“But, Mr. Postern,” said I, as the Antiquary arrived at this part of his narrative, “although Maitland tells us, in his ‘History,’ volume i., page 46, and volume ii., page 1349, that the use of Coffer-dams, or Caissons, for building of the Piers of Bridges, was first introduced into the Thames at the erection of Westminster Bridge, yet it has been supposed that even this of London was constructed somewhat after the same plan; and that those Sterlings are but the upper parts of the machines themselves, left in the water to guard the Piers; though it is certain, that in most of the Reports, illustrative of the great repair of London Bridge, the Sterlings are mentioned as additions to the original structure for the support of the Piers. I have been obligingly furnished, however, with an interesting drawing, and extract from the MS. Journal of Mr. William Knight, of Mr. Rennie’s office, by which we are enabled to understand the construction of these parts of the Bridge in a much clearer and more perfect manner. Mr. Knight observes, that having received several different statements as to the way in which the Piers of the old London Bridge had been erected, he determined upon convincing himself by an actual survey. This he effected on August 14th, 1821, when an excavation was made for ascertaining whether the original structure would support new Arches of a larger span; and he then found it to be built in the following manner. ‘The foundation of the Piers on the North side,—between the Great Lock and what is called the Long Entry Lock,—and in the Sterling round it, appeared to be about 3 feet above low-water mark. The bottom of the masonry originally laid of the pier, is about 2 feet 3 inches above low-water mark; and the first course is laid upon a sill of oak, 16 inches wide, by 9 in thickness, and perfectly sound. Immediately beneath this is a mass of Kentish rubble, mixed with flint, chalk, &c., thrown in irregularly, but not mixed with any cement. The masonry above the sill seems well bonded together, with good mortar joints, but there are no piles under the oak sill. The external parts of the pier seem to have been new-fronted at some period,—probably at the time when the centre Arch was formed in 1759,—as the base of this new fronting projects about 1 foot before the original Pier. There are no piles under the original part of the Pier; but to the new part there are some small ones driven into the rubble,—which can be of little service,—with some planks laid upon their edges. The new masonry is well bonded into the old work.’ Mr. Knight concludes, by observing that, in all the accounts which he has hitherto met with, the old Piers of this Bridge are described to stand upon piles; but that, as he found this to be erroneous in the present instance, he considers it to be a fair conclusion that all the other Piers were constructed upon the same principle. His drawing represents a Section of the North Pier of the Great Arch of London Bridge,
shewing the original manner of constructing it, and the Sterling, or ancient Coffer-dam, standing around it; which, it thus appears unquestionably evident that, not having the art to pump dry, was filled up with loose stones. The Arch on the right hand is denominated the Long Entry Lock, and that on the left is a part of the Great Arch in the centre. I should remark also, that Mr. Knight has examined several other parts of this edifice with no less care and industry, in order to ascertain the plans adopted at the famous alteration of London Bridge, of which we are now speaking; of all of which observations he has made interesting sketches and memoranda. He states that he has felt with his measuring rods the timber, &c., placed in the river to strengthen the piers of the Great Arch, and that his sounding leads have been broken by catching in it. In April, 1826, the opening of the roadway of London Bridge for throwing of two more Arches into one, to increase the water-way during the building of the New Bridge, also made a curious discovery of many of the more ancient parts of the original building. The crowns of the old Arches, observes Mr. Knight, were about 8 feet 6 inches from the present surface of the ground, which appeared to have been raised at different periods; and five several strata were evidently to be traced over the centre of the original Bridge, which was 20 feet in width. Immediately over the crowns of the Arches was a layer of fine gravel, about 20 inches in depth, perhaps the ancient roadway, as its upper surface had the appearance of being trodden down and dirty, when contrasted with that beneath it. The next stratum consisted of mixed chalk and gravel; the third of made ground of various materials; the fourth, a thick layer of burnt wood, ruins, and black earth; and the last another bed of different substances, over which was the granite paving. The filling-in between the Arches was composed of chalk and mortar, of so hard a nature that it was taken out with great difficulty. With respect to the building itself, he observes, that the stone of which the Arches were formed consists of two courses: that of the soffits or flying ribs, being Merstham Fire-stone, and the course above very similar to the stone of Caen, or Normandy. In the additions, or casings, on each side of the original structure, Portland stone has been used, as well for the facing, as for the Arches; whilst the backing and filling-in, between the spandrils of the Arches, was composed of chalk and mortar; which latter was evidently of a very bad quality and carelessly applied. Indeed, the ashler facing had been so little attended to in the bonding of the work together, that it is surprising, with the great weight behind, the careless manner of throwing in the backing, and the slight nature of the facing itself, that the whole work has not been thrown outwards some time since. Having thus, Mr. Barnaby, added these curious observations to your narrative, I must once more entreat you to proceed.”
“After making you my acknowledgments,” recommenced the Antiquary, “for the very curious illustration you have now furnished; and before quitting the Great Arch of London Bridge, let me observe, that it contains the Trinity Standard of High Water, which is placed there for the benefit of persons erecting buildings on the banks of the Thames, and originally inscribed upon a metal plate, affixed under the Great Arch upon the North East side, as it may be seen beneath the centre Arch of Blackfriars Bridge. It is at present engraven in the centre of each Pier of the Great Arch, in black Roman letters, about 7½ feet above the springing line of the Arch, or 8½ feet over the sterling; and consists of the inscription,—
Trinity.
H. W.
1800.
the character beneath being the average point of the ordinary rise of a Spring Tide at High Water, which, above Bridge, is 14½ feet or 15 feet, being 5 feet 3 inches above the Neap Tides. At high Spring Tides, however, it has risen 16 feet and upwards; and in that remarkable one combined with a land-flood on December 28th, 1821, it rose 2 feet, 10 inches, and five parts, above the mark below Bridge. From the official tidal observations of the Trinity Company, it has been ascertained, that, from Blackwall to London Bridge, the High Water ascends to the same level; and that from the upper side of London Bridge to that of Westminster the River is likewise generally level, excepting under the influence of winds or land-floods. During that of 1821, to which I have just referred, the banks of the River, and the marshes and gardens above Westminster, were overflowed and damaged to a very considerable extent; which has been attributed to the obstruction offered by the present London Bridge to the passage of the water towards the sea, as we learn from the ‘Report of Ralph Walker, delivered into the House of Commons, 11th of April, 1823,’ octavo, page 9; where he states, that the tides below this edifice during the flood, rose only to the ordinary height, whilst at Low water the fall was increased by several feet. This celebrated fall is, of course, most evident at Low water, when it is about 4 feet 6 inches, or 6 feet in the Winter season; and the most hazardous time for passing through any of the Bridge Locks, is probably half an hour previous to, or, for barges, the last two hours before, Low water below Bridge. The safest time of the tide is at High water, or slack Low water: but boats may pass with safety for 2½ hours after flood, and the last half hour of the drain of the tide at ebb, above Bridge; the tide having then flowed nearly 4 feet below. Deeply laden barges also take the drain through at Low water. The Great Arch is doubtless one of the safest to pass under, and is always used by craft and barges; but before the erection of the New Bridge works, most of the other Locks were employed at the flood tide, when the fall is extremely trifling. When the tide is on the ebb, the Arches which are chiefly used for boats are, the Draw-Lock,—the 4th from the Great Arch,—on the South; and St. Mary’s Lock,—adjoining the Great Arch,—on the North, which is always taken on the first part of the ebb. The Long-Narrow, once a favourite Lock, is now nearly abandoned; but the Draw-Lock is perhaps considered the safest, and is the most generally used since the erection of the New Bridge Coffer-dams. The approach, however, is dangerous, and requires a skilful waterman, who is obliged to pull his boat into the draft or eddy of the dam before he can make the Lock. Though the works of the New Bridge have at present closed several of the Arches of the ancient edifice, yet the 4th and 5th Locks from the Southwark end have been thrown into one, with a strong wooden vaulting, parapet, and roadway above, to increase the water-way beneath. Since the commencement of these works, the fall of the river has also become less dangerous for barges, from the returning tide sooner meeting with resistance; and instead of a direct fall of 6 feet in 50, it is now only about 6½ feet in 250. The draft of the tide, however, round the Coffer-dams, makes it very difficult for lightermen to enter the Locks fairly; and some of the outer rows of piles are driven inwards from their barges being carried against them. In 1820 and 1822, the average fall at High water was only from 8 to 13 inches; and in 1823, after the removal of the London Bridge Water-works, it decreased to between 3 and 4.
“Mr. Barnaby! Mr. Barnaby!” exclaimed I, fretted by this long digression in the Antiquary’s narrative, “I protest you really put me out of all patience: there’s no keeping you to one subject; for the last of your annals referred to that most wearisome alteration and repair of London Bridge which began in 1757, and now you are bewildered in a discourse on the navigation and tides of the Thames! Truly, it’s intolerable!”
“I am aware,” replied the placid Mr. Postern, whom there seemed to be actually no putting into a passion, “I am aware how much these observations serve to lengthen and interrupt our history; but still they are vastly important to its illustration. ‘Our life,’ says an interesting and romantic author, ‘cannot be like an Arabian manuscript, all flowers and gold,’ and neither can history be composed only of the facts which naturally belong to it. There must be various incidental notices, seemingly unconnected with it, which are at last found to combine with the story, and to render it much more intelligible; and if ever, Mr. Barbican, you publish these Chronicles of London Bridge, make my words both your defence and your apology. The fact is, I really am half unwilling to proceed to the close of the alterations of this edifice, because we have subsequently so few interesting particulars on record concerning it; and other events,—excepting the usual unhappy accidents beneath its Arches,—are almost entirely wanting. At the time of the formation of the Great Arch, it appears that the wooden Draw-Bridge was first taken away,—though it had then long ceased to be used,—and the present Stone Arch, entitled the Draw-Lock, about 30 feet in width, or 16 feet between the Sterlings, was erected instead of it. This we learn from the ‘Public Ledger,’ of Monday, January 28th, 1760, which states ‘that the centre of the new Draw-Lock Arch of London Bridge is struck; so that there is now a free passage for boats, &c.’ In this very Lock, however, only a few months afterwards, an accident occurred which might have almost proved fatal to the Bridge itself; and it is thus related in the ‘Public Advertiser’ of Monday, December 29th, 1760. ‘On Tuesday, a large old French ship, that was coming through the Draw-Lock at London Bridge, to be broken up above Bridge, stuck in the Lock, and still continues there, having done considerable damage to the same; and it is thought that she cannot now be got out, but must be broken up where she now lies.’ The same paper for Friday, January 9th, 1761, states, that ‘yesterday the workmen, who have been employed, for this fortnight past, in breaking up the large French ship that stuck in the Draw-Lock at London Bridge, as she was going up the river, endeavoured, on the strong flow of the tide, to get her through the Bridge, but could not effect it. This ship, it appears, was but 18 inches wider than the Lock.’ At length, however, in the same paper for Friday, January 30th, it was announced that ‘Yesterday the watermen cleared the Draw-Lock at London Bridge, of the large French ship that stuck there some weeks ago.’
“The destruction of part of St. Magnus’ Church, by most authors attributed to the year 1759, but which actually took place in 1760, was the cause of a further improvement of the North-East end of London Bridge; by the opening of that arched passage beneath the Church Steeple, which the wisdom of Sir Christopher Wren had foreseen, and provided for, fifty-five years before. This destruction then, took place by a fire, which brake out between 9 and 10 o’clock, in the morning of Friday, April 18th, at the house of Messrs. Barrow and Reynolds, Oilmen, in Thames street, adjoining to the Church. It consumed seven dwelling-houses, all the warehouses on Fresh Wharf, with a considerable quantity of goods contained in them, and the roof of the Church itself; which, falling in, very much damaged the pews and altar-piece. The organ, the excellence of which we have already noticed, was taken away, but was considered to have received very serious injury in the removal. The whole of this destruction was estimated at £40,000; and it was occasioned, says Entick, in his ‘Continuation of Maitland’s History,’ page 29, by the neglect of a servant, who was appointed to watch the boiling of some inflammatory substances, and who left his charge on the fire, whilst he went to see the famous Earl Ferrers return from his trial and condemnation. Before he could get back, the whole shop was in flames. Some of these particulars you will also find recorded in the ‘Public Advertiser’ for Saturday, April 19th, 1760; and in the ‘Gentleman’s Magazine’ for that year, volume xxx., page 199. Before this fire, the main body of St. Magnus’ Church extended to the tower, which was originally about equal with the houses on London Bridge; but when they were taken away, the West end so greatly interfered with the foot-path, that it was proposed to take down so much of the building as enclosed the tower on each side, and to form a passage under the steeple by arches. This plan, however, does not appear to have been proposed, until after the Church had been repaired; because the first notice of it which we meet with, is in the ‘Public Advertiser’ of Monday, September 29th, 1760, in the following terms. ‘The workmen have paved a great part of the foot-path on the lower side of London Bridge; and the tower part of St. Magnus’ Church has been lately surveyed, in order to make some alteration in the lower part thereof, conducive to the convenience of the passage of the Bridge.’ The danger which was supposed to be attendant upon its alteration, was probably the cause of delay in its execution; but the surveyor who was employed, had the ingenuity to discover, that Sir Christopher, conceiving that such a convenience must be required at some future period, had contrived the arch on which the steeple stood, of such strength, that it was essential only to clear away the intermediate space to perfect the alteration. Still the work proceeded but slowly, since the next notice of it is contained in the ‘Public Advertiser’ for Wednesday, August 4th, 1762. ‘The North and West Porticoes adjoining to the tower of St. Magnus’ Church at London Bridge, are taking down, in order to form a passage to and from that building, through the spacious arch upon which the steeple is built; the South Portico is also down, which fronts the Bridge, and makes a very agreeable appearance; and the taking down of the West Portico, to compleat that useful work, is in great forwardness.’ It was yet, however, almost another twelvemonth before this improvement was perfected, as we learn by the following notice, from the last mentioned paper of Thursday, June 30th, 1763. ‘On Saturday last,—25th,—the foot-passage under the arch of St. Magnus’ steeple was opened; which, besides the convenience for foot-passengers, makes a very pretty appearance. A vestry, built of stone, is to be erected in the Church-yard, to front the new Toll-house, just erected at the corner of London Bridge.’ Before we finally part with St. Magnus’ Church, I must not forget to state, that Malcolm, in his ‘Londinum Redivivum,’ volume iv., page 31, observes,—though without citing his authority,—that ‘in October, 1713, the Rector received an anonymous letter, which discovered a design of setting fire to London Bridge, for the purpose of plundering the inhabitants. The greatest precautions were adopted in consequence, and nothing uncommon occurred.’ I find, however, no notice of this letter in any of the periodical prints of the time.