Читать книгу The Gallery of Portraits (All 7 Volumes) - Arthur Thomas Malkin - Страница 82
SMEATON.
ОглавлениеJohn Smeaton will long be remembered as one of the most laborious and most successful civil engineers whom Britain has produced: a class to which our country is deeply indebted for its commercial greatness. He was born at Austhorpe, near Leeds, May 28, 1724. His father was an attorney, and intended to bring his son up to his own profession: but the latter finding, to use his own words, “that the law did not suit the bent of his genius,” obtained his parent’s consent that he should seek a more congenial employment.
From a very early age he had shown great fondness for mechanical occupations. “His playthings,” it is said by one long acquainted with him, “were not the playthings of children, but the tools men work with; and he appeared to have greater entertainment in seeing the men in the neighbourhood work, and asking them questions, than in any thing else.” At the age of eighteen he was in the habit of forging iron and steel, and melting metal for his own use: and he possessed tools of every sort for working in wood, ivory, and metal. Some of these were of his own construction; and among them an engine for rose-turning, and a lathe by which he had cut a perpetual screw, a thing little known at that time.
In the year 1750 he established himself in the Great Turnstile in Holborn, as a philosophical instrument-maker. While he followed this trade, he became known to the scientific circles by several ingenious inventions; among which were a new kind of magnetic compass, and a machine for measuring a ship’s way at sea. He was elected fellow of the Royal Society in 1753; and contributed several papers to the Philosophical Transactions, one of which, entitled ‘An Experimental Enquiry concerning the natural powers of water and wind to turn mills and other machines, depending on a circular motion,’ obtained the gold medal in 1759.
In 1755 the Eddystone light-house was destroyed by fire. At this time Smeaton had never practised as an architect or engineer. But the proprietors, to use his own words, “considered that to reinstate it would require, not so much a person who had been merely bred, or who had rendered himself eminent in this or that given profession, but rather one who from natural genius had a turn for contrivance in the mechanical branches of science.” Thinking thus, they applied to the President of the Royal Society to recommend a fitting person, and he without hesitation named Smeaton. We shall speak hereafter of the difficulties which attended this work, and the method of its execution; the nature of it is familiar to every reader. Two light-houses had been destroyed within half a century: his own, after the lapse of seventy-three years, stands unimpaired;—a proud monument of the power of man to overcome the elements. This building was finished in 1759, and established his reputation as a civil engineer: but it was some time before he devoted his attention solely to practising in that capacity. In 1764 he was appointed one of the Receivers of the Greenwich Hospital Estates, and in the discharge of his duty, he suggested various improvements which were of material service to the property. He resigned that office about 1777, in consequence of the increase of his other business. In 1766 he was employed to furnish designs for new light-houses at the Spurn Head, at the mouth of the Humber, and after considerable delay, was appointed Surveyor of the Works in 1771. These were completed in April, 1777. Among other undertakings he repaired and improved the navigation of the river Calder; he built the bridge over the Tay, at Perth, and some others on the Highland road, north of Inverness; he laid out the line, and superintended the execution of a considerable portion of the great canal connecting the Forth and Clyde. His high reputation was shown shortly after the two centre arches of old London bridge had been thrown into one. The foundations of the piers were discovered to be damaged, and the danger of the bridge was esteemed so imminent that few persons would venture to pass over it. The opinions of the architects on the spot were deemed unsatisfactory; and Smeaton, being at the time in Yorkshire, was summoned by express, to say what should be done. He found that the increased volume of water passing through the centre arch had undermined the piers; and removed the danger by the simple expedient, the success of which he had proved on the river Calder, of throwing in a large quantity of rough stone about them. The interstices of the heap soon are filled up by sand and mud, and the whole is consolidated almost into one mass, and forms a secure and lasting barrier. The best known of Smeaton’s works, after the Eddystone light-house, is the magnificent pier and harbour of Ramsgate. This undertaking was commenced in 1749, and prosecuted for some time with very imperfect success. In 1774 Smeaton was called in; and he continued to superintend the progress of the works till their completion in 1791. The harbour is now enclosed by two piers, the eastern nearly 2000, the western 1500 feet in length, and affords a safe and a much needed refuge to ships lying in the Downs, even of five and six hundred tons, which before, when driven from their anchors by stress of weather, were almost certain to be cast ashore and wrecked.
It would be vain to enumerate all the projects in which he was consulted, or the schemes which he executed. The variety and extent of his employments may be best estimated from his Reports, of which a complete collection has been published by the Society of Civil Engineers, in consequence of the liberality of Sir Joseph Banks, who had purchased, and presented them to the Society for this purpose. They fill three quarto volumes, and constitute a most interesting and valuable series of treatises on every branch of engineering; as draining, bridge-building, making and improving canals and navigable rivers, planning docks and harbours, the improvement of mill-work, and the application of mechanical improvements to different manufactures. His papers in the Philosophical Transactions are published separately, and fill another quarto volume. They contain descriptions of those early inventions which we have mentioned, and of an improved air-pump, and a new hygrometer and pyrometer; together with his treatise on Mill-work, and some papers which show that he was fond of the science of astronomy, and practically skilled in it.
His health began to decline about 1785, and he endeavoured to withdraw from business, and to devote his attention to publishing an account of his own inventions and works; for as he often said, “he thought he could not render so much service to his country as by doing that.” He succeeded in bringing out his elaborate account of the Eddystone Light-house, published in 1791. But he found it impossible to withdraw entirely from business: and it appears that over-exertion and anxiety did actually bring on an attack of paralysis, to which his family were constitutionally liable. He was taken ill at his residence at Austhorpe, in September, 1792, and died October 28, in the sixty-ninth year of his age. He had long looked to this disease as the probable termination of his life, and felt some anxiety concerning the likelihood of out-living his faculties, and in his own words, of “lingering over the dregs after the spirit had evaporated.” This calamity was spared him: in the interval between his first attack and his death, his mind was unclouded, and he continued to take his usual interest in the occupations of his domestic circle. Sometimes only he would complain, with a smile, of his slowness of apprehension, and say, “It cannot be otherwise: the shadow must lengthen as the sun goes down.”
His character was marked by undeviating uprightness, industry, and moderation in pursuit of riches. His gains might have been far larger; but he relinquished more than one appointment which brought in a considerable income, to devote his attention to other objects which he had more at heart; and he declined the magnificent offers of Catharine II. of Russia, who would have bought his services at any price. His industry was unwearied, and the distribution of his hours and employments strictly laid down by rule. In his family and by his friends he was singularly beloved, though his demeanour sometimes appeared harsh to strangers. A brief, but very interesting and affectionate account of him, written by his daughter, is prefixed to his Reports, from which many of the anecdotes here related have been derived.
Of the many great undertakings in which Smeaton was engaged, the most original, and the most celebrated, is the Eddystone light-house. The reef of rocks known by the name of the Eddystone lies about nine miles and a half from the Ram Head, at the entrance of Plymouth Sound, exposed to the full swell of the Atlantic, which, with a very moderate gale, breaks upon it with the utmost fury. The situation, directly between the Lizard and Start points, makes it of the utmost importance to have a light-house on it; and in 1698 Mr. Winstanley succeeded in completing one. This stood till 1703, but was entirely carried away in the memorable storm of November 26, in that year. It chanced, by a singular coincidence, that shortly before, on a doubt of the stability of the building being uttered, the architect expressed himself so entirely satisfied on that point, that “he should only wish to be there in the greatest storm that ever blew under the face of the heavens.” He was gratified in his wish; and perished with every person in the building. This building was chiefly, if not wholly of timber. In 1706 Mr. Rudyerd commenced a new light-house, partly of stone and partly of wood, which stood till 1755, when it was burnt down to the very rock. Warned by this accident, Smeaton resolved that his should be entirely of stone. He spent much time in considering the best methods of grafting his work securely on the solid rock, and giving it the form best suited to secure stability; and one of the most interesting parts of his interesting account, is that in which he narrates how he was led to choose the shape which he adopted, by considering the means employed by nature to produce stability in her works. The building is modelled on the trunk of an oak, which spreads out in a sweeping curve near the roots, so as to give breadth and strength to its base, diminishes as it rises, and again swells out as it approaches to the bushy head, to give room for the strong insertion of the principal boughs. The latter is represented by a curved cornice, the effect of which is to throw off the heavy seas, which being suddenly checked fly up, it is said, from fifty to a hundred feet above the very top of the building, and thus to prevent their striking the lantern, even when they seem entirely to enclose it. The efficacy of this construction is such, that after a storm and spring tide of unequalled violence in 1762, in which the greatest fears were entertained at Plymouth for the safety of the light-house, the only article requisite to repair it was a pot of putty, to replace some that had been washed from the lantern.
To prepare a fit base for the reception of the column, the shelving rock was cut into six steps, which were filled up with masonry, firmly dovetailed, and pinned with oaken trenails to the living stone, so that the upper course presented a level circular surface. This part of the work was attended with the greatest difficulty; the rock being accessible only at low water, and in calm weather. The building is faced with the Cornish granite, called in the country, moorstone; a material selected on account of its durability and hardness, which bids defiance to the depredations of marine animals, which have been known to do serious injury by perforating Portland stone when placed under water. The interior is built of Portland stone, which is more easily obtained in large blocks, and is less expensive in the working. It is an instructive lesson, not only to the young engineer, but to all persons, to see the diligence which Smeaton used to ascertain what kind of stone was best fitted for his purposes, and from what materials the firmest and most lasting cement could be obtained. He well knew that in novel and great undertakings no precaution can be deemed superfluous which may contribute to success; and that it is wrong to trust implicitly to common methods, even where experience has shown them to be sufficient in common cases. For the height of twelve feet from the rock the building is solid. Every course of masonry is composed of stones firmly jointed and dovetailed into each other, and secured to the course below by joggles, or solid plugs of stone, which being let into both, effectually resist the lateral pressure of the waves, which tends to push off the upper from the under course. The interior, which is accessible by a moveable ladder, consists of four rooms, one over the other, surmounted by a glass lantern, in which the lights are placed. The height from the lowest point of the foundation to the floor of the lantern is seventy feet; the height of the lantern is twenty-one feet more. The building was commenced August 3, 1756, and finished October 8, 1759; and having braved uninjured the storms of seventy-three winters, is likely long to remain a monument almost as elegant, and far more useful, than the most splendid column ever raised to commemorate imperial victories. Its erection forms an era in the history of light-houses, a subject of great importance to a maritime nation. It came perfect from the mind of the artist; and has left nothing to be added or improved. After such an example no accessible rock can be considered impracticable: and in the more recent erection of a light-house on the dangerous Bell-rock, lying off the coast of Forfarshire, between the Frith of Tay and the Frith of Forth, which is built exactly in the same manner, and almost on the same model, we see the best proof of the value of an impulse, such as was given to this subject by Smeaton.
Light-houses of (1) Winstanley, (2) Smeaton, and (3) Rudyerd.