308 



MAGNETIC STATION'S. 



CHAPTER 

 XXVI II. 



Astrono- 

 mical obser- 

 vatories. 



Magnetic 

 EUtious. 



Anticipated 

 results. 



r>istribution 



of liCat. 



the fortresses of science, — spread over so vast a portion 

 of the known world. No longer confining itself to the 

 European centre of civilization, observatories for watch- 

 ing the stars, and extending the established truths relat- 

 ing to the vast system of worlds that glitter in our mid- 

 night sky, have been established in Africa and America ; 

 while across the hemispheres, which includes an import- 

 ant portion of the old continents of Asia and Europe, a 

 long continuous chain of magnetic stations has been 

 formed, extending from Moscow to Pekin, across the 

 whole of Northern Asia. At these stations, also, com- 

 plete meteorological observatories are established, so that 

 it can hardly be doubted important truths must result 

 from these, in relation to the great laws of nature, of 

 which these phenomena are only the indices or results. 

 On this Humboldt obsei-ves in his Cosmos : — " The com- 

 parison of observations made at places lying so many 

 hundred miles apart, will decide, for instance, whether 

 the same east wind blows from the elevated desert of 

 Gobi to the interior of Russia, or whether the direction 

 of the aerial current first began in the middle of the 

 series of the stations, by the descent of the air from the 

 higher regions. By means of such observations we may 

 learn, in the strictest sense, whence the wind cometh. 

 If we only take the results on which we may depend 

 from those places, in which the observations on tho 

 direction of the winds have been continued more than 

 twenty years, we shall find, that in the middle latitudes 

 of the temperate zone, in both continents, the prevailing 

 aerial current has a west-south-west direction. 



" Our insight into the distribution of Iieat in the atmos- 

 phere has been rendered more clear since the attempt 

 has l)een made to connect together by lines those places 

 where the mean annual summer and winter tempera- 

 tures have been ascertained by correct observations. 

 The system of isothermal, isotheral, and isochimenal 

 lines, wliich I finst brought into use in 1817, may, per- 

 haps, if it be gradually perfected by the united eftbrts 



