It has recently been announced that this electro-magnetic induction has been made a means for the instantaneous registration of astronomical observations. We have already to draw attention to another practical application of the principle. M. Niklès has just invented an arrangement of apparatus that enables him to make the wheels of locomotives bite the rails with any degree of force without increasing the weight that has to be carried to the extent of a single grain. Our readers are aware that in wet weather the driving-wheels of locomotives often slip round upon the rail without acquiring the power of moving the weight that is attached behind them. Whenever they are asked to ascend inclined planes with a weight that is beyond the adhesive powers of their wheels this result invariably follows; and the only practical escape from the difficulty hitherto has been the adoption of one of two expedients--either to increase their own intrinsic weight, so that the earth's attraction might bind the wheels down more firmly, or to let the railway be level and the load to be dragged proportionally light. In either of these cases a waste of power is experienced. Power is either expended in moving a superfluous load, or the same amount of power drags less weight even upon a level rail than it otherwise could upon an ascending one, that would have required less outlay in its construction. It therefore becomes a great desideratum to find some means of making the locomotive wheels bite more tenaciously without increasing the load they have to carry. The important problem of how to do this it is that M. Niklès has solved.