November 17, 19 10] 



NATURE 



93^ 



in enormous quantity of very fluid basic lava has been 

 Jischarged. This has flowed by a sinuous course of about 

 ten miles into the sea, devastated some of the most fertile 

 land in the island, and covered it up with lava fields 

 probably not less than twenty square miles in area. 



The crater contains a lake, or rather river, of molten 



Fig. 2. — Pit Crater in Lava Field, on the line of the Lava Tunnel to the Sea. 



lava so fluid that it rises in incandescent fountains, beats 

 ii waves on the walls, and rushes with great velocity 

 iown into a gulf or tunnel at one end of the crater. 

 The lava, still liquid, runs in a passage, or perhaps system 

 f passages, under the surface of the lava field, its course 

 in<i traceable by a line of large fumaroles until, still 



1 



The term pillow lava, originally applied to the results 

 of a peculiar form of spheroidal weathering, is now- 

 extended to various smooth-surfaced lobular masses, which 

 have been considered by Teall, Cole, and Gregory to be 

 formed by lava flowing into water. This view has been 

 combated by others; but Dr. Anderson watched the process 

 actually going on, and photographed the. 

 results. 



The fornSation of ordinary " cocded- 

 lava " or " pahoehoe " takes place by a 

 kxral quiet outflow of lava which forms 

 a pool or lobe. The surface, being 

 slowly cooled by the air, forms a more 

 or less tenacious, treacly scum, which is 

 pushed forward by the liquid mass under- 

 neath, and is puckered up into a cord or 

 festoon. While this is taking place the 

 new surface is becoming treacly, and in 

 its turn is pushed forwacd into another 

 fold, and so on until the whole surface is 

 solidified, often with a very regular 

 pattern. 



Dr. Anderson said he had seen this 

 taking place on Vesuvius, and had 

 watched the same process going on at 

 the sea-level at Matavanu. The surface 

 of the lobes, however, being in that case 

 exposed to the waves, was rapidly chilled, 

 and solidified before it had time to be 

 pushed forward to form " corded struc- 

 ture." A photc^raph of a recent flow 

 into the lagoon showed corded structure 

 above high-water mark, while lower 

 down there was ever}- transition into 

 t>-pical pillow lava. 



The surface of the lava field shows 



several large pits along the line of 



the lava-eonduit to the sea, out of which 



steam and vapours escape. They are larger than ordinary 



fumaroles, and appear to be formed by the remelting and 



falling in of the crust owing to the heat of the lava which 



flows beneath. The sections exposed in their walls show 



the lava field to consist of numerous \tr\ thin beds, partly 



surface flows, but probably in many cases intrusive sheets. 



Ihis structure is very similar to that of 



the " pit craters " in Hawaii, the mode 



of formation of which is still unsettled. 



Possibly they may have been formed in 



the same way. 



Other interesting points noticed were 

 the formation of moulds by lava flowing 

 round living tree trunks. The trees 

 were, of course, killed, and when they 

 decayed hollows were left corresponding 

 to their former shapes. Occasionally, 

 after the lava had solidified round a tree 

 the remainder had flowed away ; when 

 the tree decayed a sort of hollow pillar 

 was thus left, in which smaller plants 

 sometimes grew. 



2 



I'keto.] 



Fig, 3. — Las a in 1 agjoa corteu aoov 



jw i_a\ci 



n a fluid condition, it reaches the sea, into which it flows 

 vith energetic explosions and the discharge of large 

 volumes of steam, black sand, and fragments of lava. 

 ^\ here the action is less violent a structure resembling that 



t some varieties of pillow lava is produced. 



NO. 2142, VOL. 85] 



UN/VERSnV A\D EDi'CA- 

 IIONAL INTELLIGENCE. 



BiRMiXGH.AM. — ^The Huxley lecture will 

 be delivered on November 23 by Prof. 

 Percy Gardner, professor of classical 

 archaeology in the University of Oxford. 

 The subject of the address is '* Rational- 

 ism and Science in Relation to Social 

 Movements. " 



Bristol. — In connection with the 

 faculty of engineering provided and main- 

 tained in the Merchant Venturers' 

 Technical College, a course of five 

 monthly lectures on " .\viation " has been arranged. The 

 selected lecturers are Prof. \V. Morgan, Mr. .\. R. Low, 

 Mr. E. S. Bruce, Mr. L. Blin Desbleds, and Mr. Joseph 

 Clarkson. 

 .A new wing erected for the chemical and physiological 



