ANNIVERSARY ADDRESS. 3 
These finished, he began and completed the description of the 
plants of Australia,—perhaps the most extensive local exotic flora 
ever published. 
The most important work of his life was carried out in conjune- 
tion with Sir Joseph Hooker, being a revision after examination 
of the known “Genera of Phanerogams.” This work was begun in 
1860, and not finished until 1883. The strain of this great work 
over, and his aim accomplished, his health seems to have failed, 
and after a few months of weakness he died, September 20, 1884. 
Had I consulted my own inclination, and perhaps ease, I should 
in what follows have prepared a résumé of the science of the past 
twelve months ; but when I came to consider such a course, I found 
that the harvest in Europe had been well gathered, and that here 
the President of another Society had not only harvested first all 
that was of interest in the Colony, but had gathered in even our 
own little contributions to the general stock of human knowledge; 
and in reading to you the list of papers read before our Society 
last year, I felt that I was but repeating what had already been 
published. I have therefore turned to some unpublished items 
of scientific news, in the hope that they may prove interesting to 
you. The telegraphic determination of the longitude of Australia 
was, so far as the observations are concerned, completed some time 
since; but there were several links in the chain incomplete when 
Mr. Todd published the first statement of results, and, since the 
values for these sections now accepted differ from those used by 
Mr. Todd, his statement was incorrect. It may seem strange to 
some of the members that there should be any question about 
what is determined accurately ; but no determinations of longi- 
tude are absolute—they are only relatively accurate, and where 
the observations are few in number and disagree it is necessary 
to determine, or perhaps it is better to say “agree,” which shall 
be accepted. For instance, the longitude of Singapore, one of the 
links in the chain, has been determined twice, and the values 
differ by 0-78s., and it was impossible to get a new determination. 
Now one of the two had been obtained by using the telegraph line 
