634 Jaggar — Activity of Mauna Loa. 



quite different from the wind below, and gradually developed 

 the habit of puffing up in distinct volutes, as the supply became 

 less. 



December 26, the slender single fume column was glowing 

 in the evening. December 27, from 7 to 9 a. m. (fig. 11), 

 with light northeast wind at Volcano House, the fume column 

 on Manna Loa rose high, bent eastward and thinned out over 

 Puna to a bluish iridescent fume cirrus, quite unlike any rain 

 cloud in color and luster. It showed a slight transverse ripple- 

 marking in the middle part of its course. There was possibly 



Fig. 10. 



\ 



WMIMA LOA DEC Z2 13 \"r 



a slight increase in volume of fumes, which continued through 

 the week, but owing to varying conditions of wind and of 

 clear atmosphere, with frequently no seeing at all, it is impos- 

 sible to judge slight changes accurately. 



An increase of fumes was to be looked for, by analogy with 

 the habit of Kilauea, if the fountains in Mokuaweoweo were 

 still diminishing. The glow at night continued through the 

 week. December 28, in the morning, small volutes of fume 

 were rising ; December 29, a straight funnel column in still 

 air with traces of vortex motion in a spiral (fig. 12); Decem- 

 ber 30, the same, bending in a counter current eastward in 

 upper atmosphere, while the wind was northeast below. 

 (Fig. 13.) At 1 p. m. the high column was bending south- 

 ward, the puffs showing brownish below and blue above. The 



