Mathematical and Geological Papers. 45 



while the appalling detonation in that forenoon and the greater 

 wave accompanying it resulted, perhaps, from that still more 

 titanic effort which lifted the greater portion of Krakatoa — 

 several thousand million cubic yards of material — out of its 

 170-fathom root, hurled it through the air over Lang Island, 

 and plunged it into the sea some seven miles to the northeast, 

 where Calmeyer Island now blocks the channel, which marines 

 have known so long as East Passage, ... To what height 

 the supreme outburst propelled the smoke, dust, and the lighter 

 portion of matter, it is impossible at present to estimate. Mr. 

 Whymper saw Cotapaxi, in by no means one of its extraordi- 

 nary expirations, eject a column over 20,000 feet in height; 

 but many multiples of this distance will doubtless be required 

 to measure the spire that was shot skyward on the afternoon of 

 August 27 last. At least it rose so high that months have been 

 required for it to descend." — Popular Science Monthly, vol. 

 25, pp. 373, 374, 375. 



In speaking of the eruption of Krakatoa, Johnson's Mineral 

 Encyclopedia (vol. V, p. 26) says: "The eruption began in 

 May (1883) and continued till August 27, when a large part 

 of the island was blown away and fragments of pumice and 

 dust thrown to a height, by estimate, of twenty miles. Gaining 

 the region of the upper air currents, the dust was carried 

 around the entire earth, and produced wonderful twilight 

 glows for many months. The sound of the explosion was heard 

 at a distance of 2247 miles. The waves produced in the air 

 traveled four and one-half times around the world. Sea waves 

 fifty feet high swept the neighboring shores, and similar waves 

 were observed on distant coasts over half of the globe. One 

 hundred sixty-three villages were destroyed and 36,380 human 

 beings perished." 



Could not the discreet particles forming Saturn's rings have 

 been hurled into space from the planet in some tremendous 

 volcanic cataclysm in the same way as Krakatoa hurled her dust 

 particles beyond the upper region of our atmosphere, so that 

 it took it two years to return to the earth again. If such oc- 

 curred, the rings would, of course, be distant from the planet 

 in proportion to the immensity of the eruption that hurled the 

 particles of the respective rings into space ; and if hurled far 

 enough into space, gravity and counter forces would prevent 

 them from returning to Saturn. The motion of the planet 



