C. G. Rockwood, J'.—Ischian Earthquake. 475 
line of cleavage, from whence come these manifestations of 
subterranean activity. He also traces another line similarly 
completely destroyed. 
In view of these facts L. Baldacci states his conclusions thus: 
“That the residual volcanic activity of the island is manifested 
along two principal fissures, one a curve with its convexity to 
the north, from the baths of Ischia to Forio, the other directed 
approximately north-northwest and south-southeast between 
Lacco Ameno and the stufas of Testaccio; and that the place 
where Casamicciola stood is upon the intersection of these two 
lines and, therefore, at the very focus of seismic activity and 
that it always has been and always will be the locality most 
liable to be devastated by earthquakes.” 
But other facts also point in the same direction. H. J. John- 
ston-Lavis has drawn the isoseismal lines about the focus and 
these isoseismal ellipses is nearly in the line of Baldacci’s north 
and south fissure. Johnston-Lavis states his conclusion thus: 
To conclude, then, it seems to be pretty clearly made out as 
probable, that this earthquake shock had its origin and cause 
in a rupture taking place along an old volcanic fissure, directed 
roughly north and south, and extending radially in or under 
