VULCANOLOGX AND SEISMOLOGY. 47o 



The first i»art of Verbeek's Report on the Krakatoa eruption, issiK'd 

 by the Dutch East Indian Government (Batavia, 1884), dealt witii the 

 prior liistory of the island and the-eveuts of the catastrophe it.^elC, leaving 

 to the second part the scientific results of the inv'estigation. The edi- 

 tor examined 1,300 reports of eye-witnesses, and has endeavored from 

 them to construct a chronological statement of the events preceding and 

 accompanying the eruption. {Nature^ xxxi: 279.) The second part 

 has now been comj^leted, and has fully realized the expectations raise<l 

 by the publication of the first part. It contains twenty-five colored draw- 

 ings and forty-three maps, and reflects the greatest credit not only on the 

 author, bijt on the Dutch Indian Government which sent him to study 

 the causes and efi'ects of this catastrophe, and which so efficiently aided 

 him in the work. A few of his conclusions may be mentioned here. 

 Krakatoa lies at the intersection of three fissures in the earth's crust, 

 and the earthquake of September 1, 1880, which damaged the light-house 

 on Java's First Point, probably affected the Sunda fissure and facilitated 

 the entrance of greater quantities of water to the volcanic furnace be- 

 neath. Here may be found the remote cause of the outburst of 1883. 

 The geology of Krakatoa is presented by two mai)s and four sections 

 showing different stages of its development, the formation of the peak 

 Kakata by a lateral eruption, the addition of the two parasitic cones of 

 Danau and Perbvewatan, and finally their destruction by the explosion 

 of 1883, The first three stages antedate any authentic records. In the 

 last stage Perbvewatan became a«tive in May, 1883, Danan joined it in 

 June, and in August both these with half of liakata were destroyed and 

 are now covered by the sea. Portions of the j)umice from the eruption 

 were carried westward to the coast of Africa. Another portion, after 

 floating for months in the straits, was, in 1884, driven eastward, and in 

 1885 was encountered in the Pacific Ocean near the Caroline Islands. 

 {Mature, xxxi: 288.) The author expected that this might reacli the 

 west coast of America early in 1886. The distance to which the ex})lo- 

 sions were heard is illustrated by a map, and the curious fact that certain 

 detonations were heard at distant places and not noticed at nearer ones 

 is attributed to the presence of a dense ash cloud surrounding the peak 

 and checking the transmission of sound through the lower atmosphere. 

 About seventy pages are devoted to a discussion of the atmospheric wave 

 which made the circuit of the globe. With the aid of accurate barograms 

 from Sydney, N. S. W., and from Batavia he was able to calculate the 

 hour of the greatest explosion and origin of the wave as 10 hours 2 min- 

 utes a. m., Krakatoa time. Forty places are named where the passage 

 of the air-wave was recorded by barometers. Treating of changes in 

 the sea bottom, he says the northern part of Krakatoa is now cov^ered 

 by the sea to a dei)th of 200 to 300 meters, and within the ring of islands 

 which are fragments of the old crater-ring an area of 41 square kilom- 

 eters has subsided. Outside these islands also the sea is deei)er than 

 formerly over an area of 34 square kilometers, so thai in all there has 



