ON ATMOSPHERIC WAVES. 127 
November 9: 3 we have the following altitudes reduced to the level of the 
sear November 9:3, Munich ..........ccsccseessseee veeee 30°256 
November 9:3, Bardsey .. ......ssessescececseseerses 29°38 
“871 diff. 
The close approximation of these differences appears to indicate that the 
slope from Munich to Bardsey was due to, and a representation of, the form 
of the posterior slope of A°, and that at this epoch the crest of the wave was 
situated near Munich; if so, we have for the first approximate amplitude and 
progress of this wave the following numbers :-— 
Amplitude...... 1856 miles 
Progress.......... 31 miles per hour 
Wave A 2. 
Taste XIII. 
Barometric Differences arising from the Anterior and Posterior Slopes of A 2. 
Epochs. | Dublin. | Bardsey. | Dublin. + Phases. ° 
8 21 |m29°391 | 29-458 | — -067 | Anterior trough. 
9 3 395 Im °385 | +°-010 
9 530 468 |+ 062 9 3 F 
15 | 576 lm +537 |+ -039 |9 9} | Anterior slope. 
21 555 506 |-+ 049 | Crest. 
10 3 323 342 | — -019 110 3 Posterjor sl 
9 189 | 208 | — -019 j10 9 f « S¥enOT Slope. 
15 021 | 28-979 | + :042 | Posterior trough. 
9:15 m Dublin. m Bardsey. Crest of B°. 
This Table exhibits the barometric differences at Dublin and Bardsey 
arising from the transit of wave AQ; it is an instance in which the transit of 
a crest is rendered apparent from the relative changes of pressure at the 
stations, although the barometer is falling at both from the passage of the 
posterior slope of B°. The following are the elements of the wave :— 
Wave A2. Between Bardsey and Dublin. 
Anterior Trough. Crest. Posterior Trough. 
1842. November 9:2 November 10:2 November 10: 14 
Amplitude in time, 36 hours. 
Elements of Waves. 
In the following Table the elements of the waves hitherto detected are 
brought together in one view. It is necessary to mention, that, from the na- 
ture of the inquiry and the present state of the investigation, these numbers 
are subject to correction. 
TasLeE XIV. Elements of Waves, Nov. 6 to 12, 1842. 
Epoch of | Amplitude. lyelocity, 
é 
a 2 Epoch of Epoch of Dian OP eRe Loe wr: | AS 
ES Direction: ifetiar Tough: Ren., ‘Trough Time Miles, permed ay 
é h d h mjd bh mj} bh by 
BolScilly to Longstone. ......s+sssseesses Nov. { FL t| 9 18 O11 0 30] 102] 2600] 25 
B}\Scilly to Longstone. ...............008 FPN BAW BW Gh HOP aa aah 341] 25 
AolSouth Bishop to St. Catherine’s Point.|...........s00e00 721 019 3 O} 60/1856) 31 
Ail J Glasgow to St. Catherine’s Pt. 
Banedein hy Wenevn ra Oe Lirig  PeReee Ted esa toy Cet LSS deditineii. 
A2/Dublin to Bardsey .....0...s0eeses scene » 9 2 110 2 O10 14 OF 36)1........ 
It appears highly probable that the direction of wave A? was similar to that 
of wave A! which it succeeded. The direction of wave A! is well-determined, 
