National Progress

In tracing the progress of science during the past half century, we find that it has become more and more practical in its tendencies, has dwelt less upon abstract theories and speculations, and has drawn more largely upon experiment as a means of arriving at truth, and of employing it when discovered for purposes of utility. This practical turn was given to speculative minds chiefly by the example of Newton, whose unparalleled sagacity and genius brought to a speedy and dazzling climax the preparatory labours of one hundred and fifty years. The same tendency has caused the knowledge acquired to be applied with more freedom and boldness to the exigencies of mankind, and to the further investigation of the secrets of nature. "If," says Professor James Forbes, " we compare the now extensive subjects of heat, electricity, and magnetism, with the mere rudiments of these sciences as understood in 1750, or if we think of the astonishing revival of physical and experimental optics (which had well nigh slumbered for more than a century, during the too short lives of Young and Fresnel), we shall be disposed to admit the former part of the statement; and when we recollect that the same period has given birth to the steam-engine of Watt, with its application to shipping and railways; to the gigantic telescopes of Herschel and Lord Rosse, wonderful as works of art as well as instruments of sublime discovery; to the electric telegraph, and to the tubular bridge, we shall be ready to grant the last part of the proposition, that science and art have been more indissolubly united than at any previous period." Of the great discoverers of the former period, several survived and continued their efficient labours during no small portion of the latter, claiming, as they were well entitled to do, the respect and veneration of their disciples and successors; but the vast steps so recently made in optics, in electricity, in magnetism, in the theory of heat, and in chemical principles, tended of necessity to call forth such an amount of laborious detail in the defining and connecting of facts and laws, and the deductions of the theories started to explain them, as seemed to render fresh and striking originality somewhat hopeless; whilst they occasioned a vast amount of useful employment to minds of every order of talent. The undulatory theory of light, developed by the massive labours of Young and Fresnel, has afforded still unexhausted material to the mathematician on the one hand, and to the experimentalist on the other; and ably have they fulfilled the double task, adding at the same time discoveries, whose importance and difficulty would have made them still more prominent had they not been the legitimate consequences of a still greater discovery already in our possession. Nearly the same might have been said for the sciences of electricity, electro-magnetism, electro-chemistry, had not the comparative newness of the whole doctrine of these sciences, the suddenness of their first rise, and perhaps still more the appearance of a philosopher of the very highest merit - Faraday, who fortunately attached himself to this special department - made the last thirty years an almost unbroken period of discovery. Radiant heat, too, has been successfully advanced by labours, comparable perhaps to those which marked its first rise as a science: and some other topics connected with heat have risen into great and practical consequence. Astronomy has been prosecuted with a systematic assiduity and a success, especially at the British and Russian national observatories, which have been exceeded at no former period; whilst physical astronomy has been cultivated by methods of still improved analysis, and has achieved what is admitted to be one of the most brilliant discoveries of the present century. This was the prediction, simultaneously by an English and a French astronomer, of the position in space of the planet Neptune, whose existence was unknown except by the disturbance which it produced in the movements of the planet Uranus. Terrestrial magnetism has for the first time aspired to the rank of an exact science. In an illustrious philosopher of Germany it has found its Kepler; and the combination of national efforts in collecting reliable data from the remotest corners of the globe, is characteristic of the practical energy of the age. Chemistry has been cultivated with extraordinary assiduity; but none of the many discoveries in that science is comparable in importance to that which was made by Dalton. To cite, then, at present but a few names, amongst the most conspicuous benefactors of science of the last or contemporary period are - Airy, Cauchey, Hamilton, and M'Cullagh; Faraday, Melloni, and Gauss; Sir John Herschel, M. Struve, and Lord Rosse; Plana, Poisson, Leverrier, and Adams; Mitscher' lieh, Liebig, and Dumas.

Until the commencement of the present century, the state of mathematical science was very low in England, and was regarded on the Continent with the greatest contempt. The commencement of a better era originated with Woodhouse at Cambridge and Playfair in Edinburgh, by both of whom the Continental methods were introduced into the studies of their respective universities; whilst Ivory, a native of Scotland, earned for himself, by his writings, a place in the list of great living mathematicians. About 1820 the translation of La Croix's " Differential Calculus," superintended by Sir John Herschel and Dean Peacock, came into use as a university text-book. Soon after, the writings of La Place and Poisson, as well as other Continental mathematicians, were generally read in our universities; and a few men of active and daring minds, chiefly of the Cambridge school, such as Prof. Airy and Sir John Lubbock, grappled with the outstanding difficulties of physical astronomy; whilst a larger number applied themselves to the most difficult parts of pure analysis, and acquired great dexterity in its use, in the solution of geometrical and mechanical problems. Such, for example, were Mr. Babbage, Mr. A. De Morgan, Mr. Murphy, and Mr. Green; and in the first rank of such mathematicians stood Sir William R. Hamilton and J. M'Cullagh of Dublin. No new calculus, or great general method in analysis, has resulted from these persevering labours, whether from British or foreign mathematicians; but an increased facility and power in applying the existing resources of mathematics to the solution of large classes of problems previously intractable, or resolved only indirectly, or by approximation, have been obtained. Every year and every civilised community contributed to these real improvements. An almost new branch of abstract science (faintly shadowed by Leibnitz) came into existence at this time - the separation of symbols of operation from symbols of quantity, and the universal employment of the former. Sir John Herschel and Olinthus G. Gregory were among the most active introducers of this improvement in algebra; but few of the more eminent living British or foreign mathematicians have failed to contribute their share to the metaphysical department of analysis. Sir John F. W. Herschel, son of Sir William Herschel, conversant with almost every branch of science^ devoted himself with remarkable success to the cultivation of sidereal astronomy, bearing a name honoured and revered by all. Science owes much to Sir William Herschel and his son. Sir William was one of those who may be said to have created physical astronomy. He was born at Hanover in 1738. His father being a musician, with limited means and a large family, he was under the necessity of devoting the first portion of his life to the musical profession; but this did not prevent him from indulging his predilections for the study of philosophy. Desiring more favourable opportunities for advancing in the path of knowledge, and hoping to find them in England, he left Hanover in 1757; but when he arrived in this country he had to struggle with great difficulties at first, and was dependent on his skill in music for a means of support. Having obtained a situation, however, as organist, he was enabled to purchase a few mathematical works; and he soon devoted himself to astronomy with all the ardour of a passion. He was not able to procure a telescope, on account of his limited means; but he determined to construct one, and succeeded. With it he saw Saturn's ring and the satellites of Jupiter; and, seven years after, Uranus, a planet situated beyond what had been, up to that time, considered as the limits of the universe. This turned the eyes of all Europe towards him. George III. bestowed on him a pension and a residence, where, in his observatory, he continued his astronomical researches with great success. He was now loaded with honours, and the most celebrated scientific bodies eagerly enrolled him among their members; and he persevered in his valuable researches until his death, in 1822. He was succeeded in his labours by his son, John Frederick William; who was worthy to inherit a name on which he reflected additional lustre. England could claim the father only by adoption: she calls the son hers by birth. The latter evinced very early a taste for mathematics, but did not devote himself to astronomy until after his father's death. He then gave himself up to it without reserve; and the value of his laborious observations was recognised, not only here, but on the Continent. At that period the Southern Hemisphere was to astronomers little more than an unknown region. For the purpose of exploring it, he visited the Cape of Good Hope, where, making use of his father's method, he continued his observations for more than four years, examining with great care, among other things, the nebulae and double stars. On his return to Europe, he gave the results of his labours to the world in a work of great interest, and of the highest importance; and the value of the services he had rendered to science was recognised, not only by the scientific world, but by his sovereign also, who created him a baronet, and he was appointed Master of the Mint. After this period he took no further part in practical astronomy, but he published many excellent works, not only on that subject, but on science generally; and he displayed a thorough acquaintance with natural history, the belles lettres, and the fine arts, and translated a portion of the "Iliad." This great astronomer and mathematician died in May, 1871.

It is a remarkable circumstance that as the reflecting telescope was of British invention, so the more important improvements and applications of it have been almost confined to the United Kingdom. It is also worthy of notice that its manufacture has prospered more in the hands of amateurs than of regular opticians. Sir William Herschel appeared at one time to have brought the invention to its highest perfection, but the earl of Rosse has made an important step further, not only by constructing a larger telescope, but by adapting machinery driven by steam- power to the grinding and polishing of the mirrors; so that the largest speculum may be finished with nearly the same accuracy and expedition as the smallest. The chef- d'œuvre of Lord Rosse is a telescope of six feet aperture, and 53 or 54 feet of focal length. It was completed in the latter end of 1844, and erected in his demesne at Parsonstown, King's County, Ireland. It is the largest telescope ever constructed. The machinery is supported on massive walls, and, notwithstanding its great weight and size, it is moved with the utmost ease, and can be lowered to any angle, while it sweeps the horizon, by means of wheels running on a graduated circle. Its cost exceeded £30,000. Lord Rosse's success was the triumph of persevering exertion and mechanical skill. His assistants were his own countrymen, instructed by himself in his own workshops, where the very steam-engine -which drives the polisher was fabricated. His labours to improve the telescope commenced about 1828, and continued unremittingly until 1844. " Commencing with a variety of ingenious attempts to correct spherical aberration, and to overcome the extreme difficulty of procuring and manufacturing large castings of so excessively brittle a material as speculum metal, they terminated in the rejection of all minor helps and expedients, and in the fortunate completion, at a single casting, of immense mirrors, which were of a correctly parabolic figure when ground and polished. The speculum of his large telescope, weighing four tons, and having a surface considerably more than twice as large as that of Sir William Herschel's forty-feet instrument, was polished in six hours. Many difficulties in detail were met in the mounting and use of so gigantic a mass, particularly on account of the distortion of the mirror by flexure; but these were gradually overcome, and he was amply rewarded for his efforts by the success of his observations. Many nebulae which resisted the power of former telescopes were 'resolved' into stars by the six-feet speculum. The aspect of a great number of nebulae described by the two Herschels is materially modified, by the power of Lord Rosse's telescope to embrace the fainter prolongations of these singular objects. In general, the regularity of form is very much lessened, and in many cases vanishes altogether. Instead of these, a certain species of symmetry, of a vague yet remarkable description, has been detected. It is a spiral arrangement of the nebulous coils round a centre, resembling somewhat the emanations of revolving fireworks."

M. Arago, who was forty years in charge of the observatory of Paris, was a great astronomer, but he did not, indeed, avail himself of that position to enlarge the domain of his science as much as he might have done; he made, however, some important optical discoveries, and was very instrumental in calling forth the genius of Fresnel, and obtaining a public recognition of the labours of Young. " The undulatory theory of light " stands where it does in no slight degree through the instrumentality of Arago. In 1838 he indicated the application of Mr. (afterwards Sir) C. Wheatstone's invention of the revolving mirror, as a means of measuring intervals of time incredibly short, in order to compare the velocity of light in air, and in a corresponding length of water, Arago was regarded as having proved the long-suspected connection between the aurora borealis and the freely suspended magnet.

Amongst the foremost of the promoters of science, and the most eloquent of its expounders, was Sir David Brewster, who died full of years and of honours in 1868. Arrived at manhood at the opening of the present century, having been born in 1781, he continued his brilliant course during fifty years, pursuing his investigations into the laws of polarisation by crystals, and by the reflection, refraction, and absorption of light, in which he made important discoveries. " His papers," says Professor Forbes, "are so numerous, and their variety so great, as to render an enumeration, even of those containing what may reasonably be termed discoveries, impossible within our limits. Few persons have made with their own eyes so vast a number of independent observations; few have ever observed better or recorded their observations more faithfully. His scientific glory is different in kind from that of Young and Fresnel; but the discoverer of the law of polarisation, of biaxal crystals, of optical mineralogy, and of double refraction produced by compression, will always occupy a foremost rank in the intellectual history of the age."