Pl. XXI.
This scene, which is intended to represent the Bell Rock after a storm at north-east, will hardly admit of any adequate description, from the evanescence of the form of the waves upon these occasions. It is, however, founded upon observations made at the Light-house, between the years 1810 and 1822, or during twelve successive winters. The great rise of the sea during a gale, as delineated in the Vignette to the Narrative of the Edystone Light-house, being so surprising, the writer was at much pains to ascertain the effect also at the Bell Rock; and themaximumheight of the sprays hitherto observed has been about 105 feet, or as high as the central part of the Light-room windows.
Mr Andrew Masson, an artist who in early life had been at sea, having expressed a desire to reside in the Light-house for some time during winter, that he might observe the waves in a storm, was readily furnished with an opportunity. He went there in the month of December 1816, and remained for six weeks and four days, when he produced various sketches of the appearances which he witnessed; and Mr Macdonald, noticed at page519, made several outlines from actual observation, in the winter of 1820. All of these were put into the hands of Mr Turner, Royal Academician; who gave the very spirited drawing from which Mr Horsburgh, an artist of much promise, has succeeded in producing the striking representation in the Frontispiece. The writer has also the pleasure of acknowledging the obligations he owes to Mr Williams, author of Views in Greece, for his friendly advice and assistance.
It may here be remarked, as not a little surprising, that while the sea is running nearly to the height represented in the Frontispiece, the entrance-door of the Light-house, or at least one of its leaves, may nevertheless be left open; and the portion of water which on these occasions makes its way into the passage, is found to be very trifling. This is owing to the fortunate position of the door; for, while the sprays on the eastern side fly with the quickness of lightning to the top of the house, the waves separate below, and are sent round the building with such force, that their collision upon the lee-side produces the wonderful appearance in the picture; where a downy spray, white as snow, rises at some distance from the house, to the height of 20 or 30 feet above the medium surface of the sea, and comes in minute particles upon those within the entrance-door, producing a sensation as if dust were falling upon them.
Pl. XXII.
The night scene of the Bell Rock Light-house, in the Vignette of the Second Title-page, was drawn by Miss Stevenson, from a sketch by the masterly hand of Mr Skene of Rubislaw. To Miss Stevenson, also, as an amanuensis, the writer takes this opportunity, with parental affection, of acknowledging his obligation for almost the entire manuscript written to his diction. The reader will be gratified to find, in connection with this Vignette, inserted at page64., afac-simileof the handwriting of Sir Walter Scott, Bart. in the expressive and beautiful lines which he wrote in the Album kept at the Light-house, as noticed at page419.
SKETCHES of a NEW DESIGN for a LIGHT HOUSE.Drawn by G. C. ScottEngd. by J. Moffat Edinr.PLATE XXIII.
SKETCHES of a NEW DESIGN for a LIGHT HOUSE.Drawn by G. C. ScottEngd. by J. Moffat Edinr.PLATE XXIII.
SKETCHES of a NEW DESIGN for a LIGHT HOUSE.
Drawn by G. C. Scott
Engd. by J. Moffat Edinr.
PLATE XXIII.
Pl. XXIII.
In the range of aquatic buildings applicable to the purposes of a Light-house, which the writer has examined, he was forcibly struck with the magnitude of the Tour de Corduan, on the French coast. This magnificent edifice measures about 145 feet in diameter at the base, and 150 feet in height. Its cubical contents may perhaps be stated at the immense quantity of 339,432 feet; of which the basement alone forms about 200,000 feet. This building has undergone considerable alterations since its completion in the year 1609, as appears from Belidor’sArchitecture Hydraulique, tom. ii. At the time of its alteration from a coal fire to an oil light with reflectors, the upper parts in particular seem to have been greatly simplified, by the removal of several of its exterior ornamental appendages.
The Edystone Light-house, owing to the smallness of the rock, as appears from Mr Smeaton’s Narrative of this celebrated building, measures only 26 feet in diameter, at the level of the first entire course; but if there had been space on the Rock for extending it equally on all sides, the ground-course, according to the curve of the outward walls, and the position of the foundation-stone, would have measured 32 feet in diameter. The height of the cupola of the Edystone Light-house is 90 feet, and the cubical contents of the masonry is about 13,147 feet. The Bell Rock Light-house, measures 42 feet in diameter at the base; its height, from the foundation to the cupola,is 118 feet; and the cubical contents of the masonry, as appears from the Table in Appendix, No.VI.is 28,530 feet.
Though the design represented in Plate XXIII., is more or less applicable to several situations upon the coast, yet the writer, in making this Sketch, had special reference to the Wolf Rock, which, as noticed at page423, he visited in the Orestes sloop of war, commanded by Captain Smith. The extreme dimensions of the upper surface of this rock are about 115 feet, by 90 feet. It is not liable to be covered by the ordinary rise of the tide, though little of it appears above water in spring-tides. The Rock consists of grey porphyry, and is extremely hard. Its outline is somewhat uniform, and the depth of water in its vicinity is from 20 to 40 fathoms. The dangerous position of this reef, in reference to the navigation of the British Channel, led to the proposition of having a Light-house upon it many years since. The erection, however, was ultimately made upon the Long-Ships Rocks, lying about one mile off the Land’s-End.
With the construction and dimensions, therefore, of the Light-houses above alluded to in view, the design delineated in this Plate is given, as the result of the writer’s knowledge and experience on subjects of this kind. Without, however, entering into particulars as to the mode in which such an operation should be conducted, he merely notices, in reference to the various curves delineated in Figs. 1, 2, 3, and 4. as applicable to Light-houses upon sunken rocks, that he prefers the curve of the diagram represented in Fig. 3., as the outline of a building for a situation like the Wolf Rock.
Fig. 1. is formed by the supposed revolution of the cycloidal curve round the axis of a building, whose base is 50 feet, and which, at the entrance-door or top of the solid, measures 25 feet in diameter; the lines produced beyond these dimensions, which would form the habitable part of the Light-house, being tangents to the curves below. Between the basea b, and its parallelc d, this Figure contains 29,635 cubic feet.
Fig. 2. is in like manner formed by the revolution of the logarithmic curve round the axis of a building of similar dimensions at the base and top of the solid with Fig. 1., and contains 31,867 cubic feet.
Fig. 3. is obtained by the revolution of a parabola round the axis of the supposed building. The contents of the solid part, ascertained as in the two former Figures, is 34,006 cubic feet, being 4,371 cubic feet more than that of the cycloidal curve, and 2,139 cubic feet more than in the logarithmic curve.
Fig. 4. is formed by the revolution of the hyperbola between the two parallelsa b, andc d, and contains 39,655 cubic feet, or 5,649 cubic feet more than the parabola. But, from the divergent nature of this curve, it is not applicable to the purposes of a Light-house tower, in its pure or simple form.
Fig. 5. is the section of a design formed by the revolution of the parabola round the axis of a building, as its asymptote, whose basea b, measures 56 feet in diameter, and parallelc d, at the top of the solid, is 36 feet; and height to the entrance-door, 35 feet. The contents of this Figure between these parallels is calculated at 45,000 cubicfeet; but the whole of the masonry of the design is estimated at 70,624 cubit feet. Its general features may be stated as similar to those of the Edystone and Bell Rock Light-houses, the parts being only enlarged and the parabolic instead of the logarithmic curve, adopted for its outline. In this design, the parabolic curve is continued from the basement to the cope-stone of the Light-room, exclusively of the projection for the cornice and balcony. The masonry is intended to be 120 feet in height, estimating from the medium level of the sea, of which the solid, or from the foundation to the entrance-door, forms 35 feet, the stair-case 25 feet; and the remaining 60 feet of its height is occupied with six apartments, and the walls of the Light-room. In the stair-case a recess is formed for containing the machinery, for raising the stores to the height of the entrance-door; here a small hole, markedg g, is perforated through the building, for the admission of the purchase-chain. The thickness of the walls immediately above the solid, markedc c, is 12 feet; at the top of the stone staircase or levele f, they are 8 feet, and where the walls are thinnest, as ath i, immediately under the cornice, they measure 2 feet.k krepresents a drop-hole formed in the courses of the stair-case and solid, for the range of the weight of the machinery of a revolving Light. The ascent to this building, as at the Bell Rock, is intended to be by an exterior stair or ladder of brass, and the interior communication between the several apartments by means of flights of circular oaken-steps.
Fig. 6. represents the first entire course of this design, drawn to a scale double the size of the former Figure, and shows the manner in which the courses are proposed to be built or connected with each other. In every building of this kind, it is proper that two or more of the lower courses, according to the situation and circumstances of the rock, should be sunk or imbedded in it. Since the erection of the present Light-house on the Edystone, the practice of dove-tailing and trenailing stones in water-buildings has been occasionally followed; and there can be no doubt that in some instances it is attended with advantage. But it is also true, that, independently of the extra quantity of rock and workmanship required, the stones are thereby greatly weakened, and rendered much more difficult to be landed in safety in such situations, and that there is often more apparent than real utility in cutting them agreeably to this system of building, as the great bond of the fabric still resolves itself into the gravity of the materials. It may likewise be noticed, that, unless in very peculiar circumstances, the process of trenailing stones newly laid in mortar ought to be avoided, as it becomes necessary to bore holes into the course immediately below, which is apt to break the bond of the mortar by the tremulous motion of the jumper or chisel and hammer.
To avoid these disadvantages, and more effectually to preserve the square or simplest form of the stones, it is proposed, in this new design, to adopt the same mode throughout, that was followed with the courses of the void or habitable part of the building at the Bell Rock, viz. to have zones or joggle-belts worked on the upper beds, and corresponding grooves cut into the under beds, of all the stones. In the plan represented in this Figure these zones are intended to be 1 foot in breadth, and 1½ inch in depth or thickness, forming the concentric rings, markedc c c c c c, which becomeso many girths to the course, superseding the necessity both of the dove-tailing system, and of the cubic joggles described inPlate XVI.
In tracing the general aspect of Fig. 6., it may be observed that the outer circle of stones is more lightly shaded, being intended for granite, while the hearting or interior part is of a darker shade, as descriptive of sandstone. The whole course of the building here represented, is uniformly simple, and when laid in its place, no mode of attachment can be conceived more effectually to add to the strength and connection of the fabric than these circular belts. Letterdrefers to the recess worked in the outward wall of the solid, measuring 2 feet in breadth and 1 foot in depth, for the reception of a flight of brazen-steps for ascending to the entrance-door, instead of the greater projection of the spiral-formed stair delineated inPlate VII., Fig. 6., or the uncertain means of communication by a rope-ladder. The recess alluded to on the outward wall is worked with a small projection, which gradually falls into the circle of the building, without presenting any abrupt face to the waves. A stair of this description, upon a sloping wall, is ascended with great ease.
Fig. 7. is a section of part of the solid of the building, of whicha bis the foundation course, and, in reference to Fig 6., lettersc c, &c. correspond with the zones or joggle-belts;d d, shew a section of part of the brazen-ladder, answerable to the purposes of a stair, and a pair of skids, for preventing the joints of the building from being injured in taking up stores to the Light-house. This ladder may also be applied as a part of the thunder-rod, as is the case at the Bell Rock.
Fig. 8. is a plan of an entire course of the void or habitable part of the Light-house, showing one of the joggle-belts of the bed-joints. The form of joggle for the end-joints here shewn is also simple, and suited for preserving the strength of the materials more entire than the method of dove-tailing.
Fig. 9. is a section of three courses of the void of the building, showing the connection of the bed-joints.
FINIS.
P. Neill, Printer.
The View of the Light-house in a Storm, to be placed as a Frontispiece, opposite the General Title-page.The Engraved Title-page, with the Vignette representing the Light-house during Night, to be placed immediately after p.64.The General View of the Works, or Plate XVIII, to be placed immediately after p.424.
The View of the Light-house in a Storm, to be placed as a Frontispiece, opposite the General Title-page.
The Engraved Title-page, with the Vignette representing the Light-house during Night, to be placed immediately after p.64.
The General View of the Works, or Plate XVIII, to be placed immediately after p.424.
Transcriber's NoteThe following printed corrigenda have been incorporated into the text:CORRIGENDA.Page 90, line 10.aftermatterinsertrested---- 414, marginal note,forAprilreadAugust---- 516, line 38. — one of the —— the twoThe following further apparent errors have been corrected:p. vi "Inchkeith Light-hoouse" changed to "Inchkeith Light-house"p. vi "Corsewall Light-houuse" changed to "Corsewall Light-house"p. vii "92–74" changed to "72–74"p. vii "93–81" changed to "75–81"p. viii "is passed" changed to "is passed."p. ix "137–130" changed to "127–130"p. x "a Life-boats" changed to "a Life-boat"p. xii "hree" changed to "three"p. xii "562–277" changed to "272–277"p. xiv "Tinber" changed to "Timber"p. xvii "Mr Forest" changed to "Mr Forrest"p. xix "Instructions" changed to "Instructions."p. xix "VI Schedules" changed to "VI. Schedules"p. xix "wth Sections" changed to "with Sections"p. 5 (sidenote) "1736" changed to "1786"p. 10 "E," changed to "E.,"p. 10 "SE," changed to "SE.,"p. 20 (sidenote) "Sanday." changed to "Sanday"p. 26 "From the" changed to "“From the"p. 28 "uinformity" changed to "uniformity"p. 29 "nonoticed" changed to "noticed"p. 44 "Turnberry Point." changed to "Turnberry Point,"p. 50 "Langnees" changed to "Langness"p. 53 "Masters’ Names" changed to "Masters’ Names."p. 55 "Plate II,;" changed to "Plate II.;"p. 56 "Puzzolano" changed to "Pozzolano"p. 67 "sea-cost" changed to "sea-coast"p. 74 "them," changed to "then,"p. 79 "Bell Rock;" changed to "Bell Rock,"p. 79 (sidenote) "Dee." changed to "Dee"p. 81 "southernside" changed to "southern side"p. 100 (sidenote) "Loan" changed to "Loan."p. 105 (sidenote) "reading" changed to "reading."p. 116 (sidenote) "7th August" changed to "7th August."p. 133 "duty," changed to "duty."p. 142 (sidenote) "Monday, 31st" changed to "Monday, 31st."p. 159 "artifieers" changed to "artificers"p. 172 "Plate XII" changed to "Plate VIII"p. 194 "Plate XIII" changed to "Plate XIII."p. 196 "Plate XII." changed to "Plate IX."p. 206 "Bell Rock," changed to "Bell Rock."p. 213 "the a species" changed to "a species"p. 225 (sidenote) "12th" changed to "12th."p. 238 (sidenote) "13th" changed to "13th."p. 238 (sidenote) "the Rock" changed to "the Rock."p. 239 "circumtances" changed to "circumstances"p. 247 "applyed" changed to "applied"p. 250 (sidenote) "pram boats" changed to "praam-boats"p. 254 (sidenote) "a a small" changed to "a small"p. 259 (sidenote) "February," changed to "February."p. 267 "lowt hey" changed to "low they"p. 272 "windlas" changed to "windlass"p. 282 "obliged slip" changed to "obliged to slip"p. 282 (sidenote) "to day" changed to "to-day"p. 288 (sidenote) "Mortar makers" changed to "Mortar-makers"p. 292 "hyp num" changed to "hypnum"p. 293 "opportuty" changed to "opportunity"p. 296 "tthe Rock" changed to "the Rock"p. 303 (sidenote) "5th" changed to "5th."p. 305 (sidenote) "Beacon" changed to "Beacon."p. 308 "with rain," changed to "with rain."p. 311 "A. M" changed to "A. M."p. 329 (sidenote) "Beacon" changed to "Beacon."p. 329 "bridge, which which" changed to "bridge, which"p. 331 "measuer" changed to "measure"p. 334 "cr e" changed to "crew"p. 334 "ballass" changed to "ballast"p. 335 (sidenote) "Thirty-fifth" changed to "Thirty-first"p. 335 (sidenote) "Beacon" changed to "Beacon."p. 340 "provided" changed to "provided."p. 343 "Thirtieth" changed to "Fortieth"p. 343 "balance-crane" changed to "balance-crane."p. 348 "petticoat-trowers" changed to "petticoat-trowsers"p. 363 "3rd" changed to "3rd."p. 364 "respresented" changed to "represented"p. 373 (sidenote) "20th." changed to "19th."p. 373 (sidenote) "21st." changed to "20th."p. 374 (sidenote) "3d." changed to "23d."p. 374 (sidenote) "2d." changed to "24th."p. 376 (sidenote) "27th." changed to "26th."p. 376 (sidenote) "26th." changed to "27th."p. 383 (sidenote) "Station" changed to "Station."p. 383 "29.90." changed to "29.90"p. 386 "&c" changed to "&c."p. 389 (sidenote) "landed" changed to "landed."p. 410 (sidenote) "house" changed to "house."p. 411 (sidenote) "Rock" changed to "Rock."p. 412 "propritey" changed to "propriety"p. 418 "premisses" changed to "premises"p. 422 "seeiug" changed to "seeing"p. 428 "prosions" changed to "provisions"p. 433 "eef, Bin Llb." changed to "Beef, in Lib."p. 433 "Galls" changed to "Galls."p. 433 "Butter in Lib." changed to "Butter, in Lib."p. 433 ",Beer in Qts." changed to "Beer, in Qts."p. 434 "Articers" changed to "Artificers"p. 434 "89.225" changed to "892.25"p. 435 "Syevenson" changed to "Stevenson"p. 440 "Cssist" changed to "Assist"p. 443 "of a a" changed to "of a"p. 449 "foretel" changed to "foretell"p. 459 "cubit" changed to "cubic"p. 471 "7 4" changed to "7.4"p. 496 "Forest’s Passage." changed to "Forrest’s Passage."p. 501 "Plate XXIII" changed to "Plate XXIII."p. 503 "faint lines" changed to "faint lines."p. 505 "Plate XVII" changed to "Plate XVII."p. 523 "Fig.1." changed to "Fig. 1."p. 523 "in this way" changed to "In this way"p. 527 "lense" changed to "lens"p. 533 "Plate VII" changed to "Plate VII."(plate) "PLATE II" changed to "PLATE II."(plate) "PLATE XII" changed to "PLATE XII."(plate) "PLATE XVI" changed to "PLATE XVI."(plate) "PLATE XXI." changed to "PLATE XXIII."The following additional changes have been made from the printed text:Plates I to XXI have been moved next to their descriptions.Duplicate sidenotes have been removed.Totals carried forward at the end of each page of the Account of Expence have been removed.Large tables have been split and reformatted with keys and altered punctuation, in order to fit smaller displays.Spacing of sums of money has been regularised in the form L. 61,331:9:2.The text contains many Scottish and archaic words and spellings, as well as inconsistent capitalisation and punctuation, which have otherwise been retained. Apostrophes are not consistently used in possessive plurals.Compass directions are inconsistently presented in the forms SW. and S.W.; S. SW. and S.SW.References to diagrams are given in the forms á and a´.The colours mentioned in the description of plate III. on p. 490 are not apparent.The following possible errors have been left as printed:p. 239 "35 persons"p. 334 "with it mortar"p. 339 "Thirty-eighth"p. 346 "slump sum"p. 353 "alwise"p. 457 "begin to the"p. 500 "plat"p. 519 "several apartment"The name of the engraver of Plate I was not intact in the copy of text transcribed.In addition to variant spellings in quotations, the following are used inconsistently in the text:adrift and a-driftahead and a-headaisler and aislaralongside and along-sideBelider and Belidorblacksmith and black-smithbrushwood and brush-woodbucky and buckieBurlington Bay and Burlington-Baycast iron and cast-ironcoalfish and coal-fishcoboose and co-boosecofferdam and coffer-damconveniencey and conveniencyCopinsha and Copinsaycoxswain and coxwaincreeking and creakingdaylight and day-lightdovetail and dove-tailforepeak and fore-peakfreestone and free-stonehalfpenny and half-pennyhawsehole and hawse-holeIsland Glass and Island-GlassKinghornness and Kinghorn-nessKinnaird Head and Kinnaird-Headlandmark and land-marklengthway and length-wayLewis bat, Lewis batt, Lewis-bat and Lewis-battlighthouse and light-houselightkeeper and light-keeperlightroom and light-roommanhole and man-holemillwright and mill-wrightMilnfield and MylnefieldMull of Kantire and Mull of Kintyreoatmeal and oat-mealoverboard and over-boardpraam boat, praam-boat and Praam-boatrailway and rail-wayRedhead and Red-headrelaid and re-laidroadway and road-wayRubislaw, Rubieslaw and RubeslawScottish and Scotishshackle and shakleshipboard and ship-boardshipmaster and ship-mastershipowner and ship-ownershipwreck and ship-wreckskylight and sky-lightstaircase and stair-caseStart Point and Start-Pointstorehouse and store-housetie chain and tie-chaintorchlight and torch-lighttopmast and top-masttorchlight and torch-lightTraill and TrailUnited Kingdom, United kingdom, and united kingdomvice versaandvice versâworkshop and work-shopworkyard and work-yard
The following printed corrigenda have been incorporated into the text:
CORRIGENDA.Page 90, line 10.aftermatterinsertrested---- 414, marginal note,forAprilreadAugust---- 516, line 38. — one of the —— the two
CORRIGENDA.
The following further apparent errors have been corrected:
The following additional changes have been made from the printed text:
The text contains many Scottish and archaic words and spellings, as well as inconsistent capitalisation and punctuation, which have otherwise been retained. Apostrophes are not consistently used in possessive plurals.
Compass directions are inconsistently presented in the forms SW. and S.W.; S. SW. and S.SW.
References to diagrams are given in the forms á and a´.
The colours mentioned in the description of plate III. on p. 490 are not apparent.
The following possible errors have been left as printed:
The name of the engraver of Plate I was not intact in the copy of text transcribed.
In addition to variant spellings in quotations, the following are used inconsistently in the text: