268 



NA TURE 



yjan. J 7, 1884 



speed at which the latter was continually rising. The 

 steadiness of the rise of the latter from early manhood to 

 late years is very striking ; it is almost in a straight line. 

 1 have not sufficient data to justify me to say when its 

 curve culminates ; I have closed it at 70 with a dotted 

 line. 



It is only necessary to add that the ledgers of Messrs. 

 Berry are a quarry from which, with some labour, much 

 further information of the kind just given might be drawn. 

 Perhaps the publication of this paper will suggest methods 

 of treating them that have not occurred to myself. 



Francis Galton 



THE ERUPTION OF KRAKATOA^ 

 " O I^TEEN volcanoes now working between the spot 



'--' where Krakatoa was before and Sebesie." Such 

 was one of the first reports which was sent by cable to 

 Singapore, and which we heard at Pontianak. Never 

 before had we been so longing for news from Java, for 

 when H.M. ship Hydrograaf steamed into the Padang- 

 Tikar River, we heard heavy detonations and explosions 

 like far-off shots, so that we were alarmed about Java. 

 As we expected, our ship was soon ordered to survey the 

 Sunda Straits. This survey was finished at the end of 

 October, and the reader will probably feel interest'jd to 

 know what really has happened there. 



Krakatoa has not entirely disappeared, while, till now, 

 no new volcanoes are visible in the neighbourhood. 

 But the report that new islands were said to have 



Fig. I.— Krakatoa during ihe erupti in of May, after a draning of the 

 Military Survey Bureau, Batavia. 



arisen between Sebesie and Krakatoa is easily to be 

 explained, for the new islands are like a mass of smoking 

 and steaming rocks, and if seen from afar they ma\ 

 easily suggest the idea of a great number of working 

 volcanoes. But, when looked at closely, it appeared that 

 the masses of rock were composed of hot pumice- stone, 

 mixed with eruptive masses. In them there were a 

 great many cracks and splits, in which, by the heavy 

 breakers, steam of water was continually generated. 



The northern part of the island has entirely dis- 

 appeared. At what is now the northern edge the peak 

 rises nearly perpendicul.irly from the sea, and forms a 

 crumbled and rugged wall, and shows a vertical cutting 

 (which is more than Soo metres high) of Krakatoa. 



Where was land before, there is now no bottom to be 

 found ; at least we could not fathom it with lines of 200 

 fathoms (360 metre?) long. When we had quite cahii 

 weather, and steamed slowly and cautiously to and fro 

 along the base of the peak, or had turned oft" steam and 

 let the ship drift, and were busy in measuring the depth, 

 we could distinctly see the difterent strata and rocks of 

 the bare, opened mountain. Only here and there a slight 

 trace of melted volcanic matter was to be seen, which, 



■ By M. C. v.-m Doom, officer in comna-id of H.M ship //j',/n>fr,i,./ 

 Translated (an i parlially abridged) by E. Metzger from Ei^en Haard, 

 i88i. No. 51. 



after half of the mountain had crumbled away, had 

 flowed over the wall, which is still there. What remains 

 of the slopes is covered with a grayish-yellow stuff 

 (which, as plainly appears, had been in a melted or fluid 

 state), full of cracks or splits from which steam is con- 

 tinually coming out. 



In the same way steam is also coming forth from the 

 deeper cracks of the steep wall, which is still remaining. 

 .Sometimes this is accompanied by slight explosions ; at 

 tli.it time clouds of brown dust fly up from the cracks, 

 and stones roll down which are often so big as to disturb 

 the sea around the entire base of the mountain. Our 



entire survey of the north of Krakatoa suggested the idea 

 that we were above a crater which had been filled with 

 water and quenched by it, and this idea was still strength- 

 ened on observing that the decrease of depth, south of 

 Sebesie, had principally been caused by matters which 

 were cast out and flung away. 



Almost in every place here the lead came up from the 

 bottom, filled with black sand or carbonised dust, some- 

 times mixed with pulverised pumice-stone and little black 

 stones, which apparently had been in a red-hot or melted 

 state. Moreover, the soundings were very different, and 

 the new rocks resemble clods of substances which, when 



Fig. 3. — Peak of Krakatoa after the eruption 



in a melted or very hot state, had contact with water. 

 Probably such a whimsical shape of the rocks above the 

 sea-level suggests the state of the bottom of the sea in 

 the neighbourhood. The stones were still too hot to 

 allow us to discover whether massive stones are under 

 the pumice-stone also. It was not difficult, it is true, to 

 knock off large pieces of these rocks by a hatchet or a 

 chopper, but when a big block fell unexpectedly down, 

 ihe sailors had often to flee on account of the gases 

 which suddenly arose. The knocked off pieces which 

 were brought on board were still warm after they had 

 been in the boat for an hour. 



As is to be seen from the map, a great part of the 

 lost ground of Krakatoa is found again at the bottom of 

 the sea, a few miles to the north at least, if we suppose 

 that no undulations of the ground took place. After 

 Iiaving passed the limits to which the matters were 

 thrown out, one finds the same soundings as were found 

 before, and the decrease of depth is so local that the idea 

 of an upraised bottom is dissipated at once. If such an 

 elevation had taken place, it certainly would be remarked 

 o\er a far greater extent and be more regularly ascending 

 and descending. The firmer and stronger part of the 

 crater wall, the peak of Krakatoa, which is still there. 



