284 



REPORT 1889. 



occurred, followed by the oozing forth of some lava, which rapidly 

 developed into a stream, and by the time my apparatus was ready and in 

 position the crater plain was in part flooded quite close to my camera. 

 My porters abandoned me, and I proceeded to take two instantaneous 

 views. The intense heat, the constant attention to the advancing lava and 

 falling lava fragments, and the whirlwinds produced by the incandescent 

 lava, prevented me observing that a corner of my focussing cloth in part 

 covered the lens. The consequence was that only a corner of one plate 

 showed any picture, and only half of the other was exposed, which is much 



Fig. 1.— Diagram of the Summit of the Great Vesuvian Cone, Spring of 1887. 



a. Limit of the 1872 crater ; the dotted line represents the part covered hy over- 

 flows of lava at different times since ; the part a' a" is still uncovered, b, rem- 

 nants of crater ring of 1881-2 ; c, double crater of May 1886 divided by the 

 ridge m ; d, remnants of the base of the coue of eruption of 1S85-6 ; e, active 

 vent ; f, fissure across 1872, emitting acid vapours ; h, very ancient hot air 

 passages or fumaroles ; /, depression on site of the lateral "fissure of 1881-2 

 and May 1886. 



to be regretted, as the sight was a very fine one. The lava as it poured 

 forth from the opening gradually carried away the arched roof as this 

 sunk upon the pasty rock, so that the opening eventually became a deep 

 notch in the upper edge of the eruptive cone with the lava flowing along 

 its bottom — in fact, a diminutive baranco. The lava spread rapidly over 

 the crater (1872) plain, so that within half an hour the place I had stood 

 upon could not be approached by many yards. It divided into three 

 tongues : one overflowed the plain edge on to the S.S.E. slope of the 

 cone and descended for about thirty metres, another just overlapped the 



