PETRIFYING SPRING, &c. 14} 
weighed eight or ten pounds, the surface was 
cavernous, or excavated into pits of irregular shape 
and size, a powdery, though somewhat unctuous, 
substance covered the exterior, it had I believe, 
an external coating, and the general mass was dark 
grey colour within, but not shining. Allowing this 
to have been a meteorolite, it is the first that has 
been found in our neighbourhood, or perhaps in the 
the county, and though there is a want of natural 
evidence of a decisive kind to support Polwhele’s 
assertion, that volcanoes have been numerous in 
Devon, and that there have “ been a few (though 
not very destructive) earthquakes in former years, 
this meteorolite certainly takes its station as an 
indication of one of the more terrific agencies of 
Nature with which our county has been visited. 
There is yet one other illustration of recent 
geological operations to be included in this chapter, 
this consists of a petrifying spring at Hooe near 
Plymouth. Calcareous matter is so abundantly 
deposited from the water of this stream as to incrust 
most liberally substances which fall into it ; they 
acquire after a short time a beautiful white crystal- 
line envelope, and eventually become dense and 
stony. A great proportion of our springs appear 
to contain a large amount of calcareous matter, 
which thus renders the water “ hard” as it is termed, 
and which accumulates as every one knows, on the 
sides and bottoms of tea-kettles. | Although these 
springs are so often found to rise in slate rock, as 
indeed happens with that at Hooe, the water pro- 
bably in its rise encounters lime-rock, from whence 
_ these limy particles are derived. 
Throughout the whole series of epochs of the 
earth, atmospheric and other natural agencies have 
uninterruptedly exercised their powers in decompos- 
ing and converting into fragments the exposed 
surfaces of every description of rock. This has 
le 
