_Sir G.B. Airy, K.C.B., &c., &c., Astronomer Royal._ * * * * * ROYAL OBSERVATORY, GREENWICH, _1881, August 13_. MY DEAR MR CHRISTIE, and Gentlemen of the Royal Observatory, With very great pleasure I have received your letter of August 11. I thank you much for your recognition of the general success of the Observatory, and of a portion of its conduct which--as you remark--can scarcely be known except to those who are every day engaged in it: but I thank you still more for the kind tone of your letter, which seems to shew that the terms on which we have met are such as leaves, after so many years' intercourse, no shadow of complaint on any side. Reciprocating your wishes for a happy life, and in your case a progressive and successful one, I am, My dear Mr Christie and Gentlemen, Yours faithfully, G.B. AIRY. * * * * * Throughout his tenure of office Airy had cultivated and maintained the most friendly relations with foreign astronomers, to the great advantage of the Observatory. Probably all of them, at one time or another, had visited Greenwich, and to most of them he was well known. On his retirement from office he received an illuminated Address from his old friend Otto Struve and the staff of the Pulkowa Observatory, an illuminated Address from the Vorstand of the Astronomische Gesellschaft at Berlin signed by Dr Auwers and the Secretaries, a complimentary letter from the Academy of Sciences at Amsterdam, and friendly letters of sympathy from Dr Gould, Prof. Newcombe, Dr Listing, and from many other scientific friends and societies. His replies to the Russian and German Addresses were as follows: ROYAL OBSERVATORY, GREENWICH, _1881, August 5_. MY DEAR SIR, I received, with feelings which I will not attempt to describe, the Address of yourself and the Astronomers of Pulkowa generally, on the occasion of my retirement from the office of Astronomer Royal. I can scarcely credit myself with possessing all the varied claims to your scientific regard which you detail. I must be permitted to attribute many of them to the long and warm friendship which has subsisted so long between the Directors of the Pulkowa Observatory and myself, and which has influenced the feelings of the whole body of Astronomers attached to that Institution. On one point, however, I willingly accept your favourable expressions--I have not been sparing of my personal labour--and to this I must attribute partial success on some of the subjects to which you allude.