April 8, 1909] 



NA TURE 



157 



LETTERS TO THE EDITOR. 

 [The Editoi 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 anonytnous communications .] 



" Structural Geography." 



I MUST thank the reviewer of my " Structural Geo- 

 graphy " in Nature of March ii for pointing out the 

 accidental omission in printing of the red line that should 

 have occurred over the course of the Apennines (Plate 

 XV'l.). If he thinlcs that Fig. 97 is really likely to hurt 

 the feelings of the Polynesians, I may replace it by one 

 with a more pleasing expression ; but the other suggestions 

 for the improvement of any possible second edition, which 

 Jill nearly three columns of Nature, I cannot accept. 

 Thus the use of isobaths instead of actual figures on Figs. 

 37 and 38 would obscure the lessons those figures were 

 inserted to teach. Where, as on Fig. 41, isobaths seemed 

 anore useful, they were used. 



The " strange blunder " in the figures on pp. 84 and 

 85 exists only in my critic's imagination. In both 

 diagrams the wind is correctly shown as blowing at a 

 (ow level out of the high-pressure area, and not into it. 

 This movement, of course, requires the replacement of the 

 air by a high-level inflow, and that is also indicated on 

 tile diagrams. In support of this well-known fact refer- 

 ence may be given to a work on elementary physiography, 

 ivhich should be regarded as of authority by Nature. It 

 says, p. 326 : — " A barometer stands high . . . when in 

 any way an upper current sets in towards a given 

 area. ..." 



The reviewer remarks that it is not clear why certain 

 branches of the subject are omitted or merely mentioned. 

 That course was adopted deliberately. The object of the 

 book was to supplement existing text-books, and, as stated 

 in the preface, I omitted various " questions that are 

 adequately treated in current elementary text-books." 



My critic objects to the view that the Cotswold and 

 Chiltern Hills show the geographical grain of England, 

 as he says those hills are sculptural rather than structural ; 

 but the sculpturing in both cases has been determined by 

 and displays the structural grain of the country. 



The reviewer devotes most attention to Plate XVI., a 

 diagrammatic map of Europe. He complains that the 

 European plain is shown extending to County Clare, dis- 

 regarding the Welsh and Wicklow Hills; but his state- 

 ment is not correct. The name European plain is written 

 only across Germany and Russia, and the text states 

 (p. 132) that it is " the eastern extension of the eastern 

 plain of England." The site of the Wicklow Hills is left 

 white, and the boundaries of the English and Irish plains 

 are not marked, for they were not needed for the map 

 and were left unelaborated. No intelligent student is likely 

 to include all the area left white in that map, including the 

 Bay of Biscay, the Atlantic Ocean, &c., as belonging to 

 the European plain. 



Objection is also taken to the reference in that map to 

 the Scottish Highlands and Scandinavia as parts of an 

 Archaean plateau ; but that they belong to a dissected 

 plateau is explained in reference to Scotland on p. 105, 

 and illustrated by a photograph (Plate XIII.), which, as 

 the credit is due only to the photographer and the pub- 

 lishers, I may say is excellent. Then follows an objection 

 to the Armorican and Variscan Mountains being differently 

 coloured from the Central Plateau of France. That 

 plateau has such a different geographical history that 

 I think it is advisable to indicate its special importance 

 by a different shade. The reviewer quotes the new Geo- 

 logical Survey map of France and some borings to confirm 

 the connection of the Central Plateau and the Armorican 

 Mountains. He might also have quoted the text of the 

 book under review (p. 133) : — " The southern border [of 

 the Armorican Mountains] was to the south of Brittany 

 and extended through the Vendue into that mass of old 

 rocks known as the Central Plateau of France." The 

 reviewer also attacks the representation of Spain on this 



NO. 2058, VOL. 80] 



map. It shows the essential feature in the Spanish 

 Peninsula, which 1 still think it was desirable to show, 

 viz. the divergence of strike between the mountains south 

 of the Guadalquivir fault and that of the western Meseta. 

 The .-isturian nest and its " confocal parabolic curves " 

 would not have made for clearness. His severest criticism 

 of this map of Europe relates to Asia Minor. He notes 

 one difference between the representation of Asia Minor on 

 the maps of Europe and Asia. He could have noted 

 others, for on the map of Europe no attempt was made 

 to show the structure of .Asia Minor, as it was included 

 more suitably in the map of Asia (Plate XIX.), which 

 includes both Naumann's Pontic and Tauric Mountains. 

 ('Ihe reviewer refers to Naumann's paper in the Geo- 

 graphische Zeitschrift, 1896 ; anyone interested in the 

 question will find a simpler statement of that author's 

 view, in English, in his paper before the Geographical 

 Congress of 1895, Report, 1896, pp. 662-8.) These 

 features were omitted from Asia Minor on the map of 

 Europe ; all that was inserted there was a dotted line to 

 show both the continuation of the Cyprus branch of the 

 Tauric line and its passage into the mountain knot south 

 of the Caucasus. The line would no doubt have been 

 better if, as in the map of Asia, the curve at its eastern 

 end had been somewhat sharper. 



In the explanation of Fig. 83 it is pointed out that 

 Japan is exaggerated in width, and a student may be 

 trusted to apply that remark to the sea beside Japan. 



My critic apparently doubts the Mongolian affinity of 

 the Eskimo. It is true that some authorities regard the 

 American aborigines as a distinct race-group from the 

 Mongolian, but there is ample authority for the other 

 view. The difference in opinion is indicated by the warn- 

 ing that the American Indians are " generally regarded " 

 as a Mongolian race. No doubt the Eskimo of Green- 

 land differs markedly from the typical Mongolian. Their 

 extreme dolichocephaly is one of the best-known facts in 

 American anthropology ; but as this character diminishes 

 to the west, the view that the Eskimo are a modified 

 variety of the American section of Mongolians is at least 

 reasonable. The Caucasian affinity of the Australian 

 aborigines seems to me better established, and the view 

 has been gaining ground since its first authoritative 

 advocacy by Dr. A. Russel Wallace, who justly claims 

 it as one of his chief contributions to science. 



The " so-called tetrahedral theory " has been growing 

 steadily into favour since 1899, when I happened to support 

 it in a lecture to the Geographical Society. Although its 

 advance has probably been hampered by my crude explana- 

 tions, I am quite satisfied with its progress, otherwise I 

 should not have included it in a text-book. It seems to me 

 quite unnecessary to refer to the earlier theories, though 

 perhaps my critic would have been less displeased if I had 

 referred to one later theory. 



One great difficulty in writing elementary text-books is 

 the necessity for a shortness that must often seem dog- 

 matic, and for unqualified statements that are therefore 

 liable to the charge of crudeness ; but, fortunately, one can 

 usually trust as safely to the common sense of students 

 and teachers as to the fair appreciation by critics of the 

 difficulty of presenting in brief statement and graphic 

 diagrams the complex and confused data that have to 

 be summarised in geographical text-books. 



J. W. Gregory. 



4 Park Quadrant, Glasgow, March 16. 



I FULLY acknowledge that the diagrams on pp. 84 and 85 

 are correct if taken by themselves, but in the explanatory 

 letterpress given below Fig. 57 it is stated that the dis- 

 tribution of pressure is " owing to the condensation of 

 the cooler air over the sea and the expansion of the 

 warmer air over the land." The necessary inference is 

 that the area over the land is one of low pressure and that 

 over the sea of high pressure, with the winds blowing into 

 the latter. On examination of the diagram I see that this 

 is opposed to the inference which may be drawn from the 

 course of the " level " of equal pressure, and hence I con- 

 clude that the error arises from a misprint, which may 

 be easily set right by transposing the words " sea " and 

 " land " in the statement I have put in italics. 



