fallen snow sticks badly in the sun even if the temperature is well below freezing.

Once, however, that the snow has settled it soon gives perfect running. One night’s really hard frost is sufficient to produce excellent snow. _Powder snow_ remains good almost indefinitely in winter on northern slopes, provided it is not spoiled by wind. It steadily improves. In sheltered places the crystals gradually grow in size so that sometimes you find large leaf-like formations, which rustle under the ski like autumn leaves. Such snow is a dream of paradise.

_Powder snow_ is the ideal running surface. It is equally good for straight running and for swings. In deep soft powder the Telemark is the best swing, but in fairly compact powder any turn or swing is easy and safe.

The ski-runner who visits the Alps in winter, and has good luck, may run for day after day on perfect powder. He is in danger of thinking himself a better runner than he is. If he concentrates on Telemarks, the first tour in the High Alps, where he will meet varieties of hard and soft crust, will find him out badly. He should therefore make a point of spending a day or two on south slopes so as to master the Stemming turn on hard snow. If he is getting pleased with his Telemarks, let him try a Telemark on the soft breakable crust to be found on south slopes at midday, and if he can do a series of fast-linked Telemarks in such crust, he may then return to his powder snow with a good conscience.

[Sidenote: The Effect of Wind on Powder Snow.]

Snow which is spoiled by the sun is never quite impossible, and is always curable by a hair of the dog that bit it; in other words, by another and stronger dose of sun. But snow which has been wrecked by the wind is the despair of the ski-runner.

The wind does not affect snow that has once been crusted, so that wind-swept snow is almost unknown in spring. The favourite victim of wind is precisely that light, dry powdery snow which is so common in winter.

The effect of wind depends on three factors, the strength of the wind, the time during which the snow is exposed to the wind, and lastly the type of snow exposed to the wind. Powder snow is the most sensitive, the quickest to spoil and the most trying when spoiled. Hard crust is entirely unaffected; heavy wet snow is very little affected.

A light wind produces on powder snow the markings which are known as _ripplemark_, a term which has been applied by scientists to the rippled effects which can be traced, not only in snow, but also in sand, and even in clouds which have been influenced by wind. Sand and snow behave very similarly under the influence of wind. A slightly stronger wind, or a wind blowing for a longer spell, produces caked powder, which is dense and compact, but has not quite lost its powdery quality. The ski sink in to a depth of an inch or more, and though fast running is dangerous and apt to produce broken ski points, a good runner can derive much pleasure from caked powder, and can force linked Telemarks without much trouble. The third stage in the deterioration of snow occurs when the wind produces a hard crust. _Windboard_ is hard and slippery, but so long as it is not varied with soft patches of sticky snow or of breakable crust, windboard yields a surface which may annoy the novice but which should not prove, at any rate on slopes of moderate gradient, too troublesome to an expert who has mastered his hard snow turns. Windboard is common during the winter months in the High Alps; in appearance and texture it is not unlike the hard marble crust, which is found on south slopes after a long spell of fine weather, but it is vital to discriminate between windboard and marble crust, because the former may sometimes break away in slab avalanches whereas the latter never avalanches. Windboard betrays its origin by ripple markings, sometimes faint but seldom invisible to the practised eye. Windboard is often varied by pockets of sticky snow.

If wind produced nothing worse than caked powder or windboard, the ski-runner would have less cause for complaint. Unfortunately the wind often produces horrible surfaces which resemble each other only in their general unsuitability for ski-ing. _Skavla_ is the generic Norwegian name for wind-swept snow, and skavla is common on the exposed fjords of Norway and Sweden, where it attains a degree of unpleasantness seldom matched in the Alps. Skavla varies. Sometimes skavla consists of patches of glittering ice varied by treacherous pockets of sticky snow; sometimes a breakable trap crust interspersed with windboard; sometimes waves of hard, icy snow which occasionally attain a height of two feet or more. The prevailing wind determines the direction of the waves and acts in precisely a contrary fashion to that of wind on water; for wind on snow has a burrowing effect, and forms these waves by excavating and eroding a slope, gradually forming a series of steps. In other words, whereas on the sea the wind will be found to be blowing up the longer slope of a wave, on snow the wind will have been blowing against the short steep side of the snowy waves.

To sum up: The effect of wind on powder snow is always bad. The stronger the wind and the longer that it blows, the worse the snow. Hence in winter avoid exposed slopes and seek out sheltered valleys. The summit slopes of winter mountains will usually be spoiled by the wind, which is one of many reasons why spring is so superior to winter as far as ski-ing in the High Alps is concerned.

[Sidenote: The Effect of Sun on Powder Snow.]

Powder snow acquires a crust if it is exposed to wind, to sun shining at a sufficiently direct angle, and to an air temperature above freezing. Wind alone has the power of forming crust without a preliminary melting of the surface. I do not know why this should be so, but no doubt the reason is to be found in the law that pressure lowers the freezing-point, so that the increased pressure caused by wind lowers the freezing-point, or, in other words, produces the effects of a thaw at the point where the wind acts even though the general air temperature may be well below zero centigrade.

At any rate, sun, wind and thaw are alike in producing a surface crust.

The effect of the sun depends mainly upon the angle of inclination. In midwinter, snow will remain unaffected by the sun on northerly slopes even though they receive several hours of sunshine in the course of the day.

In fact, in midwinter eastern and western slopes retain powder snow for a very considerable time, while a slope that is a few degrees north of west or a few degrees north of east retains powder snow throughout the winter, always providing that it is not exposed to wind or to thaw.[20]

I use the term _‘thaw’ to denote a general air temperature above freezing as opposed to the purely local melting caused by the sun’s rays_, which may be, and in fact normally is, accompanied by an air temperature in the shade of several degrees below freezing.

The thermometer will often be registering more than ten degrees of frost in the shade and twenty or more degrees of warmth--centigrade--in the sun. It is, as icemakers know, quite common to find a belt of cold air, two feet in height, just above the snow and just below a strata of warm air several degrees above freezing-point.

In normal winter weather you may be uncomfortably warm in the sunshine, and yet the sun has no power to affect powder snow on any slope which has not a touch of south in it.

The steepest south slopes are the first to lose their powder snow. Afterwards, the gentler south slopes follow suit. Towards the end of February western and eastern slopes begin to crust. In March due north slopes still hold powder,--at any rate above 5000 or 6000 feet,--but slopes which are only a few degrees north of east or of west begin to crust. Finally, the level outruns get crusted, then the gentle due north slopes, and last of all steep north slopes.

Of course at high altitudes winter conditions prevail until well on into April.

In midwinter good ski-ing is usually to be had on south slopes for three or four days after a snowfall, though steep due south slopes soon crust. The time during which gentle south slopes or slopes which are just south of west or east will hold powder depends on the general air temperature and on the altitude. I have known pretty steep due south slopes hold powder below 4000 feet for three days of cloudless weather, but the temperature was about 15 degrees centigrade below freezing.

This is, however, unusual, and south slopes soon crust up even in midwinter. The sun melts the snow by day, and the melted snow refreezes at night, producing a crust. Such a crust will, at first, be soft and breakable.

_Soft breakable crust_ is not a bad running surface. It is quite true, i.e. does not vary in pace from one place to another, and is usually soft enough to enable the ski-runner to make Telemark swings, either stop or linked, without much difficulty. Sometimes the crust is harder, and in this case the jump-round or _quersprung_ is the only possible manœuvre.

A peculiarly villainous form of crust, fortunately rather rare, is known by the appropriate name of _Trap crust_. This crust is perfectly solid at one spot, and bears the weight of the ski without breaking, only to crack a few yards lower down. The ski-runner skids with great speed over the hard crust, only to be pulled up suddenly as his ski break through the soft crust below.

Trap crust is more usual in spring than in winter, especially on slopes which change in direction, so that the ski-runner passes from snow which has been sufficiently thawed to form a hard solid crust at night to slopes which have only been superficially melted. Trap crust is only found after fairly heavy falls of snow which require considerable time to form a solid crust. As a rule, trap crust covers a foot or more of powder snow.

To return, however, to more normal winter conditions. _Under normal conditions the snow on south slopes in winter is gradually transformed into crust._

This crust is at first soft and breakable, but the continuous process of melting and refreezing gradually produces a solid unbreakable crust.

_Unbreakable crust_, as the ski-runner soon discovers, varies greatly in quality from hard crust which is so hard that the ski slip sideways without obtaining the least grip, crust which on any slope but the most gentle is almost unskiable, to the other extreme, crust which though quite hard and unbreakable is rough enough to permit even a Telemark and to make Christianias and Stemming turns delightfully easy.

The solid crust formed in winter is usually very hard and slippery before the sun strikes it. This crust is known as _Marble Crust_. You find marble crust on southern slopes in winter, and at high altitudes in spring. It is common in the High Alps. Even at the very end of April I have known a slope at a height of 12,000 feet remain hard, slippery and unsoftened for some little time after the sun had struck it because a bitter north wind had lowered the temperature several degrees below freezing.

In mid-winter a slope of marble crust will yield good ski-ing after the sun has struck it, unless the air temperature is several degrees below freezing. Marble crust, touched by the sun, yields a surface which will puzzle the beginner but which is pure delight to the man who has mastered Stemming turns and Christianias. The excellent running that may be obtained on south slopes is too little exploited, for winter ski-runners are firmly convinced that good ski-ing can only be found on north slopes where powder lies.

Mid-winter may be said to last till the end of January. In February you often find perfect spring snow, Telemark crust, etc., on south slopes, and in February, as often as not, the best running is obtained on southern slopes. This type of running will be dealt with later.

[Sidenote: Summary of Winter Snow.]

Winter snow may therefore be summarized as follows. The normal winter snow which is found throughout the winter on northern slopes and occasionally on southern slopes is powder snow which is perhaps the ideal ski-ing snow.

Powder snow deteriorates under the influence of wind and sun. Wind is the more mischievous. A little wind does no great harm, and the expert can even ski with pleasure on the hard crust formed by wind, but the extreme action of wind often produces varieties of snow which are all but unskiable.

The High Alps and lofty summits in general being most exposed to wind will usually yield inferior ski-ing to sheltered slopes. The best ski-ing in winter will therefore seldom be found on the glaciers.

Snow also deteriorates under the influence of sun, which forms a crust. This crust, however, once formed is often improved by a further dose of sun.

Though the best ski-ing is usually obtained on north slopes, excellent ski-ing is often obtained on south slopes by those whose knowledge of snow craft is sufficient to time their descent and to choose their route accurately.

Abnormal conditions produced by Föhn and thaw are dealt with on pp. 417-422.

SPRING SNOW

We have seen that good ski-ing in winter depends largely on the absence of wind. A sudden thaw may also produce a disastrous result, for snow which has once been rained on and refrozen will remain covered with crust until there is a new snowfall.

The best winter snow is without rival, but spring snow is, on the whole, safer and less capricious. In normal spring weather all snow is crusted in the early morning, for the sun is powerful enough to melt snow even on northern slopes. But this spring crust, as we shall soon show, is much less troublesome than crust in winter and yields very fine ski-ing indeed. Wind, the great enemy in winter, has no effect in spring, for wind cannot affect hard crust, and if wind blows while the snow is falling a few days of strong sun will melt any wind-formed crust and produce exactly the same surface as if the snow had never been touched by wind. It should, however, be added that, in the early spring, wind, though powerless on snow which has once been melted and crusted, is a great nuisance if it blows on snow which is still powdery, as is usually the case for twenty-four hours or so after a snowfall; snow which has once been crusted by the wind has a very strong resisting power to the action of the sun; I have known south snow in March retain irritating effects of wind action after several days of strong sun that would have been sufficiently potent to melt any ordinary crust.

Spring ski-ing is, as a rule, delightful. Snow is troublesome in the intermediate stage between powder and crust. Once a crust is formed, the more often that crust is remelted and refrozen the better, as there is nothing better than old crystalline snow which has been through the mill of melting and refreezing again and again. Unless wet Föhn blows such snow will always retain its crystalline character, even when remelted by the sun, and will always yield good ski-ing. Of course in the late spring at low altitudes the sun is powerful enough thoroughly to thaw and drench the snow, and in the middle of May below 7000 feet wet snow in the middle of the day is unpleasant. But in March and April ski-ing on melted crust is wholly delightful. Incidentally the best ‘Spring snow’ is often found at the end of or in the middle of February on southern slopes.

From the beginning of March onwards all slopes, save those at very high altitudes, begin to crust over. The process is gradual on northern slopes. There is a period when the northern slopes no longer hold the dry loose powder of winter but have not yet begun to crust.

_Spring powder_ is common on north slopes in March. It is denser than winter powder, and is not so dry. It is slightly moist on the surface, and much heavier. It yields, however, a first-class running surface, and will take any turn or swing. Its main objection is the fact that it is peculiarly liable to avalanche.

Gradually, however, Spring powder disappears, save at great heights, and all slopes are covered by crust. In the afternoon the crust is melted, and the snow is soft and wet on all slopes. At night the snow is refrozen.

The normal cycle, then, of a normal spring (say April, at altitudes between 3000 and 9000 feet) is as follows: Hard crust at dawn; crust superficially softened between sunrise and midday; soft melted snow in the afternoon; soft breakable crust as the sun loses in strength; and solid hard crust after the sunset.

First let us consider the hard crust usually found at dawn.

This differs materially from the marble crust of winter, and from any of the crusts formed by wind action. It is, as a rule, slightly softer. What is more to the point, it is rougher. The surface of normal spring crust is perforated by numberless little holes. Sometimes these holes are quite small, mere pockmarks, sometimes they are as large as half-crown pieces. It is the presence of these holes and the roughness of the crust that makes steering easy, so that control is not difficult, and linked Christianias or Stemming turns are within the power of the good runner.

_Perforated crust_, in fact, is a delightful running surface. It is common at low altitudes in March, at moderate altitudes in April, and is normal in the High Alps in May, June, July and even August.

_Film crust_ is found in May and June on the glaciers, and occasionally at low altitudes in April. It forms a delightful running surface. Unlike marble and perforated crust, it is not quite homogeneous. It is composed of a hard under-surface of solid crust, covered by a very thin, soft, and transparent film of ice, which glistens in the sun like burnished silver.

This film of soft ice is shorn away as the ski begin to come round on a turn. It provides a splendid purchase, preventing effectually all side-slip, and yet not sufficiently strong to make turns difficult.

Film crust is admirable for fast straight running, because at any moment the pace can be regulated by a swift turn. There is nothing finer than a run down the glaciers in the early morning on film crust.

We have seen that the cold nights of winter produce marble crust, which is hard and slippery. Marble crust is the kind of surface which needs crampons or a chip with the axe if it is climbed on foot.

Further, marble crust, and all forms of crust produced by winter winds, yield a very unsatisfactory surface, too slippery to give good purchase.

We have seen that the milder nights of April produce perforated crust which is much rougher and gives good ski-ing, while the even warmer nights of May and June produce film crust in which Christianias and Stemming turns are easy and safe. In fact film crust gives such a wonderful grip that even Telemarks are possible.

From this we deduce the following law:

Provided the night’s frost is sufficient to produce a solid unbreakable crust, the crust will give the best ski-ing when the frost has been least severe.

In other words, “THE MILDER THE FROST THE BETTER THE CRUST.”

This rule is important. It often happens in spring that one has to start down before the sun has produced a surface melting. Again and again the first thousand feet or so of descent have been spoiled because the crust was too hard and slippery. But the lower one ran down the better the ski-ing. The hard marble crust of winter gave way to the perforated or film crust of spring. In April, in the High Alps, winter conditions often prevail at high altitudes to give way to spring conditions lower down. You start a run on marble crust and end on perforated or film crust. The lower the altitude the milder the night frost, and hence the better the crust.

But of course the hard crust of dawn is soon changed under the influence of the sun. At first the sun produces a slight surface softening which is, however, quite sufficient to make a great deal of difference. Even marble crust, if superficially softened, yields excellent running. Gradually the melting process becomes more pronounced. Sun-touched crust with a slight surface moistening--quite sufficient to make Christianias and Stemming turns a joy--yields to crust covered by an inch or two of melted snow. Such crust is known as _Telemark crust_--not because Christianias are not easy, but because Telemarks are very simple, whereas Telemarks are difficult, if not impossible, on hard crust.

Telemark crust is a normal stage in the passage of hard crust to melted snow. It is the practical certainty of finding Telemark crust at certain hours in spring that makes spring ski-ing in fine weather such a delight.[21]

As the sun increases in strength all trace of the underlying crust disappears. The snow is melted through and through, and becomes dangerous on steep slopes.

This wet snow is often slow, but it never sticks like the wet snow of winter. On steep slopes it gives good running--if unsafe.

Snow sticks in the intermediate stage between freezing and thawing. Thus powder snow which is beginning to thaw sticks abominably, but snow which is melted through and through does not stick. Snow which has once been thoroughly melted and then refrozen will never stick badly again. A surface of wet snow overlying powder will, of course, stick, but melting snow which rests either on hard crust or on the hard ground does not stick. It may be slow, but it does not adhere in sticky lumps to the running surface.

Thus two inches of melted snow on top of crust (Telemark crust) gives a fine running surface, and an inch or even less of wet snow on grass also gives excellent sport.

Snow that has been melted and refrozen night after night soon acquires a crystalline character. When the crust begins to melt after the sun has struck it, the melting surface is composed of numerous wet crystals, sometimes about the size of salt crystals, sometimes much larger.

This _granular_ snow is familiar to all spring runners, and gives an excellent ski-ing surface. Occasionally towards sunset, as the wet heavy snow that is usually found in the afternoon during the wet spring begins to freeze again, you will find the snow assuming a very marked crystalline formation, which resembles the wet hypo crystals with which photographers are familiar.

In general, so long as snow retains a crystalline formation it gives good running. Salt snow or hypo snow yields excellent sport. In May at _low_ altitudes the sun, however, is so powerful that it dissolves the crystals and reduces all the snow to one consistent heavy wet slush. Such snow does not stick--that is to say, it does not adhere to the running surface--but it is very slow. Furthermore it is dangerous, because if you run suddenly on to a patch of this very heavy snow you are liable to be pitched on to your face. Often the snow is not only melted downwards but upwards, for the ground is very warm in spring, and thaws the snow from below, so that you will often find a patch of soft heavy snow resting in the form of a shallow bridge on an empty space. The ski break down the bridge of snow, and the ski-runner pitches heavily forward. Such hollow snow is seldom found in April, but is common in May at lowish altitudes. In May the best ski-ing at low altitudes (5000-7000 feet) is obtained before 10 a.m. and after 7 p.m. In the early morning and just after sunset I have often enjoyed first-class ski-ing right down to 5000 feet and lower, well on into the middle of May.

We may therefore sum up the normal cycle of a spring day as follows:

At dawn every slope will be covered by a hard homogeneous crust. This crust will be either marble crust, in which case it will yield very difficult and unpleasant ski-ing, or perforated crust or film crust. Perforated and film crusts give excellent ski-ing even _before_ the sun has begun to soften the crust.

When the sun begins to gain in strength the hard crust is superficially softened, and gives good running even in the case of marble crust.

A later stage is reached when the hard crust is softened to a depth of about two or three inches (Telemark crust). This again gives good running.

Either before or after midday, according to altitude and inclination, all traces of crust disappear, and all slopes at moderate altitudes are reduced to wet, heavy and more or less water-logged snow. In the early spring this stage is perhaps only reached on southern slopes. In the late spring it is reached on all slopes at low altitudes and on north slopes, save, perhaps, at very high altitudes. In general, the ski-runner should not be abroad at such hours. Towards evening the slopes begin to refreeze. There may be an interval of hypo snow--soft hypo-like crystals in which fast running and every kind of swing is perfectly safe and easy. This is soon followed by the formation of a soft breakable crust, which gradually hardens until at last the cycle is complete by the formation of a hard solid crust.

THUS IN GENERAL THERE ARE TWO PERIODS OF A SPRING DAY WHEN SKI-ING IS EASY, FAST AND SAFE. THE FIRST PERIOD IS WHEN THE HARD CRUST BEGINS TO SOFTEN, AND THE SECOND PERIOD IS WHEN THE WET MELTED SNOW BEGINS TO FREEZE. THE SKI-ING IS LEAST PLEASANT AND MOST DANGEROUS BETWEEN MIDDAY AND SUNSET.

THE EFFECT OF FÖHN AND THAW

So far we have discussed normal winter and spring conditions. Föhn is, unfortunately, associated not only with spring but with winter. The conditions that are produced by Föhn are, however, spring conditions rather than winter conditions; for Föhn, though by no means uncommon in winter, is at least abnormal, whereas periods, more or less prolonged, of Föhn weather may be regarded as normal in spring. The peasants have a saying that, if the Föhn did not blow, the good God and the warm sun could do little with the snow. Certainly but for Föhn Switzerland would still be covered with glaciers.

Föhn, strictly speaking, should be used only for the warm dry wind that blows from the south, and which has been the cause of so many fires. The fire of Grindelwald was caused by this type of Föhn. The wind dries up the wooden chalets, and a spark from a cigar or a kitchen fire, carried on the wind, is enough to kindle wooden buildings from which the wind has absorbed every trace of moisture. But the word Föhn is also used for the warm, damp south-west wind, which is in every way utterly different from dry Föhn. They are alike only in that both dry and wet Föhn raise the temperature and melt the snow.

I propose to call the true Föhn DRY FÖHN and the wet, warm south-west wind WET FÖHN.

Dry Föhn is often associated with long spells of warm dry weather. The skies are cloudless, and there is no hint of rain to be seen. You know that there is Föhn in the air by a peculiar warm dryness, a marked absence of coolness and moisture in the atmosphere.

The wet Föhn always brings rain. Sometimes dry and wet Föhn will fight for the mastery. Sometimes dry Föhn will emerge into wet Föhn and bring down the rain, only to recover its mastery a day or two later.

[Sidenote: Föhn in Winter.]

Let us consider the effect of wet Föhn in winter proper. The ski-runner is bound to detect the first hint of wet Föhn in the air by a slight stickiness in any powder snow that he may chance to be ski-ing on. If the wet Föhn is slight, copious waxing will eliminate its effects; but if it is pronounced, the snow will ball and stick atrociously.

Should the Föhn disappear, it leaves its legacy behind. All slopes of powder snow which have been affected are covered with a crust, which will be more or less thick according as the thaw has been more or less severe. I assume, of course, that the thaw had been followed by the frost at night, without which crust cannot be produced. Only a new snowfall can restore a slope of powder snow which has once been melted by Föhn to its pristine conditions.

Sometimes the Föhn is so slight that the surface of the powder snow is barely touched. It is not covered by crust, but there is a suspicion of resistance as the ski drive through due to an embryo crust. Telemarks are not quite so easy, and a very fast swing is apt to throw the ski-runner outwards, owing to the fact that the side-slip is less pronounced; for the snow gives less easily when covered by the first hint of crust. More usually the Föhn, if it once begins, is accompanied by rain. Often even in December heavy rain will fall on all slopes below 12,000 feet. Directly the Föhn disappears the usual winter frosts will convert such slopes into solid icy crust which is harder and more slippery than any marble crust produced by sun or wind. I have seen crust, formed by Föhn followed by frost, so hard that neither ski nor hobnailed boots left any perceptible trace; and on an easy slope which a beginner could take straight I have slid down helplessly on my back some hundred yards, only to be saved from a further and probably fatal fall by a guide, who thoughtfully received my head in the pit of his stomach, breaking a thumb in the effort to arrest me.

That was an extreme case of ice crust produced by Föhn, but it is not uncommon to find every slope below 10,000 feet covered by an icy crust, on which ski-ing is impossible. The wise ski-runner climbs on crampons, and selects a due south slope for the descent, and times his descent for midday. The slight surface softening produced by the sun is usually enough to produce superficial stickiness, which gives capital running, provided that you have mastered the Stemming turn and Christiania. But, except at or near midday, and except on south slopes, ski-ing is impossible during such periods.

Sometimes good ski-ing is obtained near stream beds when all other slopes are covered by hard crust. The mist that rises from the stream bed descends in hoar frost and covers the crust with a layer of crystals deep enough to take a turn. But such slopes are scarce.

Occasionally the wet Föhn is followed by a period of dry Föhn.

In this case the frost at night is much milder, and you will often find instead of marble or icy crust typical spring formations. I have found perforated crust and even film crust in January, when a period of dry Föhn with high temperatures by day and mild frosts by night had followed two or three days of rain.

For weeks together I have known the crust formed by dry Föhn to resemble perforated crust, but formed of a much smoother and more slippery texture. Imagine a hard surface pitted by numberless smooth little round hollows about the size of half-crown pieces. This type of hard perforated crust gives good running, but calls for a thorough mastery of hard snow turns.

Often the dry Föhn produced a surface-melting to a depth of two or three inches--_typical spring conditions in midwinter_.

This again is an illustration of the law stated on p. 414: “The milder the frost the better the crust.” In other words, once the snow in midwinter has been thoroughly spoiled by thaw followed by frost, the ski-ing will be best when the conditions approximate as nearly as possible to those characteristic of spring.