F. A. Perret — Lava Fountains of Kilauea. 145 



seen issuing from spatter cones on the shore or from blow-holes 

 in spatter grottoes at the lake margin, are generally described 

 as having a blue or green color, but we must here guard against 

 effects complementary to the glare of the lava. A stream at 

 Etna emitted vapors which were colorless by day but, as twi- 

 light came on, the lava glowed strongly red and the vapors 

 appeared green, while at night their tint was violet against 

 the golden yellow glare. 



The flames are faintly luminous and are only visible against 

 a dark background. In fountains with a pronounced spatter 

 phase the flame is lost to sight in the brightness of the scat- 



Fig. 6. 



Fig. 6. Cloud of burnt gases from a lava fountain (seen over x ). 



tering drops, but in fountains limited to the dome formation 

 (fig. 3) the flame may always be seen (but not photographed) 

 issuing from the top of the dome as a flash of brief duration. 

 During three months of continuous observation comprising a 

 rising, stationary, and falling lava level, every fountain dome 

 produced its flame, and the many visitors, to whom it was pointed 

 out, had no great difficulty in observing the phenomenon. 



But here again we are fortunate in being able to appeal to 

 the photographic record, for, if the gases which leap from the 

 fountains are invisible by daylight, the products of their com- 

 bustion are not so, but form a transparent cloud of light blue 

 vapor — also faintly visible — but which, by reason of its highly 

 actinic color, is easily photographed. In fig. 6, above the 

 mark X, niay be seen the round area of a subsiding fountain 

 dome and, over it, the cloud of burnt gases, undisturbed, in 



