98 



NATURE 



\_Dcc. 2, i8So 



too, American writers are dismissed without notice, save a 

 passing allusion to F. A. Walker. Carey's theories are 

 occasionally referred to in connection with other names, 

 but no specific account is given of them, nor are other 

 American authors, orthodox or heterodox, better treated. 

 Even a general history ought not, one would think, to 

 have omitted notice of such writers as Lord Lauderdale 

 (whose treatment of Demand and of the Functions of 

 Capital has not received the attention it deserves), R. 

 Jones (whose essay on the Early English Economists 

 might also have been noted in its proper place), Jacob, 

 Stirling (the translator of Bastiat and author of an 

 excellent but well-nigh forgotten work, " Philosophy of 

 Commerce"), Bernhardi (the author of a remarkable 

 treatise on Large and Small Landed Properties), Hiibner, 

 H. Thornton, Baumstark, Skarbek, Cieskowski, Saint- 

 Chamans, Esmenard de Mazet, Louis Say, Schon, 

 Canard, and Cazeaux, Dureau de la Malle's work might 

 have been noted in connection with the political econ- 

 omy of the Romans, and De Tracy's name should not 

 have passed without reference to his commentary on 

 Montesquieu. 



The translation appears to us generally excellent, and 

 the translator, who is evidently well acquainted with the 

 subject, deserves much credit for the clear and concise 

 English into which she has rendered Prof. Cossa's work. 



0[/R BOOK SHELF 

 Avis j>rUiminaire d'une nouvclle Classification de la 

 Famille ties Dytiscida. Par D. Sharp. (Extrait des 

 Comptcs rcndits de la Soci^t<$ Entomologiqiie de Bel- 

 gique, Stance du 4 septembre, iSSo.) 

 Dr. Sharp is well known to have been long occupied on 

 a work on the water-beetles of the world (at any rate on 

 those of this particular family). The author announces 

 it as ready for the press, and has forwarded to the Belgian 

 Entomological Society a sketch of his ideas of the limits 

 of the family and its classification,from which we learn that 

 about 8b genera are recognised. One of the most important 

 characters, as separating true Dytiscida from Carahida 

 and from all other Colcoptcra, appears to consist of the con- 

 dition of the metathoracic episternum in connection with 

 the intermediate cotyloid cavities. The family as a whole 

 is divided into two great divisions, termed " fraomentati\ 

 and " complicati," the latter being headed by the anoma- 

 lous genus Atnpliizoa, the position assigned to which will 

 perhaps not find universal favour. No one can doubt 

 that the book, when it appears, will mark an era in this 

 department of entomology. It is a great pity therefore 

 that Dr. Sharp should tlirow himself open to the shafts 

 of ridicule in his choice of terms wherewith to designate 

 some of his new genera. We need only allude here to 

 such terms as Huxclhydrus (presumably a misprint foi 

 Huxleyhydr2is), Darwinhydrus, and Tyndalhydnts ! ! ! 

 We all revere the honoured names that form the prefixes, 

 and fail to realise the watery connection suggested ; if 

 we mistake not, the bearers of them are not disciples of 

 Sir'jjWilfrid Lawson. 



Aid to the Identification of Insects- Edited by Charle 

 Owen Waterhoiise. Lithographs by Edwin Wilson. 

 Small 4to, Part L (London : E. W. Janson, 35, Little 

 Russell Street, W.C.) 

 Mr. Waterhouse, whose duties in the zoological de- 

 partment of the British Museum have probably continu- 

 ally caused him to feel the want of some such work as 

 that which he now commences under the above title, has 

 conceived the idea of issuing, at intervals of a month or 

 six weeks, a series of hand-coloured drawings of insects 

 of all orders not previously figured. Every working 

 naturalist knows that a good pictorial representation con- 



veys a more accurate and ready perception of a species 

 than the most elaborate verbal description ; and we can 

 imagine no more reidy way of widely disseminating a 

 knowledge of the arcana of science than this. Each part 

 is to contain eight or nine plates, each representing a 

 single species, with its generic and specific names, the 

 name of its describer, and a reference to its locality and 

 place of description. The plates can be classified on the 

 completion of a volume (t^velve parts), when a title-page 

 and index will be issued. 



The first part, just issued, contains some well-executed 

 figures of Colcoptcra, Hcmiptcra, and Lepidoptera. The 

 whole idea is unconsciously a repetition of Prof. McCoy's 

 '• Prodromus of the Zoology of Victoria," but with no 

 Government money to back it up. 



LETTERS TO THE EDITOR 



{The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. A'either can he undertake to return, or 

 to correspond with the writers of, rejected ynanuscripts. No 

 notice is taken of anonytnoiis communications. '\ 

 The Editor urgently requests correspondents to keep their letters as 

 short as possible. The pressure ojt his space is so great that it 

 IS itnpossible othenuise to ensure the appearance even of com- 

 munications containing interesting and novel facts. ^ 

 Geological Climates 

 I n.WE read Avith much interest Mr. Starkie Gardner's letter 

 in Nature, vol. xxiii. p. 53. 



It is not necessary for me to discuss the question whether I 

 am right in requiring an increase of 20° F. mean annual tem- 

 perature at Bournemouth in Eocene times, or whether he is 

 right in demanding an increase of only 14° F. to 15°, for I am 

 able to show that the one increase is as impossible as the other, 

 on the principles held by Lyell and his followers. 



Mr. Starkie Gardner's ideas on the subject of oceanic circu- 

 lation and its effects upon climate are expressed in the following 

 words : — 



" The general cooling effect of incessant oceanic circulation 

 between the North Pole and the Tropics is, I think, scarcely 

 tal:en into sufficient account ; and although it may be contended 

 t'uat conversely the northerly flow of the Gulf Stream mitigates 

 climate, I think that its action in Europe is chiefly in fending 

 off the ice-laden currents from our coasts," &c., cS:c. 



This statement, to my mind, involves so complete a misappre- 

 hension not only of the physical causes of oceanic circulation, 

 but also of the whole problem of geological climate, that I shall 

 ask your permission to lay down a few elementary propositions 

 on the subject, which are capable of demonstration. 



1. The Gulf Stream of the North Atlantic, so far from 

 acting the part of a policeman in " fending oft " imaginary cold 

 water streams from the Polar regions, is the cause of their exis- 

 tence. If there were no Gulf Stream thci-e could be no Labrador 

 current of cold water running south. The same statement is 

 true of the KuroSiwo of the North Pacific, of the Brazilian 

 current of the South Atlantic, and of the Mozambique curren 

 of the Indian Ocean. 



2. If the globe were covered with water, or in the condition of 

 an archipelago pretty uniformly distributed, there would be no 

 exchange of currents between the Tropics and the Poles, and 

 consequently no effect upon climate. Within the Tropics there 

 would be a broad, slow current of ^varm \\ater moving from 

 east to west, and producing no effect upon climate. In the tem- 

 perate zones there would be in the northern hemisphere a feeble 

 interchange of south-westerly and north-easterly currents, and 

 in the southern hemisphere a similar interchange of north- 

 westerly and south-easterly currents, both incapable of affecting 

 climate to any sensible degree. 



3. If a north and south barrier be constructed to the westward 

 of a locality like the West of Europe ; such a barrier as North 

 and South America affords, a gulf stream is, at once, formed, and 

 a corresponding Labrador current running in the' opposite direc- 

 tion.i The effect of the Gulf Stream is to raise the temperature 

 of the West of Europe to its maximum, and the effect of the 

 Labrador current is to depress the temperature of the east coast 

 of North America to its nnnimum. 



4. It is impossible to suggest any rearrangement of land and 

 water which shall sensibly raise the temperature of the H'est of 



» The earth's rotation compel? the Gulf Stream to impinge on the west 

 coast of Europe, and the Polar current on the east coast of North America. 



