134 Mr. W. U. Birt on Atmospheric Waves, 



29'3, accompanied by an approacli to a cyclonic movement of 

 wind; second, a stream of N.E. winds reaching the force of a 

 gale in the E. of Scotland; third, a stream of S.W. winds over 

 the N.W. of France drawn over the central parts of England 

 into the vortical movement around the point of lowest pressure ; 

 fourth, the posterior slope of a S.W. wave extending from Va- 

 lencia to Cuxhaven. These arrangements appear in a great 

 measure to have been brought into existence by the diminution 

 of pressure in the west of Ireland. 



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

 west of Europe on April 23, 1872. 



First zone on S.W. of anterior slope above trough of S.W. wave, 



Barom. 

 Biarritz . . 29*55 + 0-19 

 Rochefort . . 2949 + 0-19 

 L'Orient . . 29-28 + 0-15 

 Scilly . . . 29-04 -f 0-1 7 

 Roche's Point. 29-00-0-06 

 Valencia . . 29-14-0-11 

 Trough of N.W. wave between Scilly and Roche's Point. 



Trough of S.W. wave. 

 Plymouth . . 29-09 + 0-12 S. +5 



Pembroke . . 28-99-0-02 S.S.E. +8 



Trough of N.W. wave N.W. of, but near Pembroke; the baro- 

 meter having fallen by the progression of the S.W. trough, the 

 two trous'hs intersected near Pembroke. 



Direction. 



Force 



s. 



-4 



S.W. 



5 



S.W. 



+ 8 



w.s.w. 



+ 6 



N.N.E. 



-5 



N.E. 



-5 



•O' 



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



Portsmouth . 29'29 + 0-14 S.S.W. +6 



I-Iolyhead . . 29*14 E. 3 



Greencastle . 29-25-0-15 N.N.E. +3 



Trough of N.W. wave between Portsmouth and Holyhead. 



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



Toulon . 

 Lyons . 

 Charleville 

 Paris 



Ardrossan 

 Trough of N.W 



29-74 + 0-11 S.S.W. 4 



29-61 S.E. 



29-55 + 0-21 S.W. 6 



29-50 + 0-19 S. 2 



CapeGrisNez f>9-39 + 0-15 S.S.W. +5 

 Dover . 

 London 



Liverpool . . 29-24 + 0-02 E.S.E. +3 



. 29-28-0-08 E.N.E. -4 



wave between London and Liverpool, 



29-38 + 0-16 S.W. 4 



29-32 + 0-12 S. 4 



