146 AET. 3. — B. KOTO: 



ix. The Spatter Eruptions and the Formation of Domes.— The writer 

 will say a few words on what he calls the spatter eruptions, a 

 sort of Strombolian type, at the main vent of Yuno-hira on the 

 western slope (Text-fig. 19, No. 2)— a scene described by Azunia^^ 

 on January 22nd.^^ It was the actual scene on the 11th day after 

 the first eruption. The crater pit was wide open and choked 

 up with black vesiculatcd crust. A rent suddenly opened at one 

 spot, and no sooner did the red tongue appear therefrom than a 

 tremendous cannonading took place. Then a black curdy smoke 

 (dust cloud) ascended, throwing up black lustrous fragments of 

 fl.oating crust to a considerable height, which mostly fell again to 

 the crater-bottom. The act was finished by emission of white 

 (salmiac) fumes. After o or 4 minutes the same manifestation 

 was repeated at another spot within the same crater. 



These spatter eruptions explain all the phenomena, seen from 

 a distance, of the volcanic display since the 13th of January, and 

 the writer believes this is the jKittcrn of activity of the volcanoes of 

 andesitic magma. 



The above-mentioned Yuno-hira vent^^ also presents some 

 remarkable features of uncommon interest. The venthole is of 

 large dimensions, having really a claim to be named a crater. It 

 is the main orifice which supplied nearly all the lavas of the 



1) K. Azuma, 'The Great Eruptions at Salau-a-jima in 191i,' Kagosliima, 1914, p. 92. 

 (Japanese) 



2) See p. 87. 



3) The above is Azuma's account of an adventurous attempt in peeping into the interior 

 of the new active crater-pit No. 2 in Geologic Map and also Sketch-map, Fig. 19. This is a 

 valuable contribution to the present paper ; for, what he has done is exactly that which the 

 writer wished to have done. Azuma was the first who m.ide such an undertaking, which is 

 often attended with risk. One investigator was mortally wounded by falling hot blocks at the 

 cracking lava-front, and two others by unexpected explosions, one of them being the well-known 

 vulcanologist, F. A. Perret. We have a ' Eeport ' from the pen of the American vulcanologist. 

 • Eapporto preliminare sulla grande eruption del vulcano Sakurashima.' Zi'dschr, f. Vulkanologie, 

 Bd. I. p. 133 d. seq. 



