242 



NA TURE 



{Jan. 13, 1 88 1 



temperature. From this it follows that the temperature of the 

 air at the surface of the sea corresponds with the surface- 

 temperature of the water. This hai been fully confirmed 

 by observations Biade in every latitude, which show that the 

 difference of temperature between the air and sea is never more 

 than one or two degrees Fahrenheit. 



(h) Gulf Stream. — The temperature of the air above the Gulf 

 Stream is : — 



45° F'. at latitude 60" 

 35 .. .. 70' 



62° F. at latitude 40° 

 53 .. ,> 5°° 



and the quantities of water contained in the Gulf Stream are : — 

 36 cubic miles per hour at latitude 50' 

 36 ,, ,, f, 60° 



24 „ „ ,, 70° 



The mean annual temperatures of the several latitudes, in the 

 northern hemisphere, are, taken all round the globe — 



29 3° F. at latitude 60° ... 4'5° F. at latitude So° 



I4"4 )) >. 70° ■•■ O'o >> >> 90° 



From this it is evident that the Gulf Stream is inadequate to 

 keep the temperature of the Polar cap, from the Pole to 6o°lal., 

 above the freezing-point of water ; so that if the heat and cold 

 were uniformly distributed, the whole of this great area would 

 be permanently frozen over, the thickness of the ice being 

 greatest at the Pole, and least at lat. 60°. 



This ideal icecap (in the suppisition of uniformly distributed 

 heit aid cold) represents accurately the amount of heat that must 

 b; introluced into the Arctic regions before their temperature 

 rises to that of the freezing point of water. Its southern liinit 

 is lat 58° 51', where the mean annual temperature all round 

 the globe is 3 2° F. 



The thickness of this ideal ice-cap at the Pole is unknown, but 

 from what we kniw of the pala;ocrystic ice of Bank's Land and 

 Grinnel Land must be measured by hundreds of feet ; and its 

 mean temperature must be at least 20° F. below the freezing 

 point of water. 



Mr. Wallace has put forward the supposition that the intro- 

 duction of an equal proportion of the' Kuro-siwo (to tliat of 

 the Gulf Stream) would prevent the formation of sea-ice in the 

 Arctic Sea. Before this could happen, the Kuro-siwo must first 

 melt the ice-cap, and then keep it from freezing again. 



To show how inadequate this supposition is, I shall calculate 

 what the Gulf Stream has already done, and then show what the 

 Kuro-siwo could do. 



Let us suppose that the whole heat of the Gulf Stream, 

 parsing northwards through the parallel of 70° N., is employed 

 in melting a supplementary ice-cap extending from the Pole to 

 70° N. and that this supplementary ice-cap is at the temperature 

 of 32° F. only [mere ice-sludge) ; I find the thickness of ice melted 

 is only 5 874 feet ' yearly. 



If therefore the Gulf Stream were cut off by a barrier at 70° 

 N. lat. an additional growth of ice at 32° F. less than 6 feet 

 thick might grow upon the area from the Pole to 70° N. lat. 



Of c rare the Gulf Stream expends its heat in melting local 

 ice in the Spitzbergen and Barentz Seas, and perhaps still further 

 east in summer along the Siberian coast, and not in melting the 

 suppleme ital ice-cap I have imagined ; nevertheless the whole 

 work done by it does not exceed the melting of the ice-cip from 

 the Pole to 70° lat., and of a uniform thickness of 5'874 feet. 

 In other words, the work done by the Gulf Stream north of 

 70° lat. is equivalent to the melting of 43S2 cubic miles of ice at 

 32° F. , which represents a definite quantity of heat. It is how. 

 ever much easier to conceive the ice-cap from the Pole to 70° 

 lat., of $'874 feet thick, than 43S2 cubic miles of ice. 



As the ice melted between the Pole and 70° lat. has a tern- 

 pera'ure of 6° F., instead of 32° F., it is easy to see that the 

 thickness of ice-cap melted by the Gulf Stream is 4'8i3 feet 

 instead of 5-874 feet. 



(c) The Kuro-siwo admitted through Bchring's Strait.— iU. 

 Wallace quotes me as stating that the volume of the Kuro-siwo 

 is 24 times the volume of the Gulf Stream : I believe it to be s i, 

 but in the present discussion shall consider it to be only twice as 

 great ; for at least one-fifth of it obtains partial entrance into 

 Behring's Strait, and behaves like the Gulf Stream ; as appears 

 from tiie le-ser rigour of the climate of the Parry Islands, from 



' I assume the following data : — I 

 sq.gr. m : latent heat of ice-c Id w; 

 miles per hour : temperature = 35°at'- 



the open water discovered by Collinson along the northern coast 

 of America, and from the return cold current of the coast of 

 China. 



From the calculations I have just given it appears that the 

 Kuro-siwo current admitted through a widened Behring's Strait 

 would be competent to melt a thickness of ice-cap extending from 

 the Pole to 70° lat., amounting to 9626 feet. 



I shall leave your reader-, to judge whether this amount of 

 ice-melting justifies Mr. Wallace in asking " Suppose that only 

 an equal proportion (to that of the Gulf Stream) of the Kuro- 

 siwo entered the Arctic Ocean, is it not probable that no sea-ice 

 at all would form there?" 



To me this question appears like a proposal to Hercules to 

 clean out the Augaean stables with a teaspoon. 



{d ) Let us now add on the Mozambique Current, converted 

 into a Caspian depression Gulf Stream. Of this current I cannot 

 allow Mr. Wallace to appropriate more than half, unl&ss he 

 shiws cause for a land barrier preventing the other half from 

 continuing its present course into the southern hemis, here, there 

 to aid in mitigating the climates of the Temperate and Antarctic 

 zone--. 



The Caspian Gulf Stream will then cut off another slice of 

 3'6o9 feet in thickness from the ice-cap extending to 70" lat. Is 

 this amjunt of ice-meltitig sufficient to perform the feat assigned 

 to it by Mr. Wallace of **rai-ing the former [the Polar sea] to 

 perhaps 15° or 20° F. above the freezing point " ? 



{e) If there be any truth at all in the power of Gulf Streams 

 to modify the climates of the Temperate and Polar zones, the 

 southern hemisphere should be warmer than the northern hemi- 

 sphere, as it receives three Gulf Streams instead of l\ Gulf 

 Streams (without discussing their relative volumes). 



This is the actual fact, as is easily proved, notwithstanding 

 the iterated parrot-like statements to the contrary copied from 

 text-book to text-book. 



I have shown that, taking the annual mean temperature at all 

 longitudes, the cold of the northern hemisphere is represented 

 by an ideal ice-cap which is thickest at the north pole and ter- 

 minates in the latitude 58° 51' N., where the mean annual 

 tem; erature is 32" F. 



In the southern hemisphere, the latitude at which the mean 

 annual temperature for all longitudes is 32° F., is found at 

 62° 41' ij. This limit of the ideal southern ice-cap (measuring 

 the Antarctic amount of cold) lies nearer to the South Pole by 

 3° 50', or 230 geographical miles, than the corresponding limit 

 of the northern ice-cap from the North Pole. 



These limits of ideal ice-cap at the North and South Poles are 

 independent of the wholly different question as to which of the 

 Poles has the largest volume of ice surrounding it, into which I 

 shall not enter at present. 



(/) From what I have proved above it is evident that the 

 two return co npensating currents from the Arctic seas will still 

 consist of ice-cold water, one of which, on the coast of Asia, of 

 double the volume of the Labrador current, will reduce the 

 climate of China and Northern Japan to a condition compared 

 with which the present climate of Hudson's Bay would be a 

 Garden of Eden ; and the other would bring the Ural range 

 and Eastern Europe into the present condition of Labrador. I 

 think it is evident, under these latter conditions, that Bourne- 

 mouth would suffer, and not gain, by Mr. Wallace's arrange- 

 ments of land and water. The services rendered to the Arctic 

 lands by the two new Gulf Streams would, in my opinion, be 

 dearly purehised by the damage done by their compensating 

 currents in the sub-tropical latitudes of Ea.^lern Asia and Eastern 

 Europe. Saml. Haughto.v 



Trinity College, Dublin, December 31, 18S0 



In Nature, vol. xxiii. p. 169, Mr. Ingram mentions the 

 growth of Bambusa metake in Leicestershire. I have found 

 large varieties of bamboo cultivated on a great scale in Northern 

 Nippon, where the winter temperature is certainly much 

 colder than in England. The northernmost place where I found 

 them was the vicinity of Yo'iobori, about 39° 12' N., at a small 

 distance (twenty-five miles) from the west coast. The nearest 

 place to the south where observations were made is Niigata, 

 37° 55', and to the north Hakodate, 41° 46'. The coldest month 

 has a temperature respectively of 33'''0 and 27° -3 F. Yusawa 

 being situated about 450 feet high, and in the interior, the coldest 

 month there must have not over 30°, and a heavy snowfall is the 

 rule every winter. Again, on descending the dividing ridge 



