t 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.

In glancing over the marginal list of scientific pursuits, I remark
with pleasure the reference to _Optics_. I still recur with delight to
the Undulatory Theory, once the branch of science on which I was best
known to the world, and which by calculations, writings, and lectures,
I supported against the Laplacian School. But the close of your
remarks touches me much more--the association of the name of W. Struve
and my own. I respected deeply the whole character of your Father, and
I believe that he had confidence in me. From our first meeting in 1830
(on a Commission for improvement of the Nautical Almanac) I never
ceased to regard him as superior to others. I may be permitted to add
that the delivery of his authority to the hands of his son has not
weakened the connection of myself with the Observatory of Poulkova.

Acknowledging gratefully your kindness, and that of all the
Astronomers of the Observatory of Poulkova, and requesting you to
convey to them this expression,

I am, my dear Sir,
Yours most truly,
G.B. AIRY.

_To M. Otto von Struve,
Director of the Observatory of Poulkova
and the Astronomers of that Observatory._

*