NATURE 



SJMay 31, 1877 



and from the equator to the poles — channels which will not 

 intersect or interfere with one another, except when affected by 

 disturbing causes. 



One possible cause of change in this direction of least resist- 

 ance or normal channel in the case of the south-west wind of 

 these latitudes may possibly be a shifting of the thermal pole. 

 Suppose, lor instance, we have any reason to surmise that the 

 centre of greatest cold is now on the American side of the true 

 North Pole and at another time on the Asiatic side, we have 

 at once a satisfactory explanation of observed variations in the 

 prevalent direction of the main channels of the water-laden 

 winds of the northern hemisphere. 



I will now as briefly as possible state my reasons for suspecting 

 that such is actually the case. 



Since 1873 the south-west winds have prevailed very consider- 

 ably over the average in Europe, and as a natural consequence 

 we have had continued floods all over the west of this continent. 

 In Asia, duiing the same period the water-laden winds have been 

 featfally under the average, the rainfall during the last three years 

 having been about nine inches below the average of the previous 

 half-dozen. Famines, of course, have been the result. 



If my theory is correct we should expect to find that the 

 thermal pole has been situated during the last three or four years 

 on our own side of the North Pole. 



Now in 1872 Capt. Hall, of the Polaris, saw unmistakable 

 signs of an open polar sea where Capt. Nares, in 1S75, saw 

 nothing but a vast wilderness of ancient ice. In a former letter 

 of mine which appeared in Nature (vol. xv. p. 116) I at- 

 tempted to reconcile these apparently conflicting observations on 

 the supposition that this pala;ocrysiic wilderness is in reality a 

 vast floatmg island of ice some hundreds of miles in diameter. 

 I called to mind Sir E. Parry's disappointing experiences in 

 1827 in the Htcla, when, after a toilsome journey northwards on 

 what he believed to be the main pack, he found he was after all 

 drilling southwards ; whereupon he concluded his supposed main 

 pack must be a loose floe of immense extent. 



Is it not equally probable, to say the least of it, that he was 

 on the main pack — on the palieoci-ystic island — and that he 

 caught it on the move towards our shores of the Arctic Sea? 



Be this as it may (and it is merely a suggestion) it is certain 

 that five years later occurred the terrible famine of 1832 in India, 

 and five years is just the time required, according to Dr. Hunter, 

 for the effects of the proximate cause of drought (whatever that 

 may be) to attain its maximum, according to the law of tiie 

 " multiplication of effects. " 



Although I have examined the records of the winds at the 

 Meteorological Office, I will add nothing more, as I fear I have 

 already exceeded my proper limits. 



Wordsworth Donisthorpe 



Yellow Crocuses 

 A LETTER in Nature (vol. xvi. p. 43) calls attention to the 

 destruction of the flowers of the yellow crocus by the sparrow. 

 I have for many years been a cidtivator of the crocus, both 

 yellow, white, and purple ; this spring they flowed abundantly, 

 the white and purple blooming undisturbed, the yellow picked 

 and torn. My gardener and I talked the matter over but could 

 find no solution of the problem. As this has been my expe- 

 rience in former years, and the fact is now corroborated by 

 general experience, can norraturalist discover the reason, or must 

 it still be left a secret in the bosom of pert little Frijigilla 

 domestica i A. II. 



Complementary Colours 

 In connection with this subject, which was referred to in Mr. 

 Terrill's letter in Nature for ^tay 17, perhaps the following 

 homely way of illustrating the fact that the combination of two 

 complementary colours produces white may interest your readers. 

 If a tumbler of beer be held in front of the green glass shade of 

 an ordinary reading lamp, it will be found on looking through 

 the beer at the shade that the tumbler appears to be filled with 

 an almost colourless liquid. J. Komilly Allen 



Chromatic Aberration of the Eye 



TliEiiE is a slight inaccuracy in your report of my communi- 

 calion of May 12th to the Physical Society, wherein I am made 

 to affirm that a blue object and a red object cannot both be in 

 focus at once unless the blue object be the more distant. The 

 next sentence of your report, and indeed the whole tenor of my 

 communication imply the reverse condition, that the blue rays 



should come from the less distant source. The dispersion of the 

 eye takes place in the same sense as its refraction ; hence the 

 adjustment of the eye to focus may be the same for blue rays 

 proceeding from a body near the eye as for red rays proceeding 

 fr'om an indefinitely distant luminous source ; as, indeed, Fraun- 

 liofer proved half a century ago. S. P. Tho.mpson 



University College, Bristol, May 25 



A Correction 

 Permit me to explain that the subject of my note, read at the 

 last meeting of the Astronomical Society, was not my chart of 

 324,912 stars, though I had occasion in the course of it to 

 mention that chart. My note referred in reality to a paper read 

 at the preceding meeting, and relating to the general subject of 

 the distribution of stars in space. Richard A. Proctor 



DR. PHILIP P. CARPENTER 

 '\'X /"E regret to announce the death at Montreal, in his 

 * ' fifty-eighth year, of Dr. Philip P. Carpenter, 

 formerly of Warrington, one of the most scientific con- 

 chologists of our lime. Taking up this pursuit, in the 

 first instance, merely as a recreative occupation, he was 

 led by his friend, Dr. J. E. Gray, who saw his remarkable 

 aptitude for it, to make it one of the principal objects 

 ot his hfe ; and he brought to it a mind trained in those 

 scientific habits which prevented him from ever becoming 

 the mere species-monger, whilst specially delighting in 

 that study of minute detail which is required for the 

 true determination of specific types and their geographi- 

 cal distribution. It was well observed by Dr. Hooker, 

 in his introductory essay to the " Flora of New Zea- 

 land," that "a wider range of knowledge and a greater 

 depth of study are required to prove those dissimilar 

 forms to be identical, which any superficial observer can 

 separate by words and a name ; " and this wide range of 

 knowledge and thoroughness of research were the essential 

 characteristics of all Dr. P. P. Carpenter's conchological 

 work. The opportunity having occurred to him more 

 than twenty-five years ago, while residing at Warrington, 

 of studying a la/ge collection of shells formed at Mazat- 

 lan, in California — after Mr. Cuming had selected from 

 it what he considered the new specific types, which he 

 caused to be described by Mr. C. B. Adams — Dr. P. P. 

 Carpenter v/as impressed with the fact that Mr. Cuming 

 had left behind him those iiiii-nnediatc forms, the study 

 of which would prove that many of his supposed species 

 are mere varieties ; and having brought the importance 

 of such study before the Zoological Section of the British 

 Association, he was requested to prepare a report 

 on the present state of our knowledge with regard 

 to the moUusca of the west coast of North America, 

 which was published in the Transactions of the Asso- 

 ciation for 1856, and at once took rank as a most 

 able and conscientious work. A Supplementary Re- 

 port on this subject, marked by the same "wide range 

 of knov/ledge and depth of study,'' was published in 1863. 

 Besides these, several monographs, prepared by Dr. P. P. 

 Carpenter on particular groups of sliells in the Cumin- 

 gian Museum, were published in the Zoological Pro- 

 ccedini^s. So high was the reputation which his Reports 

 acquired for him among American naturalists that he 

 was invited by Prof Henry of the Smithsonian Insti- 

 tution at Washington to assist him in the arrangement 

 of its national collection of shells ; and having been led 

 in 1S65 to take up his residence in Montreal, he was sub- 

 sequently engaged in similar work for other museums in 

 the Northern States. He soon acquired in the city of 

 his adoption the character he had left behind him in 

 Warrington, of being ever ready for any kind of philan- 

 thropic labour ; and especially distinguished himself by 

 his untiring advocacy, through evil as well as good report, 

 of the sanitary reforms which he saw to be greatly needed. 

 There is reason to believe that the typhoid fever which 

 brought his useful life to a close was engendered in the 

 foul air of the building in which he was accustomed to 

 carry on his scientific work. 



