654 GEOLOGY OF SAMOA AND THE ERUPTIONS IN SAVAII, 



the thickness of the flow is between 10 and 40 feet, the lava has 

 in several instances flowed round buildings of stone, piling itself 

 higher and higher, without crushing in the walls. Such houses 

 are now represented by holes, except where the flow has been 

 sufficiently high to enter by the roof, or sufficiently liquid to 

 overcome its own sluggishness and flow in through the windows. 

 At one place, near Saleaula, where the lava is between 6 and 10 

 feet thick, a native house was removed before the stream 

 advanced, but the spot where it stood is now a depression 

 surrounded by almost vertical lava walls, and has grass growing on 

 the bottom. This spot was preserved by a ring of stones about 

 eighteen inches high, such as the natives make round their 

 houses. These facts show that, on fairly level ground, when a 

 piece of land is not in the very front of the main lava stream, but is 

 being threatened by the backwash, so to speak, the quick erection 

 of a stone mound may save it from destruction. 



The coral reef has acted in the same way as the stones of the 

 native house referred to. The lava, on reaching it, stops flowing- 

 seaward, and rises by new masses being thrust under and lifting 

 the cooled surface. It now flows along the coral reef. Mr. 

 Williams informed me that as soon as a lava stream reached the 

 sea it became "quick-flowing and full of life." The increased 

 mobility may be due to mixture with water, or to diminished 

 resistance. 



Before the eruption the coral reef extended from Sasina to 

 Asuisui. Lava has filled the space between the reef and the 

 shore from Asuisui to Toapaipai, and has further followed the 

 reef so as to build a long peninsula, several miles in length, 

 enclosing a fine sheet of water, which forms a safe harbour at 

 Saleaula. 



Mr. Williams tells me that, in the early stages of the eruption, 

 in August, 1905, no actual lava could be seen, and yet the whole 

 countryside near the volcano rose and flowed like lava, and 

 seemed like a mountain on a " melanga " (journey). When you 

 thrust a stick into the moving mass, you saw only reddish cinders. 

 The explanation of this phenomenon is, of course, that the first 



