December 2, 1895.] 



KNOWLEDGE 



267 



rounding atmosphere. The rush of steam through craters 

 or other fissures would also contribute to these disturb- 

 ances. 



From these causes also the compasses of passing ships 

 were much disturbed. And yet the fall of magnetic oxide 

 of iron (magnetite), a constituent of volcanic ash, possibly 

 had some share in creating these perturbations. On the 

 telephone line from Ishore, which included a submarine 

 cable about a mile long, reports like pistol shots were 

 heard. At Singapore, five hundred miles from Krakatoa, 

 it was noted at the Oriental Telephone Company's station 

 that, on putting the receiver to the ear, a roar like that of 

 a waterfall was heard. So great was the mass of vapour 

 and dust in the air that profound darkness, which lasted 

 many hours, extended even to one hundred and fifty miles 

 from the focus of eruption. There is the record, among 

 others, that it was "pitch dark" at Anjer at 2 p.m. on 

 the 26th. 



So great, too, was the ejective force that, according to 

 Dr. Verbeek's estimate, the fine volcanic dust was blown 

 up to a height of fifty thousand feet, or over nine miles, 

 into space. Another estimate gives, as before stated, the 

 enormous altitude of seventeen miles to which the dust 

 had been blown. The volcanic ash, which fell upon the 

 neighbouring islands within a circle of nine and a half miles 

 radius, was from sixty-five to one hundred and thirty feet 

 thick. At the back of the island the thickness of the ash- 

 beds is from one hundred and ninety-five to two hundred 

 and sixty feet. Masses of floating pumice cumbered the 

 Strait. The coarser particles of this ash fell over a known 

 area equal to two hundred and eight-five thousand one 

 hundred and seventy square miles — a space equal to the 

 whole of the German Empire, Holland, Belgium, Denmark 

 and Iceland. It has been calculated that the matter so 

 ejected must have been considerably over a cubic inile in 

 volume. 



consciences, for, being guilty of murder, they fled, fearing 

 that such sounds signified the approach of an avenging 

 force. Again, in the island of Timor, one thousand three 

 hundred and fifty-one miles away, the people were so 

 alarmed that the Government sent off a steamer to seek 

 the cause of the disturbance. At that time also, the 

 shepherds on the Victoria plains. West Australia, thought 

 they heard the firing of heavy artillery, at a spot one 

 thousand seven hundred miles distant. At midnight, 

 August 26th, the people of Daly Waters, South Australia, 

 were aroused by what they thought was the blasting of a 

 rock, a sound which lasted a few minutes. " The time and 

 other circumstances show that here again was Krakatoa 

 heard, this time at the enormous distance of two thousand 

 and twenty-three miles." And yet there is trustworthy 

 evidence that the sounds were heard over even greater 

 distances. Thundering noises were heard at Diego Garcia, 

 in the Chagos Island, two thousand two hundred and sixty- 

 seven miles from Krakatoa. It was imagined that some 

 vessel must be in distress, and search was accordingly 

 made. But most remarkable of all, Mr. -Tames Wallis, 

 chief of police in Rodriguez, across the Indian Ocean, and 

 nearly three thousand miles away from Krakatoa, made 

 the following statement, that " several times during the 

 night of August 26th-27th reports were heard coming 

 from the eastward like the distant roar of heavy guns. 

 These reports continued at intervals of between three and 

 four hours." Obviously, some time was needed for the 

 sounds to make such a journey. On the basis of the known 

 rate of velocity, they must have been heard at Rodriguez 

 four hours after they started from their source. ■' 



And yet, great as was the range of such vibrations, 

 they could not be compared with that of the air-wave 

 caused by the mighty outburst. This atmospheric wave 

 started from Krakatoa at two minutes past ten on that 

 eventful Monday morning, moving onward in an ever- 



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Krakatoa, at'tev the Eruption, as seen from the south-east. 



Another distinguishing feature of this display of Nature's 

 powers was the magnitude and range of the explosive 

 sounds. It has been well remarked by Sir Robert Ball 

 that were Vesuvius so to act, everyone in Great Britain 

 would be near enough to hear the awful detonations. 

 Lloyd's agent at Batavia, ninety-four miles distant from 

 Krakatoa, reported that on the morning of the 27th the 

 reports and concussions were simply deafening. At 

 Carimon, -Java Island, which is three hundred and fifty- 

 five miles distant, the natives heard reports which led 

 them to suppose that a distant ship was in distress ; boats 

 put off for what proved to be a futile search. The explosions 

 were heard not only all over the province of Macassar, nine 

 hundred and sixty-nine miles from the scene of the eruption, 

 but over a yet wider area. At a spot one thousand one 

 hundred and sixteen miles distant — St. Lucia Bay, Borneo 

 — some natives heard the awful sound. It stirred their 



widening circle, like that produced when a stone is thrown 

 into smooth water. This ring-like wave travelled on at 

 the rate of from six hundred and seventy- four to seven 

 hundred and twenty-six miles an hour, and went round 

 the world four, if not even seven times, as evidenced by 

 the following facts. Batavia is nearly a hundred miles 

 from the eruptive focus under review. There was connected 

 with its gasholder, the usual pressure recorder. About 

 thirteen minutes after the great outburst, this gauge 

 showed a barometric disturbance equal to about four-tenths 

 of an inch of mercury, i.e., an extra air-pressure of about 

 a fifth of a pound on every square inch. The effects on 

 the air of minor paroxysmal outbreaks are also recorded by 

 this instrument ; but barometers in the most distant places 



* Later on, it was stated that booming sounds were lieard on that 

 day at Caiman Brae, in the West Indies, the antipodes of Krakatoa. 



