142 REPORT—1846. 
 Slopes.—Lines of greatest diminution of pressure. 
” ” ” Zs ” Paris wees ee ee +29 
Currents.—Wind on N.E. side of Crest No. 1, N.W. 
gt aS. Wem) 85 bs e changing to S.E. 
A decided crest or line of maximum pressure passes across Ireland and 
England with a general direction N.W.—S.E. The stations in the first 
column are N.E. of this crest, the pressure gradually decreasing. The line 
of greatest diminution is Belfast to Christiania. This indicates the anterior 
slope of the wave; altitude from Christiania ‘55. The wind along the slope 
is N.W. The stations in the second column are S.W. of the crest; at these 
stations the pressure. but slightly differs from the maximum; the wind ap- 
pears to be changing to S.E. in the S.W. part of our island; this wind is 
that due to the posterior slope. The diminution of pressure from Belfast to 
Paris =*29. This indicates the anterior slope of a wave at or nearly at 
right angles to the former. At two stations the wind is N.E., that of the 
anterior slope of this system. 
November 2, 1842. 
Crest No. 1. 
N.W.———————_ SE. 
Crest No. 2. 
S.W. N.E. 
Anterior slope, Crest No. 1. Anterior slope, Crest No. 2. 
Max. Orkneys.... 30°23 Max. Orkneys .. 30°23 
Christiania... 30°11 Shields.... 30°19 
Belfast .... 30°18 
London .. 30°10 
Bristol .... 30°05 
Plymouth.. 30°04 
Cork... © .> 29°92 
Paris... <3: - 29°86 
Slopes.—Lines of greatest diminution of pressure. 
Anterior slope, Crest No. 2, Orkneys to Paris...... 37 
Posterior slope, Crest No. 1, ” Corks 20. “31 
Currents.—Wind on S8.W. side of Crest No. 1, mostly S.E. 
” S.E. ” ” ae afew N.E. 
The progression of the crest, which was so distinctly developed on the Ist 
towards the N.E. and the succeeding S.E. current, is most decided. The 
altitudes at Belfast and Christiania are nearly equal, indicating that the crest 
is between them. The wind, with but few exceptions, is S.E. over nearly 
the whole of Great Britain and Ireland, while at Christiania on the anterior 
slope itis N.N.W. The posterior slope from the Orkneys to Cork is well- 
exhibited. Altitude from Cork to Orkneys = °31. 
The line of greatest diminution of pressure this day, Orkneys to Paris, 
crosses that of yesterday nearly at right angles; this arises from the advance 
of the anterior slope of the wave (Crest No. 2); at a few stations the wind 
is N.E. that of the advancing slope, and these in the neighbourhood of a 
line where the wind appears to have been variable. Altitude from Paris to 
Orkneys = °37. 
