The magnetic diurnal variation of the horizontal force near the magnetic equator

In a communication to the Edinburgh Meeting of the Association of Terrestrial Magnetism and Electricity, Dr. A. G. McNish has given the results from an analysis of the diurnal variations of the magnetic elements for five observatories in the Western Hemisphere. In this analysis also the diurnal variations at Huancayo are used. McNish points out that the establishment of the observatory at Huancayo “has led to the discovery of magnetic diurnal variations markedly different from those expected for such a region.” In using these new data from Huancayo the analysis of McNish has become of great value.