contents, and the great mathematical skill of its author, recommended
that, before being published, it should be still further developed and
simplified. During the next three years the paper grew to an
immense bulk, principally by the additional details which had been
inserted at the desire of the committee. But it also assumed a much
more intelligible form, and the grand features of the new method
were now easily to be seen. Hamilton himself seems not till this
period to have fully understood either the nature or the importance
of his discovery, for it is only now that we find him announcing his
intention of applying his method to dynamics. The paper was
finally entitled “Theory of Systems of Rays,” and the first part was
printed in 1828 in the Transactions of the Royal Irish Academy.
It is understood that the more important contents of the second
and third parts appeared in the three voluminous supplements (to
the first part) which were published in the same Transactions, and in
the two papers “On a General Method in Dynamics,” which appeared
in the Philosophical Transactions in 1834–1835. The principle
of “Varying Action” is the great feature of these papers; and it is
strange, indeed, that the one particular result of this theory which,
perhaps more than anything else that Hamilton has done, has
rendered his name known beyond the little world of true philosophers,
should have been easily within the reach of Augustin Fresnel and
others for many years before, and in no way required Hamilton’s
new conceptions or methods, although it was by them that he was
led to its discovery. This singular result is still known by the name
“conical refraction,” which he proposed for it when he first predicted
its existence in the third supplement to his “Systems of
Rays,” read in 1832.
The step from optics to dynamics in the application of the method of “Varying Action” was made in 1827, and communicated to the Royal Society, in whose Philosophical Transactions for 1834 and 1835 there are two papers on the subject. These display, like the “Systems of Rays,” a mastery over symbols and a flow of mathematical language almost unequalled. But they contain what is far more valuable still, the greatest addition which dynamical science had received since the grand strides made by Sir Isaac Newton and Joseph Louis Lagrange. C. G. J. Jacobi and other mathematicians have developed to a great extent, and as a question of pure mathematics only, Hamilton’s processes, and have thus made extensive additions to our knowledge of differential equations. But there can be little doubt that we have as yet obtained only a mere glimpse of the vast physical results of which they contain the germ. And though this is of course by far the more valuable aspect in which any such contribution to science can be looked at, the other must not be despised. It is characteristic of most of Hamilton’s, as of nearly all great discoveries, that even their indirect consequences are of high value.
The other great contribution made by Hamilton to mathematical science, the invention of Quaternions, is treated under that heading. The following characteristic extract from a letter shows Hamilton’s own opinion of his mathematical work, and also gives a hint of the devices which he employed to render written language as expressive as actual speech. His first great work, Lectures on Quaternions (Dublin, 1852), is almost painful to read in consequence of the frequent use of italics and capitals.
“I hope that it may not be considered as unpardonable vanity or presumption on my part, if, as my own taste has always led me to feel a greater interest in methods than in results, so it is by methods, rather than by any theorems, which can be separately quoted, that I desire and hope to be remembered. Nevertheless it is only human nature, to derive some pleasure from being cited, now and then, even about a ‘Theorem’; especially where . . . the quoter can enrich the subject, by combining it with researches of his own.”
The discoveries, papers and treatises we have mentioned might well have formed the whole work of a long and laborious life. But not to speak of his enormous collection of MS. books, full to overflowing with new and original matter, which have been handed over to Trinity College, Dublin, the works we have already called attention to barely form the greater portion of what he has published. His extraordinary investigations connected with the solution of algebraic equations of the fifth degree, and his examination of the results arrived at by N. H. Abel, G. B. Jerrard, and others in their researches on this subject, form another grand contribution to science. There is next his great paper on Fluctuating Functions, a subject which, since the time of J. Fourier, has been of immense and ever increasing value in physical applications of mathematics. There is also the extremely ingenious invention of the hodograph. Of his extensive investigations into the solution (especially by numerical approximation) of certain classes of differential equations which constantly occur in the treatment of physical questions, only a few items have been published, at intervals, in the Philosophical Magazine. Besides all this, Hamilton was a voluminous correspondent. Often a single letter of his occupied from fifty to a hundred or more closely written pages, all devoted to the minute consideration of every feature of some particular problem; for it was one of the peculiar characteristics of his mind never to be satisfied with a general understanding of a question; he pursued it until he knew it in all its details. He was ever courteous and kind in answering applications for assistance in the study of his works, even when his compliance must have cost him much time. He was excessively precise and hard to please with reference to the final polish of his own works for publication; and it was probably for this reason that he published so little compared with the extent of his investigations.
Like most men of great originality, Hamilton generally matured his ideas before putting pen to paper. “He used to carry on,” says his elder son, William Edwin Hamilton, “long trains of algebraical and arithmetical calculations in his mind, during which he was unconscious of the earthly necessity of eating; we used to bring in a ’snack’ and leave it in his study, but a brief nod of recognition of the intrusion of the chop or cutlet was often the only result, and his thoughts went on soaring upwards.”
For further details about Hamilton (his poetry and his association with poets, for instance) the reader is referred to the Dublin University Magazine (Jan. 1842), the Gentleman’s Magazine (Jan. 1866), and the Monthly Notices of the Royal Astronomical Society (Feb. 1866); and also to an article by the present writer in the North British Review (Sept. 1866), from which much of the above sketch has been taken. His works have been collected and published by R. P. vols., 1882, 1885, 1889). (P. G. T.)
HAMILTON, a town of Dundas and Normanby counties,
Victoria, Australia, on the Grange Burne Creek, 19712 m. by
rail W. of Melbourne. Pop. (1901) 4026. Hamilton has a
number of educational institutions, chief among which are the
Hamilton and Western District College, one of the finest buildings
of its kind in Victoria, the Hamilton Academy, and the Alexandra
ladies’ college, a state school, and a Catholic college. It has
a fine racecourse, and pastoral and agricultural exhibitions are
held annually, as the surrounding district is mainly devoted to
sheep-farming. Mutton is frozen and exported. Hamilton
became a borough in 1859.
HAMILTON (Grand or Ashuanipi), the chief river of
Labrador, Canada. It rises in the Labrador highlands at an
elevation of 1700 ft., its chief sources being Lakes Attikonak and
Ashuanipi, between 65° and 66° W. and 52° and 53° N. After
a precipitous course of 600 m. it empties into Melville Lake
(90 m. long and 18 wide), an extension of Hamilton inlet, on the
Atlantic. About 220 m. from its mouth occur the Grand Falls
of Labrador. Here in a distance of 12 m. the river drops 760 ft.,
culminating in a final vertical fall of 316 ft. Below the falls are
violent rapids, and the river sweeps through a deep and narrow
canyon. The country through which it passes is for the most
part a wilderness of barren rock, full of lakes and lacustrine
rivers, many of which are its tributaries. In certain portions of
the valley spruce and poplars grow to a moderate size. From
the head of Lake Attikonak a steep and rocky portage of less
than a mile leads to Burnt Lake, which is drained into the
St Lawrence by the Romaine river.
HAMILTON, one of the chief cities of Canada, capital of
Wentworth county, Ontario. It occupies a highly picturesque
situation upon the shore of a spacious land-locked bay at the
western end of Lake Ontario. It covers the plain stretching
between the water-front and the escarpment (called “The
Mountain”), this latter being a continuation of that over which
the Falls of Niagara plunge 40 m. to the west. Founded about
1778 by one Robert Land, the growth of Hamilton has been
steady and substantial, and, owing to its remarkable industrial
development, it has come to be called “the Birmingham of
Canada.” This development is largely due to the use of electrical
energy generated by water-power, in regard to which Hamilton
stands first among Canadian cities. The electricity has not,
however, been obtained from Niagara Falls, but from De Cew
Falls, 35 m. S.E. of the city. The entire electrical railway system,
the lighting of the city, and the majority of the factories are
operated by power obtained from this source. The manufacturing
interests of Hamilton are varied, and some of the establishments
are of vast size, employing many thousands of hands each,
such as the International Harvester Co. and the Canadian
Westinghouse Co. In addition Hamilton is the centre of one of
the finest fruit-growing districts on the continent, and its open-air
market is a remarkable sight. The municipal matters are
managed by a mayor and board of aldermen. Six steam railroads
and three electric radial roads afford Hamilton ample facilities
for transport by land, while during the season of navigation
