TRANSACTIONS OF SECTION C. 663 



suites. The acidulous water spreads over the floor, rapid evaporation takes place, 

 the calcite or carbonaceous residuum forming loose granular tula or sinter, which 

 slowly indurates in the form of compact travertine of variable depths. 



Calc-Spar. — Found in abundance, tons of it having been removed by dynamite 

 while levelling obstructions and battering doorways through intervening walls. The 

 crystals are of the usual rhomboidal form. 



Cucumbe7-s.— Oblong convoluted objects found in the Coral Spring, and origi- 

 nating from nuclei. 



Pga,.fo.— Mechanical formation similar to the above, but differing in size and 

 probably in material. 



The collection of objects and photographs is sufficiently large toconvey a fan- 

 idea of the several growths found in the caverns, and the characteristic appearance 

 of the same in situ. 



The writer's memoir on this subject embraces a vast amount of information on 

 the early or incipient growth of stalactites, some of which is believed to be \yholly 

 original. He is also engaged in studying the ratio of stalagmitic growth in the 

 Atlantic coast caverns. The result now obtained shows that the vertical growth 

 of stalagmite is one inch in forty years. The growth of stalactites is nearly twice 

 as fast, or one inch in twenty years. The glasses exhibited show the following :— 



(1) The small glass, two years' deposit of carbonate under a medium drip. 



(2) The goblet, three years' deposit under a constant, heavily-impregnated cal- 

 careous drip. 



The caverns embrace a circuit of seven miles. 



The specimens exhibited to the British Association for the Advancement of 

 Science are the products of Luray and Weyer's caves. The polished sections are 

 from Luray. They consist of stalagmites and stalactites— primary, compound, and 

 drapery. 



7. Report on the rate of Erosion of tie Sea Coasts of England and Wales. 



See Appendix, p. 802. 



MOJV^DAT, SEPTEMBER 10. 

 The following Papers and Eeports were read : — 

 1. The Volcanoes of the Two Sicilies. By Tempest Andeeson, M.D., B.Se. 



The author has recently visited the volcanoes of Naples, the Lipari Islands and 

 Sicilv, including Vesuvius, Stromboli, Vulcano, and ^Etna, and taken photographa 

 of their craters and some of their lava streams, and other most important parts, in 

 order to obtain a record of their present condition which may be available for 

 comparison in case of future eruptions. Some of these photographs were shown as 

 projections on a screen by means of a lime-light lantern. 



The summit of Vesuvius presents a sort of plain, consisting of the lava of 1872, 

 in the north-eastern portion of which is the great crater excavated by the eruption 

 of 1885, now nearly filled up by matters ejected since that time. A small secondary 

 crater on the north-east part of its floor emits white vapour and occasional showers 

 of red-hot pasty lava. An instantaneous photo of one of these explosions showed 

 many of these up in the air. 



DiUerent lava streams exhibit different characteristics. The lava of 1872 was 

 very quick flowing. Its surface is covered with angular masses of scorise with 

 sharp edges, and it is still devoid of vegetation. 



On the other hand, that of 1858 was pasty and slow moving. Its surface pre- 

 sents rounded bosses with curious contortions, almost like great coils of ropes. It 

 is now beginning to weather and support a few tufts of vegetation. 



The island of Stromboli, one of the Lipari Islands, consists of a great volcanic 



