374 Transactions. — Miscellaneous. 



successive explosions, and are exceedingly interesting. The air-wave 

 following the 10.5 eruption seems to have travelled three and a quarter 

 times round the world before it allowed the atmosphere to regain its normal 

 condition ; journeying at the rate of 674 or 706 miles an hour according as 

 it passed to the east or to the west, i.e., according as it was assisted or 

 retarded by the upper currents of wind (Col. Strachey, Eoyal Society). 

 Besides this " atmospheric shudder," as Ellery graphically calls it, there 

 were enormous sea-waves — tidal-waves as they are improperly called — 

 formed by the tumbling-in of the burnt-out mountain, or the falling into the 

 sea of vast bodies of ashes, or by submarine explosions or otherwise. These 

 waves were, as you know, awfully destructive to human life — perhaps 

 carried off 100,000 people. To show their force and rapidity, I may state 

 that they reached Geraldton in Western Australia so early as the 27th, 

 Mongonui and Timaru, New Zealand, on the 29th, and Nelson on the 30th. 

 Shortly afterwards they reached places more distant still, even the coast of 

 France. Verbeek computes that 18 cubic kilometres — nearly twenty-five 

 thousand million cubic yards — of solids, and more of gas, were ejected. The 

 steam cloud rose to the height of 11,000 metres (nearly seven miles) even 

 on 20th May, when the eruption was trifKng, and probably to the height of 

 20,000 (over thirteen miles) on the 27th. But naturally enough, nobody in 

 the vicinity on that exciting day was sufficiently calm to note with accuracy 

 snch phenomena. Before the eruption the Island of Krakatoa contained 

 83-| square kilometres (nearly thirteen square miles), now it contains only 

 10^- square kilometres, that is, less than one-third of the old area. It 

 consisted of three large peaks, one of which was 2,500 feet high ; the two 

 smaller of these and a cleanly-cut half of the largest one have disappeared 

 entirely, and the sea over the place where they were is now over 1,000 feet 

 deep. The whole neighbourhood is changed. One island, Poelsche Hoedje, 

 has vanished entirely. Others are trebled hi size. Within a radius of 

 15 kilometres (say nine miles) the ashes are 20 to 40 inches deep, and an 

 area as large as Germany, Holland, and Belgium put together is covered to 

 a less extent. A locality subject to visitations of this kind, with sixteen 

 active volcanoes, some of them 12,000 feet high, and many more only quiet 

 for a time, is well called " The Lid of Hell," and after such a visitation to 

 any one part of the world, we need not wonder at all to see curious 

 meteorological phenomena as a consequence, even in very distant places. 



But, as I have already pointed out, this eruption of Krakatoa was by no 

 means the only outbreak through the earth's crust during last year. That 

 of Hecla on 26th March, and that of Alaska, were anything but insignificant. 

 The latter especially must have resulted in the throwing up of a vast 

 quantity of matter. The whole Alaskan peninsula was in volcanic activity, 



