226 



THE POPULAR SCIENCE MONTHLY, 



Volcanic conS- 



COMDVIT AND OVERI^Lg'*Vf.D *r THIS Lo/c ■ 





of the ash-bed ridge, it must be still underground and not dis- 

 coverable at present. It may be revealed to distant future ages, 

 but to us it is buried. But if the vent lay to the west of the 

 ridge, it may be discovered, not as the cone for which we looked 

 at first, but as a pipe or neck of lava. Indeed, it must in this 

 case be discoverable, for the lava and ashes must somewhere have 



risen from a deep subterranean 

 reservoir, through the country 

 rocks, up to the surface ; and if 

 their point of escape lie west of 

 the ash-bed ridge, it must be in 

 sight somewhere. We may not 

 now hope to find the cone where 

 the lavas rose and burst out 

 through the body of water in 

 which the muddy sandstones 

 were accumulating ; we can not 

 now hope to discover the crater 

 from which the ashes and bombs 

 were scattered far and wide, and 

 from whose flanks the lava-floods 

 were poured over the low grounds 

 around about it ; but we may 

 hope to find a knob or hill where 

 the lava -pipe has been worn 

 down to an undetermined depth beneath the surface on which 

 its cone was built. 



This seems to be the fact. Some ten miles southwest of Meri- 

 den lie the rugged Blue Hills, one of which is known as Mount 

 Carmel. These may be seen to the west of Wallingford, on the 

 railroad between New Haven and Hartford, or east of Mount 

 Carmel station on the New Haven and Northampton Railroad. 

 They consist of a network of thick necks and dikes of lava ; not 

 of loose texture like the ashes, not slaggy like the backs of the 

 lava-sheets, but dense and solid, as if they had been driven there 

 under great pressure. Mount Carmel and its fellows have not the 

 simple outline of the Zuni buttes; they are of irregular form, 

 corresponding to their complicated structure, as if a compound 

 fracture had been opened to give passage to the ascending lavas, 

 or as if repeated eruptions had forced their way surfaceward at 

 this point, every one increasing the size and complexity of the 

 lava pipes and cracks. There is no other vent of the kind to be 

 found so near to the ash-bed and lava ridges of the Meriden dis- 

 trict as Mount Carmel ; and while it is entirely possible that a 

 vent may exist at a less distance on the east, concealed beneath 

 the overlying strata in that direction, it is at least permissible 



Fig. 6. 



