on July 21st by a letter in the Athenaeum addressed to Sir Robert Inglis, in terms so strong and so well supported that Sir James South was effectually silenced.”  The following extract from a letter of Airy’s to the Earl of Rosse, dated Dec. 15th 1846, will shew how pronounced the quarrel between Airy and South had become in consequence of the above-mentioned attack and previous differences:  “After the public exposure which his conduct in the last summer compelled me to make, I certainly cannot meet him on equal terms, and desire not to meet him at all.” (Ed.).—­“In the Mag. and Met.  Department, I was constantly engaged with Mr Charles Brooke in the preparation and mounting of the self-registering instruments, and the chemical arrangements for their use, to the end of the year.  With Mr Ronalds I was similarly engaged:  but I had the greatest difficulty in transacting business with him, from his unpractical habits.—­The equipment of the Liverpool Observatory, under me, was still going on:  I introduced the use of Siemens’s Chronometric Governor for giving horary motion to an Equatoreal there.  I have since introduced the same principle in the Chronograph Barrel and the Great Equatoreal at Greenwich:  I consider it important.—­On Feb. 13th I received the Astronomical Society’s Medal for the Planetary Reductions.—­In the University of London:  At this time seriously began the discussion whether there should be a compulsory examination in matters bearing on religious subjects.  After this there was no peace.—­For discovery of Comets three medals were awarded by Schumacher and me:  one to Peters, two to De Vico.  A comet was seen by Hind, and by no other observer:  after correspondence, principally in 1848, the medal was refused to him.—­With respect to the Railway Gauge Commission:  On Jan. 1st, in our experiments near York, the engine ran off the rails.  On Jan. 29th the Commissioners signed the Report, and the business was concluded by the end of April.  Our recommendation was that the narrow gauge should be carried throughout.  This was opposed most violently by partisans of the broad gauge, and they had sufficient influence in Parliament to prevent our recommendation from being carried into effect.  But the policy, even of the Great Western Railway (in which the broad gauge originated), has supported our views:  the narrow gauge has been gradually substituted for the broad:  and the broad now (1872) scarcely exists.—­On June 20th Lord Canning enquired of me about makers for the clock in the Clock Tower of Westminster Palace.  I suggested Vulliamy, Dent, Whitehurst; and made other suggestions:  I had some correspondence with E. B. Denison, about clocks.—­I had much correspondence with Stephenson about the Tubular Bridge over the Menai Straits.  Stephenson afterwards spoke of my assistance as having much supported him in this anxious work:  on Dec. 11th I was requested to make a Report, and to charge a fee as a Civil Engineer; but I declined to do so.  In January I went, with George Arthur Biddell, to Portsmouth, to examine Lord Dundonald’s rotary engine as mounted in the ‘Janus,’ and made a Report on the same to the Admiralty:  and I made several subsequent Reports on the same matter.  The scheme was abandoned in the course of next year; the real cause of failure, as I believe, was in the bad mounting in the ship.