126 REPORT—1845. 
mingham, South Bishop, and St. Catherine’s Point, from November 6 : 21 to 
7:1, leads to the very interesting fact that the anterior slope of this wave 
extended in the direction from Glasgow to St. Catherine’s Point. In the 
Report of last year we have this statement, “that a line cutting the crest of 
wave A 1 transversely appears to have passed through Genevaand Brussels.” — 
Report, 1844, p. 270 (2.). Now the line joining Glasgow and St Catherine's 
Point is nearly parallel with that joining Geneva and Brussels, anda line cut- 
ting the crest of wave A 1 transversely appears to have passed through Glas- 
gow and St. Catherine’s Point at 6:21. There can be but little doubt that 
from results so nearly similar at pairs of stations a considerable distance from 
each other and at epochs separated by an interval of 48 hours, we have iden- 
tified a distinct and well-developed wave. It will be the object of future 
research to trace this wave entirely across the area. 
Wave A°. 
The large wave alluded to in the remarks on B? is designated A°. Table XII. 
exhibits the barometric differences or variations at the stations on the line 
Scilly to Longstone ; at November 7 : 21, the stations Bardsey, South Bishop 
and Scilly, experienced a rise indicating the transit of the crest ; the greatest 
curvature occurred on this line at 8: 15, and the posterior trough at9:3. By 
combining these epochs we have the principal phases of the posterior slope 
of this wave ; all these phases occur on the same line, clearly indicating that 
they are connected, and result entirely from a distinct and different cause to 
that which produced the bulge or posterior slope of A 1. 
Tase XII. Wave A°. 
Barometric Differences every six hours, exhibiting the Phases of A®, 
Epochs. |Longstone.| Bardsey. |Sth.Bishop. Scilly. Phases. 
6 21 |— -010 | — -O11 | — -010 | +4 -048 
7 3 |— -:040 | — -031 | — :010 | — -041 
9 | — -051 |— -020 | — -000 | — -018 
15 | — ‘161 | — -031 | — -000 | — +029 
21 |— -071 |+4 -041 | 4+ +020 | +4 -032 | Apex. 
8 3 |— 094 | — -311 | — -216 | — -103 
9 | — -142 | — +152 | — -165 | — -104 
15 | — -277 | — -206 | — -126 | — °217 | Greatest curvature. 
21 |— 174 | — °169 | — -299 | — -147 
9 3 |— ‘071 |— :073 | — -083 | — -108 | Posterior trough. 
During the whole of this period B° exerted its elevating tendency. 
The projections of the synchronous curves for Munich, Prague, Geneva, 
Brussels, Paris, Haisboro, Greenwich, St. Catherine’s Point, Birmingham, 
Bardsey, South Bishop, and Dublin, November 8: 15 to 9: 3, exhibit four di- 
stinct areas of elevation, so that there are only certain curves of the group that 
intersect from the passage of B°; the remaining differences most probably 
arise to a great extent from the transit of A° 
The crest of A° passed Scilly to Bardsey, November 7:21 
The trough passed Scilly to Bardsey, ...November 9: 3 
diff. 30 hours 
Half breadth of wave in time ...........csseeeeseeeeeeeeee SO hours 
Altitude of crest at South Bishop. .................. 30°317 
Altitude of trough at South Bishop............0.+0 . 29°428 
"889 diff. 
Altitude of wave from posterior trough ............ ‘889 inch.” 
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