298 Baron Humboldt's View of the Scientific Researches 



duced to a small number of figures are published by a central 

 committee who watch over the uniformity of the observations and 

 the calculations. — (See this Journal^ No. xvi. and No. ii. New 

 Series, p. 249.) I have already mentioned, in a memoir where 

 I have discussed the general causes on which the difference of 

 climates in the same latitude depends, upon what a great scale 

 this fine example of the United States may be followed in the 

 Russian empire. 



We are fortunately far from the epoch when philosophers 

 believed that they knew the climate of a place when they knew 

 the highest and the lowest temperature during the year. An 

 uniform method, founded on the choice of hours, and on a level 

 with the knowledge recently acquired respecting the true means 

 of the day, the month, and the year, will replace ancient and 

 defective methods. By this labour several prejudices on the 

 choice of culture, on the possibility of planting the vine, the 

 mulberry tree, fruit trees, the chesnut or the oak, will disappear 

 in certain provinces of the empire. To extend it to the most 

 distant parts we may reckon upon the enlightened co-operation 

 of many of the young and well educated officers of the Corps 

 of Mines, — upon that of medical men, animated with a zeal for 

 the physical sciences, — and the pupils of that excellent institu- 

 tion the School of Roads and Canals, in which the higher ma- 

 thematical studies create an instinctive tact for order and pre^ 

 cision. 



Besides these two objects of research which we have examin- 

 ed in reference to the extent of the empire, (terrestrial magne- 

 tism and the study of the atmosphere which leads at the same 

 time by the aid of barometrical measurement to a perfect 

 knowledge of the configuration of the ground,) I will place 

 a third kind of investigation of a more local interest, though 

 connected with the great question of physical geography. 

 A considerable part of the surface of the globe round the Cas- 

 pian Sea is found inferior in level to that of the Black Sea and 

 the Baltic. This depression, which has been suspected to exist 

 for more than a century, and measured by the laborious opera- 

 tions of MM. Parrot and Engelhardt, may be ranked among 

 the most interesting phenomena of geognosy. The exact de- 

 termination of the mean annual barometric height of the town 



