486 HARRY 0. WOOD 



sulphur salts, or to the escape of fumes in very small quantity 

 from numerous cracks distributed over the area. No other expla- 

 nations of this light color suggested themselves. 



Cones of medium size could be seen within the area. Fumes 

 were rising from them and around them. It is uncertain whether 

 these were new cones, or old cones freshly riven. In general, 

 here, eruption does not take place through old fissures reopened; 

 but exceptions are known. There was no great amount of action 

 at night at this upper source. However, the fuming action in the 

 cleft and on the sides of one of these cones strongly suggested that 

 it was of new origin. 



Certain features of older origin, found in the neighborhood of 

 the lower source, claim bare mention here. 



Above Puu o Keokeo there is a long, narrow flow of fresh, 

 black a-a (with long narrow tongues projecting from it over the 

 great flat to the eastward), which stretches along the eastern 

 margin of the 191 6 flow source, and in part lies under the 191 6 

 outflow. This begins much farther up the mountain, in the course 

 of the rift, than the 1916 head. Undoubtedly this is lava of 1907, 

 and it is mapped by Baldwin as of this date (see the map, Plate I). 

 However, on his map it is shown as extending down past Puu o 

 Keokeo on the east of that group of cones. Nevertheless, on the 

 writer's short reconnaissance he went on horseback up between the 

 flow of 1887 and the Kahuku branch of 191 6 onto the ancient 

 lava ridge that projects uninterruptedly eastward from Puu o 

 Keokeo without crossing this lava stream. Hence it is clear that 

 no part of this flow follows the course past Puu o Keokeo shown on 

 that map. This upper stream did, however, pass down on the 

 western side of Puu o Keokeo. While the detailed expression of its 

 course, therefore (and of that of a contributory stream from a source 

 below Puu o Keokeo), must await adequate topographic survey, 

 the writer has diagrammatically sketched its course on the west of 

 Puu o Keokeo on the map, Fig. 1, showing these southwestern 

 flows. However, he has not attempted to indicate the long tongues 

 which project southeastwardly over the great flat north of Puu o 

 Keokeo, on account of want of data, and of the cartographic con- 

 fusion that might result. 



