50 



NEW ENGLAND FARMER. 



Jan. 



For the New England Farmer. 



SOME REMAKKABLE FACTS IN RELA- 

 TION TO CLIMATE. 



Compiled from Meyen for the N. E. Farmer. 



Alexander Humboldt connected those places 

 which possess an equal degree of heat, by lines 

 which ho called I.fothcrmal, from the Greek words, 

 isos, (equal,) and theriae, (heat) — that is, lines 

 of equal heat. As the mean temperature of dif- 

 ferent places are exceedingly various, there must 

 also be various isothermal lines, which are always 

 designated by the mean temperature of the place. 

 Observations have shown that these isothermal 

 lines by no means run parallel to the parallels of 

 latitude, but incline towards them, particularly 

 in the higher latitudes, but less near the equa- 

 tor, where they pretty nearly coincide with the 

 parallels of latitude. 



In the northern hemisphere of the globe, all 

 the eastern coasts of continents and isolated 

 masses of land are colder than the westeim coasts 

 of the same latitude. Thousands of observations 

 have confirmed this phenomenon, although its ex- 

 planation is not yet quite found out, and, there- 

 fore, the isothermal lines frequently rise and fall. 

 For example, Ireland, England and Belgium are 

 countries which have the same isothermal line ; 

 but on the eastern coast of Asia, it passes just 

 above Pekin, which is in the same latitude as Na- 

 ples. Canada is further south than Paris, and it 

 nas the temperature of Drontheim. The trees 

 ■which grow in New York — the latitude of Naples 

 — flower at the same time as they do at Upsal. 



The isothermal lines do not run in straight 

 lines, but in carves. The isothermal lines rise in 

 their course, from the eastern coast of America 

 towards Western Europe, but they sink again 

 towards the south in the interior of the continent, 

 and that so quickly, that Scotland lies in the same 

 isothermal line as Poland, and England as Hun- 

 gary. We find, however, that it is only near the 

 coast that they sink so rapidly, and that it is in 

 consequence of the great difference which was 

 previously shown to exist between coast and con- 

 tinental climates of the same latitudes, it is prob- 

 able that it does not take place in the interior of 

 large continents, but that there the isothermal 

 lines run in a straight direction. 



In the interior of the New, as well as of the Old 

 World, the isothermal lines incline towards the 

 south. Thus if we go towards the pole in the in- 

 terior of the two great continents, we find that 

 the temperature decreases much more rapidly 

 than in the interjacent seas. It is well known 

 that for many years, attempts have been made to 

 penetrate the frozen Arctic seas. By Behring's 

 straits, where the voyager is constantly near the 

 great continent, he has penetrated only a little 

 further than 70^ north latitude ; by sailing along 

 the American coast through Baffin's Bay, he has 

 reached the 77th degree north latitude ; while in 

 the open sea, in the meridians of Norway and 

 Sweden, it is easy to sail to Spitzbergen, which 

 lies above 81° north latitude. We thus learn that 

 the pole is 7iot the coldest point of the earth, but 

 that there are two poles of cold, one in the interior 

 of each continent. 



But we have all seen that the mean temperature 

 of the whole year has not so great an influence on 

 the vegetation as the mean temperature of the 



diff'erent seasons, and therefore, it is still more 

 important to know the places which, though in 

 diflerent latitudes, possess the same summer or 

 winter temperature. Baron Humboldt was the 

 first also who paid attention to this principle. He 

 named the lines which connect places of the same 

 mean winter temperature, isochimenal lines, (from 

 ochiemon, cold,) and those which connect places 

 of the same mean summer temperature, isolheral 

 lines, (from theros, summer.) 



The isochimenal lines in the interior of conti- 

 nents bend considerably towards the south, which 

 is principally obvious near the Atlantic, where 

 the curves, when they come near the coast, make 

 a sudden turn towards the north. This shows the 

 greater coldness of the winter in the interior, com- 

 pared with the coast of the same degree of lati- 

 tude. 



The course of the isotheral lines that bend * 

 towards the north is directly opposite that of the 

 isochimenal, for the summers on the coast ai'e 

 colder than the summers in the interior of the 

 same degree of latitude, and in a great many 

 cases, they are colder near the coast than in the 

 interior, in a much higher latitude. The summers 

 of Paris and Moscow are nearly equal, though the 

 winters of Paris are mild, and those of Moscow 

 almost insupportable. 



Differences in the mean temperature of the 

 eastern and western coasts have already been al- 

 luded to. There are also equal differences in the 

 summers and winters. While the inhabitants of 

 Quebec in winter complain of the piercing cold, 

 the natives of the same latitude en the western 

 coast of America go with scarcely any clothing. 



The importance of the difference between the 

 climates of the east and west coasts of North 

 America to the distribution of vegetation was 

 early observed. Burton has remarked that the 

 plants of North America grow on the west coasts 

 in higher latitudes than on the east, and the east- 

 ern coasts of Hudson's Bay are desert and herb- 

 less, while on the western coasts there is a toler- 

 ably rich vegetation. 



The difference between the climates of the east 

 and west coasts of continents and islands has al- 

 so been observed in the southern hemisphere — 

 but here the principle is reversed — for the west 

 coasts are colder than the east, while in the north- 

 ern hemisphere the east coasts are the colder. 

 South America shows very decidedly this arrange- 

 ment of a warm eastern coast, and a cold western 

 coast. Various attempts have been made to ex- 

 plain the proportionably very cold climate of the 

 western coasts of South America, and many caus- 

 es have been assigned which would indeed dimin- 

 ish the heat there. The chief cause is evidently 

 the same which operates in the opposite manner 

 in the northern hemisphere. 



The successful cultivation of certain plants does 

 not depend so much on the mean annual temper- 

 ature as on the temperature of summer. Thus, 

 Indian corn cannot be raised in Great Britain, 

 though it possesses a higher mean temperature 

 than New England, but the hotter summers of 

 New England are more favorable to it than the 

 longer and colder summers of England. The same 

 remark is true of annuals as a general rule, they 

 are governed by isotheral lines, flourishing equal- 

 ly well in different latitudes, if they have equally 

 hot summers. Thus the Californian annuals euc- 



