BAKOMETEIC GBADIENTS. 



121 



Date. 



Jan. 16 



17 



Evening 



Morning 



Wind. 



S. 

 S. 



s.s.w. 

 s.s.w. 



s. 

 s.s.w. 

 s.w. 

 s.w. 

 s.w. 

 s.w. 



w. 

 s.w. 

 s.w. 



8 

 12 

 8 

 9 

 8 

 8 

 8 

 9 

 9 

 9 

 8 

 9 

 8 



Station. 



Holyhead - 

 Valencia 

 Penzance • 

 Plymouth ■ 

 Wejonouth 

 Portsmouth 

 Leith - ■ 

 Ardrossan ■ 

 Cape Clear 

 London 

 Yarmouth 

 Plymouth 

 Portsmouth 



Preceding 

 Gradient. 



S.W. 21 

 S.W. 25 



S.S.E. 5 



S.S.E.12 



S.W. 25 



W. 12 



W.S.W. 14 



Line. 



+14 

 +10 



+11 



+25 

 +10 



— 6 



— 2 



Liverpool — Greencastle, 

 Penzance — Roche's Point 



London — Penzance. 



Leith — Greencastle. 

 Penzance — Eoche's Point 

 London — Scarborough. 



Brest — Penzance. 



" This shows us that the only gradient exceeding 0-12 on the 16th, which 

 was not followed by a very decided fulfilment, was that of West 13 from 

 Weymouth to Liverpool. The predominating storms on the South coast 

 of England were Southerly, and had very little Westing in them. They 

 gave, however, abundant indications of their approach in the change of 

 gradient of (+ 11) in the direction S.S.E. from London to Penzance. 



" On the whole it will be seen that on the morning of the 16th there was 

 a gale at only one station, viz.. South 10 at Valencia, and on the morning 

 of the 17th there were only two, viz., S.W. 9 at Plymouth, and S.W. 8 at 

 Portsmouth, while between these two dates gales were felt at 10 stations 

 which might reasonably have been foreseen by an examination of the 

 morning reports of the 16th, on the principles laid down in the preceding 

 pages. 



(41.) What has been said previously, as to the Isobaric Lines and Baro- 

 metric Gradients, refers exclusively to the observations made and collected 

 N. A. 0. 17 



