January 4, 1884.] 
elected fellow of the American academy of arts 
and sciences — 
“Ueber linder und meer reichen sich beide die hand.”’ 
A picture of curious interest may be drawn 
from Mr. Graves’s occasional touches, portray- 
ing Hamilton as a speaker and lecturer. He 
**had two voices — one deep, rich, sonorous, 
rhythmical, and solemn, which flowed forth 
when he delivered a prelection or a speech, or 
recited poetry ; the other soaring acutely into 
high regions, when he burst into an explana- 
tien, or gave vent to some ebullition of good 
spirits or cheerful comment.’’ At the meeting 
of the British association in 1832, at Oxford, 
his speech returning thanks on behalf of the 
Royal Irish academy contained ‘‘a graceful ex- 
pression of the feelings stirred in him by his 
peculiar position as the solitary and youthful 
representative of Ireland on the occasion.’’ 
Babbage told him, in congratulation, that ‘‘ an 
astronomer had no business to be able to speak 
so well.’’ We have space for only a word from 
Mr. Graves’s charming sketch of Hamilton as 
a lecturer (pp. 497-498) : — 
** When he spoke . . . it was plain to see that he 
was absorbed by a reverential consideration of the 
grandeur of astronomy. ... As he poured out in 
his sonorous tones his thoughts thus blending poetry 
and science, he appeared. . . absorbed in awed and 
delighted contemplation of the truths he had the 
solemn privilege of enouncing; there was no ap- 
parent consciousness of his own personality, he was a 
worshipper revealing the perfections of the object of 
his worship; and towards the youthful audience who 
surrounded him he took the attitude not so much of 
a superior authority and a teacher as of a worshipper 
desirous that other intelligent spirits should take fire 
from the flame of his devotion. . . . In these intro- 
ductory lectures he was wont to indulge himself in 
refined and eloquent disquisition, in poetic language, 
quotation and allusion, in tracing the history of the 
development of the science, and in marking out the 
achievements of its great promoters. . . . The subse- 
quent lectures of the course were altogether different 
in style, being rigorously mathematical and demon- 
strative. ... They were delivered with an eager 
simplicity, in a voice often breaking into a high key, 
strangely contrasting with the deep roll of his oratori- 
cal effusions.”’ 
One of Hamilton’s grandest achievements 
was the theoretical discovery of conical refrac- 
tion ; and in the popular history of physics he 
is chiefly known by this. Its prompt confirma- 
tion by Dr. Lloyd, in the laboratory of the 
Dublin university, tended strongly to heighten 
the dignity of the discovery. It was charac- 
terized in terms of most extravagant applause 
by the greatest physicists of that day. But 
Hamilton himself, with the unaffected simplicity 
of true genius, describes it to Coleridge as a 
‘subordinate and secondary result.’ The dis- 
covery had no parallel in the history of exact 
SCIENCE. 23 
science ; apd, as Mr. Graves appropriately re- 
marks, it is only ‘‘ to be classed with that pre- 
diction of the existence of the planet Neptune 
which has immortalized the names of Adams 
and Le Verrier.’’ 
Nothing, perhaps, will better exemplify Ham- 
ilton’s rare elevation of character than the fol- 
lowing brief words of his biographer : — 
‘“Tt is to Hamilton’s honour that the impression he 
made upon young men, his coevals and his juniors, 
was such as to create in them the warmest affection, 
admiration, and respect. This arose from his unaf- 
fected humility and his cheerful communicativeness, 
combined with his power to solve most difficulties ad- 
mitting of solution, his frankness in confessing igno- 
rance, his reverential and profound treatment of all 
great questions.’’ 
In so far as it is possible to know the dis- 
tinguished Irishman from his letters, — and they 
are presented in the fullest profusion, — the 
most commanding feature of his character is 
the absolute absence of every thing akin to 
meagreness of build : in other words, a thorough 
and genuine nobility. Repeated illustrations 
of this might be cited from his correspondence ; 
and it is the most conspicuous element of the 
admirable frontispiece which has been auto- 
typed from a photograph by Chancellor, Dublin, 
of a miniature bust executed by Terence Far- 
rell in 1838. We should like to express the 
hope, that, before the conclusion of his task, 
Mr. Graves will present a print from the other 
bust of Hamilton, executed, at the request of 
Lord Dunraven, by the Dublin sculptor, Kirk ; 
in preparation for which a cast was taken from 
the head, and which thus, as faithfully repre- 
senting his cranial development, can hardly fail 
to possess a permanent value. 
It is most irksome to be forced from the con- 
templation of this great genius; for, with this 
initial volume of his biography, we have to 
leave him at the age of twenty-seven, and al- 
most in entire anticipation of his characteristic 
scientific life. His unique researches in the 
highest fields of mathematical investigation, 
his great contributions to the science of dy- 
namics, were yet unmade; and the calculus of 
quaternions, if at all thought of, had no more 
taken shape than the vague indefiniteness of a 
dream. If Mr. Graves has disappointed any 
of his readers in the execution of his task, they 
must be few, and among those who were so 
favored as to have enjoyed the intimate ac- 
quaintance of the great mathematician. The 
successive instalments of this exceedingly valu- 
able biography cannot fail to be watched for 
with eagerness, and welcomed with enthusiasm, 
by all whose interests embrace the history and 
development of the exact sciences. 
