ed by calculation how long it is since
the Glacial Period existed:

_1882, July 4_.

SIR,

I should have much pleasure in fully answering your questions of July
3 if I were able to do so: but the subject really is very obscure.

(1) Though it is recognized that the glacial period (or periods) is
late, I do not think that any one has ventured to fix upon a rude
number of years since elapsed.

(2) We have no reason to think that the mean distance of the earth
from the sun has sensibly altered. There have been changes in the
eccentricity of the orbit (making the earth's distance from the sun
less in one month and greater in the opposite month), but I do not
perceive that this would explain glaciers.

(3) I consider it to be certain that the whole surface of the earth,
at a very distant period, was very hot, that it has cooled gradually,
and (theoretically and imperceptibly) is cooling still. The glaciers
must be later than these hot times, and later than our last
consolidated strata: but this is nearly all that I can say.

I am, Sir, Your obedient Servant,
G.B. AIRY.

_James Alston, Esq._

1883

From May 2nd to 29th he was at Playford. From July 10th to 20th he was
travelling in South Wales with his daughters.--From Oct. 10th to
Nov. 10th he was at Playford.--Between Nov. 20th of this year and
Jan. 4th of the year 1884, he sat several times to Mr John Collier for
his portrait: the picture was exhibited in the Academy of 1884; it is
a most successful and excellent likeness.

Throughout the year he was very busy with the Numerical Lunar
Theory.--In March he was officially asked to accept the office of
Visitor of the Royal Observatory, which he accepted, and in this
capacity attended at the Annual Visitation on June 2nd, and addressed
a Memorandum to the Visitors on the progress of his Lunar Theory.--On
March 12th he published in several newspapers a statement in
opposition to the proposed Braithwaite and Buttermere Railway, which
he considered would be injurious to the Lake District, in which he
took so deep an interest.--In May he communicated to "The Observatory"
a statement of his objections to a Theory advanced by Mr Stone (then
President of the Royal Astronomical Society) to account for the
recognized inequality in the Mean Motion of the Moon. This Theory, on
a subject to which Airy had given his ince