298 THE POPULAR SCIENCE MONTHLY 



wire cables there suddenly yawns below the climber the bowl of the 

 ancient crater, and he looks directly into the irregular naked chasm of the 

 new vent torn in the opposite slope (Fig. 3). It is impossible for a cam- 

 era with its narrow field of view to give correct impressions of the con- 

 ditions of the mountain top. The observer standing upon that solitary, 

 sharp, rocky pinnacle, although he narrows his vision to the new crater 

 steaming below, is conscious of the steep slopes behind him and he also 

 sees subconsciously the surrounding ragged edge of the bowl of the 

 ancient crater. 



Descending into the irregular basin, the new vent was photographed 

 at closer range from various directions. ISTo appreciable change oc- 

 curred between June 26 and June 28, except the rapid disappearance 

 of the new snow as a result of the warmer weather. The northwesterly 

 end of the new crater (Fig. 2) was of most interest because of escaping 

 steam. On close approach, the sulphur fumes became oppressive and 

 yellow sulphur deposits near the vents were distinctly noticeable. The 

 crater was apparently being extended longitudinally along cracks at 

 either end. The northern wall showed also a transverse crack running 

 back from the vent more than a hundred feet. The depth of the crater 

 did not seem to be over eighty feet, but the continually caving sides sug- 

 gested that the present bottom is but piled up debris. No suggestion 

 could be obtained of the depth of the holes from which steam was 

 escaping. By pacing a line parallel to the side and some fifty feet 

 distant the length of the crater on June 28 was estimated at somewhat 

 more than four hundred feet. This estimate is less than that given by 

 some observers, but agrees closely with that made by Mr. Diller on 

 June 20. 



During the last week in July the writer again spent several days at 

 the base of Lassen, this time approaching the mountain by the Susan- 

 ville ai,;to road which terminates at Drakesbad, a resort in Hot SjDrings 

 Yalley at the southeastern base of the peak; Unfortunately, the time 

 of the second visit proved to be a period of quiescence, as had the first. 

 Tn the month since the previous visit thirteen eruptions had taken 

 place, the one on July 18 being reported by the Forest Service as " by 

 far the most violent eruption to date. Ash, steam, etc., arose to a 

 height of 11,000 feet. Duration practically the entire morning." 

 Mewspaper accounts of this eruption stated that the crater had been 

 greatly enlarged yet the writer's photographs of July 25 compared with 

 those taken June 26, with the same camera and from the same view- 

 point were strikingly similar at first glance. Careful comparison in- 

 dicated a lengthening of the crater of from forty to sixty feet and a pro- 

 portionate widening, but the general shape and appearance were similar. 

 The linear extension of the crater was evidently along the same crack 

 marked by the steam jets in the June photograph (Fig. 3), and a sharp 



