ON ATMOSPHERIC WAVES. 127 
‘Transit of anterior trough, Nov. 9. 
Transit of apex ........ » 16 
Transit of posterior trough ,, 23. 
Amplitude in time, fourteen days. 
1830. The symmetry of the great wave not so apparent; the subordinate 
undulations strongly marked. 
Transit of anterior trough, Nov. 15. 
Branstt of ‘apex 5...) leisy) of GBs 
1831. The symmetry of the great wave clearly observable; its amplitude 
much smaller ; éwo subordinate waves, one on the anterior, the other on the 
posterior slope, well-developed. 
Transit of anterior trough, Nov. 6. 
Transit of apex ........ ys, bd 
Transit of posterior trough ,, 165. 
Amplitude in time, nine days. ; 
1832. The symmetry very distinct on this occasion ; the curve somewhat 
resembled that of 1842; the two anterior and two posterior undulations well- 
developed. 
Transit of anterior trough, Nov. 9. 
Transit of apex ........ 39° GS 
Transit of posterior'trough ,, 23. 
Amplitude in time, fourteen days. 
The trough succeeding one of the posterior undulations is deeper than the 
posterior trough of the great wave, a circumstance that occurred in the year 
1845 at this station (Dublin). The similarity between the transits of the 
great wave in 1829 and 1832, especially as to time, is highly interesting. 
The remaining movements in this month were also strikingly symmetrical. 
1833. The great wave very difficult to recognize; taking the well-marked 
depressions of the seventh and twenty-first as the anterior and posterior troughs, 
and regarding the movements between these epochs as due to the great wave, 
although greatly concealed by the strongly developed subordinate waves, we 
may regard the whole as a transit of the great wave at a station considerably 
removed from the line of greatest symmetry ; the two anterior subordinate 
waves are strongly marked ; the posterior appear to be broken into a number 
of smaller undulations. 
' Transit of anterior trough, Nov. 7. 
Transit of apex ........ Pa oy 
Transit of posterior trough ,, 2i. 
Amplitude in time, fourteen days. 
1834. The great wave very distinct, the subordinate waves but slightly 
_ developed. 
Transit of anterior trough, Noy. 7. 
DCTSNBIE OPER ol 6 a udrnioscipo-cr Ltn 
Transit of posterior trough ,, 21. 
Amplitude in time, fourteen days. 
_ _ 1835, The great wave very distinct and considerably amplified ; the subors 
’ dinate waves distinct but not strongly developed. 
j Transit of anterior trough, Nov. 3. 
Transit of apex ........ CNANIGE 
Transit of posterior trough ,, 21. 
; Amplitude in time, eighteen days. 
__ 1836. The great wave extremely difficult to recognize ; two well-marked 
depressions on the 4th and 17th mark the terminations of a somewhat sym- 
metrical system of movements. If these movements may be considered as 
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