Every Ski runner going across country should carry a map. Even on a short run a great deal can be learnt from a map, which will prove useful later on a longer run. Both time and risk can be saved by people who run by their map and who know how to avoid dangerous places and how to take advantage of narrow safe openings.

There are different types of maps to be had in Switzerland. The best are the official Ordnance Maps published by the Eidg. Landestopographie at Bern. The mountain districts are produced at a scale of 1 centimetre in 50,000 centimetres or 2 centimetres in one kilometre, and large or small sheets can be bought almost everywhere. The gradients are clearly shown by contour lines. The equidistance being 30 metres, or roughly 100 feet, the dotted contour lines when height is marked some every 8 or 10 ordinary contour lines. This differs according to the edition. Cliff and rock are shown grey, while glacier contour lines are blue.

Some districts, such as the Bernese Oberland, have produced this map with red lines showing all the Ski runs. In other places they also provide Ski-ing maps, but on a different scale and not as good as the Ordnance Map.

All maps are best when mounted on linen, as the weathering they receive on a run may reduce a paper map to pulp or rag.

It is easy to work out the distance of runs or the gradient of slopes from the large scale Ordnance Map. 1 in 50,000 metres means that 1 centimetre on the map equals a run of 50,000 metres; 2 centimetres equal a kilometre or 100,000 metres; 8 kilometres equal five English miles. Therefore, if a centimetre measure be carried, the distances are soon ascertained with a minimum of arithmetic.

Throughout this chapter I have taken the mathematical or map gradient and not the engineer's gradient. The latter is generally used, I understand, to measure the gradients of roads, railways, etc.

To avoid confusion when Ski-ing, the gradient is usually named by the angle of the slope.

The gradient of slopes is shown by the contour lines, the drop between each being 30 metres or approximately 100 feet. The table on p. 92 was got out by Commander Merriman, R.N., and has proved very useful to me in setting tests as well as in judging whether slopes are comparatively safe from avalanche or not.

A slope showing eight 30-metre contour lines in one centimetre works out roughly at 27°, which is a steeper slope than most people care to take straight, running over unknown country. Anything steeper than this is apt to avalanche in certain conditions, though a 30° slope should usually be safe. (A 25° slope may be dangerous under some conditions.)

A comfortable slope is 5 contour lines in 1 centimetre, or a gradient of 17°. Taking English measurements as in Commander Merriman's scale, 16 contour lines in one inch on the map.

The beginner will probably content himself with slopes where 10 contour lines are shown in one inch, or a gradient of about 13°.

ROUGH TABLE OF GRADIENTS.

Assuming 30 metre contours to be equal to 100 feet contours (actually this is 98.4 feet). Natural Scale 1: 50,000.

——————————————————————
Drop per inch " Average angle " Gradient
on map. " of slope. " 1 in.
——————————————————————
100' " 1° 24' " 40.9
200' " 2° 45' " 20.8
300' " 4° 07' " 13.9
400' " 5° 29' " 10.4
500' " 6° 50' " 8.3
600' " 8° 12' " 6.9
700' " 9° 33' " 5.9
800' " 10° 52' " 5.2
900' " 12° 11' " 4.6
1,000' " 13° 30' " 4.2
1,100' " 14° 47' " 3.8
1,200' " 16° 04' " 3.5
1,300' " 17° 20' " 3.2
1,400' " 18° 34' " 3.0
1,500' " 19° 48' " 2.8
1,600' " 21° 00' " 2.6
1,700' " 22° 11' " 2.5
1,800' " 23° 22' " 2.3
1,900' " 24° 30' " 2.2
2,000' " 25° 39' " 2.1
2,100' " 26° 45' " 2.0
2,200' " 27° 50' " 1.9
2,300' " 28° 53' " 1.8
2,400' " 29° 56' " 1.7
2,500' " 30° 58' " 1.6
——————————————————————

Up till now I have only been describing the official Ordnance Maps.
There are several other maps which may also be useful.

The Dufour maps are good for direction and lie of country, but their scale being 1 in 100,000 they are not much help for actual running.

The local Ski Tour Map is useful to show where the usual tours go, but cannot always be trusted for gradients or cliffs and rocks. The Pontresina map, for instance, though showing an equidistance of 30 metres as in the Ordnance Maps, really has 50 metres contour lines, which might be a terrible snare to the unwary, who would confidently run towards a slope, thinking it was about 20° and find that it was nearer 35°, or an avalanche slope. In a case like this the Ordnance Map must be used for actual running, while the Ski Tour Map is used to show the line to be followed.

In some districts, such as the Bernese Oberland, the Ordnance map has been used for the local Ski tour map, and the tours shown on it in red. This is a great saving of weight and money for the runner, who then only has one map to carry.

Most Ski maps show dangerous avalanche slopes. The local Summer map published in most tourist centres in Switzerland is not much use to the Ski runner, because it shows walks which may be along slopes or down cliffs, which are perfectly safe in Summer and very dangerous in Winter.

I strongly advise all beginners who are bitten by the joy of Ski-ing to buy, at any rate, the small local sheet of the Ordnance Map which usually only costs Frs. 1.30, or roughly 1s., and to study it carefully, noticing the contour lines on the well-known Nursery slopes, and gradually realizing the gradient represented by the different widths between them.

Let him also notice the difference between a hill and a hole on the map. This is easily recognized either by the thin blue line of a stream emerging from a lake, or by comparing the nearest heights shown on the dotted lines or some marked point. Contours are often puzzling to a beginner in map reading, but knowledge of what they represent may save a party from a weary climb back up a place they have gaily ski-ed down, thinking they could get through but finding an impossible slope or fall of rock which forced them to retrace their steps.

Before going on tour even with a Guide, it is wise to study the map with a view to knowing where an Alpine hut can be found in case of need, or where a hay chÂlet could offer shelter.

When once the Ski runner has begun to appreciate the fun and interest of running by a map, he will never leave it behind, and he will be able to enjoy all sorts of runs he would never know of if he were content with the sheep habit of "following tracks."

The greatest fun of Ski-ing is in finding one's own way, and this one can never hope to do without a map.

The following scale of comparative heights in metres and feet may be of use in estimating the heights of points which the Ski runner wishes to reach:

10 metres equal 33 feet (approximately).
50 " " 164 "
100 " " 328 "
250 " " 820 "
500 " " 1,640 "
1,000 " " 3,281 "
2,000 " " 6,562 "
3,000 " " 9,843 "

A compass is, of course, useful when running by map, but as precipices are apt to get in the way when running straight for any given point, a compass cannot be trusted alone. In the case of fog, it is very difficult to avoid difficulties, and points on the map can only be identified by the use of an aneroid, as well as a compass. Set the aneroid at the point you start from and check your heights by this as you climb or descend, referring constantly to the map to ensure that you are running on the right line. It is wise to practise this on clear days in order to get accustomed to running by map, compass and aneroid. As the weather also affects the aneroid, it should be constantly reset at known levels.

All this may sound very confusing, and most beginners will probably prefer to take a Guide who knows his country well rather than trust to elementary map-reading knowledge in unknown country. Most runners who go on tour will find running much more interesting, however, if instead of following a Guide blindly they also watch the map or get a knowledge of what is good or bad country to run over. There are sometimes cases also when the party must necessarily divide, and an amateur may have to take the lead over unknown country.