Geological Society. 519 



revised by the author's son. The text itself here occupies 379 

 pages and is followed by an alphabetical index of terms explained and 

 by a Table of Contents. Then there is a collection of the most 

 important passages in which the present work differs from the 

 "1862 "text. This occupies pp. 384-396. Then the important 

 " .Notes " take up pp. 397-495. A full index completes the 

 volume. What is now wanted— as has been pointed out else- 

 where more than once we think — is a translation into English 

 which should render Grassmann's original views easily accessible 

 to a much larger circle of readers than exists at present. 



Graphical Calculas. By A. H. Barker, B.A., B.Sc. (Longmans, 



1896. Pp. viii + 188.) 

 Prof. Goodman, who furnishes a brief introduction, writes: — "I 

 have frequently had students come under my notice who, although 

 fairly good mathematicians as far as bookw"ork is concerned, yet 

 through not having had the advantage of a practical mathematical 

 training were utterly at sea when they came to apply their mathe- 

 matics to a simple engineering problem." It is Mr. Barker's object 

 in this book to help such a one to acquire an intelligent working 

 knowledge of the Calculus, and after a perusal of the major portion 

 of it we can endorse Prof. Goodman's commendations. The stu- 

 dent who carefully goes through all the constructions and keeps 

 in mind the author's injunction to aim at grasping the meaning 

 underlying all the symbols employed should be no mean proficient 

 in their use, and not one " who performs algebraical operations in 

 a haphazard fashion without making himself acquainted with the 

 principle involved." Besides a careful discussion of the principles 

 -and of the methods of differentiation and integration there are 

 numerous applications to practical questions. In an appendix 

 there is a figure and a description (given here for the first time) 

 of a Planiineter devised by Mr. Barker. We have detected very 

 few slips : on p. 5 it is not stated that the curve is a circle ; on 

 pp. 61, 133 + is given where the sign should be — ; on p. 96 the 

 value of e is slightly incorrect ; and on p. 156, ex. (1), there would 

 seem to be some slip. The type and the figures are good, but the 

 punctuation is defective. One little point the author might cor- 

 rect in subsequent editions, viz. the frequent statement "as will be 

 presently explained," and the like references to future chapters. 



LX. Proceedings of Learned Societies, 



GEOLOGICAL SOCIETY. 



[Continued from p. 147.] 



January 22nd, 1896.— Dr. Henry Woodward, F.R.S., President, 



in the Chair. 



r PHE following communications were read : — 



-■- 1. ' On the Speeton Series in Yorkshire and Lincolnshire.' By 



U. W. Lamplugh, Esq., F.G.S. 



Further work on the Speeton section, while extending our 



