February 20, 191 3] 



NATURE 



671 



Heredity. By J. Arthur Thomson. Second 

 edition. Pp. xvi + 627. (London: John 

 Murray, 1912.) Price gs. net. 

 In the present edition of his book, the original 

 edition of which was reviewed in Nature for 

 August 20, igo8 (vol. Ixxviii., p. 361), Prof. 

 Thomson has included references to some of the 

 new discoveries that have been made in the last 

 five years in the branch of biology with which the 

 volume is concerned. 



An Elementary Historical Geography of the British 

 Isles. By M. S. Elliott. Pp. x+172. (London: 

 A. and C. Black, 1913.) Price is. 6d. 



This little book shows very convincingly how pro- 

 foundly the geography of a country can influence 

 its historv ; and it serves to demonstrate also the 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond ■with 

 the ■writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.'} 



Iceberg Melting. 



I HAVE pleasure in sending you a photograph of 

 the iceberg around which we obtained the isothermal 

 lines published in Nature of December 12, igia. I 

 did not make an instrumental survey of this berg, 

 but it was larger than the average of those met with 

 in the Strait of Belle Isle. We sighted more than 

 200 bergs during our trip, and made traces of many 

 of them. Invariably the temperature rose on the 

 approach to a berg. Sometimes a small fall of tem- 

 perature resulted abeam of the berg, but the rise of 



[.—Iceberg used for the purpose of studying the isothermal lines published in the issue of Natuke for Decembe 



necessity of a good knowledge of geography for 

 teachers of history. The volume may be recom- 

 mended as suitable for supplementary reading for 

 boys and girls in secondary schools who are study- 

 ing history or geography . The book is well illus- 

 trated and contains numerous helpful maps. 



The Interpretation of Radium. By F. Soddy. 



Third edition. Pp. xvi + 284. (London: John 



Murray, 1912.) Price 6s. net. 

 The general characters of this work were given 

 in the review of the first edition which appeared 

 in the issue of Nature of May 27, iqog (vol. Ixxx., 

 p. 368). In the present issue Mr. Soddy has 

 included the latest and most complete data avail- 

 able, and those new discoveries for which there 

 is trustworthy evidence. A new final chapter 

 upon the thorium and actinium series has been 

 ?ddod. 



NO. 2260, VOL. 90] 



temperature was the one characteristic effect. The 

 two other photographs [not reproduced] I send you 

 illustrate the fantastic shapes seen in ice. I wish it 

 were possible to furnish in some way an idea of the 

 wonderful colouring, but I am totally unable to do so. 

 In the "swimming moose" you can see the danger- 

 ous overhanging ridge, which is caused by the under- 

 water melting and the lapping of the warmer water 

 waves against the ice. This ridge is always found in 

 here's which have not recently turned over. In the 

 records which Mr. King was able to get for me in 

 1910, besides the rise of temperature, a fall of tem- 

 perature was obtained, when the ship approached the 

 various icebergs, with the exception of one. These 

 bergs were all floating in the main arctic current off 

 the eastern coast of Labrador. In the light of my 

 recent work I feel sure that the drop in temperature 

 was due to the influence of the cold current in which 

 the iceberg w^as floating. These cold currents exist in 

 the main arctic current, whether ice is present or rut, 

 but the effect of the presence of the ice is to elevate 

 the temperature slightly. 



