intellectual work these researches, though intrinsically of such
importance, assume what might almost be described as a relative
insignificance.

The most famous achievement of Hamilton's earlier years at the
observatory was the discovery of conical refraction. This was one of
those rare events in the history of science, in which a sagacious
calculation has predicted a result of an almost startling character,
subsequently confirmed by observation. At once this conferred on the
young professor a world-wide renown. Indeed, though he was still
only twenty-seven, he had already lived through an amount of
intellectual activity which would have been remarkable for a man of
threescore and ten.

Simultaneously with his growth in fame came the growth of his several
friendships. There were, in the first place, his scientific
friendships with Herschel, Robinson, and many others with whom he had
copious correspondence. In the excellent biography to which I have
referred, Hamilton's correspondence with Coleridge may be read, as
can also the letters to his lady correspondents, among them being
Maria Edgeworth, Lady Dunraven, and Lady Campbell. Many of these
sheets relate to literary matters, but they are largely intermingled
With genial pleasantry, and serve at all events to show the affection
and esteem with which he was regarded by all who had the privilege of
knowing him. There are also the letters to the sisters whom he
adored, letters brimming over with such exalted sentiment, that most
ordinary sisters would be tempted to receive them with a smile in the
excessively improbable event of their still more ordinary brothers
attempting to pen such effusions. There are also indications of
letters to and from other young ladies who from time to time were the