New Geological Maps. 395 



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- 

 lurian divisions made in the slate rocks, by Mr. Murchison, in the 

 border districts of England and Wales ; and the new distribution 

 very recently assigned to the slate rocks of Devonshire and Corn- 

 wall. 



A great improvement also has been made by the substitution of an 

 entirely new Map of Wales and Siluria, founded on the Ordnance 

 surveys of those regions, of which no accurate physical map ex- 

 isted at the time of Mr. Greenough's first publication. Another 

 improvement in the execution consists in the union of linear shadows 

 with the colours representing the superficial extent of the strata. 

 The combined effects of these elements of expression, judiciously 

 employed, has been to exhibit, more distinctly, the subdivisions 

 of formations, without destroying the unity of the general mass to 

 which they belong. By the frequent introduction also of conven- 

 tional signs, and figures of reference, Mr. Greenough has produced 

 a more condensed assemblage of scientific information, of varied 

 kinds, than has been put together in any map of equal extent yet 

 published. Extreme attention has also been paid to the physical 

 features of the country, and in the orographic details more than 

 500 heights are given. The hydrographic features also are deli- 

 neated with scrupulous exactness. 



GEOLOGICAL MAP OF IRELAND. 



The last summer has witnessed the production of Mr. Griffith's 

 large and splendid Geological Map of Ireland, containing the results 



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. 



