504 Mr. R. Mallet on the 



island, either of which is. physically impossible. While we remained ob- 

 serving, the outbursts from the bottom of the crater were found to be 

 very irregular as to time, varying, as timed by the watch, from a minimum 

 of two minutes interval to a maximum of thirty minutes, and in one case, 

 after we had commenced our descent, to forty minutes. I could not trace 

 a very distinct correspondence between the largeness of this interval and 

 the violence and volume of the outbursts following it, although the ten- 

 dency seemed to be to such a correspondence ; and the duration of the 

 outburst was certainly greater as the interval between two was so. At 

 each outburst a huge volume of dust and small material, and with more 

 or less of large fragments of solidified lava, all angular or subangular, and 

 with a few fragments and shreds of different sizes of lava still hot enough 

 to be slightly plastic while falling, were ejected ; none of the fragments 

 were of any great size, none appearing to exceed in weight about 500 or 

 600 pounds, and none of the pieces of plastic lava reaching half this 

 weight. The light wind blew from us towards the sea, out over which 

 a portion of the finer dust was wafted after each outburst ; but the great 

 mass of the dust and fragments, whether small or large, fell back into 

 the crater upon its bottom and steeply sloping funnel, a few only, and 

 generally of the largest fragments, being thrown out over the crest of the 

 crater at its sea side, and landing amidst the debris of the slope, down 

 which they clattered. It was obvious that the orifice of the tube at the 

 bottom of the crater was greatly obstructed by the loose material forming 

 the funnel above it, which seemed after each outburst to be continually 

 slipping, more or less en masse, and so blocking up the tube, along with 

 the mass of ejected material which dropped back upon the orifice ; for 

 it was easily remarked that successive outbursts apparently took place 

 from different points, distant occasionally some yards from each other, in 

 the bottom of the crater the main axis of the column, or its greatest 

 thickness, varying thus in position, and also more or less diverging 

 slightly from the vertical, sometimes one way and sometimes another, as 

 though the ajutage of discharge was through loose material of partly 

 large and entangled blocks, mixed with finer material, the positions 

 of which were more or less altered after each discharge. None of 

 the large fragments which we saw thrown out rose higher than the posi- 

 tion at which we stood, and few even so high that is, they did not rise' 

 more than 400 to 500 feet above the orifice at the bottom of the crater ; 

 but occasionally the height of projection must a good deal exceed this, as 

 I found many angular fragments and large shreds of lava, which had 

 fallen in a leathery or plastic state, to the landward and eastward sides of 

 the brim of the crater, 150 feet or more above the level of our point of 

 observation. The black sand and dust and crystals of augite are found 

 in large masses still higher and further from the crater on the land side ; 

 but much of the latter are blown inland by the strong winds from the 

 northward that prevail in winter. The solid mural precipices which form 



