the Britannia and Conway tubular bridges were made last autumn.  For this purpose I detached an Assistant (Mr Carpenter), who was aided by Capt.  Tupman, R.M.A.; in other respects the enterprise was private and at private expense.—­The rates of the first six chronometers (in the annual trials) are published, in a form which appears most likely to lead to examination of the causes that influence their merits or demerits.  This report is extensively distributed to British and Foreign horologists and instrument-makers.  All these artists appear to entertain the conviction that the careful comparisons made at this Observatory, and the orderly form of their publication, have contributed powerfully to the improvement of chronometers.—­Very lately, application has been made to me, through the Board of Trade, for plans and other information regarding time-signal-balls, to assist in guiding the authorities of the German Empire in the establishment of time signals at various ports of that State.  In other foreign countries the system is extending, and is referred to Greenwich as its origin.—­The arrangements and preparations for the observation of the Transit of Venus occupied much attention.  With regard to the photoheliographs it is proposed to make trial of a plan proposed by M. Janssen, for numerous photographs of Venus when very near to the Sun’s limb.  On Apr. 26th the engaging of photographic teachers was sanctioned.  Observers were selected and engaged.  A working model of the Transit was prepared, and the use of De La Rue’s Scale was practised.  There was some hostile criticism of the stations selected for the observation of the Transit, which necessitated a formal reply.—­Reference is made to the increase of facilities for making magnetical and meteorological observations.  The inevitable result of it is, that observations are produced in numbers so great that complete reduction becomes almost impossible.  The labour of reduction is very great, and it is concluded that, of the enormous number of meteorological observations now made at numerous observatories, very few can ever possess the smallest utility.—­Referring to my Numerical Lunar Theory:  on June 30th, 1873, a theory was formed, nearly but not perfectly complete.  Numerical development of powers of a/r and r/a.  Factors of corrections to Delaunay first attempted, but entirely in numerical form.”—­In March of this year Airy was consulted by Mr W.H.  Barlow, C.E., and Mr Thomas Bouch (the Engineer of the Tay Bridge, which was blown down in 1879, and of a proposed scheme for a Forth Bridge in 1873) on the subject of the wind pressure, &c., that should be allowed for in the construction of the bridge.  Airy’s report on this question is dated 1873, Apr. 9th:  it was subsequently much referred to at the Official Enquiry into the causes of the failure of the Tay Bridge.—­At the end of this year Airy resigned the Presidency of the Royal Society.  In his Address to the Society on Dec. 1st he stated his reasons in full, as follows:  “the severity of official duties, which seem to increase, while vigour to discharge them does not increase; and the distance of my residence....  Another cause is a difficulty of hearing, which unfits me for effective action as Chairman of Council.”