226 REPORT— 1886. 



(iii.) The position of definiie groups of erratics in relation to each other. 

 For example, around Birmingliam and Bromsgrove the erratics are 

 chiefly "Welsh ; but a vast collectioB of Scotch and Lake erratics lies right 

 across the path the Welsh erratics must have taken. 



(iv.) The distribution of erratics in relation to the physical geography 

 of the district. — On the table-land north of Wolverhampton, Lake and 

 Scotch rocks are intermixed, the Scotch being abundant. Journeying 

 westward the intermixture becomes more complete. The stream of 

 Welsh erratics crosses the northern stream ; then the Welsh erratics be- 

 come more and more abundant, only a few northern stragglers being 

 found, until at Clent and Bromsgrove not a single erratic of granite has 

 yet been found among thousands of Welsh origin. 



Taking a line of country in another direction — between Wolverhamp- 

 ton and Stafford — cretaceous and Jurassic debris appears. The same 

 ■debris may be noted pushing itself around Coventry. 



(v.) The distribution of erratics in relation to the physical geography 

 of England and Wales. — The various Midland glacial deposits cannot be 

 understood apart from a careful examination of their relation to the 

 various levels of the plains, highlands, and mountains of the whole of the 

 surrounding country. 



Report of the Committee, consisting of Mr. H. Bauerman, Mr. 

 F. W. EuDLER, Mr. J. J. H. Teall, and Dr. Johnston-Lavis, for 

 the Investigation of the Volcanic Phenomena of Vesuvius and 

 its neighbourhood. Drawn tip by H. J. Johnston-Lavis, M.D., 

 F.G.S. (Secretary). 



During the last twelve months Vesuvius has shown slight variation from 

 the state of activity which it has exhibited during the past few years. 

 Lava has from time to time found fresh openings around the higher parts 

 of the crreat cone, and has flowed from them one after another, so that 

 the intervals of time during which no fluid rock was issuing were very 

 short. This regularity of action was, however, broken on June 28, when, 

 a lower outlet being formed on the eastern side of the great cone, the 

 consequent depression of the lava level in the main chimney resulted in 

 the crumbling in of the cone of eruption, which before this date bad 

 attained very considerable dimensions. During the whole month of July 

 the ash-forming stage prevailed, so that the usual continuous vapour and 

 lava-cake ejections were replaced by intermittent puffs of ash and sand- 

 laden vapour and accompanied by the ejection of stones. The craterial 

 cavity, which is double or bifurcated, which has been excavated within 

 the cone of eruption, is of very considerable size, being about 60x80 

 metres in diameter. The lava that issued during July, on two occasions 

 entirely ci'ossed the Val d'Inferno, and following one of the wooded 

 glens or ravines on the property of the Prince of Ottajano destroyed 

 a considerable number of trees. These different changes will be made 

 apparent by the photographs taken by the reporter and exhibited at 

 the meeting. 



In a paper read before the Royal Society the writer has given compara- 

 tive curves of the activity of Vesuvius, the barometric pressure, and the 



