Reviews — Geology of East Anglia. 37 



additional buildings to tlie New Museum and Colleges at Cam- 

 bridge. 



We are glad to find the author recognizes the value of microscopical 

 research as partly essential to the determination of the composition 

 of igneous and other rocks, and to which attention has been so well 

 directed by the labours of Prof. Zirkel and Mr. D. Forbes ; and we 

 think that additional illustrations under this head, instead of one 

 only, would have enhanced the utility of this acceptable volume. 



IL — Geologt of East Anglia. 



IN the Geological Magazine for July attention was called to the 

 25th volume of the Monographs of the Paleeontographical 

 Society, issued for 1871, and to a Memoir on the Geology of East 

 Anglia, accompanied by a Map, prepared by Mr. S. V. Wood, jun., 

 and Mr. F. W. Harmer, which formed an introduction to the first 

 part of the Supplement to the Crag Mollusca by Mr. Wood, sen. 



This memoir deserves . a more special notice on account of the 

 coloured geological map, which is by far the most elaborate one ever 

 published on this area. 



All of our readers may not be aware of the immense amount of 

 labour and time which Mr. Wood and his coadjutor Mr. Harmer have 

 devoted to the working out and classification of the Drift deposits of 

 the East of England. Not content with merely visiting the principal 

 sections in the country, they have actually surveyed on the one-inch 

 Ordnance map the greater part of the geology of Norfolk, Sufl"olk, 

 and Essex, and often with a detail which equals in minuteness some 

 of our most elaborate Government Survey Maps. The Geological 

 maps of parts of Essex, and the memoir on the Glacial and Post- 

 Glacial beds of the South and East of England, which a few years 

 ago Mr. Wood deposited in the Library of the Geological Society of 

 London, alone exhibit a vast amount of patient labour and field 

 work, which not many amateur geologists have equalled. In early 

 times, De la Beche and Logan did a large amount of private field- 

 work in the West of England and South Wales, and more recently 

 Mr. William Sanders published his large maps on the scale of four 

 inches to one mile of the Bristol Coal-fields. Such detailed labours, 

 demanding of necessity much uninteresting but necessary work, will 

 be lasting monuments to the honour of its authors. 



In 1865 Mr. Wood privately printed and circulated a little map 

 of the Upper Tertiaries of the whole of the Eastern Counties, accom- 

 panied by an explanatory memoir, which showed the general 

 extent of the Drift deposits. The present map takes in the country 

 east of a line drawn between Holt in Norfolk and Ipswich, and it 

 extends as far south as Walton-on-the-Naze. It thus takes in the 

 whole of the Crag country which it is intended mainly to illustrate. 

 It has been reduced from the Ordnance Survey maps to a scale of 

 four miles to the inch, and is accompanied by twenty-one coloured 

 horizontal sections and twenty-two vertical ones. 



