5i8 



NATURE' 



{Sept. 12, 1878 



which are used by the Herald Office (with which Mr. Collins seems 

 to be connected) to issue storm-warnings from the United States 

 to Europe, no objection could be made against him. But Mr. 

 Collins is more ambitious, and makes some assertions which run 

 against the most authenticated facts known to meteorology, and 

 others which may be true, but ought yet to be proved, while Mr. 

 Collins, without any proof whatever, seems to consider them 

 quite well established. 



I must first object to the absence of distinction between the 

 seasons, which is so important a feature in storms, especially in 

 lower latitudes. Mr. Collins seems not to know that the West 

 India hurricanes and other destructive tropical storms are frequent 

 only at certain seasons. This is quite enough to dispose of the 

 author's assertion " that the conditions which combine to develop 

 nearly all areas of low pressure are of eqitatorial origin." The 

 most violent storms of Europe and the United States happen in 

 the colder months of the year, when there are no storms in the 

 tropical belt north of the equator (very few exceptions are known) ; 

 besides the use of the word " equatorial " must be objected to as, 

 so far as I know, no cyclone has ever originated between 5" N.L. 

 and 5° S.L., at least.^ so that we may call the storms of the 

 West Indies, the South Indian Ocean, about the Mascarenes, 

 of the Bay of Bengal, &c., tropical storms — because they cer- 

 tainly originate in the tropical belt — but certainly not equatorial. 

 So far as Europe is concerned, there are some few cases in 

 which West India hurricanes have reached it, but this is confined 

 to the months of July to October, At the same time of the year 

 it is not impossible that cyclones originating in the tropical belt 

 of the Pacific may strike the Pacific coast of the United States. 

 As tj the storms mentioned by Mr. Collins, which strike the 

 west coast of Mexico, pass over the plateau, and thence into 

 Southern Texas, I very much doubt their existence. In any case 

 no storm of this kind has ever been follow ed on this route, and 

 so Mr. Collins ought to be rather careful in speaking of them. 

 So far as I know, from books published about Mexico, and 

 from personal information, no storms are experienced on the 

 Mexican plateau. 



The same absolute want of facts and general improbability 

 can be urged against the storms which Mr. Collins takes from 

 the Asiatic continent to the Pacific and thence to the American 

 continent. Here the distinction of the seasons is especially neces- 

 sary, as all Eastern Asia is under the influence of monsoons or 

 periodical winds.- In winter, when pressure is so enormously 

 high in the interior of Eastern Siberia,^ and the winds are north- 

 west and north on the coast, that is, bring the cold dry air 

 of the interior towards the Pacific Ocean, these conditions are 

 favourable neither to local depressions nor to the propagation of 

 European storms, which generally die out in Eastern Russia or 

 Western Siberia. In summer the pressure is low in the interior 

 of Asia, and air io constantly drawn from the Pacific Ocean to 

 supply the deficiency towards the end of the rainy season or 

 summer monsoon— in August to October is the time of the ty- 

 phoons, that is, of the cyclones of the China Seas ; but they do not 

 originate on the Asiatic continent, and only strike it on a very 

 limited area, that \^, the coast of Southern China. These 

 typhoons may perhaps reach California, as the West India 

 hurricanes reach Europe, but it is not yet proved that this has 

 ever been the case. 



I admit that in autumn, that i--, September and October, storms 

 may perhaps pass from the Asiatic continent to the Pacific, and 

 thence to America ; but in latitudes far to the north of those 

 visited by the typhoons. At Yakutsk, in North-East Siberia, 

 the prevailing winds of that season are west and south-west, the 

 amount of cloud great, and rains frequent, if not abundant, 

 while the temperature is generally above freezing-point to the 

 middle of October. I consider it possible that Atlantic (Euro- 

 pean) storms may, at this season, travel over the whole of 

 Northern Siberia and reach the Pacific. In winter this is im- 

 possible, on account of the low temperature and high pressure 

 then existing in Siberia. 



I resume a few facts either well authenticated or very 

 probable about storm-centres (cyclones) of the northern hemi- 

 sphere. 



I. By far the most of them originate in the middle latitudes 

 (35°-6S° N.) in Europe, North Amei-ica, the Atlantic, and 



^ It would be too long to state why, there are no equatDrial cyclones. I 

 would advise Mr. Collins to consult " Etudes sur les Mouvements de 1' At- 

 mDsphere, by Guldberg and Mohn. 



, 1^^ "Winds of the Globe." by CofFin.— S.nkhsonian Contrlb. vol. xx. 



3 Mee Pctermann's Mittheilu7igen, July, 1878, p. 2^9, and the shcrt 

 natice in Nature, vol. xviii. p. 288? 



Pacific. As to the three first-named regions it is abundantly 

 proved by the observations we have already. As to the Pacific, 

 we want the direct proof, because observations are too few. 

 But nobody will doubt that, in conditions of climate so analo- 

 gous to those of the Atlantic cyclones do also originate. 



2. Cyclones are of much rarer occurrence in Asia, except the 

 great summer depression, which is of a different nature, and 

 remains the whole summer over the dryest parts of the 

 continent. 



3. Tropical cyclones are confined to a few months of the 

 year, and even these seldom reach the latitudes north of 35° N. 



Lastly, a few words about Mr. Bennett's storm-warnings. I 

 do not doubt that some storms may reach Europe from America. 

 But it is not at all certain that every storm that has passed from 

 the eastern coast of America should reach Europe. This is the 

 first difficulty in storm-warnings from America. The other is, 

 that neither the path the storm will take nor its rate of progress 

 can be known with certainty. Every one who has examined 

 European and American synoptical maps will have noticed how 

 different the paths of the centres are. So long as the storm can 

 be followed on land, by means of numerous stations, a great 

 approximation to certainty in predicting it is possible, as the 

 durations are caused by certain pre-existing states of pressure, 

 temperature, humidity, &c. But how is this to be done on the 

 ocean ? 



Meteorologists of great ability, especially Prof. Buys Ballot, 

 have often advocated telegraph lines to the Azores and Iceland, 

 so that these islands might serve as advanced guards to predict 

 storms in Europe. At such a distance as thty are from our 

 continent they certainly could serve this purpose, as is clearly 

 shown by the French Atlas Meteorologique and Hofi'meyer's 

 synoptical maps. As to American predictions for Europe, I 

 must confess that most European meteorologists are very doubt- 

 ful about it. It is to be noticed also that, as storms are very 

 frequent in western Europe, and as the rate of progress of 

 storm-centres over the Atlantic is not accurately known, there 

 may be a seeming success in American predictions which the 

 facts, when accurately known, would not justify. 



This is not meant to cast a shade on the spirit of enterprise of 

 Mr. Bennett in organising the Herald weather predictions. The 

 observations thus collected, or saved from oblivion, will cer- 

 tainly be useful, even if it be proved that storm- warnings from 

 America are not reliable. A. WoEiKOF 



St. Petersburg 



A White Grouse 

 When shooting, yesterday, on the moors near Dunrobin, I 

 fired at an ordinary grouse and killed it ; just as it fell, another 

 bird rose that seemed to be a ptarmigan, from the complete 

 whiteness of its plumage ; a third bird then rose, and was shot. 

 The three were picked up not far from each other, and were all 

 very fine birds. It seemed strange that a ptarmigan should be 

 so low ; we were not very high above the sea, and far below the 

 elevation affected by these birds. On examining it, it proved to 

 be a very fine grouse, snowy white, with a few dark feathers in 

 the tail and wings. It was not an albino ; I think the eyes 

 were dark. It is a very beautiful bird, has been sent off" to 

 Inverness to be stuffed, and will be preserved in the Dunrobin 

 Museum. 



No one here had seen a specimen of the white grouse before, 

 and it excited considerable interet. No doubt it is only an 

 accident, and its progeny, if it had any, would have been the 

 ordinary grouse. 



It may be less rare than I suppose, but you may deem its 

 occurrence worthy notice in Nature. J. Fayrer 



Dunrobin Castle, Sutherland, September 8 



Brehm's "Thierleben" 



In last week's Nature you have copied a drawing, " cobra 

 charming," from Brehm's " Thierleben," presumably for its 

 excellence. Permit me, however, to point out a most serious 

 defect in its truthfulness — the relative proportions of the snakes 

 to the charmers. 



Take the youth blowing the horn to be 4 feet 6 inches in 

 height (he could not be much less), the hoods of the cobras 

 must be 8 to 9 inches across. Now I will venture to say that a 

 hood of 4^ inches across has never yet been measured, in a live 

 specimen at least. 



I cannot now lay my hands on a cobra skin I have, and give 



