Page images
PDF
EPUB

done in favour of the Lady Elizabeth. They have removed Courtenay from the Tower, and taken him to a castle in the north. Your Majesty may well believe in what danger the Queen is, so long as both are alive; and when Paget, in whom she has so much confided, has so far forgot himself, and proceeded to such an extreme, that, to revenge himself of the Chancellor, he professes himself a heretic, and neglects the service of her Highness,' -Vol. ii, 398-401.

Our extracts have sufficiently exemplified the historical value of the documents in Mr Tytler's work, and proved its importance as a collection of materials for English history. All enquirers respecting the two reigns to which it relates, will do well to consult it; and we shall be glad to find that he is encouraged to continue his researches, at any rate through the reigns of Elizabeth and James. They are fruitful in unpublished materials, which his industry and intelligence could not fail to turn to good account.

Art. VI.-I. Eloge Historique de James Watt. Par M. ARAGO.

Lu à la Séance publique de l'Académie des Sciences du 8 Décembre 1834. Annuaire pour l'An 1839. 2.- Life of James Watt. By M. ARAGO, Perpetual Secretary to the Academy of Sciences. 8vo. Third Edition. Edinburgh : 1839. 3.-Historical Eloge of James Watt. By M. Arago, Perpetual Secretary to the Academy of Sciences. Translated from the French, with additional Notes and an Appendix, by James PATRICK MUIRHEAD, Esq. A M., of Baliol College, Oxford, Advocate. 8vo. London : 1839.

W
ERE

guished names which adorn the history of our intellectual and social progress, it might be a matter of national controversy who should take the precedence on the one; but there would be no hesitation in determining who should be placed at the head of the other. England, and France, and Italy, and Germany, might contend about their Newtons, their Laplaces, their Descartes', their Galileos, and their Keplers; but Europe and America would simultaneously pronounce the name of Watt as the most illustrious of the benefactors, whose inventive genius has administered to the luxuries and wants of mankind.

Nor was this enviable pre-eminence the result of any brilliant conception, or of any felicitous creation of the mind, to which the name of invention or discovery could be distinctively applied. Mr Watt was the improver, not the inventor of the Steam-Engine. He found the crazy machines of Savery and Newcomen labouring and creaking at our mine-heads, and occupying the same rank as prime movers with the wind-mill and the water-wheel; and by a succession of inventions and discoveries, deduced from the most profound chemical knowledge, and applied by the most exquisite mechanical skill, he brought the steam-engine to such a degree of perfection as to stamp it the most precious gift which man ever bequeathed to his race.

Whether this wonder of mechanism is presented to us in the form of a model, with the feeble power of an infant's arm, or as a gigantic machine, wielding the strength of a whole squadron of horse, the elegance of its form, the harmony of its movements, and the ingenuity of its details, never fail to command our admiration. But the sentiment thus excited is not very different from that with which we view a piece of exquisite clockwork, or a machine of great power ; whether it is driven by wind, or water, or animal exertion.

It is only when we see the steamengine in its applications, and recognise its capacity of adaptation to all the mechanical arts, that we can form a just idea of its value, and rightly appreciate the debt of gratitude which it should inspire.

Io employing wind and water as the first movers of machinery, they are available only in particular localities, where the wind blows or the water falls; and in serene weather, or in dry seasons, the powers on which we rely altogether fail us. The steamengine, on the contrary, serves us at all times and in all places. We can erect it on the arid heath, on the loftiest ridge, at the bottom of the deepest mine, or in the heart of the most crowded city; and when it has performed its functions in any of these localities, we can send it elsewhere on another errand.

But while the steam-engine thus surpasses all other prime movers as a stationary power, it rises infinitely above them all as an organ of locomotive force. On a level surface, or even a gentle acclivity, it outstrips the antelope in its speed, and it propels, with almost equal velocity, a hundred loaded waggons, or carries along with it the whole rank and file of a regiment.

But it is on the boundless ocean

• Calm or convulsed-in breeze, or gale, or storm,
Deep-heaving'--

that its triumph is most complete; and, were we to replace the gods of antiquity by modern sages, James Watt would be our Neptune, the column of vapour his trident, and the steam-ship his throne and his footstool. And yet the sceptre thus wielded over the deep is but a bucketsul of its own waters, whose elastic breath defies tide and tempest,-thus contracting the aqueous dimensions of the globe, wafting to the remotest shores the truths of reason and inspiration, and hastening that era of peace when the philosopher and the savage shall be united in the same brotherhood of faith and charity.

The history of inventions which have produced results like these, and of the individuals to whom society owes them, must ever excite a deep interest throughout every class of the community. To gratify a curiosity so laudable, volumes have been written on the history of the steam-engine; and the records of ancient and modern times have been ransacked for the earliest traces either of a toy or of a machine in which the impulse or the elastic pressure of steam had been employed. Facts the most frivolous and insignificant have thus been treasured by national partiality as the basis of serious claims to the invention of the steam-engine! Hero of Alexandria, for example, produced å rotatory motion by the reaction of steam issuing from an aperture. About A. D. 997, Gerbert sounded the pipes of the organ at Rheims by a current of steam in place of air. Previous to 1629, Brancas, an Italian architect, drove a wheel by directing a current of steam upon its vanes, and before 1658, Jack of Hilton, a brazen figure, performing the part of an æolipile, was used to blow the fire (and no doubt also to consume the smoke) with a current of stearn from his mouth! The elastic force of steam, too, was not unknown to the ancients, who attributed earthquakes to the sudden conversion of water into vapour. In 1605, Florence Rivault, preceptor to Louis XIII., discovered that a bombshell, enclosing water, exploded when brought to a bigh temperature; and in 1615, Solomon De Caus, who, though generally resident in England, seems to have been a native of Dieppe, carried the idea suggested by this experiment still farther by proposing to insert a tube in the bombshell, and to raise the water enclosed in the tube by the pressure of its own steam. The Marquis of Worcester proposed a machine similar to that of De Caus; but it is a matter of doubt whether he or De Cans ever constructed the apparatus which they contrived.

In these rude experiments and speculations we may have recognised the ovarium, but we have neither seen the egg nor the germ of the steam-engine. Towards the close of the seventeenth century, however, its embryo form may be detected in the albuminous mass; and henceforth the organs of life and motion are gradually developed. Denis Papin, a Frenchman by birth, but an Englishman by a better tie, proposed, so early as 1690, to raise a piston, fitted into a cylinder, by the elastic force of steam, and then to condense the steam by withdrawing the fire with which it had been generated, in order that the pressure of the atmosphere might force the piston to the bottom of the cylinder. That this proposal involves the general idea of a modern steam-engine, both in its form and principle of action, cannot be doubled; but notwithstanding this admission, and with every anxiety to throw off the incubus of tational prepossessions, we cannot award to the French physician the high merit which M. Arago has so skilfully claimed for him. When we first hear of the upright cylinder-its nicely fitted pistonthe introduction of the steam beneath it--the subsequent rise of the piston-the condensation of the steam, and the consequent descent of the piston in the cylinder--we are misled by a succession of words and ideas before we have formed a just estimate of their historical meaning. But when we recollect that Otto Guericke had, previous to 1672, used an upright cylinder with a packed piston and piston rod; and that he actually raised heavy weights with this apparatus, by means of the pressure of the atmosphere rendered effective by the extraction of the air beneath the piston, we cannot avoid the conclusion, that the apparatus of Papin is the apparatus of Otto Guericke; in which he substituted the elastic force of steam, and its subsequent condensation, in place of the exhaustion of the air beneath the piston. But as the elastic force of steam was not a new invention, Papin can claim no other merit than that which belongs to the idea of forming a vacuum, by condensing the steam after it had elevated the piston ;-an idea, too, which he carried into effect with so little ingenuity, that we are led to view the whole proposal as a speculation on which its author placed but little value.*

[graphic]

The true inventor of the steam-engine was Captain Savery.t The first steam-engine that was ever made was made under his direction. The first steam-engine that ever performed really useful work, performed it at his command. Previous to 1691, he had not only carried into effect the crude ideas of De Caus and extended those of the Marquis of Worcester, but he constructed a real steam-engine, in which the pressure of the atmosphere, and the elasticity of the steam, acted in succession as moving powers. We owe to him, also, the two great improvements of generating the steam in a separate vessel; and of condensing it in the cylinder by the injection of a jet of cold water. One of Savery's engines was exhibited to King William III. at Hampton Court, and also to the Royal Society, and to the leading proprietors of English mines; and such was its excel

* We regret that we cannot view the labours of Papin so favourably as M. Arago has done. We admit that he made a real step in the march of invention; but this step has been amply ackowledged by three English authors, namely, Stuart, Farey, and the author of the article SteamEngine in the Edinburgh Encyclopædia--the last two of which have given Papin's own drawing descriptive of his contrivance. In these views we have the support of Mr Muirhead, the very intelligent translator of M. Arago's Memoir.

t. Une autre preuve que cette machine a pris sa naissance en Angleterre, et que'lle l'emporte sur tout ce qui a été tenté en France et en Allemagne à cette occasion, c'est que toutes les machines à feu qu'on a construite ailleurs que dans la Grande Bretagne ont été executées par

des Anglais.'-Belidor, Architecture Hydraulique. Tom. ii. p. 211, S 1281. Mr Gensanne, too, a French inventor, describes an apparatus of his own as an improvement on a machine which,' he remarks, every

one knows was invented by M. Savery, and executed on a great scale • in London • and in other parts of England.'—Machines approuvées par l'Académie, tom. vii. p. 2012

6

« PreviousContinue »