ON ATMOSPHERIC WAVES. 159 
November 26, 1842. 
Crest No. 13. 
S.E. 
Crest No. 6. 
PN ns eid EE oe EN 
Crest No. 15. 
NENA eee eee ee 
Max. Christiania,. 29°57 
Orkneys.... 29°10 
Min. Shields .... 28°99 Trough. 
Belfast «... 29:04) 
\ Under posterior slope, No. 13. 
Corks css 29°04: 
rea? Bee ai + Under anterior slope, No. 15. 
Pariatisé.. 803 29°17 
Plymouth .. 29°20 
Paristie gee 29°17 ) 
London .... 29°17 | 
Bristol .... 29°14 pe posterior slope, No. 6. 
Belfast .... 29°04 
Cork:.4 4% . 29°04 j 
Slopes.—Lines of greatest diminution of pressure. 
Posterior slope, No.13. Christiania to Shields .. °58 
eS 3 gy Oe.” Paris tot @ork: men en: 13 
Anterior ,,  ,, 15. Plymouth to Belfast .... °16 
Currents.—W ind on posterior slope of Crest No. 6, S.W. 
” ” ” » » 15, N.W. - 
The advance of the anterior slope of crest No. 15 is well-seen from the 
observations of this day. The wind proper to it, N.W., has increased in the 
S.W. portion of the area. It appears that the motion of the waves—crests 
Nos. 13 and 15 with the included trough—is slower than that of the waves, 
erests Nos. 3 and 5 (see Nov. 11 and12). The same arrangement of stations 
as to the distribution of pressure which required only ene day to establish 
in the case of waves 3 and 5, has occupied éwo days in the case of waves 13 
and 15. The distribution of pressure was similar on the 11th and 24th; it 
was also similar on the 12th and 26th. 
Section III. 
Results of the foregoing Discussion, 
In collecting the results of this discussion, I have arranged in Tables XI. and 
XII. the principal lines of diminution of pressure; the succession of waves 
as well as the distinct systems become very apparent from these tables. The 
succeeding Tables XIII.and XIV. exhibitthe principal features of the respective 
waves of each system. The most prominent result appears to be the con- 
firmation of Prof. Dove's suggestion of parallel and oppositely directed cur- 
rents. The diagrams of the wind in connection with the barometric obser- 
vations clearly exhibit such currents, and we see by a glance at Tables XIII. 
and XIV. that the beds of these currents varied considerably in breadth. At 
the opening of the observations they were very much broader than at the 
close, and the N.W. system (waves No. 2, 4, 6) were altogether larger than 
the S.W. We have in fact two systems of waves or currents crossing each 
