8 
THE (iEOLOGIST. 
is coal enough yet to last for centuries, so that we need not feel any 
alarm on that head. Many fruitless attempts have been made in 
different parts of the country, to sink for coal where no one, with 
any knowledge of the nature of the surrounding Geological for- 
mations, would ever have dreamt of attempting it. If persons of 
competent authority had been consulted, no such errors could have 
been committed, and many thousands of pounds would have been 
saved. Formerly, perhaps, it might have been in some instances 
difficult to find an able practical Geologist at hand, but now no 
such excuse can be urged, since the Geological Government Survey 
has been established on purpose to decide questions of difficulty 
as they arise, and to employ the efficient means at their command 
for the benefit of the public. 
The phenomena of Springs is another important consideration, 
inasmuch as from them we derive oui* purest supply of water, 
the abundance and quality of which has everything to do 
with the sanitary condition of our large towns. Now, since the 
certainty of procui'ing a sufficient quantity of water depends upon 
the inclination and character of the various beds of sand, stone, 
or gravel through which the rain percolates, it is requisite that this 
should be correctly imderstood before wells are sunk or reservoirs 
made. To determine this is one of the es2)ecial and most 
serviceable labours of the Geologist. In illustration of this we 
may refer to an able paper by Mr. Prestwich, on the water-bearing 
strata in the London clay with reference to the water supjjly of 
the metropolis. 
In the selection of building materials a most necessaiy enquiry 
is "where can good, lasting building-stone be obtamed ?" The 
selection of the best for the purpose, is most essential, and can 
only be effected by a thorough knowledge of the structure and 
properties of the rock from which it is to be taken. Oxford is a 
memorial of the choice of a defective stone, and other instances 
of a similar kind might be mentioned. 
Of late years the application of geology to agriculture has assumed 
an importance it justly deserves, and as the productive or non- 
productive power of soils depends in most cases upon the different 
constituents of the rocks themselves, it is necessary to understand 
theii- mineralogical character as well as their chemical ingredients. 
