ON ATMOSPHERIC WAVES. ° 153 
The posterior slope of crest No. 5:is well and strikingly developed, and the 
advancing slope of crest No. 4, the succeeding wave to that of No. 2, is in- 
dicated by the line of greatest pressure, Orkneys to Paris, *72 (see Nov. 2, 
when the first wave from the N.W. was coming up). 
Symmetrical Wave.—London is situated under the posterior slope of crest 
~ No. 5 and anterior slope of crest No. 4, and slightly rising from the latter. 
: 
J 
November 17, 1842. 
Crest No. 7. 
ON eer 
Crest No. 4. 
Anterior slope, Crest No. 4. Anterior slope, Crest No. 7. 
Max. Belfast .... 30°51 Max. Belfast .... 30°51 
Shields .... 30°45 Orkneys... .~ 30°35 
Bristol .... 30°36 Christiania.. 29°94 
Plymouth .. 30°36 Posterior slope, Crest No. 7. 
London .... 30°36 Max,,. Belfast. ... 30°51 
Prarie iat 6 ae. 29:99 rl) sion 6 30°31 
Slopes.—Lines of greatest diminution of pressure. 
Belfast to Paris........ "52 
Belfast to Christiania .. *57 
Currents.—Wind on anterior slope of Crest No. 4, N.E. 
» posterior ,, > Sil des 
In the south-west of Ireland and England the wind is easterly, being the re- 
sultant of these forces. 
The anterior slope of crest No. 4, extending from Belfast to Paris, is well- 
developed with its proper wind N.E. This anterior slope may be advantage- 
ously compared with the anterior slope of crest No. 2, which occupied the 
same area on the 5th (interval twelve days). The altitude on that occasion 
from Paris to Belfast was equal to °80, on the present it is only equal to ‘52. 
This may to a certain extent be explained by the presence of crest No. 7, 
which this day passes over Belfast, so that this crést elevates the anterior 
slope of No. 4. The anterior slope of crest No. 7 is well-developed towards 
the Orkneys and Christiania, and the diminution of pressure resulting from 
_ the posterior slope is conspicuous at Cork; we have consequently two crests 
_ traversing the area and crossing each other at Belfast. 
Crest No. 4 passes the Orkneys, Belfast, Shields and Cork this day. 
Symmetrical Wave.—London is situated nearly under the crest of No. 7 
_ and under the anterior slope of crest No. 4, and rising from the latter. 
November 18, 1842. 
Crest No. 7. 
N.W.——______———-S..E.. 
Crest No. 4. 
S.W.——_——__——_—_——_N.E. 
Transit of the Crest of the Great Symmetrical Wave. 
a Anterior slope, Crest No. 4. Crest No. 4: 
— Max. London .... 30°53 Max. London.... 30°53 
WAPIG/ <i! 2 1,42 D010 Plymouth .. 30°47 
Bristol .... 30°42 
Shields .... 3042 
Christiania,. 30°11 
