ON THE SHELL-BEARING DEPOSITS AT CLAVA, AND OTHER PLACES. 315 



that we generally find in the post-Tertiary shell-bearing clays. The 

 samples of sand are of a very uniform colour, and any little variation that 

 appears may have been caused by the black grains being lighter and 

 coming more to the surface than the white in one case than another. 



From the abrasions on the above samples of coal, there can be little 

 doubt that it belonged to the deposit. 



As no rubbing is noticed on any of the pieces of slag, and the fractured 

 edges appearing sharp, it is most likely that it got into the clay accidentally. 

 At the same time it is curious that it is met with in so many of the 

 samples both of the pits and bores. 



So far as I can judge from the samples of the clay and the average 

 proportion of stones and mud, also the paucity of the floatings, and the 

 entire absence of animal remains (with the exception of a small fragment 

 of shell embedded in a piece of Carboniferous shale), I have no doubt 

 whatever that the deposit is characteristic boulder-clay. 



The Volcanic Phenomena of Vesuvius and its Neighbourhood. — Report 

 of the Committee, consistinrj of Mr. H. Bauerman, Mr. F. W. 

 iluDLER, Mr. J. J. H. Teall, and Professor H. J. Johnston- 

 Lavis. (Brawn up hy Professor H. J. Johnston-Lavis.) 



Vesuvius. — Since the last report lava has continued to pour forth from 

 the top of the new lava-cone in the Atrio del Cavallo, sometimes in small 

 quantities, at others in considerable abundance. On no occasion, how- 

 ever, did the lava issue beyond the limits that it had reached in the years 

 1891-92. In fact, the whole of that eastern part of the Atrio known as the 

 Val d'Inferno has not been invaded at all by the new lava during or 

 since its issue in the spring of 1891. The consequence of this has been 

 that it has continued to pile itself up around the line of fissure by which 

 it issued, and still further add to the dimensions of the great lava-cone 

 that it had built up in the Atrio. So great has this cone become that it 

 constitutes a prominent feature in the outline of the volcano as seen from 

 Naples. The eminence of Somma is separated from Vesuvius by the 

 depression of the Atrio. This notch, so to speak, in the general outline 

 was terminated below by an almost horizontal line, which is now replaced 

 by an obtuse cone, so that many people speak of three summits to the 

 Vesuvian volcano. This is rather an exaggeration, for although the new 

 lava-cone is of very considerable dimensions, for the time occupied in its 

 growth, yet it cannot compare with that of the cone of Vesuvius on one 

 side or the ridge of Somma on the other. 



The whole of this new cone is entirely built up of lava, by far the 

 greater part being of the j^ahoehoe or corded type ; only now and then 

 during marked activity has there been produced any lava with a rugged 

 scoriaceous surface. The occasion was therefore a very valuable one to 

 determine the slope of such a lava-cone. This was done only normally to 

 the line of fissure by which the lava issued, and which makes the cone ter- 

 minate in an elongated ridge rather than in a point. Practically all these 

 clinometric observations, which were taken with great care, gave angles 

 Aarying from 13° to 15°. 



Comparing this angle with that of .such mountains as Etna or 

 Mauna Loa, we must consider that both are composite cones, have experi- 

 enced many disturbing influences such as the formation of parasitic erup- 



