In this year the cube of the Transit Circle was pierced, to permit reciprocal observations of the Collimators without raising the instrument.  This involved the construction of improved Collimators, which formed the subject of a special Address to the Members of the Board of Visitors on Oct. 21st 1865.—­From the Report to the Visitors it appears that “On May 23rd 1865, a thunderstorm of great violence passed very close to the Observatory.  After one flash of lightning, I was convinced that the principal building was struck.  Several galvanometers in the Magnetic Basement were destroyed.  Lately it has been remarked that one of the old chimneys of the principal building had been dislocated and slightly twisted, at a place where it was surrounded by an iron stay-band led from the Telegraph Pole which was planted upon the leads of the Octagon Room.”—­“On consideration of the serious interruptions to which we have several times been exposed from the destruction of our open-air Park-wires (through snow-storms and gales), I have made an arrangement for leading the whole of our wires in underground pipes as far as the Greenwich Railway Station.”—­“The Committee of the House of Commons, to whom the Greenwich and Woolwich Line of the South Eastern Railway was referred, finally assented to the adoption of a line which I indicated, passing between the buildings of the Hospital Schools and the public road to Woolwich.”—­“The Galvanic Chronometer attached to the S. E. Equatoreal often gave us a great deal of trouble.  At last I determined, on the proposal of Mr Ellis, to attempt an extension of Mr R. L. Jones’s regulating principle.  It is well known that Mr Jones has with great success introduced the system of applying galvanic currents originating in the vibrations of a normal pendulum, not to drive the wheelwork of other clocks, but to regulate to exact agreement the rates of their pendulums which were, independently, nearly in agreement; each clock being driven by weight-power as before.  The same principle is now applied to the chronometer....  The construction is perfectly successful; the chronometer remains in coincidence with the Transit Clock through any length of time, with a small constant error as is required by mechanical theory.”—­“The printed volume of Observations for 1864 has two Appendixes; one containing the calculations of the value of the Moon’s Semi-diameter deduced from 295 Occultations observed at Cambridge and Greenwich from 1832 to 1860, and shewing that the Occultation Semi-diameter is less than the Telescopic Semi-diameter by 2”; the other containing the reduction of the Planetary Observations made at the Royal Observatory in the years 1831-1835; filling up the gap, between the Planetary Reductions 1750-1830 made several years ago under my superintendence, and the Reductions contained in the Greenwich Volumes 1836 to the present time:  and conducted on the same general principles.”—­“Some trouble had been found in regulating the temperature of the Magnetic Basement, but it was anticipated that in future there would be no difficulty in keeping down the annual variation within about 5 deg. and the diurnal variation within 3 deg..—­Longitudes in America were determined in this year by way of Valencia and Newfoundland:  finished by Nov. 14th.”