Third: That the heel-band be of the nature of a continuous rope, or closed circuit, passing through the handle of the lever which, when opened or shut, releases the foot, or presses it down into the toe-strap.
Fourth: That the heel-band hang upon each apex of the rotatory axis instead of being tied there.
There are many reasons for accepting the above remarks. For instance, the point of rotation works out too high in many manufactured bindings. The heel-strap then cannot adhere as it should to the boot. Its radius and that of the heel do not coincide. In the case of a well-known Norwegian binding, the strap, on the contrary, starts from a point of attachment which, on each side of the ski, is placed lower than the toe-line. Thus the heel-strap is wrongly centred again. The boot undergoes irregular pressure, a cause of additional fatigue and a waste of mechanical power.
Most makers have been led into this fault by the bulk and thickness of the material ordinarily employed—namely leather. Leather does very well for circling the heel, a flat band being there the proper thing to be used, but it is less useful to the front, where tension is called for.
The fore part of the heel-band might perhaps be replaced by a rope of fine strands of wire, with a breaking strain equal to, say, six hundred pounds, by far exceeding the strength of the stoutest ski-thong. At the point of rotation, the strap, in which is placed the heel, would meet the wire. Thus the connecting-point between the heel-strap and its wire extremities to the front would coincide with the pivots on which the heel revolves in the axis of the foot.
Under those conditions, when lifting from the ski the heel of the boot, the tension of the heel-band remains uniform in every position.
This part of the binding apparatus may be practically autonomous. Free from any direct connection with the wood, it ceases to be a medium through which shocks may disturb the balance of the body. The foot then is free to exercise unhindered its own balancing power and to obey its spontaneous “statics.”
When cheeks are used, they generally consist of two steel plates, with turned-up sides or ears, and frequently provided with holes at suitable distances. Hammered into shape, the plates usually overlap each other on the centre line of the ski. Sometimes a pin driven through any two holes in the superposed plates (by means of a spring, to which it is attached) maintains the plates at such a distance from each other as may fit the boot of the runner.
Plates need not be inserted through the wood of the ski, as is the case with most bindings with cheeks, but they may be laid on the flat of the blade, quite on a level with the rotatory axis of the foot. A steel spring may then be adjusted along the middle line of the foot-rest. It may be raised with the greatest ease, bringing the pin with it.