162 COMPENDIUM OF GEOGRAPHY AND TKAYEL 



Of the former history of the volcano, geology tells us 

 something. The island of Krakatau and its satellites, 

 previous to the eruption, formed in reality only the lip 

 or edse of a crater, the wreck of some former volcanic 

 cone, which was probably not less than 10,000 or 12,000 

 feet high and 25 miles in circumference at its base. 

 That this great mountain must have been gradually built 

 up in comparatively modern times is evident from the 

 fact that beneath the mass of which its ruins are com- 

 posed there are deposits of post-Tertiary age, which in 

 turn rest on the widely distribvited Tertiary rocks so well 

 developed in Java and Sumatra. Subsequent to the 

 ancient eruption which destroyed this mountain, secondary 

 craters must at some time have formed within and around 

 the eviscerated cone, and the volcano was in this condition 

 when the great eruption of 1883 ensued. The only out- 

 burst previously recorded in history occurred in 1680, 

 when all the forests clothing the islands are said to have 

 been destroyed. 



On the morning of May 20th, 1883, the dormant 

 volcano again woke suddenly to life. The explosions 

 were sufficiently violent to be heard at Batavia, 100 

 miles distant, where dust fell on the following day, and 

 the officers of a German man-of-war in the vicinity 

 estimated the height of the column of matter vomited 

 forth as over 36,000 feet. Considerable as the dis- 

 turbance must have been, it does not appear to have 

 been attended with any very injurious results, and 

 although the eruption lasted without intermission until 

 the appalling finale on August 26th and 27th, it steadily 

 decreased in violence until tlie end of June. Pleasure- 

 parties were even arranged in Batavia to visit the island, 

 and photographs were taken of the scene. Towards the 

 beginning of July an exacerbation of the phenomena 



