302 THE POPULAR SCIENCE MONTHLY 



vember is doubtless far from complete — the region extending from 15 to 

 20 miles around the mountain being almost if not entirely deserted 

 by the last of October. The resort at Drakesbad at the southeastern 

 base of the mountain closed for the season on September 21 and the 

 headquarters of the forest service were removed to Eed Bluff on October 

 12. The houses on the stock ranches in the vicinity are also deserted 

 during the winter and the few wagon roads are blocked by deep snow 

 until late in spring. Under the conditions indicated, the fact that 

 October and November together are credited with but sixteen recorded 

 eruptions furnishes no basis for any inference that volcanic activity on 

 Lassen Peak is decreasing. At the date of reading proof the activity 

 continues. A dispatch published in the San Francisco Chronicle, Jan- 

 uary 23, 1915, describes an eruption from a new crater on the east as 

 equal to any which have gone before. The dispatch adds that no one 

 has visited the volcano's summit for over two months. 



An interesting suggestion concerning the November record comes in 

 a private letter from Mr. Eushing. The eruptions from the summit 

 which were observed during November were all ranked as medium in 

 severity. The suggestion is that this may be explained by the fact that 

 a new vent has been opened at a much lower level. The eruption of 

 November 18 as seen by two observers at stations situated north of west 

 from Lassen came from a point on the north slope of the mountain 

 about a mile from the top and presumably near timber line. A com- 

 parison of distant observations from the north and from the south may 

 soon test the correctness of this supposition. 



Some further idea of the magnitude of the eruptions of Lassen 

 Peak may be gained from the record of distant observers. A" letter 

 from Professor Charles F. Shaw, who was at Amadee about 65 miles 

 eastward from Lassen Peak on October 23, contains particularly intei'- 

 esting observations. The eruption began at 5 :40 p.m. The mountain 

 showed plainly over the tops of the nearer liills and the smoke of the 

 eruption was clearly sihouetted against the western sky, extending 

 directly upward from the peak. 



The smoke rolled up uatil practically tbe entu-e height [12,000 ft.; see list 

 of eruptions] 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 extended 

 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 indicating falling 

 material became more and more apparent, but as the light was failing it became 

 rather hard to distinguish the exact outlines of the lower portion of the column. 



