G. P. Scrope on Craters, and the Liquidily of Lavas. 357 
Fig. 1.— Outline-sketch of Vesuvius as it existed in 1756. 
the outer and inner cones before this eruption, and the space be- 
tween them and the firm outline represents the amount by which 
ne cone was in the intervening ten years augmented in bulk 
and height by the ejectamenta of that eruption. An interval of 
Comparative tranquillity followed, until, in 1794, the paroxysmal 
Fig. 2.—~— Outline-sketch of Vesuvius as it appeared in October, 1767; with dotted out- 
lines of its form in July ond io May of the same year. 
€tuption occurred, described by Breislak, which completely | 
ted this cone, then solid, rere its height, and left acraterof 
ag size bored through its axis. Later eruptions, e: ial, | 
t of 1813, not ripe filled up this vast cavity with their 
e tio’ 
ity u this plain, and streams of lava 
Tom them down r outer 
Un be 
