engineering works. This led to much communication with Stephenson,
Brunel, and other engineers, who consulted him freely on the subject
of great works on which they were engaged: in particular he rendered
much assistance in connection with the construction of the Britannia
Bridge over the Menai Straits. There were various other subjects which
he read with much interest (Geology in particular), but he made no
study of Natural History, and knew very little about it beyond
detached facts. His industry was untiring, and in going over his books
one by one it was very noticeable how large a number of them were
feathered with his paper "marks," shewing how carefully he had read
them and referred to them. His nature was essentially cheerful, and
literature of a witty and humourous character had a great charm for
him. He was very fond of music and knew a great number of songs; and
he was well acquainted with the theory of music: but he was no
performer. He did not sketch freehand but made excellent drawings with
his Camera Lucida.

At the time when he took his degree (1823) and for many years
afterwards there was very great activity of scientific investigation
and astronomical enterprise in England. And, as in the times of
Flamsteed and Halley, the earnest zeal of men of science occasionally
led to much controversy and bitterness amongst them. Airy was by no
means exempt from such controversies. He was a man of keen
sensitiveness, though it was combined with great steadiness of temper,
and he never hesitated to attack theories and methods that he
considered to be scientifically wrong. This led to differences with
Ivory, Challis, South, Cayley, Archibald Smith, and others; but
however much he might differ from them he was always personally
courteous, and the disputes generally went no farther than as regarded
the special matter in question. Almost all these controversial
discussions were carried on openly, and were published in the
Athenaeum, the Philosophical Magazine, or elsewhere; for he printed
nearly everything that he wrote, and was very careful in the selection
of the most suitable channels for publication. He regarded it as a
duty to popularize as much as possible the work done at the
Observatory, and to take the public into his confidence. And this he
effected by articles communicated to newspapers, lectures, numerous
Papers written for scientific societies, reports, debates, and
critiques.

His strong constitution a