The X rays produced by electron precipitation from the geomagnetic field have been further studied by means of scintillation counters carried on balloons launched simultaneously at four sites between Waterloo, Iowa, and Flin Flon, Manitoba, Canada. The latitude and detailed time profile were measured during two magnetic storms on September 25, 1961, and October 1, 1961. The integrated photons per centimeter2 for the two storms show very different latitude profiles. On September 25 the intensity increased to the highest latitude (64.5° geomagnetic). On October 1 the profile was highest at 55° and dropped off to a very low value at the high latitude. These differences seem connected with the fact that the September storm was of the recurrent type, and the October 1 storm was more violent and was induced by a large solar flare. The detailed comparison with the total energy stored in the magnetic field, obtained from recent measurements of the trapped radiation in the energy range comparable with the balloon measurements, shows that about one or two orders of magnitude more energy was precipitated than is normally stored quiescently, indicating that during the magnetic disturbance the addition of energy to the electrons in the magnetic field is necessary. A more extreme case, observed on July 16, 1961, at Fort Churchill and at Minneapolis, shows that during a strong magnetic sudden impulse more than two orders of magnitude more energy was precipitated than is quiescently trapped. The precipitation has been observed with the data averaged in time intervals between 120 sec and 0.1 sec. We find that during periods of intense precipitation a large fraction of the precipitation occurs in bursts of high intensity lasting only 0.1 sec. It is suggested that these rapid bursts can account for the flashes or pulsations observed in strong auroral storms. Power spectrum analysis methods have been applied to the counting rate data, and we find periodic precipitation occurring with periods of 0.8, 1.6, and 3.2 sec and higher multiples. It is suggested that this constitutes direct evidence for particle bunches near 60-kev energy oscillating between conjugate points in the geomagnetic field. A Chree analysis applied with the large impulsive bursts as zero epoch confirms this picture and shows that the same periods occur in fixed phase relationship to the bursts.