8 



THE GEOLOGIST. 



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 our 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 procuring 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 understood before wells are sunk or reservoirs 

 made. To determine this is one of the especial 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 supply of 

 the metropolis. 



In the selection of building materials a most necessary enquiry 

 is "where can good, lasting building-stone be obtained?" 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 

 their mineralogical character as well as theii' chemical ingredients. 



