224 C. E. Dutton— Hawaiian Volcanoes. 
Every lava stream gives rise to long pipes or tunnels and 
there are literally thousands of them, some of which are sev- 
eral miles in length. In truth, these long caverns must form 
an appreciable portion of the entire volume of the mountalD. 
membering also the very vesicular character of the lava, it 
seems plain that while the absolute density of the materials 18 
very high, the specific gravity of the mass as a whole is by 0° 
means so. 
lect i T f the 
cannot collect in streams until the cracks and pores 0 
lava are silted up. Of course, this takes place more quickly 
upon the windward than upon the leeward sides, These facts 
oup. 
I also visited Hualalai, which has an altitude of ae 8,600 
feet. It seems to be intermediate as regards the character of 
its lavas and many of its eruptions between Mauna Kea an 
Mauna Loa; being more basic than the former, less so than the 
latter. It has many cinder cones upon it, especially at the 
