198 



APPENDIX TO MEMOIR OF PELTIER. 



their climate. Hence, for the equator, calculation gives stronger temperatures 

 than those realized by direct obsen'ation. In higher latitudes, on the contrary, 

 the values to which it leads us are too small. These two results are satisfacto- 

 rily explained l)y the opposite influence of the trade winds, which warm the 

 poles and cool the equator. The currents of the ocean join Iheir action to that of 

 the currents of the atmosphere, and concur in warming the countries of the north. 

 Such is, beyond all, the case with the Gulf Stream, which, after bathing the coasts 

 of the United States, presses on in summer as far as Iceland and even the shores 

 of Norway. 



The causes which have been signalized are evidently of a nature to modify 

 the temperature of the places on which they act, but they could not have suffi- 

 cient power to explain the great difi'crences Avhich are sometimes observed 

 between localities, although in near proximity. They cannot especially explain 

 the constant decrement of temperature in the different localities of Europe and 

 of central Asia, in proportion as we advance into the interior of the land. 



If we depart from the western coast of Europe and proceed directly towards 

 the east, always advancing un.ler the same latitude, we shall observe the follow- 

 ing meteorological phenomena : 1. In proportion as we advance towards the 

 east, the mean temperatures of the year continue to become progressively lower 

 at the places by wliich we pass. This fact is* still more remarkable if, instead 

 of taking the mean temperatures of the year, we simply take the mean tempera- 

 tures of the winters. 2. It will be found, moreover, that the mean quantity of 

 rain that falls in a year goes on diminishing in proportion as we advance from 

 the west towards the east. 3. Finally, it will be observed that the relative 

 quantity of water which falls in winter continues also to diminish ; in other 

 words, if we represent by 1.00 the annual quantity of water, it will be found 

 that in proceeding towards the east the quantity of water which falls in winter 

 becomes a fraction less and less considerable of the whole quantity. 



These three facts, namely, the diminution of the temperature, the diminution 

 of the annual quantity of water, and the diminution of the fraction of water 

 which falls in winter, are easily observed in proportion as we advance into the 

 interior of the continent, proceeding from west to east. We will cite several 

 examples : 



Mean temperature of ic inter for one and the same parallel at different longitudes. 



Names of localities. 



Edinburgh . 

 Copenhagen 



Tilsit 



Moscow 



Kazan 



Isle of Man. 

 Cuxhaven .. 

 Stralsuud. . . 



Dantzig 



Konigsberg . 

 Wilua 



55 58 



55 41 



55 04 



55 47 



55 48 



54 12 



53 53 



54 19 

 54 21 

 54 42 

 54 41 



Longitude east 

 of Paris. 



5 30 

 10 15 

 19 33 

 35 13 

 47 10 



6 50 W. 

 6 24 E. 



10 45 . 



16 18 



18 09 



22 58 



Mean temperature of 

 winter iti Centigrade 



degrees. 



-f- 3 47 



— 42 



— 3 06 

 —10 05 

 —12 29 

 -f 5 58 

 + 03 



— 17 



— I 91 



— 3 26 



— 4 GO 



