Page:Popular Science Monthly Volume 86.djvu/303

This page has been validated.
VOLCANIC ACTIVITY OF LASSEN PEAK
299


Fig. 4. Gradual Enlargement of the First Crater Developed on Lassen Peak During the Eruptions of 1914. (a) (above) the new crater on June 4, 1914. Photograph by R. H. Boerker. (Below) (b) the crater on July 25, 1914.

notch in the northern end suggested that the movement was likely to continue.

The winter’s snow had largely disappeared, although the trail still passed over deep snow banks for nearly a mile in crossing the plateau-like shoulder at the south base of the peak proper. Near the top of the mountain snow was to be found only in patches and beneath the covering of ashes. Such areas moist from the melting snow, from a distance appeared almost black in comparison with the light gray of the dry dust found over the greater part of the mountain. This dust was so fine that it was easily moved by the wind. At times a strong gust would send immense clouds into the air, giving the appearance of an