Page:Popular Science Monthly Volume 86.djvu/302

298 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 camera with its narrow field of view to give correct impressions of the conditions 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. No appreciable change occurred 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 suggested 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 Susanville auto road which terminates at Drakesbad, a resort in Hot Springs Valley 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. In 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.” Newspaper 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 viewpoint were strikingly similar at first glance. Careful comparison indicated a lengthening of the crater of from forty to sixty feet and a proportionate 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