Reviews — Enci/clopcedia Britannica. 567 



the deposits in the Sahara." We welcome these highly suggestive 

 ideas on speculative problems of geology, several examples of which 

 are scattered through the memoir. 



Chapter vi treats of faults, folds, and igneous intrusions, and 

 chapter vii of glacial deposits, which are fairly extensive. Their 

 importance may be judged from the following passage (p. 67, 

 1. 17) : "The Trent between Abbey Villas and the railway bridge 

 to the north flows in a shallow cutting, the surface of the water 

 being between 390 and 400 feet above o.d., or at a higher level than 

 the pre-glacial surface at the Hanley and Bucknall Collieries." 

 Here the drift is 81 feet thick, making the pre-glacial surface 

 366 feet above o.d. 



The chapter on the "Economic Eesources and Applied Geology" 

 is not the least important, but the section on the future of the 

 Coalfield is pregnant with interest. It is gratifying to know that 

 a rich field of coal still exists in North Staffordshire, although at 

 great depths. The Newstead boring, the journal of which is 

 generously made public by those for whom it was put down, shows 

 that the uppermost seam of the Middle Coal-measures was reached 

 at 1,946 ft. 7 in., from which it may be assumed that the Moss 

 coal is 3,400 feet and the Cockshead 4,800 feet, and between 

 these two seams ai-e all the best coal-seams and many ironstones. 

 It is therefore only a question of engineering to win them on 

 remunerative terms. 



We feel that this memoir merits unstinted praise, and it will be 

 valued by local geologists and mining men for its accurate details 

 and its thoughtful suggestions. W. Hind. 



II. — Supplement to the Encyclopedia Beitannica. 



The Encyclopedia Britannica, Supplement, is a work which 

 professes to supply the public with the very latest information on 

 those subjects of which it treats, and naturally excites the curiosity 

 of the man of science. And with this in view we have asked some 

 of our younger contributors to give our readers a few ideas on the 

 articles dealing with geological and palgeontological matters in 

 the Supplemental volumes of the Encyclopaedia Britannica, six 

 of which have been issued in the last few months. 



Arachnida, by E. Ray Lankester. More like a book than an 

 article, though one does not grumble at abundance of information. 

 A review of the group, and of considerable importance to geologists, 

 though there is nothing absolutely new palseontologically in the 

 article. 



Geology, by Sir Archibald Geikie. Compared with the last 

 article is very scrappy considering the importance of the subject. 

 Has a paragraph on zonal stratigraphy. Very curious. Still more 

 curious is the careful reference to Professor Lapworth's work on 

 the zones of the Silurian and Ordovician, and the absolute silence 

 concerning the more recent work on similar lines by Wheelton Hind 

 on the Carboniferous Limestone, by Buckman on the Inferior 

 Oolite, and by Dr. Eowe on the White Chalk. 



