NO. 29 VOLCANOES AND CLIMATE ABBOT AND FOWLE 3 



of the English Channel. The noise of the explosion was heard as 

 far as the Island of Rodriguez, 3,000 miles away, and it is believed 

 that the noise was heard over an area of one-thirteenth the entire 

 surface of the globe. The air-waves caused were noted by meteor- 

 ological observers to have made seven complete passages of the 

 globe, four going out from the volcano to the antipodes, and three 

 in return. The cloud of dust sent up from the volcano was measured 

 on the day before the greatest explosion to be 17 miles high. For 

 many months thereafter a cloud of dust, which at the beginning was 

 believed to have an elevation of about 20 miles, and which after a 

 year had descended to 10 miles, surrounded the whole world. This 

 dust caused extraordinary sunset glows, and the increased length 

 of the twilight. Other effects from it will be noted later. 



It is obvious that the violence of the explosion of Krakatoa far 

 exceeded that of Mount Katmai, for no such reports of the noise of 

 the explosion have reached us in 19 12. On the other hand the 

 quantity of ash which fell at Kodiak Island, 100 miles from the 

 volcano of Mount Katmai, exceeded by many fold the quantity which 

 fell at similar distances from Krakatoa. According to Verbeek the 

 depth of the ashes at 100 miles from Krakatoa averaged less than 

 1 centimeter. 



In connection with their report of the extraordinary atmospheric 

 conditions which followed the Krakatoa eruption, the Krakatoa 

 Committee published accounts of various earlier periods of haziness 

 associated with great volcanic action. From these we glean the 

 following. 



In the year 1783 occurred the eruption of Asamayama, Japan, 

 stated to be the most frightful eruption on record. Immense rocks 

 were hurled in all directions, and towns and villages buried. One 

 stone said to be 264 feet by 120 feet fell into a river and looked like 

 an island. The (if possible) still more extraordinary eruption of 

 Skaptar Jokull in Iceland, also occurred in the same year beginning 

 near the end of May, and with the most violent eruptions on June 

 8 and 18. Arago records that the dry fog of 1783 commenced about 

 the same day, June 18, at places distant from each other, such as 

 Paris and Avignon, Turin, and Padua. It extended from the north 

 coast of Africa to Sweden, and lasted more than a month. The 

 lower air did not seem to be its vehicle for at some places the fog 

 came on with a south, at others with a north wind. Abundant rains 

 and the strongest winds did not dissipate it. In Languedoc its 

 density was such that the sun was not visible in the morning up to 



