Читать книгу Autobiography of Sir John Rennie, F.R.S., Past President of the Institute of Civil Engineers - Sir John Rennie - Страница 5

Table of Contents

My birth and early education—I enter my Father’s office—Commencement of Waterloo and Southwark Bridges—Anecdotes of Mr. Ferguson, of Pitfour—The Stockton and Darlington Railway and Surveys between Port Patrick and Donaghadee—Account of the mode of erecting the arches of Southwark Bridge—Journey to the Continent and Field of Waterloo—Account of the building of Waterloo Bridge—It is opened in State by the Prince Regent, 1817.

I was born at 27, Stamford Street, Blackfriars, London, on the 30th of August, 1794. Having been taught my letters at home, I was sent to the care of Dr. Greenlaw, who kept a boys’ school at Isleworth. It was a large house, formerly belonging to the Bishop of London. To the house were attached excellent gardens and playground. The situation, moreover, was open and healthy, and the total number of boys was about fifty, ranging from eight to sixteen years of age. They were well fed and taken care of by the Doctor’s excellent wife, and his sister-in-law, Miss Hodgkins. The Doctor’s eldest daughter, Miss Greenlaw, taught the youngest boys their letters; whilst the Doctor and his assistants devoted themselves to the education of the others, which education consisted chiefly of classics, writing, arithmetic, French, and occasionally geography and the elements of astronomy. During the time that I was there the most remarkable scholar was the celebrated poet, Percy Bysshe Shelley, who was then about twelve or thirteen (as far as I can remember), and even at that early age exhibited considerable poetical talent, accompanied by a violent and extremely excitable temper, which manifested itself in all kinds of eccentricities. His figure was of the middle size, although slight, but well made. His head was well proportioned, and covered with a profusion of brown locks; his features regular, but rather small; his eyes hazel, restless, and brilliant; his complexion was fair and transparent; and his countenance rather effeminate, but exceedingly animated. The least circumstance that thwarted him produced the most violent paroxysms of rage; and when irritated by other boys, which they, knowing his infirmity, frequently did by way of teasing him, he would take up anything, or even any little boy near him, to throw at his tormentors. His imagination was always roving upon something romantic and extraordinary, such as spirits, fairies, fighting, volcanoes, &c., and he not unfrequently astonished his schoolfellows by blowing up the boundary palings of the playground with gunpowder, also the lid of his desk in the middle of schooltime, to the great surprise of Dr. Greenlaw himself and the whole school. In fact, at times he was considered to be almost upon the borders of insanity; yet with all this, when treated with kindness, he was very amiable, noble, high-spirited, and generous; he used to write verse, English and Latin, with considerable facility, and attained a high position in the school before he left for Eton, where, I understand, he was equally, if not more, extraordinary and eccentric.

Cotemporary with Shelley there was another peculiar character, named Tredcroft, from the same county, viz. Sussex; he also had considerable poetical talent, but unfortunately lost his health, and ultimately, I understand, died completely imbecile at an early age. I remained at this school until the year 1807, by which time I had acquired a tolerable knowledge of the Greek and Latin classics, and arithmetic as far as vulgar fractions and decimals. I was then sent to the celebrated Dr. Burney’s, at Greenwich, where there were about 100 boys, varying from ten to eighteen.

Dr. Charles Burney was considered one of the best Greek and Latin scholars of the day, and was the intimate friend of Porson and numerous other literary celebrities. His school was therefore very highly esteemed for classics, but for little or nothing else; for although a certain quantity of arithmetic and the elements of algebra and geometry were taught, yet these were quite secondary to the classics.

I therefore made little further progress in anything but classics, in which I became a tolerable proficient, and had Homer, Thucydides, Euripides, Sophocles, Virgil, Horace, &c., at my fingers’ ends, whilst I could scarcely demonstrate the Pons asinorum of Euclid; in fact, in those days a knowledge of Greek and Latin was considered as including everything else, and anything like a science or physics was considered of secondary consequence. I made the acquaintance of two men, who afterwards much distinguished themselves by their scientific acquirements, namely, the late Herbert Mayo, the well-known surgeon and physiologist; also the late Sir George Everest, the scientific Director of the Triangular Survey of India; and Dr. Milman, late Dean of St. Paul’s. Dr. Burney’s school was by no means so well managed as that of Dr. Greenlaw in everything which regarded the comfort of the boys, neither were they so well fed or looked after, and it was a great relief to me when I left the school in 1809.

It then became a question with my father whether I should go to Oxford or Cambridge, or whether I should finish my education at home, under the superintendence of proper masters. About this period, and ever since the year 1802, there was nothing but war heard or talked of all over the world. The whole country was as it were turned into a camp; every man capable of bearing arms became a volunteer, and at school even we were regularly drilled to the use of arms; and I was so excited by the extraordinary victories of Nelson and the early career of Wellington that I determined to enter the army, but to this my father was decidedly opposed, as he wished to bring me up to his own profession. I was therefore reluctantly obliged to give up all idea of the military profession and follow that of a civil engineer; and my father wisely determined that I should go through all the gradations, both practical and theoretical, which could not be done if I went to the University, as the practical part, which he considered most important, must be abandoned; for, he said, after a young man has been three or four years at the University of Oxford or Cambridge, he cannot, without much difficulty, turn himself to the practical part of civil engineering. All idea, therefore, of my going to Cambridge or Oxford was given up. My father at that period had one department of his business exclusively devoted to practical mechanics, that is, to the making of machinery of all kinds; this department, although it formed by no means the principal part of his profession, nevertheless enabled him to make experiments which were of great value in the other departments of his business, and was by no means unprofitable, as the importance of machinery and mechanical contrivances was then to a certain extent appreciated, and was daily becoming more so. My father always said that theoretical and practical mechanics were the true foundations of all civil engineering; and he therefore insisted that as I had to a certain extent learned the theoretical, so I must now learn the practical part. I was therefore sent into the mechanical department, and commenced work planing and sawing boards, making patterns, and other similar works. After this I was put to turning both wood and metal; and although I did not attain complete practical efficiency in these departments, which would have required several years, nevertheless I learned sufficient to enable me to become a tolerable judge of workmanship.

I was then put into the drawing office, where I learned to copy geometrical plans, by which, in a short time, in combination with what I had acquired in the workshop, I gained a general knowledge of design and construction.

My time was employed in this manner about eight hours daily, but my evenings were devoted to the acquisition of geometry, algebra, and trigonometry, plane and spherical; also astronomy under the late Astronomer Royal, Mr. Pond, and his father-in-law, Dr. Bradley, and in learning French, Italian, and German. Having acquired to a certain extent a proficiency in the mathematical sciences, I was placed under the direction of the late Mr. Francis Giles, a land surveyor of considerable experience and ability, who was generally employed by my father to make his various hydraulic surveys for canals and harbours under his immediate direction, which Mr. Giles executed with his usual fidelity and ability. Under Mr. Giles I learned the use of the chain, level, and theodolite, and was enabled to apply my theoretical knowledge in trigonometry, plane and spherical, to practice. About this period, viz. the year 1813, having obtained a tolerable knowledge of the rudiments of my profession, both theoretical and practical, my father determined to place upon my shoulders a certain degree of responsibility, and put me under the direction of that late worthy and excellent man, Mr. James Hollingsworth, whom my father had appointed to be resident engineer of the Waterloo Bridge, which was then building. I felt the responsibility of this office a good deal, and entered upon it with every determination and desire to meet my father’s approbation; and during the inclement winter of 1813–14, when the frost lasted about two months, and the Thames above London Bridge was frozen over for several weeks, I was obliged to attend the piling of the foundations of the first and second piers on the Surrey side of the river night and day for three days each week, which severely tried my constitution.

At this period Vauxhall Bridge was also in course of construction, and I was directed by my father to attend to this also, under Mr. Jones, the resident engineer; but they had scarcely finished the Middlesex abutment up to the springing of the first arch, and were preparing the caisson for founding the first pier, when the Company found that they had not sufficient funds to carry into effect Mr. Rennie’s design, which was very beautiful. The bridge was to be made entirely of the fine blue sandstone from Dundee, and was to consist of seven arches, segments of circles, the centre arch being 110 feet span, with a rise or versed sine of 19 feet, and depth of keystone 4 feet 6 inches; piers 18 feet 6 inches thick at the springing of the arch, the two arches next the centre being 105 feet span each, with a rise or versed sine of 17 feet, keystone 4 feet 5 inches, and springing stones 9 feet long, and the two piers 17 feet 6 inches thick each. The two next arches were 100 feet span, with a rise or versed sine of 15 feet, keystones 4 feet 4 inches, and springers 9 feet, and piers 17 feet thick each; the two sub or shore arches 90 feet span each, with a rise or versed sine of 13 feet, keystones 4 feet, and springers 8 feet, abutments 21 feet thick at the springing, having a total width of waterway of 700 feet. The arches were surmounted by a Roman Doric cornice and plain block and plinth parapet, and the projecting points of the piers were surmounted by solid square pilasters, with a niche in the centre. The roadway was 34 feet wide between the parapets, and was formed by a very flat segment of a circle rising 1 in 53. The piers were intended to be founded by caissons resting upon a platform supported by bearing and surrounded by sheeting piles. This was upon the whole a very elegant, light, and chaste design. Finding that the Company had not sufficient funds to carry into effect the stone design, Mr. Rennie proposed another wholly of iron, consisting of eleven arches, with a total waterway of 732 feet, supported upon cast-iron columns filled with masonry and resting upon a platform supported upon piles and surrounded by sheeting piles. The centre arch was to be 86 feet span and 8 feet rise, and the others diminishing regularly to each end so as to enable the roadway to be formed into a graceful curve rising 1 foot in 60. This also was an extremely light, elegant, and economical design. The total cost of this elegant design was estimated at 100,000l., and would have been executed first, but at that time even this amount was not forthcoming. The works then stopped, and some time elapsed before the Company was resumed, and ultimately constructed the present bridge.

In the year 1814–15 my father was appointed engineer-in-chief of the Southwark Bridge Company, and as this was proposed to be constructed in the narrowest part of the river between Blackfriars and the Old London Bridge, considerable opposition was made to the Act of Parliament for its construction by the Corporation of London and the Conservators of the river, on account of the obstruction which they said the bridge would offer to the navigation; this however was finally overcome, but it was decided by Parliament that the bridge should be constructed with as large arches as possible. Accordingly Mr. Rennie submitted a design consisting of three cast-iron arches, the centre being 240 feet span, with a versed sine of 24 feet, and two side arches of 210 feet each, with a versed sine or rise of 18 feet 10 inches each, with piers of 24 feet wide each at the springing, thus giving a clear lineal waterway of 660 feet, which was a great deal more than that of the Old London Bridge at that time existing. This design was approved of and ordered to be carried into effect. By this time, with the experience of the Waterloo and Vauxhall bridges and my other studies, I had gained considerable knowledge in bridge building, and my father was anxious to give me as much encouragement as possible; although, therefore, he appointed a worthy and practical man, Mr. Meston, as nominally the resident engineer, yet he confided to me the arduous task of making out the working drawings under his own direction, and of carrying them into effect. I therefore felt highly gratified with this great mark of confidence, and devoted my whole energies to the work night and day. The ironwork was carried into effect by Messrs. Walker, of Rotherham, under the able management of their experienced and able superintendent, Mr. Yeats, and the masonry and piling under the well-known contractors, Messrs. Jolliffe and Banks; and Mr. Meston, the resident engineer, faithfully discharged his duties.

As these arches were the largest of the kind ever constructed, considerable doubts as to their stability occurred to many, and the subject was discussed amongst scientific men with considerable energy; and amongst others, the celebrated Dr. Young undertook to investigate Mr. Rennie’s calculations, and came to the conclusion that the bridge was well designed, and would be a perfectly safe and stable structure, and equal to the support of any weight or amount of traffic which could be brought over it. But in order to fulfil these conditions, it was absolutely necessary that every detail of materials and workmanship should be worked out with the greatest skill and accuracy.

As the arches were of such great span with so small rise, the pressure upon the piers and abutments was chiefly lateral; it therefore became necessary to construct them in such a manner that they should offer the most effectual resistance to this pressure. In consequence, the foundations of the abutments were made on an incline, and the masonry from thence upwards to the springing of the arches was made to consist of a series of courses radiating upwards until they reached the angle of the springing courses; so that, in point of fact, the abutments formed, as it were, a continuation of the side arches to their base; and in order to connect the courses of masonry more solidly together, the courses were connected with each other from the top to the bottom by several series of vertical bond stones, thus forming one solid immovable mass. These abutments were supported on a platform composed of piles, double sleepers, and planking, the piles being 20 feet long, 12 inches in diameter in the middle, and driven solidly into the ground at right angles to the inclination of the foundation. As the pressure upon the piers was nearly equal on both sides, it was necessary that the foundations should be laid level. These also rest upon a wooden platform of double sills and planking, lying upon piles of the same dimensions as those of the abutments, driven vertically into the ground below, and the courses of masonry, which were laid horizontally, were connected together in the vertical direction by a series of bond stones in a similar manner to those of the abutments. The abutments and piers were founded many feet below low-water mark of spring tides, so as to be below the reach of any possible scour of the river. Those parts of the piers from immediately below the springing of the arches to a point above the top of the main solid ribs of the arches were composed of large blocks of stone set nearly vertically, breaking bond laterally and vertically with each other, and in the centre of this part of the piers there was a set of keystones 12 feet long and 2 feet thick, tapering on each side, forming so many stone wedges. These were very finely worked on all sides. These wedge stones broke bond laterally with the blocks in front of them, and were firmly driven into their places for a depth of 2 feet by means of heavy wooden rams. The masonry of the pilasters and salient angles of the piers is of the same character as those of the interior of the pier before described, and worked into them in the same manner, so as to form one solid bond from one point of the pier to the other. The whole of the exterior of this part of the piers, as well as of the abutments, is cased with granite from Scotland or Cornwall; and it was necessary that the blocks forming this casing should be of the largest kind, which hitherto was quite unusual, particularly for the facing of the abutments from whence the arches were to spring, which required blocks from 15 to 20 tons. These were of such unusual magnitude, and nothing of the kind had hitherto been used in London, or even elsewhere in England, that the contractors made considerable objection to obtaining them, and even went so far as to say that it could not be done. I was perfectly convinced that it could be done, and that it was merely a question of a little extra expense, and strongly recommended my father to insist upon it, as it was absolutely necessary for the security of the bridge; and he did so, and directed me to proceed to Aberdeen for the purpose of obtaining them. I accordingly started for Aberdeen; and when there, carefully examined all the quarries in the neighbourhood, which I found had only been opened up on a small scale, and were merely adapted for getting paving stones, the commerce of which with London was then upon a considerable scale; but the idea of obtaining blocks of the size required for the Southwark Bridge was considered to be entirely out of the question; or, even if they could be obtained, the price would be such that the contractors would not consent to pay. In fact, so many difficulties and objections were made that I found nothing could be done in that quarter. I therefore determined to proceed to Peterhead, 30 miles farther northward, where the red granite abounds in large masses near the coast, and where I was told that I should probably succeed; but still, they said, even there it would be very difficult to get them. Upon arriving at Peterhead I immediately set to work exploring the adjacent country for several miles round, and soon found that blocks of the size required could readily be obtained, and even larger ones if necessary. I accordingly selected, by way of experiment, a mass of solid rock about four miles to the south of Peterhead, lying within a quarter of a mile of the sea coast, and about 200 feet above the main turnpike road to Peterhead, which ran along the sea shore. This block, weighing about 25 tons, was accordingly marked out, and was soon detached from the main mass of rock by means of wedges, and was 10 feet long and 5 feet square. The workmen who executed this task were rewarded with ample wages and a good supply of whisky, and were extremely proud of their achievement. Then came the important question, how they were to convey it to Peterhead. To get it to the turnpike road was soon accomplished by means of a wooden inclined tramway formed of stout planks moved upon wooden rollers. Good wages and whisky settled this, and the workmen considered it a further great triumph; but still the greater difficulty remained, how to get this vast block (as it was then considered) four miles to Peterhead. I then went back to Peterhead, and after numerous inquiries, and as many failures and objections on all sides, at last found two large single bogies, each consisting of a pair of strong wheels 8 feet in diameter, connected by a strong axle shaft and a double pair of shafts in front. These two pairs of wheels I joined together at the axle shafts by two strong beams, cased with wrought iron, and strengthened the wheels and axles in other respects as far as necessary. I then took this carriage to the block of red granite already mentioned lying in the road, and slung the stone, by means of strong chains, to the two longitudinal bearers of the carriage. Some twelve or fourteen horses were then attached to the carriage, and off we departed in great triumph for Peterhead. The toll-keeper, never having seen such a mass of stone before, did not know what to charge. However, having at length satisfied his demand, we proceeded onwards, and we had scarcely advanced a mile when we came to a soft piece of road, which yielded under the great weight of the stone, and the wheels stuck fast, buried about 9 inches in the ground. This accident created general dismay amongst the attendant workmen, and they began to consider the task hopeless. However, nothing daunted by this mischance, I soon rallied their courage, and with plenty of screw-jacks, wedges, and levers judiciously applied, we raised the wheels out of the ground, and placed strong wooden beams under them, forming a rough kind of railway, over which we dragged and pushed the carriage with its stone in safety, until we had passed the unsound part of the road. This operation detained us about a day. Everybody worked with the greatest ardour and goodwill, which was aided not a little by a plentiful supply of ale and whisky, and the men were determined, for the honour of Scotland, that they would not be beaten. Having overcome this serious obstacle, we started again on our journey, and reached Peterhead about four hours afterwards, making the total length of the journey—four miles—a day and a half. The whole town of Peterhead, having never seen such a sight before, and having considered our task impracticable, turned out to see us, and welcomed us with the most enthusiastic acclamations.

The next thing to be done, having succeeded so far, was to get a vessel that would take this monstrous block of stone, as it was termed, to London; and although there were a considerable number of vessels in the harbour, I could not at first prevail upon any of the captains to take the charge. All sorts of objections were made, and amongst the rest, it was impossible to get the stone on board, and if they did, it would make a hole in the bottom, and the vessel would founder with all on board. At last, after a great deal of difficulty, I found a brig of about 200 tons burthen, the captain of which, after a good deal of persuasion, consented to take the block of stone to London, provided that I would put it on board at my own risk and expense, and indemnify him against all risk or loss on the voyage, which I accordingly agreed to do.

Then came the last important question, how was the block to be got on board? There was no crane in the port capable of lifting above 2 or 3 tons.

I immediately set to work to supply this deficiency by means of two sets of strong sheer-poles, capable of bearing 10 to 15 tons each. The vessel engaged was accordingly brought alongside the quay where the 4-ton crane was fixed, so that it should nearly plumb the centre of the hatchway of the vessel, which it was necessary to enlarge and strengthen considerably before it could receive the stone. I then secured the sheer-poles well at the top, and placed one set on each side of the crane, a short distance from the extremity of each end of the hatchway. The legs of the sheer-poles were firmly fixed in the bed of the harbour, striding over the vessel, so that they were perfectly independent of the vessel, and the top of each pole was directly over the centre of the hatchway. To the top of the sheer-poles I applied a pair of strong treble sheave-blocks, capable of receiving a thick rope; each block was worked by a double purchase crab or windlass manned by eight men each, besides four to work the crane, so that the block would be suspended at three points, the sheers taking the greatest weight. After a good deal of trouble I got the whole of this apparatus as complete as circumstances would permit, which were not the most favourable. From the quay a strong timber gangway was constructed over the hatchway, the outer end being supported, clear of the vessel, by piles driven into the bed of the harbour on each side, in order that the ship might be kept perfectly steady until the stone was placed within the hold, because otherwise the stone resting upon any part of the deck might have upset it. Everything being ready, the stone was brought alongside the vessel and the tackle of the crane and of the two pairs of sheer-poles was made fast to three sets of strong chains fastened round the stone, which was transferred upon rollers over the centre of the hatchway of the vessel, the purchases of the crane and sheer-poles being kept sufficiently tight so as to prevent any undue pressure upon the platform. The stone was then raised clear of the platform, when I heard a crack; in fact, one of the sheer-poles had bent and partially yielded; it was then blocked, and, the sheers having been first spliced with strong rope, the stone was again hoisted and swung clear of the platform, which was removed, and the stone was lowered into the hold of the vessel and properly secured without any further delay or accident. The whole of these operations were witnessed with intense interest by many of the inhabitants of Peterhead, and when so successfully completed the quays resounded with cheers. The gallant workmen who laboured so arduously and with such goodwill, and to whose exertions the success may be mainly attributed, were plenteously regaled, together with their friends, with all the good things which Peterhead afforded, in which the worthy inhabitants joined, and the remainder of the day was passed in mutual goodwill and festivity.

My readers will, I trust, excuse the detailed manner in which I have described these operations, which at the present day would be considered trifling to a degree, but, at the time above mentioned, more than half a century since, operations of this kind had not been attempted, and were entirely novel, and were considered extraordinary; they must, therefore, be viewed as the pioneer to the far greater operations of the kind which have followed. For now such stones are considered mere trifles, and blocks of almost any reasonable size can be quarried, polished, and transported to their destination, however distant, at comparatively much less cost and with greater facility. The cutting and polishing of granite at that time was accomplished at great expense, as it was done entirely by manual labour; now it is performed by means of machinery at greatly reduced cost, and polished granite of every kind is introduced into buildings, which was formerly considered impracticable; and thus the architect is provided with additional means of ornamenting his structures. It is true that many centuries before the Egyptians had shown the way; but then the whole power and resources of the nation had been devoted to this object, and incredible sums of money and great labour had been expended, regardless of the misery and oppression of the people. But in Great Britain it has been considered a true maxim of political economy, that every article should be produced at the least possible cost, and no work should be undertaken unless it would yield a fair profit for the capital expended; and whenever there is a reasonable prospect of obtaining this satisfactory result, any amount of capital which may be required is always forthcoming. Witness the vast sums which have been expended on railways alone, besides steam-vessels, manufactures, machinery, and other similar undertakings.

Whilst at Aberdeen and Peterhead, my father gave me an introduction to his old and intimate friend, the well-known James Ferguson, of Pitfour, the member for the county, and the intimate friend of Mr. Pitt. Mr. Ferguson possessed a large fortune; he was an old bachelor of the most amiable and charitable disposition, beloved by everybody and universally popular throughout the county. As illustrative of the manners of those days, I will simply mention that when I presented my father’s letter of introduction he received me most kindly, and invited me to spend a few days under his most hospitable roof, which I accepted, and on the first day there was assembled a large party of the most influential gentlemen of the county; as was usual wines of all kinds flowed in abundance, and universal hilarity prevailed. The consequence was that not long after dinner several of the guests fell off their chairs and took their nap under the table, from which after a short time they recovered and resumed their seats, and again set to work at their potations, which continued until long past midnight; by this time another considerable batch of guests were under the table, leaving their glasses full. I was so much amused at this unaccustomed scene, that, by way of frolic, I took the full glasses of some of the guests on the floor and poured them down their throats, which had no other effect than to make them sleep sounder. In this manner the evening passed merrily away, and it was late in the morning before the whole of the company found their way to their beds. The amiable host allowed everyone to do as he liked, and when he had had enough, which was not very soon, he retired to bed, leaving his guests to take care of themselves; in fact, Pitfour was “Liberty Hall,” and was open to all comers, the only limit being the amount of sleeping accommodation.

To give some idea of his hospitality, Mr. Ferguson seldom had less than thirty-six pipes of fine port wine in his cellars, besides claret, burgundy, sherry, champagne, brandy, and whisky, in proportion. He was so fond of Mr. Pitt, that it is believed that if Mr. Pitt had survived him, he intended to have made him heir to his estates, which were said to have been worth above 20,000l. a year.

When attending his duties in the House of Commons, he lodged in apartments in St. James’s Street, and after the parliamentary labours of the week were over, Mr. Pitt, the late Harry Dundas, First Lord Melville, and Mr. Ferguson used to retire to a country house at Wimbledon, and spend the Saturday, Sunday, and Monday in the greatest conviviality, until it was time to return to their parliamentary labours. Mr. Ferguson rarely, if ever, spoke in the House of Commons, but when he did, it was always to the purpose: his speeches, although exceedingly short, were replete with much common sense, accompanied by a terseness of wit, humour, and drollery, which convulsed his hearers with laughter, so that he was a general favourite. He used always to say that he had heard “mony a gude speech, but that he never changed his vote, he aye voted with Mr. Pitt.”

Having shown the good people of Peterhead how to get and ship the large blocks of red granite for the Southwark Bridge, and feeling that there would be no further difficulty about the matter, I returned to London, after an absence of two weeks, and resumed my duties at the Southwark Bridge. In the spring of 1814 my father, being desirous that I should be initiated into the practice of marine and trigonometrical surveying upon a large scale, sent me, under the direction of the late Mr. Francis Giles, who had then been appointed by Mr. Rennie to make an extensive survey of the different places where it was practicable to construct proper artificial harbours on the south-west coast of Scotland, such as Port Nessock, Ardwell, and Port Patrick bays, on the Scotch side of the channel, and Ballantrae, Donaghadee, Ballyhone, and Bangor bays, on the opposite coast of the Irish Channel, in order to decide which were the best places on either side of the channel to make permanent good artificial harbours for packets, for the purpose of establishing the best and most direct communication between the south-west coast of Scotland and the opposite coast of Ireland. In addition to making the surveys of the different ports above mentioned, it was absolutely necessary to make a correct chart of the channel within the above limits, comprehending a coast-line of about 30 miles on each side, including the Copeland Islands. It was also necessary to determine the exact distances between the different ports, together with the soundings, currents, rises of tide, prevailing winds, and all the other attendant hydraulic phenomena. This was a very extensive survey, and required great skill, judgment, and experience, and Mr. Giles was fully competent to undertake it.

As the shore, particularly on the Scotch side of the channel, was very precipitous, rugged, and mountainous, it was impossible to measure with anything like accuracy a base line from which a series of triangular observations could be made so as to connect the two coasts together; Mr. Griles was therefore obliged to resort to the Bay of Luce, situated about 10 miles to the east of Port Patrick; it had this disadvantage, however, that in consequence of the intervening mountains neither the Scotch nor Irish coast could be seen. But there was no alternative, for no other convenient place could be found to measure a base line. The head of the Bay of Luce, however, at low water consists of an extensive district of flat sand 6 miles long, admirably adapted for the purpose of measuring a correct base line. This plan was accordingly adopted, and a base was measured 6 miles in length, first by the common chain, then by another chain consisting of steel links each 5 feet long, and lastly by well-seasoned deal rods each 10 feet long; these measurements were repeated with great accuracy several times, and a mean was then struck by which the variation was reduced to a fraction of an inch. It should also be observed that the measurements were taken when the atmosphere was about the same temperature, so that the final measurement was reduced to as near accuracy as practicable. Having established the base, strong vertical staffs with flags at their summits were then accurately fixed upon the summits of the neighbouring mountains which overlooked the Irish Channel, and from which on a clear day the opposite coast of Ireland could be distinctly seen. From each end of the base the above-mentioned angles were taken with one of Troughton’s best 7-inch theodolites, between the different mountain stations, and the distance between the extreme points of these stations was accurately calculated, so that it gave a base line of about 30 miles along the Scotch coast, from whence correct sights were taken on flagstaffs fixed on the high land above Bangor, Donaghadee, and Ballantrae, including the Copeland Islands on the opposite coast of Ireland. These observations being taken on different levels, were subsequently reduced to the same plane, so that the exact distance was obtained between the different stations on each side of the channel, and a correct chart was made. In addition to the general survey, detailed hydraulic charts were made of the places on each coast which were best adapted for making harbours of the size required, viz. Port Nessock, Ardwell, and Port Patrick, on the Scotch side, and Bangor, Ballyhone, Donaghadee, and Ballantrae, on the Irish side of the channel; and as there was a great variety of interests concerned, each proprietor being desirous of having the permanent ports established on his own property, it was finally decided by the Government, at the recommendation of my father, that the whole of the surveys should be submitted to the arbitration of the Trinity Board, to select one port on each side of the channel which was best adapted for establishing a communication by packets between the two countries for letters and passengers in the most expeditious, convenient, and effective manner. The Trinity Board, after having given the subject their most mature consideration, ultimately decided on Port Patrick on the Scotch, and Donaghadee on the Irish side. This decision was approved of by the Government, and Mr. Rennie was desired by them to prepare designs for harbours in both of the above places; he did so, and the Government ordered them to be carried into effect under his direction: for a more particular description the reader is referred to my work on British and Foreign Harbours. During the progress of these surveys I learned a great deal in this important department of civil engineering, and personally surveyed the bay of Port Nessock and the Copeland Islands, which gave me an excellent lesson, as, on account of the rugged nature of the coasts, they were attended with considerable difficulties.

As already observed, in the following year, 1815, I was placed under Mr. Giles’ direction during the whole period of the survey of the river Tyne, which had been entrusted to him by my father also. In the same year I was under Mr. Giles during the surveys for the Barnard Castle, and Stockton and Darlington railways and canal; and I subsequently made a hydraulic survey of the port of Blythe for my father, and for which he afterwards made a design for its improvement. I had been previously employed under Mr. Giles in the surveys for the eastern extension of the Kennet and Avon Canal. During a part of this time our head quarters were at Windsor; and one Sunday afternoon I recollect very well attending the promenade on the terrace at Windsor Castle when His Majesty King George the Third, accompanied by the Queen and Royal Family, made their appearance with their attendants and joined the promenade, and were received in the most loyal and affectionate yet respectful manner. I also about the same time assisted Mr. Giles in the survey of the Thames in the vicinity of Woolwich Dockyard, the accumulation of the mud in front of which was so great at that time that it threatened to render that dockyard useless. The evil to a certain extent has since been remedied by removing a number of the projections which interfered with the currents of the ebb and flood tide, according to the plan laid down by the late Mr. Rennie, although, as he clearly pointed out, it would be impossible to improve the river to such an extent in front of Woolwich and Deptford dockyards as to render them fit for the construction and accommodation of large vessels of war; and therefore he recommended that they should be abandoned and sold, and that a proper establishment should be made at Northfleet capable of accommodating at all times of tide any number of the largest vessels of war at that time in the navy, or that might be built hereafter. This dockyard was intended to be so arranged that all classes of vessels of war could be built there; and it would contain establishments for manufacturing cordage, sails, anchors, guns, smith work of every kind, together with depôts of provisions, and stores of all sorts, all of which were to be arranged in such a manner that each operation of building, repairing, storing, and fitting out for sea should be completed in the order required; so that a vessel, after having been built, might be transferred at once into a dry dock to be coppered, then take in her masts, ballast, rigging, sails, stores, provisions, guns, boats, and seamen, and sail at once complete to her station from the centre dock-gates; in the same manner, when returning from her station, she might be repaired and fitted out again ready for sea. The saving effected by such an establishment would have been immense, and the service would have been performed in a far more expeditious and effective manner. Mr. Pitt was then Prime Minister, and his master mind at once acknowledged the advantages of such an establishment; it was accordingly approved of by the Government, the land was bought, and it was ordered to be carried into effect, but the unfortunate death of that great minister and the change of Government effectually put a stop to all further proceedings in this direction. Since that time the old dockyards of Woolwich and Deptford, Sheerness and Chatham, have been improved and enlarged, at an expenditure as great as would have completed Mr. Rennie’s establishment at Northfleet, without half the efficiency or accommodation. The old useless dockyards of Woolwich and Deptford, which the late Lord Melville, when First Lord of the Admiralty, condemned and ordered to be sold, have been retained, and the increase of unnecessary expense has been enormous, whilst the evils complained of have not been remedied till quite lately.

Having by this time a considerable knowledge of surveying, practical and theoretical, in all its departments either on land or water, so that I could undertake either, my father deemed that I had learned sufficient, and directed me to return to my practical duties in the construction of the Southwark Bridge. As this was considered a work of great importance and difficulty I felt highly honoured by my father’s confidence, and devoted my energies to it with the greatest anxiety and with a determination to do everything in my power to make it successful. The difficulty of obtaining the large blocks of granite and other stone had been successfully overcome, and they arrived with great punctuality, and the masonry of the abutments and piers was successfully carried into effect as previously described. Then came the important question of erecting the cast-iron arches; each arch consisted of eight main ribs, and each rib consisted of thirteen pieces, the lower or main part of which formed the chord or arch upon which the whole of the superstructure was to be supported. These thirteen pieces were solid, 2½ inches thick in the mass and 3 inches thick at the bottom, and 2½ thick at the top, and formed so many radiating blocks, like arch-stones. At the end of every block there was a transverse frame extending from one side to the other through the whole width of the bridge; against each side of these frames the main ribs abutted and were nicely fitted to them, and in order to prevent them from moving laterally there were projecting dovetailed cheeks cast on the frame, and between these cheeks and the ends of the main ribs solid cast-iron wedges the whole depth of the main rib were fitted, then drawn home against the ends of the rib; by this means the ribs were kept firmly within their places, and as an additional precaution strong diagonal braces, having a strong feathering rib on each side, were inserted diagonally between the ribs from one end of the arch to the other, and secured to the ribs by projecting dovetailed cheeks on them, and wedges and bolts, so that these cast-iron arches were constructed in the same manner as a stone arch, being almost as it were a solid mass depending upon the equilibrium of the different pieces for its stability. The depth of the main rib of the centre arch at the crown is 6 feet and 8 feet at the piers, whilst the depth of the ribs of the side arches at the crown is 6 feet and 8 feet at the abutments. As these ribs with their attendant transverse frames and diagonal braces formed the main part of the arches upon which the whole of the superstructure depended, it was necessary that they should be extremely well put together and properly united to the piers and abutments. Contrary to the usual mode of constructing stone arches, they were commenced at the centre instead of the sides, a strong wooden centring supported upon tiers of piles having been previously constructed between the piers and abutments to support them whilst being put in their places. Each piece of each rib was carefully placed upon the centre, resting upon nicely-adjusted strong wooden double wedges, and connected together as they proceeded by the transverse frames and diagonal braces before mentioned. By this means the whole of the arches were constructed at the same time from the centre to the skewbacks or bearing parts of the piers and abutments; but in order to connect them properly with them it was necessary to devise a particular arrangement. For this purpose a transverse frame, similar to those already described for connecting the rib pieces together, was accurately imbedded and fitted to the skewbacks or bearing places on piers and abutments, resting on a bed of sheet lead, and the joints were filled in with melted lead also; this formed a solid and to a certain extent elastic bearing, upon which the main ribs were ultimately to rest.

At the ends of the arched rib-plates next to the piers and abutments there was another transverse frame plate of the same kind as those previously described, and fixed there in a similar manner; this brought the ends of the arches within 6 inches of the abutting or bearing plates fixed in the skewbacks or springing places of the piers and abutments.

Between the frame plates fitted on the skewbacks or masonry of the piers and abutments, and those fitted on the ends of the rib plates of each arch, solid cast-iron wedges, 9 feet long and 6 inches thick at the back, and 2 inches thick at the bottom, 9 inches wide, three being behind each rib, were accurately fitted by chipping and filing, so that it would slide down to within 12 inches of the bottom; when these wedges were all accurately adjusted at the same temperature to the same depth, they were simultaneously driven home by wooden rams to their full depth, so as to reach about an inch below the bottom of each rib; by this means the whole of the three arches were gradually brought to their bearing without being raised wholly from their centres. Matters were then allowed to remain in this state for a few days in order to give time for every part to come to its bearing and to ascertain whether there was any defect in any part.

After the minutest search in every part no defect could be discovered; the wedges between the centres and the under sides of the ribs were then gradually slackened until the whole of the arches came to their full bearing, and were removed entirely, leaving the arches perfectly free of support. During the whole of these operations, from first to last, which occupied about a week, not the slightest accident or fracture occurred; the total subsidence of the main arch barely exceeded 2½ inches, whilst the subsidence of the two side arches barely exceeded 2 inches, which had been allowed for in the construction.

In order to ascertain the effects of expansion and contraction of the arches by the variation of the temperature of the atmosphere, I constructed steel, brass, and wooden gauges, accurately divided into decimal parts of an inch, and erected them upon different parts of the centres, where the effects were most likely to be apparent, and I kept the register for several weeks, during the height of summer, autumn, winter, and spring. I found that the variation in the rise and fall of the crown of the arches, the abutments being fixed, was 1/10th of an inch for every 10° of temperature, so that, taking the extremes of temperature at London to be 10° below freezing point of Fahrenheit in winter, and 80° in summer; the utmost rise and fall of the arches may be taken at 7/10ths, or at most one inch; but as any variation in the temperature, unless continued for some time, has no sensible effect upon such a large mass of iron, so, in our variable climate, the rise and fall of the crowns of the arches may be taken upon the average somewhat below the amount above given.

After the arches had been brought to their bearing and had been relieved from the centres, the superstructural framework was carried up and firmly connected and bracketed together by diagonal ties and wedges; in doing this the ends of the superstructural frames were too tightly wedged to the masonry of the piers, without my knowledge, so that they would not allow the main ribs of the arches to play freely, and some of the masonry courses above the main ribs were slightly splintered and deranged; the wedges were then slackened, and some of them removed entirely, and thus the evil was immediately remedied; the whole structure has ever since remained in a perfect state.

The bridges and approaches were finally completed and opened to the public traffic in March, 1819, the ceremony being performed by Sir John Jackson, the chairman, the directors, and a few friends.

In the month of August, 1818, having worked very hard, I may say almost night and day, for some time, I was nearly worn out, and was permitted to have a short holiday. I therefore determined to go to Belgium and visit the celebrated field of Waterloo, which closed the long and eventful revolutionary war, and attracted the admiration and interest of the whole civilized world. I accordingly started for Dover, in company with my old friend, the late Mr. Joseph Gwilt, architect, and crossed over to Calais.

On landing we repaired to Dessin’s hotel, at that time one of the best in Europe, and rendered famous by Sterne, whose rooms are still shown as one of the most interesting curiosities (to Englishmen at least) of the place. Here we passed the remainder of the day very agreeably. Everything was new to us—the people, their language, their manners, their mode of living. We had been so long considering the French as our deadly foes that we could hardly believe ourselves to be at peace with them, and to be actually in France and so civilly treated by them. Then the living was so good and cheap, compared to that of England; champagne, which with us was considered the greatest luxury, and only within reach of the highest and most wealthy, was here obtainable for four francs a bottle, whilst in England it was twenty-four, and almost everything in the same proportion. In the town of Calais there is nothing to see. The harbour is but indifferent, and almost dry at low water, and is chiefly maintained open by sluicing and dredging. On such a flat, sandy shore, with the prevailing winds and currents always driving on and accumulating the sands, it is very difficult to make and maintain a good harbour; still I think that a great deal more might be effected by pursuing a different course, and having a proper system of open piers and breakwaters on the outside. After breakfast on the following day we started in a travelling calèche, with two horses, for St. Omer, about 26 miles distant. On our way we stopped to examine the celebrated quadrangular bridge, called the Pont Sans Pareille, across the junction of the two canals of Picardy. This is certainly a meritorious, well-executed work, but the idea is by no means new, as the Gothic triangular bridge of Crowland, in Lincolnshire, across the junction of the Welland, was executed many centuries previous to the Pont Sans Pareille, and is still extant in a perfect state. Near this bridge is the celebrated maiden fortress of Ardres, which is said to have never been taken. Here also, according to Froissart, was the Champs d’Or, or Field of the Cloth of Gold. Ardres is a poor, miserable little fortress, surrounded with earthworks and ditch, on a flat plain. In ancient times it might have been formidable, with their means of attack, but now it would be utterly defenceless. From Ardres we passed through St. Omer and Lille, and after visiting Tournay and Ghent we proceeded to the capital of Belgium, where we took up our quarters at the Hôtel de Flandre, in the highest and best part of the city. We were particularly struck with the magnificent Hôtel de Ville and its lofty spire; also the remarkable place or square in front of it, which, looking to its picturesque mediæval buildings and the remarkable historical events which have taken place there, renders it one of the most interesting in Europe. The fine old Gothic cathedral of St. Gudule, the museum, fine canals, &c., particularly attracted our attention.

On the next morning we started for the scene of the celebrated battle of Waterloo, which had occurred about two months previously. In this place, like every Englishman, I took the greatest possible interest, and pictured to myself the whole of that terrific and stirring scene as being enacted before me. Notwithstanding the lapse of time since which that battle had taken place considerable traces of it were still visible, particularly in the blood-stained walls and ruined, desolate, and half-consumed buildings of the keys of the position, Hougumont and La Haye Sainte, and the remnants of shakos, arms, and military clothing which strewed the field on all sides, and the fresh-made graves, where many thousand gallant fellows lay entombed. The whole field and neighbouring villages were crowded with guides to explain the different particulars of that memorable struggle, and to sell the numerous articles which they had raked up from the field of battle; we bought some of these as mementos, and wandered for hours over every part of this field of desolation, until we fancied that we had mastered every detail of the conflict, and were almost fit to take the command of an army ourselves. We then returned to Brussels, highly gratified and instructed by the excursion.

We left Brussels much pleased with that pretty little industrious capital, and proceeded to Malines, where the fine old cathedral and town rewarded us well during our short visit. From thence we journeyed on to Antwerp, where we stopped at the Grand Labourer, a celebrated old-fashioned hotel. This famous old city, the great emporium of the Belgian trade, interested me much, with its magnificent cathedral and other churches, its fine old Hôtel de Ville, and spacious quays and docks; the Scheldt is here a fine river. There was a good museum of Dutch and Flemish pictures, but the chef-d’œuvres of Rubens and Vandyke had not yet returned from Paris. I was much struck with the extent and strength of the fortifications; also with the costume of the natives, particularly that of the women, which still resembled a good deal that of their former masters, the Spaniards. At the time of our visit everything was in a depressed state. Its trade had not yet recovered from the effects of the great war, and its then silent streets contrasted greatly with their former activity. The Roman Catholic religious ceremonies were conducted with great magnificence, and struck us simple Protestants, who had never witnessed anything of the kind before, with considerable astonishment.

We left Antwerp for Ghent, and took our departure for Bruges in one of the trackschuyts or barges, by means of which the great bulk of the goods and passenger traffic of the kingdom was carried on. These canals are magnificent specimens of the kind, and, being upon a much greater scale than our own, particularly struck me with admiration. The canal was bounded on each side with spacious banks, and was of great width, with a towing path and carriage way for general traffic. These banks were bounded by rows of trees, which serve for shade; at the same time their clippings and timber yield a considerable amount of profit.

We reached Bruges about noon, and had just time to examine the fine cathedral and townhall, as well as the interesting town, its quaint old buildings, quays, mercantile warehouses, all in the architecture of the Middle Ages, during which Bruges attained its greatest prosperity. We left this interesting town in the afternoon by another trackschuyt for Ostend, about 12 miles distant, by a canal of the same dimensions as the one above described. Most of these canals being connected with each other, Brussels, Ghent, Malines, Louvain, and the other large towns, possessed a complete network of water communication with the ports of Antwerp and Ostend, and trade is carried on with the greatest facility.

We reached Ostend in the evening, and learned that a packet was about to sail for Margate, of which we determined to avail ourselves. We had, however, sufficient time to examine this indifferent port, the second in the kingdom, which, in addition to a badly-contrived entrance by two guide piers, has two small docks. It is a mere tidal harbour, with an awkward bar at the entrance, and numerous shoals on the outside. The town possesses nothing remarkable; it was then garrisoned by English troops, and there was constant communication with England.

From this period I devoted my time almost exclusively to the Waterloo and Southwark bridges, but particularly to the latter, which was almost entirely under my direction, subject to the orders of my father. Besides the above works, I was a good deal employed in the drawing office in making drawings and estimates and calculations for a variety of new works upon which my father was engaged. I also occasionally visited the rolling and other machinery of the Royal Mint on Tower Hill, which my father at that time was constructing for the Government, and during the evenings I was employed in learning mathematics under Dr. Bradley and Dr. Firminger, and the Italian, French, and German languages, so that my time from morning to evening was fully employed. I must not omit to say that at this time I attended the lectures of the celebrated Sir Humphry Davy, the Professor of Chemistry at the Royal Institution, who at that day astonished the world by his wonderful discoveries.

The first, second, and third arches of the Waterloo Bridge being completed, Mr. Rennie determined to slacken the centres of the first arch, which was on the Surrey shore, where the bridge commenced. This was when the arches were entirely relieved from the centres, and the total subsiding of this arch was 2½ inches, which is nearly half an inch less than had been allowed; the centres were then removed from the first arch to the fourth arch, only three centres being employed. Each centre consisted of eight ribs, upon the truss principle, resting upon a compound system of wedges, supported upon struts placed upon the offsets of the piers and abutments; all the ribs were well connected together by transverse and diagonal ties, as well as the planking upon which the arch-stones rested. The trestles or bearers of the centre ribs, together with the wedges, having been first fixed in their places upon the offsets of the pier and abutment where the centre was to be fixed, four ribs of the centre were transferred, and fixed upon them in the following manner.

The ribs of the centre having been constructed upon a platform upon the shore near the bridge, a large barge or floating stage, capable of carrying four complete ribs, which weighed 40 tons each, was built to receive them. This floating stage was extremely strong, and transversely across the centre of it there were four strong stages at the same distance from each other as the ribs of the centre were intended to be when fixed in their position, to support the arches whilst building. These stages were supported by double transverse beams, resting upon powerful screws 15 inches diameter, in boxes resting upon the bottom of the vessel. Above each of these stages, yet securely attached to them, was a framework, to which the ribs of the centres were lashed whilst being transported to their places. When the centre ribs were finished and all was ready, the floating stage, at high water, was brought alongside the platform, upon which the ribs of the centre had been constructed, and were lying ready to be transferred to their places. Each rib was then raised by means of powerful sheer-poles, to which were double-purchase crabs, treble blocks, with all the necessary ropes, chains, and other tackle, by which means each rib of the centre was readily raised from the platform where it was built and transferred to its proper stage in the floating barge, and there secured in an upright position, when the ribs had been fixed in their places. The barge was then floated into the opening where the arch was to be constructed, which was generally done about half an hour before high water, so as to allow ample time to adjust and fix the ribs over the corresponding pair of wedges and trestles upon which it was ultimately to rest, which was done as the tide fell, and adjusted to the greatest nicety by the screws before mentioned; when the rib had been fixed in its place, the barge returned to bring another, which was served in the same manner as the first, and thus the fixing of one centre occupied only six days. This system answered most effectually, and was subsequently adopted by Mr. Robert Stephenson for fixing the great tubes for the Menai and Conway bridges.

The Waterloo Bridge, as well known, consists of nine equal semi-elliptical arches, 120 feet span each, with a rise of 34 feet 6 inches, the keystones at the crown being 4 feet 6 inches deep and 10 feet at the spring, and 18 inches thick at the soffit; inverted arches on each pier between the main arches 4 feet 6 inches deep. The piers were 20 feet wide, each having projecting buttresses, supported by two three-quarter Doric columnar pilasters, over each pier, the whole being surmounted by a Doric block cornice and balustrade parapet, level from end to end, the same as the roadway. The roadway above the piers was supported by six brick walls, 2 ft. 3 in. thick, covered with corbel stones. The shores being low on both sides of the river, the approaches are constructed so as to form an inclined plane rising 1 in 30 on the Surrey side, and nearly level on the north, or Middlesex side, with the Strand, upon a series of brick arches 16 feet wide each. These arches serve for storehouses. The roadway was formed by a layer of well-puddled clay 15 inches thick, then a layer of lime and of fine gravel 3 inches thick, then a layer of equally broken granite, in pieces 2 inches in diameter, 1 foot thick. Through the centre of the masonry of each pier a hole 18 inches in diameter was cut, entering the river on one side of the pier at low water, and from the top of this hole inside the pier cast-iron branch pipes of the same diameter were carried to side drains on each side of the roadway, so that all rain and surface water was effectually carried off into the river, thus preventing leakage.

The piers and abutments were founded in the solid bed of the river, which is strong gravel; they rest upon a wooden platform, supported upon piles 12 inches in diameter driven 20 feet into the bed of the river. The whole of the arches and exterior face of the bridge are built of Cornish granite, from the vicinity of Penryn, and the balustrade is made of fine grey Aberdeen granite.

The contract for the Cornish granite was taken by a very worthy man of the name of Gray, and the price was such as on so large a quantity ought to have enabled him to realize a very handsome profit; but he had no system or machinery adequate for the purpose, and instead of opening quarries properly upon an enlarged scale in the solid rock, by which he would have saved a great deal, he chiefly confined his operations to the loose outlying blocks, which reduced his profits considerably, and in the end it is very doubtful whether he did more than cover his expenses. As the dressing of granite for masonry was entirely new at that time, nothing having been built of this material in London, it was extremely difficult to find masons who would undertake it, even at such enormous prices as 1s. 9d. to 2s. per cube foot, so that the contractors, Messrs. Jolliffe and Banks, could not afford to pay it. Workmen were therefore obtained from Aberdeen, and the price was ultimately reduced from 2s. to 1s.; notwithstanding, however, the prime cost of the stone, the freight, dressing, mortar, and setting complete in the bridge cost about 7s. 2d. to 7s. 3d., so that the total cost was near 7s. 6d. It should be observed, however, that at that time there was a duty of threepence per cubic foot (or ton?) on stone, which has since been taken off. The interior stone consisted of hard sandstone from Derbyshire and Yorkshire.