336 HARRY 0. WOOD 



tree near the front the writer was able to look a long way up the 

 flow. The only hindrance to good seeing was the shimmer of the 

 air produced by the heat radiation. The surface showed many 

 oven-like openings, and a few small conelike forms were seen, but 

 these were of temporary nature, and not true cones. No explana- 

 tion of their formation occurred to the writer. One that was 

 watched was slowly destroyed as the forward motion progressed. 



The falling blocks made a tinkling sound, and the forward 

 motion of the upper surface was accompanied by a low grinding 

 sound, but these noises were low and inaudible at a short distance. 

 The quiet character of the advance at this stage was very striking. 

 At intervals loud detonations were heard. These were ascribed 

 to the action of the hot lava on buried vegetation. ' The sounds 

 made by the crackling of the falling trees and bushes were the 

 loudest of the frequent noises, and the crackling produced by the 

 burning of green vegetation was the most continuous and con- 

 spicuous. At this stage of the flow its approach was so quiet that 

 it gave practically no warning at a distance of fifty yards. Trees 

 were being felled by the flow, partly by burning through at the 

 stump, but in some instances by overturning as a result of the for- 

 ward motion of the flow. 



There were smells of subliming sulphur, sulphur acids, and of 

 cinders and charcoal. None of these was strong enough to be very 

 annoying. Others reported the smell of coal gas. This was not 

 noted by the writer, but was noticed by a large number of people, 

 and the fact must therefore be accepted. This was in the wooded 

 region, and here these carbon-gas odors could be ascribed to the 

 action of the lava on vegetation. However, along the Kahuku 

 branch of the flow such carbon-gas odors were plainly noticed by 

 many at points well above the wooded region, where vegetation 

 was so scanty as to be negligible. And some have reported noticing 

 these odors near the lower end of the source in a barren region 

 where there is strictly no vegetation. It seems, therefore, that 

 carbon gases almost unquestionably were emitted from the lava 

 of this eruption. 



{To be continued] 



