136 Mr. W, R. Birt on Atmospheric Waves, 



force, again the reverse of the usual phenomena of a wave pro- 

 gressing towards the S.E. While, therefore, we had on the 23rd 

 the area divided into two regions of rising and falling barometers, 

 differing frorti the normal conditions, the wave-form was maintained 

 in all its integrity. The reversal of the phenomena is very im- 

 portant (see figs. 1 & 2). 



Table VI. — Distribution of Pressure and Wind over the North- 

 west of Europe on April 24, 1872. 



First zone on S.W. of anterior slope above trough o/S,W. ivave. 



Barom. Direction. Force. 



Corunna . . 29'77 S.W. 



Valencia . . 29-31 +0-17 W. -4 



Trough of S.W. wave. 



Biarritz . . 29-81 + 0\26 S. -3 



Roche's Point. 29-29 + 0-29 AV.S.W. -3 



First zone above trough, posterior slope. S.W. wave. 



Rochefort . . 29-73 + 0-24 W. 5 



L'Orient . . 29-61+0-33 W. -5 



Scilly . . . 29-40 + 0-36 W.S.W. -5 



Second zone above trough, posterior slope. S.W. wave. 



Plymouth . . 29-42 + 0*33 S.S.W. -2 



Pembroke . . 29-34 + 0-35 S.W. -3 



Holyhead . . 29-30 + 0-16 S.S.E. +4 



Greencastle . 29-25 E.S.E. +5 



Third zone above trough, posterior slope. S.W. wave. 



Portsmouth . 29-53 + 0-24 S.W. 6 



Liverpool . . 29-42 + 0-18 S.S.E. 3 



Ardrossan . . 29-35+0-07 S.S.E, -3 



Fourth zone above trough, posterior slope. S.W. wave, 



Toulon. . . 29-84 + 0-10 S.S.AV. -1 



Lyons 



Charleville . 29*74 + 0-19 S.W. 6 



Paris . . . 29-72 + 0-22 S. 2 



CapeGrisNez 29-59 + 0-20 S.W. 5 



Dover . . . 29-58 + 0-20 S.W. +5 



London . . 29-52 + 0*20 S.S.W. -3 



