November ^tJi, 1 go 2?^ PROCEEDINGS. v 



particularly as the core of such mountains must be very hot, 

 these vents act almost like warm chimneys and produce an 

 upward draught which assists the already highly heated steam 

 to escape. Should such a vent get closed, then most probably 

 the superheated steam would be capable of exerting sufficient 

 pressure to burst out at the base of the mountain. It is also 

 possible that the gradual adjustment of the internal temperature 

 may cause the mountain crust to crack through its old vent, 

 through which the old activity would recommence. 



Amongst the specimens of boiler scale shewn is one mound 

 cut in two. At one time the vent reached from the boiler plate 

 to the surface ; for some reason, possibly because of less heavy 

 firing, scale has closed the vent, but should the firing have 

 increased again, doubtless the whole mound would have been 

 blown off the plate. 



Some of the samples have been photographed. Ng. i is a 

 front view of a group of three high -peaked volcanoes and one 

 mound (at the left front) whose vent is closed, but all four vents 

 can be seen in Fig. 2, which is a view of the under side. The 

 lower edge of Fig. i corresponds to the top edge of Fig. 2. 



The President read a paper " On the Adventitious 

 Vegetation of the Sandhills of St. Anne's-on-the-Sea." 



General Meeting, November 4th, 1902. 



Charles Bailey, M.Sc, F.L.S., President, in the Chair. 



Mr. Joseph Egerton Leigh, Didsbury ; Mr. Henry 

 Wentworth Bradley, Wilmslow ; and Mr. Dugald Clerk, 

 M.Inst.C.E., F.C.S., London, were elected ordinary members 

 of the Society. 



