ON ATMOSPHERIC WAVES. 119 
TABLE VII.—Wave from S.W. 
Anterior Trough (A), Crest. ' | Posterior Trough (P). £ 
Station. |Epochof Transit.} Altitude. ||Epoch of Transit.| Altitude, |/Epoch of Transit,| Altitude, 
j d h{Eng. in, d h Hing. in. d h/|Eng. in. 
Greenwich .|March 20 0} 29°672 ||March 20 22*| 29-718 '|March 21 20) 29-420 
Munich ..... 5 20 15| 30:238 » 2111 | 80342 | ,, 22 4) 30-218 
Prague....| . 21 2) 30038 |) ,, 2118] 30112 | ,, 22 16| 29°988 
Co-ordinates. 
Altitude from {Amplitude | Diff, Anterior and 
Station, PosteriorTrough.} in Time. | Posterior Troughs. 
Eng. in. hours. |A—P. Eng. in. 
Greenwich . +298 44 +252 
Munich ..... 24 37 020 
Prague....+- 124 38 050 
The next and fifth wave that transited the area was from the S.S.W,; the 
anterior trough was obliterated, as before noticed ; shortly before the crest 
of the succeeding wave of this system passed ; the W.N.W. system again made 
its appearance ; the anterior trough of the third observed wave passed Munich 
March 27:4. The following Table exhibits its features: it is altogether a 
much larger wave than the first. 
TasBLeE VIII.—Third observed Wave from W.N.W. 
Anterior Trough (A). Crest. Posterior Trough (P). 
Station. [Epoch of Transit.} Altitude. |/Epoch of Transit.| Altitude. Epochof Transit.) Altitude. 
h | Eng. in. - d h | Eng. in. 
' d_ hj Eng. in. d 
Greenwich .|March 26 4] 29°631 ||March 30 2| 29-998 ||April.. 1 16 | 29°596 
Munich ..... ” 27 = 4| 30°123 “4 30 18} 30:390 + 2 12 | 29°884 
Prague....-- on 27 «6| 29-947 re 30 20) 30-071 ei 2 10 | 29:674 
Co-ordinates. 
Station. Altitude from |Amplitude | Diff. Anterior and 
PosteriorTrough.| in Time, | Posterior Troughs. 
P Eng. ineh. hours. |A—P, Eng. inch. 
Greenwich . 402 156 035 
Munich ..... 506 152 239 
Prague...... 397 148 273 
The minimum from W.N.W,, March 30:4, appears to have been of a secon- 
dary character, that is, it was not a true trough, but was most probably pro- 
duced by the apex of the third S.S.W, wave which transited during the pas- 
sage of the anterior slope of the wave. During the transit of the posterior 
slope, the anterior slope of a small wave from S.W. passed. 
The 10th of March was characterized by exhibiting the highest barometri- 
cal reading during the year. The two highest readings of the month occurred 
* A maximum occurred March 20 : 2, two hours after the transit of the anterior trough, 
altitude 29°699. The very short interval between the anterior trough and this maximum 
most probably arose from the depressing influence of the posterior slope of the 8.S.W. wave, 
‘which passed Greenwich March 19:14, The semi-interval of the S.S.W. wave would oc- 
‘easion its minimum to pass Greenwich March 21 : 16, four hours earlier than the posterior 
trough of this, so that it is highly probable that the great depression then observed resulted 
é from both troughs. 
