THE 



GEOLOGICAL MAGAZINE 



VOLUME LVII. 



No. X.— OCTOBER, 1920. ^^^20 ]g20 



EDITORIAL NOTES/'°''^'*^"-^ 



AT this season of the year the conduct of the Geological Magazine 

 is beset with peculiar difficulties. Owing to the holidays our 

 contributors are scattered far and wide, letters have to be re-addressed 

 often more than once, and the return of proofs is unavoidably 

 delayed. Owing to distance from libraries, also, it is often impossible 

 for either author or editor to verify references, or to keep in touch 

 with the latest developments of any subject. Furthermore, the 

 supply of reviews tends to fall ofi. Another great drawback to the 

 holiday season is the impossibility of collecting information of recent 

 events of personal interest in the geological world. The Editors 

 take this opportunity of saying that they are always grateful for 

 news of new appointments to geological posts at home and abroad, 

 and other similar matters of interest to the geological world. Our 

 readers will be able to judge for themselves as to the kind of thing 

 that is wanted. Any help in the communication of such items will 

 be gratefully received. It may perhaps be permissible to mention 

 here one other matter of a quasi-editorial nature. Those of our 

 contributors who desire separate copies of their papers or other 

 communications should make a point of sending their orders for 

 the same to the Editor along with their corrected proof. From 

 motives of business economy it is necessary to break up the type 

 almost immediately after the issue is printed off, and unless orders 

 are received before we go to press separate copies cannot be 

 guaranteed. 



****** 



Messrs. W. Hefper & Son, Ltd., Cambridge, have in the 

 press a book entitled Notes on Geological Map-Reading, with forty 

 illustrations, by Alfred Harker, LL.D., F.R.S., F.G.S., Fellow of 

 St. John's College, and Reader in Petrology in the University of 

 Cambridge. Probable price, 3s. 6d. net. The object of these notes 

 is to teach the student to visualize a geological map as in three 

 dimensions, and to show him that the questions which present 

 themselves to the field-geologist reduce to exercises in very 

 elementary geometry. This simplicity is gained by reckoning all 

 slopes and dips as gradients, which enables one to dispense alike 

 with trigonometry and with the protractor. The amount of dip, 

 the thickness of a formation, the throw of a fault, etc., are thus 

 measured directly upon a contoured geological map by the use of the 

 scale alone. 



VOL. LVII. — NO. X. 28 



