118 S. SEKIYA AND Y. KIKUCHl 



kilometres, was utterly turned 'topsy-turvy' and every land-mark ob- 

 literated. For this reason it was impossible to tell the real state of 

 things in that quarter. 



It is well known that at volcanic outbursts the immense volu- 

 mes of steam, suddenly expanding occupy a much larger space than 

 that of the original bulk. This sudden expansion cools the tem- 

 perature of the surrounding atmosphere and lowers its pressure. More- 

 over, the steam in part condenses. To fill the partial vacuum thus 

 produced, and to equilibrate the reduced pressure, there follows an 

 inward rush of air towards the crater. The strong 1 winds commonly 

 described as a feature of volcanic eruptions, are probably due to this 

 cause, and the same thing doubtless happened to a certain extent in 

 the case under discussion. But the fearful blasts that wrought such 

 havoc in the forests and villages on loth of July certainly were not 

 counter currents of this class, however strong these may have been. 

 It was the gusts from the volcano that in this instance wrought the 

 real havoc. 



A whirlwind is described as having occurred during the volcanic 

 eruption* in the Island of Sumbawa, in Java, on the 5th of April, 

 1815, when, soon after the ashes began to fall, a violent whirlwind 

 ensued, which blew down nearly every house of Sangir; it tore up by 

 the roots the largest trees, carrying them into the air, together with 

 men, horses, cattle, and whatsoever came within its influence. The 

 whirlwind lasted about an hour. It is not stated in this account, 

 however, how the whirlwind was caused. 

 Conical holes. Several visitors to Bandai, ascending from the south sides and 



approaching the summit, had their attention attracted by numbers 

 of curious conical basin-like hole.-, evidently the fruits of the late 

 eruption. Their size varied from "1 to 3 metres in diameter and from 



* Lyell's Principles of Geology, 12th Ed. Vol. II, p. 104. 



