166 . REPORT—1846. 
my inquiries. The interesting conversations on this and kindred subjects that 
Ihave had with him during the last ten years, have greatly assisted me in my 
labours. I am also indebted to GEorcr GwittT, Esa. and to E. Jonnston, 
Esgq., for the assistance afforded by those gentlemen, in my earliest endeavours 
to observe and trace a complete wave. 
To the gentlemen named in the third column of Table I., I am indebted 
for observations at the stations recorded in the first column of that table, 
which have been made with great care, and mostly at the hours named in the 
instructions. 
I cannot close this report without remarking, that many of the observations 
which have thus been collected and partially discussed, owe their existence en- 
tirely to the auspices of this Association ; and should the further discussion 
of them be entrusted to my hands, the same care shall be manifested which 
I have endeavoured to exhibit in my previous labours; and by examining 
them in every point of view and under every possible aspect, I trust the re- 
sult will be such as fully to accord with the great object of the Association ; 
and should no new facts be elicited, yet it is to be hoped that these observa- 
tions, called for as they have been by the Association, will confirm the sug- 
gestions, and throw considerable light on the labours of several eminent 
meteorologists, so that in these respects subjects at which we have only ob- 
tained a glance, may be brought fully into view, and thus by means of these 
observations the science in some degree advanced. 
Of the grant of £7 placed at my disposal I have expended £3 3s. 3d. As 
nearly the whole of the observations on the return of the great wave in the 
autumn of 1845, as well as those during the previous October are at present 
unreduced, I respectfully request a continuance of the grant. 
W. R. Birt. 
Postscript, April 10, 1847. 
During the period between the sitting of the Association and this report 
passing through the press, I have been furnished, by the liberality of the 
Royal Society, with the magnetical and meteorological observations made 
during the year 1842 at various stations in the Russian empire. These 
stations embrace’an area extending over 195 degrees of longitude. The ob- 
servations at St. Petersburgh, the nearest station to those given by Mr. Brown, 
in a great majority of cases fully confirm the results arrived at in the pre- 
ceding discussion, and in others the views obtained by means of Mr. Brown’s 
observations are corrected, and considerable light thrown on the real character 
of the smaller waves traversing Great Britain and Ireland. In addition to 
these advantages, the Russian observations, in connexion with others, exhibit 
to us the vast area over which the slopes of these waves extend, so vast that 
they actually approach in the extent of their sweep and the regularity of their 
progress to the tide-waves of the ocean. But this is not all ; the records of the 
Russian observatories contain ample materials for carrying out the suggestion 
of Sir John Herschel, expressed in the close of his Report on Meteorological 
Reductions (Report, 1843, page 98), “ that when dealing with undulations of 
such extent, it is by no means a visionary speculation to consider the possi- 
bility of tracing them over the whole of our globe.” The area embraced by 
Mr. Brown’s and the Russian observations extends over 235 degrees of lon- 
gitude ; and it is apparent from the observations themselves, that the greater 
fluctuations are readily traceable. Our Colonial Observatory at Toronto will 
carry on the observations from Sitka, and the stations on the eastern shores 
of America will enable us to trace the waves from the eastern to the western 
shores of the Atlantic, over the vast continents of Europe and Asia. 
The following table contains the altitude of the barometer at St. Peters- 
burgh during the twenty-six days included by Mr. Brown's observations. 
———— 
