Meeson. — On the recent Sun-glows. 373 



28th August. Earthquakes in West Australia and Tasmania. 



29th August. Earthquakes in New South Wales and Tasmania. 



30th August. Earthquakes in New South Wales and Queensland. 



20th September. Earthquakes in New South Wales. 



8th October. Eruptions in Iceland. 



10th October. Last eruption of Krakatoa. 



11th October. Earthquakes in California. Eruptions in Alaska. 



15th October. Earthquakes in the Levant and Asia Minor, 200 

 perished. 



22nd October. Earthquake in Lisbon. 

 It is indeed, though very incomplete doubtless, a formidable list, and 

 since Christmas almost up to date, the volcanic activity has been continued. 

 Ischia and Alaska have again suffered, and even steady Old England has 

 felt the effect of internal fire, or shrinking, or whatever may cause earth- 

 quakes — having experienced a severe shock in the neighbourhood of Col- 

 chester. 



But of all these outbreaks that at Krakatoa was by far the most formid- 

 able and gigantic. Professor Verbeek, who was at the head of the Com- 

 mittee of Enquiry appointed by the Dutch Government at Batavia to 

 investigate on the spot the causes, features, and effects of the eruption, has 

 already sent in a long report, a translation of which appeared in " Nature " of 

 1st May ; it is a most complete and interesting account. Even a synopsis 

 of it, however, would be too long for me to give to-night. I must content 

 myself with mentioning a few of the particulars and estimates given, 

 mainly with the view of showing the magnitude of the operations. 



It appears that there is a rent in the earth across the Straits of Sunda, 

 and that a slight pressure on the molten matter beneath the crust, or the 

 entrance of salt water causing the generation of steam, produced the 

 explosion. The Professor naturally thinks that the simultaneous occurrence 

 of earthquakes in Australia indicates a very large area of operations. The 

 activity of Krakatoa really began in May, 1883, but culminated on Monday, 

 27th August, at 5 minutes past 10 a.m., in an explosion so terrific that 

 the noise of it was heard in Ceylon, at Perth in Western Australia (1,800 

 miles away), and even at Diego Garcia, near Mauritius, 3,000 miles away ; 

 in fact over nearly one-fourth of the earth's circumference. Seven or eight 

 air-waves were also formed in all directions — -violent throbbings of the 

 entire atmosphere of the world — ■producing effects like those of earthquakes. 

 Even at Pasoeroean 830 kilometres (say 520 miles) distant, walls were rent 

 by these jerks in the air, which were very quickly communicated and— being 

 registered at places so wide apart as Batavia, Wellington, Dunedin, Mel- 

 bourne, St. Petersburg, and London — they form, as it were, a register of the 



