>90 



NA TURE 



{Jan. 27, 1 88 1 



north of the Caledonian Canal, it seems to me that thft ii 

 extremely improbable, as along the two traverses we made — one 

 from Garve to Ullapool, the other from Laxford to Lairg — the 

 prevalent dips are eastward, and the upper quartzites forming 

 the elevations of Ben Dearig and Ben INIore are of great thick- 

 ness. One may therefore assume that the Laurentian gneiss 

 (even in the absence of the Cambrian sandstone) is deeply buried 

 beneath these beds and their succeeding schists. The region of 

 the Grampians of Aberdeenshire, on the other hand, is of great 

 extent, and until it has been explored by the' officers of the 

 Geological Survey it would be injudicious (as it appears to me) 

 to come to any opinion on the subject. Edward Hull 



Geol:)gical Survey Office, IIu ue Street, Dublin, January iS 



Geological Climates 



Having considered the effects of Mr. Wallace's proposed 

 redistribution of laud and water, intended to raise the mean 

 annual temperature of Bournemouth 15° or 20° F. above its 

 present amount, I now, with your permission, shall say a few 

 words on sime minor questions, which have arisen during our 

 discussion of the difficult problem of Geological Climates. 



1. Thi Clump of Bamboos at Co:ipt;r\^ Htil Engineering College, 

 — Prof. McLeod has kindly forwarded me a si^ecimen of the 

 foliage of the bamboo now gro.ving in his garden, and has 

 promised to send me the fruit when it ripens. 



My botanical friends cannot decide its species, with certainty, 

 from the fjliage alone, without the seeds, but think that it, 

 probably, is the bamboo called Thamnocalamus Falconeii, 

 formerly called Arundinaria fakata (not Arundinacea) and 

 aIso| called Bamluisa gracilis. If this opinion be correct my 

 rejection of its evidence in favour of Cooper's Hill now havi ig 

 the climate of " torrid India " was also correct ; for this bamboo 

 is one of the hardiest of the "hardy bamboos " growing in the 

 Himalayas, as high as the limit of perpetual snow, and being 

 exposed, at night and in winter, to extremes of cild, which are 

 never experienced in the British Islands. Whether our summer^ 

 are hot enough to ripen its seeds, and fully acclimatise it amongst 

 us, remains to be seen. 



It is a suggestive fact that at Fota, in the Cove of Cork, where 

 it grows in clumps 20 feet in circumference, from each of which 

 spring over 400 canes reaching a height of 25 feet ; the seeds 

 ripen with difficulty and take a long time to germinate, some 

 two months elapsing before they come through the soil, even in 

 a temperature of 70° F. 



2. T/'ie JMoreton Bay Pine at Bournemouth. — Mr. William 

 Ingram's letter, stating that an individual of this species, surrounded 

 with " wooded heights " about it, has lived for forty years in 

 Leicesterdiire, and attained a height of 35 feet, shows what the 

 gardener's skill can accomplish in protecting a sub-tropical tree 

 from the injurious effects of English winters, but throws no light 

 whatever upon the possibility of the Moreton Bay pine living 

 spontaneously in this country. 



In order to do so it must ripen its fruit and produce seedlings, 

 which (as I am infonned) it cannot possibly do with the moderate 

 heat of our cool summers. 



3. Tertiaty Climates in England. — Mr. Gardner states, that 

 independently of the evidence afifi.rded by the Moreton Bay pine, 

 the Tertiary fossil plants of the Eocene require an increase of 

 temperature of, at most, 20* F. 



When we add to this that the London clay contains true 

 Crocodiles, true Palms, many species of Nautilus, of Solutes, 

 and large species of Cyprna, we may be certain that 20° F. 

 increase of temperature is the very minimum required. 



The question of importance is, whence did this required heat 

 come from ? This is a question of number and magnitude, and 

 not of mere " naturalist tall;." This question cannot be settled 

 by redistributions of land and water, nor by repeating continually 

 the assertion that all former causes of change of climate were 

 the same as existing causes, not only in kind, but in degree. 



Samuel Haughton 



Trinity College, Dublin, January 14 



I AGREE with Prof. Haughton in his conclusion that no in- 

 crease in the quantity of water sent into the Arctic Ocean by 

 currents like the Gulf Stream would make much practical dif- 

 ference in the Arctic climate, though n^t altogether for his 

 reasons. I think the question of total quantities of heat is 

 irrelevant, and that the extent of glaciation and the distribution 



of plants and animals are almost exclusively determined by 

 summer temperatures. 



Respecting the distribution of plants and animals, I believe 

 this is the general testimony of naturalists, and it is certainly 

 confirmed by Nordenskjold's observations on the Siberian flora. 

 Res.iecting glaciation, I rely for proof on the well-known fact 

 that the extent of perpetual snow on mountains — in other 

 words, the height of the snow-line — depends, not on mean 

 teuijjerature, but on summer temperature. 



If this is true it shows that no change in the ocean currents 

 would make much difference ; for a glance at Dove's isothermal 

 lines for July and January shows that the effect of the Gulf 

 Stream on the temperatures of Europe and Asia and the Arctic 

 Ocean is chiefly confined to winter. The late Mr. Hopkins, in 

 his well-known paper on changes of climate (Geological Society, 

 December, 1851) estimated that the effect of the Gulf Stream 

 on the July climate of London is null. 



Joseph John Murphy 



Old Forge, Dunmurry, Co. Antrim, January 17 



Prof. Whitney on the Glaciation of British Columbia 



It must be gatifying to all geoligists interested in the 

 western part of America to find that a portion of the general 

 results of the woric of the Californian Survey is at length being 

 published under the auspices of the Museum of Comparative 

 Zoology at Harvard College, Prof. Whitney's " Auriferous 

 Gravels of the Sierra Nevada" being now supplemented by the 

 first part of a volume on the " Climatic Changes of Later Geo- 

 logical Times," dealing chiefly with the evidences of glaciation 

 on the Pacific slope. No one will question Prof Whitney's 

 observations and deductions on this subject when he deals with 

 that portion of the region with which he is personally familiar, 

 especially as these are in substantial agreement with the already- 

 published facts of Clarence King. The general result arrived at 

 in the areas of Whitney's and King's surveys is that compara- 

 tively only a very small portion of the highest ranges of moun- 

 tains has ever been covered with glaciers, and that there has 

 never been in this region anything like a northern drift period or 

 a transportation of material in any given direction independent 

 of the present topographical features of the country. 



This accords also with the statement published by Prof. 

 Whitney in 1S66 {Proc. Col. Acad. Sci. vol. iii. p. 271) as to 

 the absence of glacial traces of a general character from Cali- 

 f:)rnia, but — as it appears to me unfortunately — a clause was 

 added to this statement embracing in the generalisation the 

 whole north-western extension of the Cordillera region. Now 

 in 1S66, as Prof. Whitney himself says, almost n:>thingwas 

 definitely known of the coast north of Oregon, and for that 

 portion of it included in the province of British Columbia I have' 

 since maintained, as the results of observation, that there is con- 

 clusive proof of the occurrence of a period of general glaciation 

 comparable in its effects with that of eastern North America 

 (see Quart. Jottrn. Geol. Soc. vol. xxxiv. p. 89 ; Canadian 

 Naturalist, vol. viii. No. 7 ; vol. ix. No. i ; alsD the following 

 Reports oi the Geological Survey of Canada, 1S75-76, p. 261 ; 

 1S77-78, p. 133 B. ; 1878-79, p. 89 B.) In summarising and dis- 

 cussing the evidences of glaciation in British Columbia however 

 Prof. Whitney still thinks it necessaiy to support the correctness 

 of his paper of 1 866. As Prof. Whitney's volume appears to 

 be intended as a general, and, so far as the facts now known go, 

 finil review of the glaciation of the Pacific slope, and professes 

 to contain "all that is necessary to set forth in regard to the 

 former glaciation of the western side of the American continent," 

 it may not be amiss to state that in my view the account given 

 of the evidences of glaciation in British Columbia is in some 

 cases insufficieirt, and that in the interpretation of other points 

 misconceptions as to the nature of the facts have arisen. The 

 tendency of the whole treatment of the .subject is to minimise the 

 glacial phenomena of the northern part of the coast and assimi- 

 late the conditions there found to those of California, which 

 appear to me to be essentially different. (For a comparison of 

 these see "Travelling Notes on the Surface Geology of the 

 West Coast," Canadian Naturalist, vol. viii. No. 7.) 



To criticise minutely the numerous features which seem open 

 to such treatment in the account of this region, with which 

 seven seasons' work in connection with the Boundary Commis- 

 sion and Geological Survey of Canada has rendered me familiar, 

 would require a lengthened article, and would at best be an 

 ungracious task. I wdl therefore touch on a few salient points 

 only. 



