The whole number of stars in our new
working list is about 2500. It may be here mentioned that an extensive
series of observations was made, during the autumn, of about 70 stars,
at the request of Mr Gill, for comparison with Mars, Ariadne, and
Melpomene.--On Apr. 10th last, a very heavy fall of rain took
place. Between Apr. 10d. 5h. and Apr. 11d. 2h., 2.824 inch. was
recorded, and 75 per cent. of this, or 2.12 inch., fell in the eight
hours between 13-1/2h. and 21-1/2h.; and on May 7, 1 inch of rain fell
in 50 minutes, of which 1/2 inch fell in 15 minutes.--The
supplementary compensation continues to be applied with success to
Government chronometers which offer facilities for its introduction,
and a marked improvement in the performance of chronometers returned
after repair by the makers appears to have resulted from the increased
attention now given to the compensation. Of the 29 competitive
chronometers, 25 have the supplementary compensation."--With regard to
the reduction of the observations of the Transit of Venus: After
reference to the difficulties arising from the errors and the
interpretation of the language used by some of the observers, the
Report continues thus: "Finally a Report was made to the Government on
July 5th, giving as the mean result for Mean Solar Parallax 8".76; the
results from ingress and from egress, however, differing to the extent
of 0".11.... After further examination and consideration, the result
for parallax has been increased to 8".82 or 8".83. The results from
photography have disappointed me much. The failure has arisen, perhaps
sometimes from irregularity of limb, or from atmospheric distortion,
but more frequently from faintness and from want of clear
definition. Many photographs, which to the eye appeared good, lost all
strength and sharpness when placed under the measuring microscope. A
final result 8".17 was obtained from Mr Burton's measures, and 8".08
from Capt. Tupman's.--With regard to the Numerical Lunar Theory: A
cursory collection of the terms relating to the Areas (in the
Ecliptic) led me to suppose that there might be some error in the
computations of the Annual Equation and related terms. A most jealous
re-examination has however detected nothing, and has confirmed my
belief in the general accuracy of the numerical computations. I dare
not yet venture to assume an error in Delaunay's theory; but I
remember that the Annual Equation gave great trouble to the late Sir
J