170 COMPENDIUM OF GEOGRAPHY AND TRAVEL 



27th "like the distant roars of heavy guns." In the 

 opposite direction Dr. Guillemard records that the sounds 

 were audible on both days at Dorei Bay, on the north 

 coast of New Guinea, 2014 miles distant. Eoughly 

 speaking, the eruption was heard over one-thirteenth of 

 the entire surface of the globe. It is very remarkable 

 that in the more immediate neighbourhood of the volcano 

 the sounds were inaudible after the culminating explosion 

 at 10 a.m. on the 27th, and this curious phenomenon can 

 only be accounted for by the supposition that the 

 enormous mass of ejecta formed a sort of wall or curtain 

 so thick as effectually to exclude all sound. With regard 

 to the extraordinary sunset glows and coloured suns so 

 widely noticed during the autumn of 1883 and at sub- 

 sequent periods, Messrs. Archibald and EoUo Eussell's 

 exhaustive treatise proves beyond all possibility of doubt 

 that they were caused by the impalpable dust and vapour 

 particles ejected from the crater of Krakatau during this 

 memorable eruption. The pumice, which lay so thick in 

 the Straits of Sunda that a bank of it was reported on 

 one occasion to have almost stopped a vessel passing a few 

 weeks later, drifted completely across the Indian Ocean 

 from about 0° to 20° S., and reached Natal about the end 

 of September 1884.^ Three years after the eruption the 

 island was visited by Dr. Treub of the Buitenzorg Botanic 

 Garden, who found the cinders and pumice entirely 

 covered with fresh-water algoe of various species. He also 

 collected eleven species of ferns and twenty other plants. 



The plains, table-lands, and valleys of the mountain 

 region of Sumatra are often of great extent, and differ 



1 For further information the reader is referred to "The Eruption of 

 Krakatoa" — the Report of the Krakatau Committee of the Royal Society, 

 and M. Verbeek's " Krakatau." 



