Marshall. — Volcanic Eruptions on Ambryih Island. 389 



It appears tolerably evident that the central ash plain marks the site of 

 a former large cone which was truncated by an immense explosive eruption, 

 though Mawson refers to it merely as an old crater. 



Keport of Eruption rx Ambrym Island, New Hebrides, 7th De- 

 cember, 1913, by Dr. Bowie. 



On the 6th December, 1913, a little after 5 p.m. it was observed that 

 Mount Benbow. Ambrym Island, was in active eruption to an exceptional 

 degree. Gigantic columns of steam were seen to rise many thousands of feet 

 in the air. After each explosion a fresh pillar could be made out, boring its 

 way in a spiral fashion through the cloud which extended upwards from 

 the mouth of the crater. The succeeding explosions followed each other in 

 more and more rapid succession, as well as in added force, until within an 

 hour the intervals between the explosions were reduced from about three 

 minutes to under one minute, and ultimately there was apparently no in- 

 terval at all. 



(a.) Just before dark, dense columns of steam and smoke were observed 

 rising somewhere in the western edge of the " Great Ash Plain," and as 

 darkness fell we could easily see a great river of incandescent lava rushing 

 towards Baulap ; another was running towards Port Vato. We climbed 

 the hill immediately behind the hospital at Dip Point, and watched the 

 Baulap stream until it reached the sea, which it did a little after 9 p.m. 

 Lava, however, continued to flow down that valley for at least a whole dav 

 after this. 



(b.) About 11 p.m. a new lava-stream was sighted rushing down the 

 hillside about three miles and a half north-east along the coast. It reached 

 the sea immediately to the west of Krong Point at about 2 a.m. 



(c.) Soon after the last stream reached the sea it became very apparent 

 that another lava-flow was on its way to the sea. During the whole night 

 the sky was brilliantly -lit up, but now, though there were high hills between 

 us and the various rivers of lava, the valley in which we were was so 

 illuminated that we could discern objects hundreds of yards away. This 

 stream reached the sea two miles to the north-east of the hospital about 

 2.30 a.m., 7th December. 



(d.) Almost simultaneously with stream (c) another made its appearance 

 back in the hills at the head of Lowea Valley. This stream, one could easilv 

 observe, was coming much nearer to us, and we calculated the speed of the 

 flow at about five miles an hour. Certainly the incline was, on the whole, 

 pretty steep, and at one place the lava poured over a precipice about 60 ft. 

 or 70 ft. high. The sight was magnificent as well as awe-inspiring. The lava, 

 which was quite incandescent, came quickly on, burning up great forest- 

 trees, tossing them all aglow in the air. As they fell again into the torrent 

 they rebounded high in the air, emitting sparks like a thousand catherine- 

 wheels. Soon after 3 a.m. the lava plunged with a savage hiss and a mightv 

 roar into the sea. The sight was then superb, and never to be forgotten. 



The din as the lava flowed through the forest reminded one very much 

 of the noise of a hurricane with the boom of the ocean and the crashing of 

 great forest-trees. 



The last stream mentioned reached the sea within three-quarters of a 

 mile of the hospital compound, but the hospital was built in a valley sur- 

 rounded by hills except on the sea side. The valley behind was about a 

 mile and^a half long by about a mile broad at its widest part, and narrow- 



