observations on the question of aberration cannot be certainly pronounced until the autumn observations shall have been made; but supposing the geodetic latitude to be accordant with the astronomical latitude, the result for aberration appears to be sensibly the same as with ordinary telescopes.—­Several years since, I prepared a barometer, by which the barometric fluctuations were enlarged, for the information of the public; its indications are exhibited on the wall, near to the entrance gate of the Observatory.  A card is now also exhibited, in a glass case near the public barometer, giving the highest and lowest readings of the thermometer in the preceding twenty-four hours.—­Those who have given attention to the history of Terrestrial Magnetism are aware that Halley’s Magnetic Chart is very frequently cited; but I could not learn that any person, at least in modern times, had seen it.  At last I discovered a copy in the library of the British Museum, and have been allowed to take copies by photolithography.  These are appended to the Magnetical and Meteorological Volume for 1869.—­The trials and certificates of hand-telescopes for the use of the Royal Navy have lately been so frequent that they almost become a regular part of the work of the Observatory.  I may state here that by availing myself of a theory of eyepieces which I published long since in the Cambridge Transactions, I have been able to effect a considerable improvement in the telescopes furnished to the Admiralty.—­The occurrence of the Total Eclipse of the Sun in December last has brought much labour upon the Observatory.  As regards the assistants and computers, the actual observation on a complicated plan with the Great Equatoreal (a plan for which few equatoreals are sufficiently steady, but which when properly carried out gives a most complete solution of the geometrical problem) has required, in observation and in computation, a large expenditure of time.—­My preparations for the Transit of Venus have respect only to eye-observation of contact of limbs.  With all the liabilities and defects to which it is subject, this method possesses the inestimable advantage of placing no reliance on instrumental scales.  I hope that the error of observation may not exceed four seconds of time, corresponding to about 0.13” of arc.  I shall be very glad to see, in a detailed form, a plan for making the proper measures by heliometric or photographic apparatus; and should take great interest in combining these with the eye-observations, if my selected stations can be made available.  But my present impression is one of doubt on the certainty of equality of parts in the scale employed.  An error depending on this cause could not be diminished by any repetition of observations.”—­After referring to the desirability of vigorously prosecuting the Meteorological Reductions (already begun) and of discussing the Magnetic Observations, the Report concludes thus:  “There is another consideration which very often