268 



KNOWLEDGE. 



[December 2, 1895. 



record the same disturbance. '• The great wave passed 

 and repassed again over London, and no inhabitant wag 

 conscious of the fact." The barometer at Greenwich 

 Observatory automatically recorded this eilect ; moreover, 

 the instruments at Kew confirm those at Greenwich. 

 Evidence of the same kind was also obtained from 

 Valentia (Ireland), Paris, St. Petersburg, Berlin, Palermo, 

 Eome, New York, Toronto, Mauritius, Tokio, Bombay, 

 Melbourne, and many other places. " All the instrumeuts 

 record the first great wave from Krakatoa to its antipodes 

 in Central America, and also the return wave." The first 

 four oscillations left their mark on upwards of forty 

 barograms, the fifth and sixth on several, and at Kew the 

 existence of a seventh was certainly established. 



At the same time that this immense aerial undulation 

 started on a tour round the world, another wave, but of 

 awful destructiveness, i.e., a seismic sea-wave, started on a 

 similar journey.* There can hardly be a doubt that this 

 so-called " tidal wave " was synchronous with the greatest 

 of the explosions. A wave from fifty to seventy-two feet 

 high arose, and swept with resistless fury upon the shores 

 each side of the Straits. The destruction to life and property 

 \vill probably never be fully known. At least thirty-six 

 thousand three hundred and eighty lives were lost, and a 

 great part of the district of North Bantam was destroyed, 

 and the towns of Anjer, Merak, Tyringin, and neigh- 

 bouring villages were overwhelmed.! A man-of-war, the 

 Berouw, was cast upon the shore of Sumatra one mile and 

 three-quarters inland, and masses of coral, from twenty 

 to fifty tons in weight, were torn from the sea-bed and 

 swept upon the shore. Following this seismic sea- 

 wave, the waters of the Strait ebbed and flowed sixteen 

 times in three hours. The cause of this immense wave is, 

 of course, conjectural. Large masses of the island were 

 probably blown away by the force of the explosion, and 

 falling into the sea propagated the wave, or possibly the 

 sudden displacement of water over a submarine vent gave 

 rise to such an undulation. It is stated on high authority 

 that the missing mass of Krakatoa equals two hundred 

 thousand million cubic feet, and that a fiftieth part of 

 this mass dropped suddenly into the sea would create 

 displacement sufficient to make a circle-wave nearly one 



The captain of the Charles Ball, who was afloat a 

 few miles to the north of Anjer, and his helmsman " saw 

 a wave rush right on to Button Island, apparently sweep- 

 ing right over the south part and rising half-way up to the 

 north and east sides, fifty or sixty feet, and then continuing 

 on to the Java shore." He then adds the valuable remark, 

 " this was evidently a wave of translation and not of 

 progression, for it was not felt at the ship." This move- 

 ment coincided with the great "tidal wave," so called, 

 which was felt on the Ceylon coist, Aden, Port Blair, 

 Nagapatam, Port Elizabeth, Kurraehee, Bombay, and half- 

 way up to Calcutta on the Hooghly, the north-east coast 

 of Australia, at Honolulu (Sandwich Islands), Kadiall in 

 Alaska, San Celeto near San Francisco, and Table Bay. 



A few days after this eruption some remarkable sky- 

 effects were observed in different parts of the world. Many 

 of these effects were of extraordinary beauty. Accordingly, 

 scientific inquiry was made, and in due time there was 

 collected and tabulated a list of places from whence these 

 effects were seen, together with the dates of such 

 occurrences. Eventually it was concluded that such 

 optical phenomena had a common cause, and thfit it must 

 be dust of ultra-microscopic fineness at an enormous 

 altitude. All the facts indicated that such a cloud started 

 from the Sunda Straits, and that the prodigious force of 

 the Krakatoa eruption could at that time alone account 

 for the presence of impalpable matter at such a height in 

 the atmosphere. This cloud travelled at about double the 

 speed of an express train by way of the tropics of Cancer 

 and of Capricorn. Carried by westerly-going winds, in 

 three days it had crossed the Indian Ocean and was 

 rapidly moving over Central Africa ; two days later it was 

 flying over the Atlantic ; then, for two more days, over 

 Brazil, and then across the Pacific towards its birthplace. 

 Its course has been thus happily phrased by Sir Eobert 

 Ball : — " The dust of Krakatoa had put a girdle round the 

 earth in thirteen days." But the wind still carried this 

 haze of fine particles, now spread out over a wider track, 

 onward, and again it went round the world within a 

 fortnight. In November, the dust area had expanded so 

 as to include Europe and North America. 



Here are a few of the facts culled from the Koyal 



/#lfe... 



Krakatoa, after the Eruptiiiu, as seen from the nortli 



hundred miles in circumference, twenty feet high and 

 three hundred and fifty feet wide. 



* The sea disturbance was probably composed of two descriptions 

 of waves — long waves, w.th periods of over an hour, and shorter but 

 higher waves, with irregular and much briefer intervals. The great 

 disturbance was probably formed of both descriptions of waves, 

 originated at Krnliatoa at abiiut ten a.m. — Roi/. Soc. Report. 



t -*Vt Tvringin (tweuty-four miles from Krakatoa), as the people on 

 the hills at the back of the plain, stated to be sixty-seven to one 

 hundred feet high, were saved, it does not appear that the waie 

 could have been nuicli over seventy feet. — Soji. Soc. Report. 



Society Report. On the 28th, at Seychelles, the sun was 

 seen as through a fog at sunset, and there was a lurid 

 glare all over the sky after sunset. At the island of 

 Eodriguez, on that day, "a strange red threatening sky 

 at sunset " was seen. At Mauritius (28th y, there is the 

 record "crimson dawn, sun red after rising, gorgeous 

 sunset, first of the afterglows ; sky and clouds yellow and 

 red up to the zenith." 28fch and 29fch, Natal — " most vivid 

 sunsets, also August 31st and September 5th, sky vivid 

 red, fading into green and purple." On the last days of 

 August and September Ist the sun, as seen from South 



