272 REPORT — 1844. 



arising from the permanent depression before noticed, a normal wave, or from 

 A 1. See (5.) A slight rounding of this curve is seen very near Longstone, 

 and the depression between it and Scilly is developed as the wave B 1 ad- 

 vances. The curve at 9.15 e exhibits the crest of wave B 1 passing South 

 Bishop, and indicates the wave to be very small. Tlie blue curves on all the 

 lines are descending ; this would result from the passage of the posterior slope 

 of A 1. The curves ascend as the anterior slope of B 1 approaches: this is 

 found to be the case Nov. 9.9, Scilly to Longstone and Geneva to Brussels. 

 Brussels does not exhibit this rise, as neither the trough of A 1 nor the apex 

 of B 1 has arrived at this station. 



(8.) Wave A 1. — The trough of this wave is now passing Longstone, 

 Bardsey, and South Bishop ; the bulge at or near Birmingham is lessened, 

 and it begins to appear eastward of Haisboro (see curves b b, figs. 3 and 2, 

 Plate XLIV.). We have thus satisfactorily traced the progression of this bulge 

 from the north-west, past South Bishop, and also in the neighbourhood of 

 Haisboro ; there can be no question that its longitudinal direction was con- 

 siderable, but we have not at present sufficient data for determining it. 



(9.) Wave B 1. — The anterior trough of this wave now enters on the area 

 and passes Geneva and Scilly ; the wave also enters, producing a rise of the 

 barometer, at both stations. 



(10.) Wave A 2 (or shoulder). — This wave has now entered on the area 

 72 miles (from Dublin to Bardsey) ; the extremity of the curve b, fig. 3, Plate 

 XLIV., tinted red, shows the barometric rise due to this wave. 



(11.) Nov. 9.3 Model exhibits the general slope of A 1 (or normal) in 



the same direction as before ; the trough between Dublin and Birmingham is 

 brought fully into view. 



(12.) Nov. 9.5. — Dublin attains the altitude of South Bishop, and the two 

 curves continue nearly identical for the next nine hours ; Dublin rising from 

 the anterior slope of A 2, combined with that of B 1 and South Bishop, prin- 

 cipally from the latter wave (see coloured diagrams, fig. 2, Plate XLIIL). 



(13.) Nov. 9.9.— Wave A 1, fig. 3, curve c, Plate XLIV. As wave B 1 ad- 

 vances, the anterior slope will occasion a rise, while the barometer is falling 

 from the passage of the posterior slope of the wave A 1. This is particularly 

 observable at Birmingham, and a secondary trough is occasioned in con- 

 sequence between this station and Brussels. The normal slope is however 

 clearly seen, for the minimum, which now is situated a little north-west of 

 Birmingham, is considerably above the level of the minimum of the last terra. 



(14.) The bulge, which towards the north-east assumes a more gentle and 

 flowing character, passes beyond Brussels towards Geneva at this term ; this 

 is exhibited in curve c (red) of fig. 2, Plate XLIV. 



(15.) Wave B 1. — The crest of this wave passes over Scilly, and at the 

 same moment its anterior trough passes St. Catherine's Point ; the half-breadth 

 cannot therefore extend much beyond South Bishop, or about 1 50 miles. From 

 the red curve d, in fig. 1 , Plate XLIV., it would appear to form a part of the 

 slope of the depression before-mentioned. Since the passage of the posterior 

 trough of A 1 at Longstone, Nov. 9.3., the barometer has risen at this station 

 from the anterior slope of A 2 alone, amount -099. As this slope passes 

 over Longstone, the anterior trough of B 1 becomes more conspicuous on the 

 slope of the depression, and is fully developed next term. 



(16.) Nov. 9.9.— Model. The approach of the trough of A 1 is clearly 

 seen on the model for this term, also its direction as it cuts a line joining St. 

 Catherine's Point, Bardsey and Dublin obliquely, and is at right angles to a' 

 line joining Geneva and Brussels. According to this view, it would appear 



