478 
SECTION A. 
MATHEMATICS AND PHYSICS. 
OpENING AppREss By Pror. JOHN Purser, M.A., LL.D., 
M.R.I.A., PRESIDENT OF THE SECTION. 
In opening our proceedings to-day allow me at the outset to 
express my deep sense of the honour the Association has con- 
ferred upon me in asking me to preside over this Section. 
My predecessors in this Chair have usually given you a survey 
of some department of Mathematics or Physics, tracing what 
had been already accomplished in that department and _ indi- 
cating the nature of the problems which still awaited solution. 
May I crave your indulgence if I deviate from this course and, 
following the suggestion of some of my friends, take the oppor- 
tunity of the Association meeting on Irish soil to give you a 
slight historical sketch of our Irish School of Mathematics and 
Physics ? 
In attempting such a review, for the sake of brevity as well as 
for other reasons, I shall confine it to the work of those who are 
no longer with us, and I would not carry it further back than 
the beginning of last century. This seems a natural starting 
point, as there was at that time a very marked revival of the 
study of science in the University of Dublin, a revival largely 
due to the influence of Provost Bartholomew Lloyd. 
Lloyd won his Fellowship in Trinity College a few years 
before the century opened, and subsequently filled in succession 
the Chairs of Mathematics and Natural Philosophy. In both 
departments he imported a radical change into the methods of 
teaching. By his treatises on Analytical Geometry and on 
Mechanical Philosophy he introduced the study of what was 
then called the French Mathematics, in other words the more 
advanced Analytic Methods, which were in use on the Conti- 
nent. In 1831 he was appointed Provost of the College, and 
his tenure of the office, though brief, was signalised by many 
important improvements and new developments effected in the 
University teaching. 
Dr. Bartholomew Lloyd was President of one of the earliest 
Meetings of this Association, that held in Dublin in 1835. 
His son, Dr. Humphrey Lloyd, had a course which was a 
singularly close parallel to his father’s. 
He won his Fellowship in 1824, and succeeded his father in 
the Chair of Natural Philosophy. He also was afterwards 
appointed Provost, and he too presided over another Dublin 
Meeting of this Association, that held in 1857. He also, in this 
again following in his father’s steps, wrote important works on 
different branches of Physics; ‘‘ Light and Vision,” a system- 
atic treatise on plane as distinct from physical optics, ‘‘ Lectures 
on the Wave Theory of Light,” and lastly a treatise on ‘‘ Mag- 
netism.” 
It is, perhaps, in connection with this latter subject that his 
most important work was done. He made in association with 
Sabine an elaborate series ofobservations on terrestrial magnetism 
in twenty-four stations in various parts of Ireland, and when 
subsequently, at the instance of your Association and of the 
Royal Society, the Government established magnetic observa- 
tories in different parts of the world, it was Lloyd who was 
entrusted with the task of drawing up the manual of instructions 
for the observers and of receiving their reports. 
In the interval between the two Lloyds another name claims 
attention. Dr. Romney Robinson occupied during an excep- 
tionally long life a much honoured and influential position 
amongst men of science. It was in this city he received his 
early education, for when young Robinson was only nine years 
of age his father had occasion to move to Belfast, and he placed 
his son under Dr. Bruce, a well-known schoolmaster of those 
days. Robinson was afterwards sent to Trinity College, and 
after a distinguished course was elected to a Fellowship in 1814. 
For some years he lectured in college as Deputy Professor of 
Natural Philosophy. He relinquished his Fellowship on obtain- 
ing a College living, and a few years later was appointed 
Astronomer in charge of the Armagh Observatory. The results 
of his observations were considered so valuable as to be used by 
the German astronomer Argelander in determining the proper 
motions of stars. The range, however, of his published papers 
was by no means confined to Astronomy, but extended to the 
most varied subjects, Heat, Electricity, Magnetism, Turbines, 
Air-pumps, Fog-signals, and others. He is best known to the 
general public as the inventor of the Cup Anemometer. He 
was chosen to preside over the Birmingham Meeting of this 
Association in 1849. 
NO. 1715, VOL. 66] 
NATURE 
[SEPTEMBER II, 1902 
Robinson was intimately associated with Lord Rosse and 
keenly interested in the experiments which culminated in the 
construction of the great reflector in Parsonstown. This 
naturally leads us to speak of Lord Rosse himself. Few 
scientific achievements took a greater hold upon the public 
mind than the successful completion of his great telescope. 
Only those who have read in Lord Rosse’s own papers the 
description of the many difficulties he had to contend with in 
forging and polishing that wonderful speculum, harder than 
steel yet more brittle than glass, can adequately appreciate the 
patience and resource with which those difficulties were succes- 
sively overcome. 
Of the results obtained with this instrament the most notable 
were in the observation of the Nebulz, a department where its 
unsurpassed power of light-concentration came fully into play. 
No doubt at the time public attention was most excited by the 
resolution of a number of hitherto supposed nebula into star 
clusters, leading to the premature conclusion in the minds of 
those less instructed that all the nebulz might ultimately be so 
resolved. To us, however, a far greater interest attaches to the 
observation of the structure of what we now know to be genuine 
nebula, especially the great discovery that these had in many 
cases a peculiar spiral form. All previous telescopes had failed 
to detect this spiral character; but the drawings taken by 
Lord Rosse and his assistants put this feature beyond question, 
and these have been fully confirmed in recent years, when more 
accurate delineations were obtained by photography. I need 
not dwell upon the significance of this form, indicating, as 
it does, a rotatory movement in these mighty masses and 
fitting in with, if not actually confirming, Laplace’s Nebular 
Hypothesis. 
Sir William Rowan Hamilton was undoubtedly the most 
striking figure in the annals of the Dublin School of Mathematics. 
In limine we must make good our right to call him an Irishman, 
for his greatest admirer and disciple, Prof. Tait, has claimed 
him for a countryman of his own, asserting that Hamilton’s 
grandfather was a Scotchman who migrated to Dublin with his 
two young sons. That this was a complete misconception has 
been abundantly proved by the careful investigations of his 
friend and biographer, Dr. R. P. Graves, who shows conclu- 
sively that the only known strain of Scotch blood in Hamilton 
came through his grandmother, who was the daughter of a 
minister of the Scottish Kirk. 
It is interesting to find how early Hamilton’s remarkable 
mental powers began to show themselves. Dr. Graves has 
given us a letter from his mother in which she writes to her 
sister of the marvellous precocity of her little four-year-old boy, 
telling how ‘‘he reads Latin, Greek, and Hebrew.” 
His mental development did not belie these early indications, 
for at the age of thirteen, thanks to the teaching and care of his 
uncle, who was a most extraordinary linguist, he had not only 
acquired a considerable knowledge of the classics and the modern 
European languages, but also attained some proficiency in 
Arabic, Sanscrit and Persian. His mathematical studies, on the 
other hand, appear to have been carried on without help from 
anyone, and it is noteworthy that he does not seém to have 
used common text-books, but to have gone direct to the great 
original authors ; e.g., he read his algebra in Newton’s ‘‘ Arith- 
metica Universalis” ; while at the age of fifteen he set himself 
to read the ‘‘ Principia,” and two years later began a systematic 
study of Laplace’s *‘ Mécanique Céleste.” His own estimate 
of his powers may be gathered from a characteristic letter to 
his sister written just after he had entered Trinity College :— 
“One thing only have I to regret in the direction of my 
studies, that they should be diverted—or rather rudely forced— 
by the College course from their natural bent and favourite 
channel, ‘That bent, you know, is science—science in its most 
exalted heights, in its most secret recesses. It has so captivated 
me, so seized on, I may say, my affections that my attention to 
classical studies is an effort and an irksome one; and I own 
that, before I entered College, I did not hope that in them I 
would rise above mediocrity. My success surprised me, but it 
has also given me a spur by holding out a prospect that even in 
the less agreeable part of my business I may hope still to 
succeed.” 
This letter is interesting as indicating on Hamilton’s part a 
consciousness wherein lay his real strength and vocation. Not 
that his interest in literature ever abated. To the last he loved 
to try his hand at poetical composition, frequently inserting in 
his letters to his friends sonnets of his own. 
