_The Wood._--Skis are usually made of ash, which is, perhaps, on the
whole, a more suitable wood than any other. Hickory is excellent,
but is said to be more brittle than ash, and is also heavier. It is,
however, but little heavier than the _best_ ash, for in the latter wood
lightness means bad quality. The wood must be well seasoned, and as
free as possible from knots, especially near the bend and the binding,
though small knots which do not extend through the whole thickness of
the ski cannot do much harm.
The grain of the wood should be wide and well marked. The way it runs
in the ski is most important; it should run parallel with the long axis
of the ski throughout its length, above all at the front bend and the
binding; for if the grain run out at these points, the ski will be very
liable to break there. If anywhere else the grain runs out at all, see
that it does so in such a way that the lines on the _side_ of the ski
run backwards and downwards (Fig. 1, A), not forwards and downwards
(Fig. 1, B).
[Illustration: FIG. 1. Cross-grain; in A it does not much matter, as it
only occurs at some distance from the binding and points backwards; B
is very bad.]
If the lines of grain on the _sole_ of the ski run across at all
instead of parallel to the sides, the ski, when it gets rather worn,
will not run straight. If, of a pair of skis, one runs to the right and
one to the left, it does not much matter, for in that case the former
can be put on the left foot and the latter on the right; they will then
merely keep together and hold each other straight.
But if both skis run off to the _same_ side there is nothing to be
done, so look carefully at the grain of the sole when choosing them, to
see that there is no chance of this (Fig. 2).
[Illustration: FIG. 2. Cross-grain on running surface: A converging,
not very serious; B parallel, very bad.]
There is one more point to be noticed about the arrangement of the
grain in the ski.
If you look at the _heel end_ of the ski, you will generally see the
grain disposed in vertical lines, as in Fig. 3, B. The ski will not
only be stronger and more springy, but will wear better and run faster
if cut so that the grain lies horizontally (Fig. 3, C).[1] Fig. 3, A
shows a disposition of the grain which is likely to weaken the ski and
should be avoided.
[Illustration: FIG. 3. A bad, B good, C still better.]
The colour of a ski is a matter of taste. Dark colours have the
disadvantage of causing the snow which collects on the top of the ski
to melt more readily; it may then refreeze and accumulate, forming an
unnecessary load of ice.
A dark colour also makes it more difficult to detect faults in the
grain, and it is wiser for this reason to buy plain varnished skis, and
colour them afterwards if you want them darker.
New skis should be given several coats of boiled linseed oil, each
being allowed to sink in before the next is applied. When at last
the wood will absorb no more, give it a coat of _raw_ linseed oil;
this dries hard, with a surface just rough enough for easy climbing,
but slippery enough to make waxing unnecessary, except for the very
stickiest snow. The more often skis are oiled, even when in use, the
better.
_Dimensions._--When you are standing with your arm stretched at full
length above your head, the ski, placed upright, should be at least
long enough for its tip to reach the roots of your fingers; it may well
reach a few inches beyond the finger-_ends_.
The longer the ski the pleasanter you will find it for
straight-running. On a long ski you keep your balance more easily, run
more smoothly on rough ground, and keep a straight course with less
trouble. A short ski is slightly easier for turning, but if you learn
correct methods of turning, the difference is insignificant; and in
any case, however much you may twist and turn, you are bound for the
greater part of the time to be running straight, and you might as well
do so as comfortably as possible.
[Illustration: FIG. 4.]
The ski should be as narrow as possible, hardly more than 2-3/4 inches
(7 centimetres) at the narrowest part--_i.e._ where the foot rests on
it--even for the biggest man.
If it measures 2-3/4 inches in width at the narrowest part, it should
be about 3-3/4 inches wide at the front bend, and just over 3 inches at
the heel.
A narrow ski is in every way better than a wide one; the only object
of increasing the width of a ski is to make its bearing surface on the
snow proportionate to the weight of a heavier man, and so to prevent it
from sinking more deeply and therefore running more slowly. But this
should be done by increasing the length rather than the width.
The beginner usually imagines that the wider the ski the more easily
he will be able to balance on it. This is a great mistake. A narrow
ski is far steadier than a wide one for straight running; it is easier
for turning, and infinitely more comfortable for moving across a steep
slope of hard snow, the diminished leverage putting less strain on the
ankles, as the diagram shows.[2]
[Illustration: FIG. 5.]
The thickness of the ski is proportionate to its elasticity and the
weight of the runner, being about 1-1/4 inches at the binding and 3/8
inch at the front bend and the heel. A stiff ski runs rather less
comfortably than a thinner and more flexible one, but it is safer to
choose a ski of ample thickness near the binding, especially if it is
to be used for jumping.
The turn up at the front of the ski should begin at about one-fifth of
the distance from the tip to the heel end. _It should be very gradual_,
for a sudden bend makes the ski run more slowly and far less smoothly.
The under side of the tip need not be more than five inches above the
ground.
There is a slight upward arch between the front bend and the heel. It
should be no more than 3/4 of an inch high at its highest point, below
the heel of the boot, only just sufficient to prevent the ski when
resting on soft snow from bending downwards in the middle under the
weight of the runner. The height of this arch should therefore vary
slightly according to the length and stiffness of the ski, and to the
runner's weight.
Of course any twist in the ski will prevent it from running true. A
simple way of making sure that a ski is free from any such twist is
as follows: draw a few lines across its sole, at right angles to a
line down the middle of it, and, holding the ski so that a very much
fore-shortened view of the sole is obtained, see if all these lines are
parallel.
Nothing is more uncomfortable and difficult to run on than a ski which
has become warped and has a downward bend in the middle. To prevent
this happening and to preserve the upward arch, a pair of skis, when
not in use, should be placed sole to sole and bound together at the
front bend and the heel, with a block of wood about 1-3/4 inches thick
put between them 8 inches or so behind the binding, just where the
boot-heel rests on the ski.
Most skis are made with a groove running along the middle of the sole
from the front bend to the heel. This groove greatly increases the
ski's steadiness in straight-running, and on no account should be
omitted. A smooth-soled ski makes turning easier for the runner _who
has not learnt the right way to do it_, but this slight advantage by
no means compensates for the wobbliness in straight-running which it
entails. If you want easy steering, choose extra-_flexible_ skis, but
_not_ grooveless or extra-short ones.
Most of the ordinary foot-bindings are fixed to the ski by means of a
hole bored from side to side through its thickest part. See that this
hole is made almost entirely in the upper half of the ski's thickness,
well away from the sole. When lifted by a strap passed through this
hole, the ski should point downwards at an angle of about 45 degrees.
In order that they shall be stronger in relation to their weight and
less flexible, skis are sometimes made with a convex, instead of a flat
upper-surface. The increased stiffness makes them less comfortable for
ordinary running but safer for jumping. The convexity should always
stop short of the beginning of the front bend.
Fig. 6 shows that it depends on how this convexity is obtained as to
whether and how it is an advantage or otherwise. Supposing the wood in
each case to be of exactly the same quality, B will obviously be not
only stiffer but heavier than A, C will be stiffer but no heavier, D
will be equally stiff but lighter. It is evident, then, that one cannot
say off-hand that the convex shape is either better or worse than
the flat, but only that, _weight for weight_, the convex shape gives
greater stiffness and strength, the flat gives more elasticity.
[Illustration: FIG. 6.]
_The Binding._--The question of the binding, by which the ski is
fastened to the foot, is a very vexed one; I shall treat it as shortly
as I can.