MISCELLANEA. 
199 
Earthquake in the West Indies. — The very violent earth- 
quake which was recorded to have occurred early in the 
present year^ and was attended with such disastrous results, 
was, according to subsequent authorities, felt more or less 
violently throughout the whole volcanic range in that district. 
It is recorded to have been also felt in Spain and Hindostan. 
REVIEWS. 
Report on the Geology of the County of Londonderry, and of 
Parts of Tyrone and Fermanagh ; examined and described 
by Authority of the Master-General of the Ordnance, By 
J. E. Portlock, Esq., F.R.S. Longman and Co., 8vo. 
From Geological surveys we expect great results in every 
instance, not only in addition to our knowledge of the surface 
geology of the districts to which they relate, but the more 
minute particulars, calculated to advance the science — not 
merely the profession — although, as we have endeavoured to 
show on more than one occasion already, the value of this 
science is tested by its practical utility. All that we contend 
for is this — that an authorized geological survey should ex- 
hibit not merely the superficial extent of strata, but should 
be accompanied by the facts, calculated to add to the data of 
geological science, else a chart would be preferable to a book. 
In the work before us, we had certainly expected to find 
these two combined with more interest, and the occurrences 
explained with better reasoning than is the case. In fact 
this " government survey appears to us to add little more 
to our knowledge of Irish Geology than we already possess. 
