[Letters to Editor]

Abstract

WE have recently begun to investigate theoretically how atmospheric tidal motions should vary with height above the E-layer. The work is still in the exploratory stage, and too great reliance cannot be placed on the tentative results which have so far been obtained. These results, however, suggest that tidal motions should increase with height for some considerable way above the E-layer. Considerable phase-changes may also occur above the E-layer. Such results are difficult to incorporate into a general theory of the magnetic variations, and we do not claim to be able to do so : but Dr. Martyn‘s interpretation of the facts need not be the only possible one.