324 HARRY O. WOOD 



first seen by Joseph Moniz. Though their appearance and develop- 

 ment exhibited peculiarities, Moniz at first thought them to be 

 ordinary cumulus clouds, such as frequently rise from behind the 

 mountain. Yet they held his attention. After about ten minutes, 

 since they continued to rise straight upward at the same place, he 

 pointed them out to others; but still there was doubt as to their 

 character, and he allowed more than a half-hour to pass by before 

 he called the attention of the writer to them, at about 7:35 a.m., 

 having grown surer that they were columns of fumes. 



When first seen by the writer there were two chief standing 

 columns in which fumes were swirling rapidly straight upward and 

 merging in a double cumulus crown. The column higher up the 

 slope was somewhat larger and taller than that lower down; and 

 these were then separated by a clear interval whose width was 

 about the same as the diameter of the larger column — about 1,000 

 feet. As soon as possible the writer began making a series of 

 photographic records of this action, illustrating its development 

 throughout the rest of its duration. 1 Five of these are shown here, 

 Plate II, a, b, c, d; Plate III, a. The life of this outbreak was short. 



The higher fume column then rose above the mountain profile 

 probably from 11,000 to 12,000 feet, and the lower from 8,000 to 

 10,000 feet. Very quickly other subordinate columns appeared, 

 first at both sides and then in between the chief ones, and soon all 

 had merged into a single pillar of uprushing fumes, issuing more 

 and more copiously and rising to higher and higher altitudes. By 

 7:45 (Plate II, a) the diameter of this column had thus increased 

 to more than a mile, where a little earlier the total width including 

 the clear space did not exceed 3,000 feet. The column had now 

 reached a height of 15,000-18,000 feet above the mountain profile. 

 Its stem resembled a huge column fluted with drapery hung in 

 simple vertical folds. The cumulus crown still showed a double 

 head, and thus continued to indicate the positions of the two 

 dominant fume columns which, in reality, persisted throughout 



1 These views — 12 (14) in all — were made on Wratten Panchromatic M plates, 

 quarter-plate size, through a K 3 filter and a Zeiss Double Protar lens, F = i3 cm., 

 with a stop of /4S-. Time exposures of about five seconds were made with the earlier 

 views; but, with increasing actinicity, the later exposures were clipped a little short. 



