Royal Astronomical Society. 308 
now happy to state have been completed. The first is an extension 
of the catalogue of this Society, published in the second volume of 
its Memoirs, with certain additional columns that will render it of 
greater value to the practical astronomer. The British Association 
have granted the funds requisite for the publication of this work, 
which will soon be sent to the press. The next two catalogues con- 
tain the reduction of the stars observed by Lacaille at the Cape of 
Good Hopé, and of those observed by Lalande at the Zcole Militaire 
at Paris. These catalogues are finished, and the British Association 
propose to apply to government for agrant of the requisite funds 
for printing them. 
The Council, while reviewing the subjects connected with astro- 
nomy which have been brought before the Society since the last 
anniversary meeting, beg particularly to call the attention of the 
meeting to the labours of Professor Henderson and of M. Hansen. 
It will be remembered that in the President’s address, on delivering 
the Gold Medal to M. Bessel for his researches on the parallax of 
the double star 61 Cygni, honourable mention was made of the 
labours of Professor Henderson in a similar inquiry with respect to 
a Centauri, founded on the reduction of his own observations made 
with the mural circle at the Cape of Good Hope. This indefatigable 
astronomer has within the present year presented us with the result 
of a series of observations made at his request by Mr. Maclear 
expressly for the purpose ; and which, extending as they do con- 
siderably heyond a year, or the time during which the parallax goes 
through all its changes, and averaging from eight to ten observa- 
tions of the double altitude of each star in every month, will at 
least afford good ground for determining whether the problem of 
the parallax of this remarkable star is likely to be solved by meri- 
dian observations. But without entering into the question of the 
evidence offered by the observations, our thanks are certainly due 
to the untiring zeal of Professor Henderson in prosecuting this 
most important but too much neglected branch of astronomy, and 
in this expression the Council feel sure that the meeting will join, 
The meeting will scarcely need to be reminded of the discovery 
of M, Hansen, to which allusion has been made, his letter having 
been so recently read before the Society. The want of some 
general method of expressing the perturbations of a body moving 
in an ellipse, whose eccentricity and whose inclination to the 
ecliptic are not small, has been, as it were, the opprobrium 
of modern physical astronomy. The method which has hitherto 
been employed of dividing the orbit into several portions, calculating 
the differentials of the perturbations for the points of the orbit 
thus decided on, and then integrating them by mechanical quadra- 
tures, seems scarcely worthy of the present state of analytical 
science; andhas put the patience of astronomers to the severest 
trials as often as the return of an interesting comet, such as 
Halley’s or Encke’s, has made necessary the rigorous computa- 
tion of its disturbances by the larger planets. Still, such has been 
