40 THE WINDS AND THE BAROMETER. 



the weather to clear up somewhat suddenly and shiirp frosts to set in at 

 night. 



12. Thunderstorms — (a) When these come up with an E. wind, 

 and the barometer falls, the air is not cooled. We then very properly 

 say, 'it it sultry, and we shall have another storm.' 



{b.) If a thunderstorm comes from the W. the barometer 

 begins to rise, and the air is cooled. 



(c.) Should several thunderstorms follow each other from the 

 W. they usually come successively from more northerly points. 



{d ) When thiinderstorms come from the W. we usually see 

 an upper sky covered with fine thin clouds and undisturbed by the commo- 

 tion below. Observation wiU teach us that the wind at the surface will 

 be nearly at right angles to the direction of the upper current as indicated 

 by the lofty cirri. 



13. During continued bad weather, the vane oscillates between S.W. 

 and W., and the barometer fluctuates only to a slight extent. These are 

 the indications of the presence of the true equatorial current. 



14. If the barometer rises rapidly, it is the result of the meeting 

 of these northerly and southerly winds. They have met and stopped each 

 other's progress, and a severe storm is sure to follow. 



15. If the barometer then falls very rapidly, it shows that the S. 

 wind has prevailed in the conflict, and that the danger is now very near. 



16. The meeting of a cold and warm wind, in winter, is indicated 

 by a high barometer and a thick fog. If the northerly wind prevails 

 severe cold will follow ; if the southerly, the fog will disappear. 



17. If the barometer is much agitated, but no distui-bance in the 

 atmosphere is apparent, a storm is raging beyond the horizon. 



18. If in winter the southerly warm current prevails over a large 

 extent of country, the barometer is low and the air is soft and mild. 

 When this occurs, be sure that the winter is very severe and the barometer 

 high somewhere not far away. 



For most of the above observations we are indebted to Professor 

 Dove, of Berlin. The subject will be found fully treated by that eminent 

 meteorologist in his " Diis Gesetz der Stilrme," of which an improved 

 edition has been issued very lately. 



In oiu- next paper we ^^ropose to set forth the views of Dove on the 

 causes of the changes of the wind in England, in connexion with the 

 indications of the barometer or weather-glass. J. G. 



