Visual sensation in the alternating magnetic field

On page 80 of the March Proceedings there is an account by Dr. J. B. Whitehead on “Visual sensation in the alternating magnetic field”, in which he states that the report is interesting chiefly because there has apparently been no other observation of an influence of a magnetic field on human sensation. In 1897, however, while experimenting with some choke coils with large leakage connected across the receiving end of one of the first long distance high tension lines placed in operation in Central California, a very marked sensation of flickering light was noticed whenever the writer´s head was moved through the leakage field. The matter was reported to the late Dr. F. A. C. Perrine and was investigated by him, though, if recollections of that occurrence are correct, he was practically the only one experimenting who did not corroborate the observations of the others. At this date no record can be found of any publication of these tests, though Mr. F. G.” Baum confirms the writer´s recollections of the experiments. The reactance used was 150 kw., Stanley transformer of the vertical core type, in which the iron circuit was opened sufficiently to produce practically full load current when the 2,200-volt coils of the transformer were connected across the station bus bars and the high tension coils left open-circuited.