ON ATMOSPHERIC WAVES. 45 
pics | Taste LV. 
Distribution of Crests and Troughs on November 7,1 842 :— 
‘a Phase. Locality. 
| Crest No. 1.....| Between Christiania and Alten, approaching Alten, 
| Trough between North-east of Belfast and Paris. 
Nos. 1 and 3 
| Crest No. 3 ....| South-west of Great Britain and Ireland. 
| Crest No. 2 ....| Passing south-east of the Orkneys across Scotland 
| 5 y 
ol and England. 
| 
| 
l 
| 
: 
_ The general direction of high pressure extends over Ireland, England, 
the north of France, Holland, Northern Germany, the southern parts of 
Sweden and Norway, and the central parts of Western Russia. From this 
ridge or area of high pressure to Alten tlrere is a considerable dip. 
Orkneys to Alten... 0.05.3. cceececcerse 1S 
Christiania to Alten .....eccecceccsccses ‘60 
St. Petersburgh to Alten .......2...0..06 "54 
_ It is thus apparent that the area of greatest pressure has gradually ap- 
proached the south-east, and assumed in its progress a more curvilinear direc- 
tion than it possessed at the commencement of the month. The locality in 
ich the pressure has been more constantly maintained is the northern part 
of the British Isles, the southern part of Scandinavia, and Western Russia. 
_ It would appear from the above values of the diminution of pressure to 
Alten, that the slope from the Orkneys to Alten was an anterior slope of the 
th-west system, but other considerations, especially the trough between 
nd 3, clearly show that this is not the case ; the depression at Alten results 
from the posterior slope of the Scandinavian wave, and the altitude at the 
Irkneys evidently results from the wave-crest No. 2, which passed that 
n on the Sth. 
Nov. 8. At 9 p.m. of the 7th the barometer passed a minimum at Alten, 
ue 29°34, and at $ p.m. of this day it had risen to 29°60, a maximum. 
s very likely that this maximum is crest No.1. This movement, and the 
from the posterior slope of crest No. 2, brings the northern stations to a 
er equality of level. 
Taste V. 
of greatest pressure, November 8, 1842, slightly above 30 inches :— 
South-west. Central. North-east. 
k......-- 30°01 | Belfast ...... 30°04 | St. Petersburgh 29:96 
mouth .... 30°13 | London...... 30°08 | Lougan...... 29:98 
Bristol ...... 80°07 
Babs ig sdrcvsie «0529790 
Geneva Sat cjaate ORO 
of the barometric fall which commenced on this day (see Report, 
| 1846, p. 147):— 
Alten eeeeveeeeeeeeereeeee ee eezeeeeeeeene 29°60 
Christiania eeee ‘e eeeeeeeeoereeee ee ee toe 29°67 
Orkneys eeeeteoeeveeneeeeeeeaereeeeeeseaeee 29°63 
