.$58 Prof. Dove's Outlines of a general Theory of the Winds. 



c. The independence of the law of rotation on the differences 

 of the yearly mean directions of the wind of individual places 

 will then first be accurately proved when we possess similar 

 observations for several places. The greatest difference among 

 the places of observation above mentioned amounts, in rela- 

 tion to the meandirection of the wind, to 30 degrees. 



d. The rising and falling of the barometer with the various 

 winds is so closely connected with the mean distribution of the 

 atmospheric pressure in the wind-compass (the so-called ba- 

 rometrical wind-compass), that, if two maxima and two minima 

 occur in it, even in the intermediate wind there will be ob- 

 served a twofold rising and a twofold falling (Pog. Ann., 

 vol. xxxi. p. 478.). It must however be observed that such 

 anomalies disappear much sooner in the rising and falling 

 than in the mean barometrical values of the winds (Pog. 

 Ann., vol. xi. p. 556). The barometrical mean conditions 

 observed during the influence of the wind acknowledge the 

 existence of a barometrical wind-compass, but deny the exist- 

 ence of the law of rotation, and may therefore be said to ac- 

 knowledge the phenomenon which evinces itself indistinctly 

 and rejects the one which is clearly evident. 



2. The thermometer rises with E., SE. and south winds, 

 passes with SW. from rising into falling, falls with W., 

 NW. and north winds, and passes with NE. from falling into 

 rising. 



Observations for 5 years in Paris (1816 to 1820) give in 6 

 hours. 



( + ) signifies rising, ( — ) signifies falling. 



3. 4. That the variations of the pressure of the dry air is 

 in proportion to the barometrical variations, and the varia- 

 tions of the elasticity of the vapour, on the contrary, in pro- 

 portion to those of the temperature, will be evident from the 

 following table, which is deduced from observations in the 

 same years as the barometrical observations of London. 



