BY H. I. JENSEN. 651 



is included in and beneath it. When the steam pr-essure becomes 

 great enough, an explosion takes place. 



In March last the lava was entering the sea along a width of 

 several miles, so that a continuous wall of steam lined the coast; 

 a,nd the sea was boiling hot, and in ebullition several hundred 

 yards out. The stench from the dead coral and fishes was very 

 bad at Matauto. 



The weight of the lava poured out it is impossible to estimate, 

 even for one who perfectly understands the previous configuration 

 of the country, some of it being compact, some vesicular, and 

 some mere scoria. One can, however, say with certainty that in 

 volume it exceeds a cubic mile, and that three cubic miles may 

 not be too high an estimate. Over a considerable area it 

 probably exceeds 1000 feet in thickness. Over the coastal area 

 from Saleaula to Satapatu, and inland three or four miles, its 

 thickness varies from twenty to several hundred feet. Between 

 Asuisui and Satapatu it has flowed into deep water, and has filled 

 up the sea bottom to such an extent as to make the water 

 greenish and shallow-looking for nearly a mile out from shore. 

 The explosions where the lava runs into the sea have given rise to 

 a lot of black saud on the Savaiian beaches. This consists of lava 

 blown to cinders. 



On the crust the lava is almost wholly tachylitic. * Occasionally 

 it contains an olivine, more rarely a plagioclase (probably albite) 

 phenocryst. At Malaiola steam explosions beneath have in 

 several places broken the crust so as to form stony hills; and in 

 many of the wide cracks here formed, several feet wide and 8-10 

 feet deep, which at the time of my visits emitted steam and 

 sulphurous vapours, the nature of the more deep-seated lava may 

 be seen. The specimens obtained here have large, almond- shaped 

 vesicles forming about one-third the volume of an otherwise 

 compact and almost holocrystalline, close-grained rock.f The 

 lava surface is, generally speaking, satiny and level, of the 



* See Penological Descriptions, posted p.667, Sp. S.2. 

 t See Penological Descriptions, posted p. 666, Sp. S.l. 



