222 
ests of the Western counties, and are aware that the annual value 
of the mineral produce of Cornwall and Devon alone has recently 
amounted to 1,34.0,000/. 
In the chapter on (Economic Geology, which forms part of the 
Memoir connected with his Map of Cornwall and Devon, Mr. De 
la Beche has placed, in a more prominent light than has ever yet 
appeared, the bearing of. geological researches and mineral statistics 
upon political ceconomy; and proves, by tabular documents, the 
important fact, that the average value of the annual produce of the 
mines of the British Islands amounts to the enormous sum of 
20,000,0002.*, of which about §8,000,000/. arise from iron, and 
9,000,000/ from coal. 
Should this inquiry be extended through the endless departments 
of art, industry and commerce, which have their origin in the 
manufactories of metals, and in the power of steam, derived exclu- 
sively from the application of coal, the vast national importance of 
mineral statistics, and of models, maps and sections, on which alone 
their details can be effectually recorded, must be apparent to every 
one. 
Still more extensive will be the statistical and political importance 
of the next portion of this great work, now in progress by the same 
highly accomplished geologist, which is to comprehend the coal and 
iron districts of Monmouthshire and South Wales. 
_ GEOLOGICAL MAP OF ENGLAND. 
You have this day the satisfaction to see suspended in your meet- 
ing room a new edition of Mr. Greenough’s Geological Map of Eng- 
land, which has for many years formed the glory of this Society. 
It is truly gratifying to observe how small a change this new edi- 
tion exhibits, either in the general dispositions, which it represented 
nearly a quarter of a century ago, or in the complicated details of 
the boundaries of the different formations. Some alterations appear 
in the Greensand series, the Wealden, the Lias, and the New red 
Sandstone. The principal additions are the introduction of the Si- 
* See Geological Report on Devon and Cornwall, p. 624, and note, 1839. 
In this estimate the value of the copper is taken in the ore, before fusion ; 
that of the iron, lead, zinc, tin and silver, after fusion, in their first mar- 
ketable condition —as pigs, blocks and ingots. The coal is valued at 
the pit’s mouth, 
