From a consideration of the immense volume of newly discovered facts in the field of physics, especially atomic physics, in recent years it might well appear to the layman that the main problems were already solved and that only more detailed work was necessary.
The determination of a small, regular, daily fluctuation of radiation according to solar time (maximum at midday), which were attributed to atmospheric influences, particularly electrical and magnetic effects in the highest layers of the atmosphere.
In order to make further progress, particularly in the field of cosmic rays, it will be necessary to apply all our resources and apparatus simultaneously and side-by-side; an effort which has not yet been made, or at least, only to a limited extent.