CU NOTE*. 



a deeper insight is obtained into the intricate play of natural forces, by pur- 

 suing the strictly inductive method of investigation, resting on the secure basis of 

 correct quantitative determination. The annual variations of the meteo- 

 rological elements afford not a less striking example of the more or less imme- 

 diate dependence of several apparently unconnected phenomena on the varia- 

 tions of the temperature occasioned by the earth's annual revolution in its orbit. 

 The method and systematic direction which characterises the meteorological re- 

 searches of the present period promises in a peculiar degree to reveal the 

 " constant amid change," the " stable amid the flow of phsenomena." 



M. Dove (to whom is primarily due the new aspect which this beautiful 

 branch of physical investigation has assumed by the separation of the pressures 

 of the aqueous and gaseous portions of the atmosphere), has very recently 

 shewn, in a memoir read to the Academy of Sciences at Berlin (March 1846), 

 that the same single progression of the diurnal variation of the dry air extends 

 also into the intertropical regions. At Buitenzorg in Java the dry air is found 

 to have a single maximum and minimum, the epochs of which coincide re- 

 spectively with the coldest and warmest hours. It was previously known 

 (Sabine, Report of the British Association, 1845, pages 7382,) that at 

 Bombay, also within the tropics, a less simple law prevailed, the gaseous 

 atmosphere having there a double maximum and minimum in the twenty-four 

 hours, accompanied by a corresponding double progression in the force of the 

 wind. The phsenomena at Bombay are by no means, however, to be viewed as 

 a contradiction to the principles on which the more simple progression prevail- 

 ing elsewhere has been explained : on the contrary, an extension of the same 

 principles to the more complicated relations produced by the juxtaposition of 

 surfaces of land and sea, and by the different affections of these surfaces by 

 temperature, had led to the expectation that such exceptional cases would be 

 found within the tropics ; the mutual relations of the diurnal variations of the 

 gaseous pressure and the force of the wind have received a further and very 

 striking exemplification in this exceptional case ; one minimum of the pressure 

 is found to coincide with the greatest strength of the land-breeze, the other 

 minimum with the greatest strength of the sea-breeze, and the epochs of the 

 two maxima of pressure correspond respectively with those of the two minima 

 of the force of the wind. EDITOR.] 



C 333 ) p. 309. Bravais, in " Kaemtz et Martins, Me'te'orologie," p. 263. 

 At Halle (lat. 51 29') the oscillation still amounts to 0'28 French lines. 

 Apparently a very great number of observations will be requisite to obtain a 



