168 Reviews — A. Strahan — Geology of Purheck ^ Weymouth. 



Quite recently also five new sheets of this district, based upon 

 a new series of Oi'dnance Survey maps, have been issued coloured 

 geologically ; and thus both the topography and geology of the 

 district have been rectified and brought up to date. Manuscript 

 copies of the original six-inch working maps are to be seen at the 

 Museum of Practical Geology. 



So far as the Jurassic portion of this work is concerned, it is 

 to a considerable extent a reissue of that part of Mr. H. B. 

 Woodward's memoir on the Middle and Upper Jurassic rocks of 

 England (vol. v of the "Jurassic Rocks of Britain ") relating to this 

 district. Mr. Woodward's work was reviewed in the Geological 

 Magazine for 1896,^ when we had occasion to comment unfavour- 

 ably on the printing of some of the illustrations. Mr. Strahan 

 has been more fortunate in having his memoir on the Isle of 

 Purbeck better treated by the Stationery Office, so that the same 

 figures of Jurassic fossils, which were so indistinctly printed 

 in Mr. Woodward's memoir, come out much better in the Isle 

 of Purbeck memoir, and this remark also applies to other 

 illustrations repeated from Mr. Woodward's book. The new 

 illustrations in Mr. Strahan's work (many of them being prints 

 from photogravures) and the folding plates with coloured sections 

 are exceedingly good. But, then, we must bear in mind that 

 the price of this memoir, containing 278 pages, is 10s. Qd., as 

 against 7s. %d. for vol. v of the " Jurassic Eocks of Britain," with 

 its 449 pages. 



We quite agree with the author that the district under 

 consideration includes a length of coast which is hardly surpassed 

 in interest in any other part of England. This interest may be 

 said to culminate in the various coves, etc., about Lulworth, 

 " which furnish an example of coast erosion that cannot easily 

 be matched elsewhere." Stair Hole and Lulworth Cove are 

 illustrated by the frontispiece, which has been reproduced from 

 a photograph by Mr. Mason Good. Geologists are to be con- 

 gratulated that this piece of coast is dissected by the sea in such 

 a manner as to display stratigraphical features of the utmost 

 importance — Alpine sections, one might almost say, in miniature. 

 A few aeons further back in time the progress of erosion would 

 not have been sufficiently advanced to show these things well : 

 a few aeons later, if there are no material alterations in the level, 

 and most of the phenomena in connection with the Isle of Purbeck 

 disturbance at Lulworth will have disappeared, whilst the sea 

 will merely wash cliffs of chalk having a dip of a few degrees 

 to the northwards. 



Under the heading of Purbeck Beds a considerable amount of 

 fresh matter is introduced, though the chapter on Organic Eemains 

 is mainly derived from Mr. Woodward's memoir, with the same 

 figures of fossils somewhat better printed. A similar remark 

 applies also to such cuts as the diagram-section of part of Stair 

 Hole, the silicified mass of Purbeck wood at Portisham, and others. 



1 Dec. IV, Vol. Ill, p. 129. 



