[Illustration: FIG. 40.--"Jerked" Christiania swing, A before, B after turn.]
This reverse twist of the body has practically no effect upon the shoulders--being there neutralised (though this may not be obvious at first sight) by the back-stroke of the arms--but acts almost entirely on the _hips_, turning them until they face even farther to the right than did the shoulders at the end of their previous swing. The result, therefore, of the whole double movement, if made with force and precision, should be that you find yourself in the position of Fig. 40, B, or Plate XLIV.--the skis having whipped round to right angles, or thereabouts, with their original direction--and that, after more or less side-slip, according to your speed and the quality of the snow, you come to a standstill.
In saying that this double movement should be made with force, I do not mean that it should be made _violently_. If the turn is to be made very suddenly, so that the skis whip round instantly to right angles, some force is certainly necessary, for then the _whole_ of the turning movement of the skis is carried out by the double muscular effort of the body and arms. But this double effort--the swing of the shoulders and the immediately following jerk of the hips--may be, and indeed usually _is_, used merely to _start_ the turn by getting the heels of the skis outside the track of their points; the rest of the turn being carried through by the weighting of the heels, in the same way that, as I have already explained, the greater part of a steered Christiania can so be carried through. In this case the "swing-and-jerk," which takes the place of the "snip" of the skis in the other method, may be an almost imperceptible effort, the most obvious part of which is a slight twisting of the hips. As absence of effort is of the greatest importance in ski-ing, one may perhaps say that in a sense this is the best way of making the turn. But even though you may seldom want to make the turn fully and instantaneously it is extremely useful to be able to do so in case of need, and if you have learnt to _complete_ a turn forcibly you will find it all the easier to _start_ one gently. If, however, you never try to do more than _start_ the turn with a _gentle_ swing-and-jerk, it is quite likely that you will never do even that with real certainty--the subtlety of a gentle movement making it more difficult to learn correctly than a forcible one. You are still more likely to be unsuccessful if you leave out half the movement, as is sometimes directed, and only try to swing the shoulders, or to twist the hips, or if you try to move both round simultaneously, or if, as I myself used wrongly to direct, you treat the double movement as two quite separate ones--a merely preparatory turn of the shoulders with a pause between it and the hip-jerk. Not that the turn _cannot_ be made in either of these ways; it can in all, but only awkwardly with the help of a good deal more force than would otherwise be necessary. An expert making a "jerked" Christiania--as this sort may perhaps be called, since the jerk round of the hips and consequent thrusting forward of the ski-heels is the crucial part of it--whether he makes it powerfully or gently, will do so with just the force needed and _no more_; in other words, he will do it _gracefully_. The essential points of the movement so made are--(1) that it is a double one, (2) that the second part of the movement follows the first without the least pause, (3) that the force used, however small, is _gradually increasing_ in the first part, _sudden_ in the second, (4) _that each part of the movement is made with about the same strength_; for feebleness in the one part has to be compensated for by undue violence in the other. If these four conditions are complied with the movement will usually need very little force.