Notes and Correspondence 



93 



"The smoke rolled up until practically the entire height (12,000 feet) 

 was reached before any change in form occurred, when just below the 

 top of the column there was a tendency to stratification, and a layer ex- 

 tended out toward the south and toward the north. When this appeared, 

 the smoke column began to lean toward the north and, from our point 

 of vision, apparently toward the northeast, and with this inclination of 

 the column distortion took place, the upper part spreading out into 

 streamers. As soon as the inclination of the smoke column became very 

 plain, we could readily distinguish indications of falling material. The 

 lower two-thirds of the column seemed to be dropping some material 

 that was falling in a slightly oblique line, the obliqueness pointing back 

 toward the mountain peak. As the eruption continued and the smoke 

 column blew out more toward the north, the streaked condition indi- 

 cating falling material became more and more apparent." 



So far as known to the writer, no one reached the summit of Lassen 

 during the interval from October, 1914, to March 15, 1915. On that date 

 Mr. George Olsen and Mr. Charley Yori, who remained during the win- 

 ter, the one at Chester, the other at Drakesbad, made the ascent, using 

 skis for the greater part of the way. Their report indicated some en- 

 largement of the crater since October, but the general shape and ap- 

 pearance were still the same. 



Accompanying Mr. Hodge's article was a tabular list of eruptions, 

 closing with No. 53, October 7, 1914, compiled by Forest Supervisor W. 

 J. Rushing. Mr. Rushing has kindly furnished the list as continued by 

 him to Nov. 22, 191 5, to which date 132 eruptions are catalogued. Mr. 

 Rushing has done a valuable service in compiling this list, which is un- 

 doubtedly the best record available. It is well, however, to remind those 

 not acquainted with the topography and the winter climate of that 

 sparsely settled region that no list of eruptions can be complete, since 

 the surrounding peaks and ridges shut off the view from several of the 

 few near-by stations, particularly from the station nearest, which is 

 seven miles away. During winter clouds frequently prevent observations 

 from some directions and not from others, or shut off entirely any view 

 from near or far. Mr. Olsen at Chester, about twenty miles away in an 

 air line, was fortunate in having no hills to obstruct the view. From 

 November 11, 1914, to May 13, 1915, he reports over forty eruptions 

 with many cloudy periods intervening. During the same period Mr. 

 Rushing reports 16 eruptions not observed by Mr. Olsen, and does not 

 mention nineteen seen by Mr. Olsen. It seems therefore very probable 

 that the average number of eruptions per month during the winter ap- 

 proximated that of the preceding summer. 



During the summer of 1915 the most spectacular eruptions and the 

 most interesting, scientifically, occurred on May 20 and 22. These erup- 

 tions marked the culmination of nearly three weeks of activity, for Mr. 

 Olsen's record shows constant eruptions all day May 4, 5, 6 and 7. 

 Clouds then prevented further observation until the thirteenth, when a 

 short period of clear sky revealed another eruption ; after six more days 



