PlateVIII.BEACON-HOUSE.

DESIGNS for the BELL ROCK LIGHT HOUSE by Mr. STEVENSON.

DESIGN for the BELL ROCK LIGHT HOUSE by Mr. RENNIE.Drawn by J. SlightEngraved by R. ScottPLATE VII.

DESIGN for the BELL ROCK LIGHT HOUSE by Mr. RENNIE.

Drawn by J. Slight

Engraved by R. Scott

PLATE VII.

Pl. VII.

Fig. 1. shews the sites of the principal and diagonal supports of cast-iron of the Pillar-formed Light-house, modelled by the writer prior to his landing on the Rock in the year 1800, as alluded to in his report, included in the Appendix, No. IV. at page440. This Figure is a Plan in which lettersa a a a a a a apoint out the feet of the eight principal columns;ethe central shoe or socket, intended to receive the feet of the diagonal supports or braces, which correspond in number with those of the main columns. This fabric, at the base, was to form a common diameter of about 35 feet, diminishing to 12 feet at the top, or immediately under the Light-room.

Fig. 2. The great columns in this design, which are sunk into the Rock, and the diagonal bracesd d d d, which butt against, or step into the shoec, are also strongly connected by the bracesb b b b b b b b, and cross ties markedc c c c c c. The habitable part of this building is formed by two concentric rings of copper, markeda f,a f, the one upon the outside, and the other upon the inside, of the main columns. The space between these rings was to be filled with plaster-of-Paris, or some light substance, to render the apartments air-tight. Lettergis the position of the entrance-door, and the space below the first floor, markedh, is a coal magazine. The better to throw off the sprays of the sea, the lower part, as will be seen from the diagram, is of a conical form inverted.

Fig. 3. Shews the mode of fixing the principal columns, to the Rock, and of building or connecting them together, being an enlarged section of the foot of one of the main columns. The hollow cylindrical tube markedb b, is sunk 24 inches, and acts as a steady pin or joggle to the column which is wedged into the Rock, asshewn atc c c c, by driving oaken and iron wedges alternately, instead of running them up with melted lead. The next length of the column, markeda a a a, is slipped over this tube, and has a seat cut in the rock at right angles to the oblique direction of the column, to which it is connected by the cutter or spear-bolts markedd d d, whose directions respectively cross each other, as shewn in the section.

Fig. 4. represents one of the joints of the main columns, which occur at every 7 feet of their length, from the rock to the habitable part of the Light-house. This description of joint is what is technically termedspigotandfaucet;a ais the upper half,b b bthe lower,c cthe joint,d d d dthe collar-piece clasping the joint, and connecting it with the horizontal arms or bracese e, which, in Fig. 2, are markedb, and in connection with the cross tiesc, and diagonal-supportsd, bind the whole firmly together.

Fig. 5. represents the lower floor of the five apartments, in whicha a a a a a a a, as in the foregoing Figs. 1, 2, and 3. shew the main columns passing between the outer covering and inner lining of copper. Lettercmarks the entrance door, shewn atg, in Fig. 2., in which d is the plat at the top of the ladder, formed on one of the columns, which may also be conceived as passing up through the habitable part of the building; the floors of which are formed with plates of cast-iron.

Fig. 6. represents a Light-house of masonry, modelled by the writer immediately after his first landing upon the Rock. The better to illustrate this design, the solid or lower part is given in elevation, and the upper or habitable part in section. Compared with the Edystone Light-house, upon the principles of which it was designed, the chief differences consist in the exterior spiral-formed stair, intended to afford permanent access to the Light-house, and also to serve as a landing quay or wharf at high-water. The steps of this stair were to be 3 feet in length, forming a kind of scarsement upon the outer-wall, there being nothing to obstruct the force of the sea under the stair; as it formed part of the main-wall, it may be conceived calculated to have become a kind of spiral buttress to the building. In the upper or habitable part, the interior walls diminish gradually, instead of forming abrupt scarsements, and the floors were laid horizontally, instead of being arched.

Fig. 7. Shews one of the floors, each stone of which forms part of the outward walls, extending inwards to a centre stone, independently of which they were to be connected, by means of copper-batts, with a view to preserve their square form at the extremity, instead of dove-tailing. These stones were also modelled with joggles sidewise, upon the principles of the common-floor, termed Feathering in carpentry; and also with dove-tailed joggles across the joints, where they formed part of the outward wall, as shewn in this figure.

Fig. 8. is a plan of one of the courses of the void or habitable part of this design, shewing both the joggles of the end joint and the girth, raised upon the upper beds of the courses, and sunk into the groove cut in the lower beds of the respective covering courses.

Figs. 9. and 10. exhibit different modes of connecting the stones and courses of the solid of the building, both perpendicularly and horizontally, by means of dove-tailing.But as a certain degree of weakness is unavoidably incident to every system of dove-tailing, and, as the method of forming the bed-joints of the void above alluded to is equally effective, in its application to the solid or lower part of the building, as represented inPlate XXIII., this is considered preferable to the dove-tailing system.

Fig. 11. is part of a course, shewing a simple mode of connecting the stones in water-buildings, so as to avoid dove-tailing, and preserve, as much as possible, the entire figure of the stones. This is effected by inserting square joggles into the joints, and allowing these joggles to project 6 inches into the course immediately above, thereby forming a connection horizontally between the stones of a course, and vertically with the several courses.

Fig. 12. is also a course of masonry, in which the square or entire form of the materials is preserved, while the stones are bound both horizontally and vertically, by means of metallic-batts and plates, as represented in the enlarged diagram described in the following Figure.

Fig. 13.,ais the dove-tailed cross-head or plate;bis a section both of the batt and plate, in their places, shewing their connection with two courses of the building marked A B;cshews the mode in which the batt is fixed into the lower course, by means of wedges;dthe upper end of the batt and plate, which is also wedged, and appears, when in its place, as in Fig. 11., marked alsoa a a. But these several modes of connecting the materials of masonry are considered more or less objectionable, when compared with the girths delineated in the design represented inPlate XXIII.

Figs. 14. and 15. are a reduced plan and elevation of the Bell Rock Light-house by Mr Rennie, in the year 1807. They will be found so obvious upon inspection, as not to require explanation, and are here preserved as the only plans or drawings furnished for this work by that eminent engineer.

BELL ROCK BEACONDrawn by W. LorimerEngd. by W. H. LizarsPLATE VIII.

BELL ROCK BEACON

Drawn by W. Lorimer

Engd. by W. H. Lizars

PLATE VIII.

Pl. VIII.

Fig. 1. represents the Beacon-house, which was used as a barrack for the artificers during the working seasons of 1809 and 1810. Letter A A A is the surface of the Rock. The principal legs or beams, with their diagonal supports, radiating from the centre of the plan, are markeda a a a a a, and the bracing chainsb b b, as completed in the year 1807. In 1808 the bracing-chains were removed, and the malleable iron-bars markedc c cwere substituted. The dotted linesd d d d d, are intended to show the form of the upper or habitable part of the Beacon as it was ultimately finished, with its lantern, for ventilating the barrack-room. Oneof the figures characterised as sailors, and used for illustrating this elevation, is represented as standing upon the Rock, and laying hold of one of the bracing-chains. The next figure is ascending the trap-ladder, formed with cleats of timber nailed upon one of the principal beams; he is on a level with the mortar-gallery, marked lettere e e. The third figure is standing upon the cross or collar-beams, nearly on a level with the floor of the cook-room, markedf f. The fourth, or highest figure, is standing upon one of the principal beams, with his feet on a level with the top of the windows in the floor of the cabins of the engineer and his assistants markedg g; the head of this figure being within the artificers’ barrack, markedh h. With one hand he is supposed to be touching the provision-chest, markedi, and with the other he is laying hold of the rope for hoisting the copper signal-ballkupon the flag-staff.

Fig. 2. represents the gallery where the mortar-makers and smiths latterly worked.a a a a a arepresent the principal beams of the Beacon cut across;b b bthe position of the mortar tubs and lime-casks;cthe smith’s anvil;dhis bellows;ethe hearth or fire-place.

Fig. 3. represents the floor of the cook-room, in whicha a a a a ashew the principal beams cut across;bthe platt or landing at the entrance-door;c cthe coboose or cooking-hearth;dthe chimney or smoke funnel;e e e ethe provision casks;fthe trap stair leading to the floor above;g gthe small life-boat, suspended by davits from the principal beams of the beacon;i i i i i ithe six angular upright posts cut across, markeddin Fig. 1., which form the framing of the hexagonal apartments or floors marked III. and IV. Letterkrepresents the position of the privy, and stair leading to it.

Fig. 4. is the floor of the cabins of the engineer and his assistants. Lettersa a a a a amark the position of the six principal beams of the beacon, now approaching closely together from their diagonal direction:b b b b b bthe angular upright posts, which, together with those markedi i i i i i, as referable to Fig. 3., form the upper apartments into twelve sides;cis the trap-ladder, corresponding with letterfin Fig. 3., which communicates with the cook-room floor below;dis another ladder, leading to the artificers’ barrack above.

Fig. 5. represents the upper floor, or that of the artificers’ barrack-room, on a level with the top of the principal beams, marked a in Figs. 1, 2, and 3. In this diagrama a a a arepresent the ground-tier of beds, which were ranged in five heights, excepting at the space over the man-hole, leading up to this apartment, where there was only three heights of beds;crepresents the trap ladder answerable to letterdof Fig. 4.

Fig. 6. represents what may be termed a bird’s-eye view of the Beacon, as completed in 1807, and before it was converted into a barrack. In reference to Fig. 1., letterarepresents the six principal beams, forming a common base measuring about 35 feet across, including the bracing-chains, which are markedb b b b b b. These beams meet in a point at the top, where they rest upon a block of beechwood, to which the upper ends of the beams were fitted, the whole being girded with strong malleableiron rings or hoops, keyed with spear-bolts. Here the provision-chesti, and signal-ballk, are represented as resting upon the top of the principal beams.

Fig. 7. is an enlarged view of two of the bracing-chains, markeda a, with their tightening shakle markedb b, meeting in the ringc c. Letterdrepresents one of the batts, which were sunk into the rock A A about 20 inches, and wedged with timber and iron, as shewn ate e.

Fig. 8. represents a side view of one of the beams of the beacon, markeda a a a, cut across immediately above the great stancheonsb b b b, with its bolts, which were fitted upon each side of the beam;c crepresent the clasp-plates, which embraced each foot of the beacon, with its two stancheons. These clasp-plates were fixed with spear-bolts, as shewn atd d. Letterse erepresent the wedging with timber and iron, referred to in Fig. 7.

Fig. 9. represents a front view of a like portion of one of the principal beams, as in Fig. 8.;a a a ashew the stancheons on each side of the beam, andb bthe lower extremity of the stancheons sunk into the Rock A;c cone of the clasp-plates;d d d dthe spear-bolts.

Fig. 10. is one of the principal beams,acut across at the clasp-platec c c c. Lettersb bare the great iron-stancheons; andd d dshew the spear-bolts.

Progress of the Bell Rock Works.Drawn by J. Slight.Engd. by W. Miller.PLATE IX.

Progress of the Bell Rock Works.

Drawn by J. Slight.

Engd. by W. Miller.

PLATE IX.

Pl. IX.

Fig. 1. shews the state of the works about the close of the second season, or year 1808, with two of the moveable beam-cranes, with their guy tackles and working gear, which will be more particularly described underPlate XIV.These are placed upon the top or fourth course of the building. In the fore-ground, part of the unfinished railways are seen, with waggons and artificers at work; and on the right the beacon is partly traced in faint lines.

Fig. 2. represents the state of the works in the month of August 1809, at the close of the third season’s work, when only one of the cranes was set upon the building; the other, as the work increased in height, and became less in diameter, was placed upon a temporary stool or prop of masonry, markeda a a a. This prop was found extremely useful, as, by elevating one of the cranes upon the top of it, the lift of the materials was divided, and brought more conveniently within reach of the higher crane, which at this period was about 30 feet above the Rock. In the fore-ground of this diagram, part of the circular track of railway round the building is seen. On the right, a part of the Beacon-house appears with the rope-ladder of communication, extending from the top of the solid of the Light-house to the mortar-gallery. On therope-ladder a figure is represented walking from the Beacon to the Light-house, and a tackle, with its travelling pulley, is also stretched, for conveying the mortar-bucket, to the builders.

Fig. 3. represents a section of the void or habitable part of the Light-house as it appeared in the month of August 1810, when the masonry was nearly completed. On the right is an elevation of part of the Beacon-house, but instead of the rope-ladder of communication, a bridge of timber is constructed. Lettersa arepresent the top of the solid, or level of the entrance-door of the building, from which the stair-case ascends to the several apartments. Resting on the sill of the door atb, is seen one of the beams for supporting the road-way of the bridge, and below this, at the pointc, is the step of one of the diagonal braces of the bridge, where it is inserted about 6 inches into one of the courses of the solid masonry. Regarding the frame-work of the bridge, it may only further be noticed, that the road-way was chiefly suspended from the king-postsd d.

Lettererepresents a block of stone, in the act of being raised from the rail-way on the Rock, to the level of the bridge, by means of the crab or winch-machine markedf, with wheel and pinion apparatus; the pully of the working chain is suspended from the cross beamg, which rests or is supported upon the top of the king-posts. One of the figures on the bridge ath, is in the act of pushing forward a truck cart or waggoni, to receive the stonee; when raised through the aperture in the road-way, it is then lowered upon this waggon, and removed towards the building within the sphere of the several purchases or machines, by which it is transported to the hands of the builders.

Letterkrefers to a life-buoy, and a coil of rope, kept in readiness upon the bridge, in case of accident by the fall of any of the people from the building or beacon while the Rock was covered by the tide.l lrepresent two of the fire-buckets, which were hung round the beacon, under the projection immediately above the cook-room. The stone markede, in the second stage of its progress towards the top of the building, is now seen immediately above the lintel of the entrance-door, the purchase chain, by which it is suspended, passes over a pulley atm, attached to the beamn n, which is projected from one of the windows of the Light-room store, where it is supported upon a block of timber, so as to admit of the chain passing under it. The further end of this beam, being within the Light-house, was bolted to an upright post markedo o, and the whole apparatus was worked by means of the crab or winch-machine atp, similar to that upon the bridge markedf f. The stoneeis next supposed to have gained the height of the floor of the bed-room, where another apparatus, similar to those atfandp, is placed. Here a figure is represented atq, with a rod in his hand, in the act of hooking the chain of the balance-crane into the Lewis-batt, fixed in the stonee, still in its progress to the top of the building.r r rrepresent the strong oaken beams placed on the floor of the library, on which the foot of the cast-iron balance-crane is supported.s stwo of the four diagonal braces of oak timber, bolted into a collar-piece of cast-iron, clasping the upright shaft of the crane att t, and butting against the upright stretchers atu u; intended as a security to thewalls, in case the balance-crane should at any time get out of equilibrium. The two figures markedv v, are represented as working the balance-crane, and are supposed to be standing upon a moveable platformx x, suspended from the body of the crane by rods of irony y. This platform or stage, with the artificers upon it, being moveable with the body of the crane, gave great facility and conveniency to those who wrought it.zis the balance-weight, moveable by the machinery along the balance-beam of the crane, to keep the whole in a state of equilibrium, according to the varied load suspended from the working or opposite beam; accentedárepresents the moveable block or cross-head of malleable iron, with two eyes, into which the chains of the crane were hooked, when thebody(comprehending the machinery and beams) was to be elevated upon the shaft in the progress of building. But the cross-head, together with the other apparatus of this machine, will be better understood by examiningPlate XVII., with its letter-press description.b´ b´ b´represent the form and position of the Light-room in dotted lines;c´the mortar-bucket made to traverse upon the guide-roped´ d´, stretched between the building and the mortar-gallery of the Beacon; the end of the rope attached to the building being fixed to the stanchioné, inserted into one of the Lewis batt-holes, on the balcony of the Light-room.

CERTAIN IMPLEMENTS connected with the BELL ROCK WORKSDrawn by G. C. ScottEngd. by E. MitchellPLATE X.

CERTAIN IMPLEMENTS connected with the BELL ROCK WORKS

Drawn by G. C. Scott

Engd. by E. Mitchell

PLATE X.

Pl. X.

Fig. 1.—is an elevation of one of the three large copper Lanterns carried by the Pharos Floating-Light, which was moored off the Bell Rock while the Light-house was erecting. In order to relieve this vessel of the cumbrous yards with which Floating-lights were in use to be fitted, these lanterns were so constructed as to clasp round the masts, and traverse upon them. This was effected by constructing them with a tube of copper in the centre, capable of receiving the mast, and through which it passed. The lanterns were first completely formed, and fitted with brass flanges; they were then cut longitudinally asunder, which conveniently admitted of their being screwed together on the masts, after the vessel was fully equipped and moored in her station. Lettersa a a ashew part of one of the masts,bone of the tackle-hooks for raising and lowering the lanterns at pleasure,c c c c c c c c c cthe brass flanges, with their screw-bolts, by which the body or case of the lantern was ultimately put together;d d dshew the position of certain holes in the bottom for the admission of air,f f f fthe holes at the top, connected with the ventilation, to which the collar-piecese eandg gform guards against the immediate effects of the weather. The detached diagram, upon an enlarged scale, shows the air-hole, which is markedm. The lettersh h h hshew the part of the lantern which was glazed with plate-glass;iis one of the glass shutters, by which the lamps were trimmed; the lower half being raised, slides into a groove made for its reception;k kshew the range of ten agitable burners or lamps, out of which the oil cannot be spilt by the rolling motion of the ship. Each lamp having a silvered-copper speculum or reflectorl lplaced behind the flame, was found greatly to increase the brilliancy of the light.

Fig. 2.—is a cross section of the bottom of the lantern, shewing the mastacut across,b bis the sole or bottom of the lantern,c cthe flanges at the junction of the body, in reference to the same letter in Fig. 1.;d d d dthe small holes for the admission of air,e e ethe brass zone or chandelier, with its ten arms and sockets markedf f, &c. in which the stalks of the burners are inserted. The chandelier is made to traverse horizontally into a corresponding groove fixed upon the interior cylinder or case, through which the mast passes, and upon which the whole moves up and down. When, therefore, the lamps require to be trimmed or taken out of the lantern, the chandelier is turned until they are respectively brought opposite to the shutter markedi.

Fig. 3. is an enlarged view of one of the agitable burnersa, with its reflectorb, which last measures four inches over the lips, and is raised to the parabolic curve of three inches focus;cthe socket,dthe section of the moveable chandelier in its groove, answerable to letterskandl, Fig. 1., andfandeFig. 2. In reference to Fig. 3.,e eis a section of part of the central cylinder of the lantern and mast of the ship.

Fig. 4. represents one of the Mushroom-Anchors, constructed wholly of cast-iron, used for mooring the Floating-Light and other craft off the Bell Rock, to which part of the mooring-chain is attached. This diagram seems so obvious as to require no particular description. Towards the heada athe shank is strengthened by means of four feathers or brackets raised upon it, somewhat resembling the connecting gills of the vegetable mushroom. These anchors weighed from 14 to 21 cwt.

Figs. 5. to 9.—Quarry Tools.—Fig. 5. is a common stone-pick, weighing from 8 to 10 lb., shown with and without the handle, which measured about 2 feet in length, but is here shortened. Fig. 6. is the Aberdeen or granite pick, weighing from 6 to 16 lb. Fig. 7. is a quarry hammer, weighing from 6 to 8 lb. used for jumping or boring batt-holes in the Rock, and the trenail-holes in the courses of the building. Fig. 8. represents the boring-irons for the trenail-holes, measuring 1¾ inches in breadth at the cutting end, and varying in length according to the depth of the respective holes. Fig. 9. is the scraper used for cleaning the holes; the perforated end being applied with a piece of rag for drying up the moisture.

Fig. 10. represents one of the oaken trenails used for keeping the stones in their places while the building was within the ordinary range of the sea. The positions of these trenails may be traced in the small circular holes of the courses, in Plate XIII. Their lower ends were cut with a saw-draught as at lettera, into which a small wedge markedbwas inserted, and the trenail having been driven home, the small wedge had the effect of tightening or fixing it. The upper endcwas then cut off flush with the upper bed of the stone, when it was split, and another smallwedge, markedd, driven into the chisel-mark, which completed the operation of fixing the trenails into their places.

Fig. 11. represents a pair of the oaken wedges inserted into corresponding grooves cut into the perpendicular joints of the stones in each course of the solid or lower part of the Light-house, as may be traced in the small oblong holes, marked in the joints of the courses inPlate XIII.These wedges were chiefly intended for bringing the dove-tailed parts of the stones to a general bearing. The thick end of the wedge markedabeing dropped into its groove, the smaller end of the corresponding wedgebwas then inserted, and driven home till some degree of tension or firmness was obtained. This operation of trenailing and wedging was followed from Mr Smeaton’s practice at the Edystone Light-house.

Fig. 12. is a section of one of the cast-iron mortar-tubs, with its pestle, shod or loaded with a piece of malleable iron.

Figs. 13. to 15.—Cast-Iron Plate-railway.—Fig. 13. is a longitudinal view of one length of the cast-iron railways erected upon the Rock;a a a arepresent the stools or upright supports,b bare the tracks of the roadway,c cone of the side stays or braces. Fig. 14. is a cross section on the line A B of Fig. 15, in whicha ais the support with its cross-bracef, bolted atg g g g;b bare the railway tracks,c c c cthe stays, with their connecting bolts on each side,d dthe sleeper or horizontal brace connecting the top of the stools, and forming a chair or seat for the rails and grated roadway;e e e erepresent the batts and spear-bolts, with which the whole was connected to the Rock, by the process of wedging with timber and iron. Fig. 15. is a plan of the finished railway;a a a aare the feet of the stools,b bthe side rails or waggon-tracks,c cthe stays or side braces,d dthe sleepers, andh hthe grated footpath. The weight of a yard in length of the railways complete, of the height of four feet, as represented in these diagrams, may be estimated about 5 cwt.

Fig. 16. represents a plan of one of the railway waggons;ais the iron handle made to hook upon either end of the waggon, so as to prevent the necessity of turning it;b bis the body of the waggon, consisting of two pieces of oak timber, bolted upon the upper part of the double frame intended for accommodating the wheels to the circular track of the railway round the building. The upper and under frames are connected with the boltc c, so as to admit of the movement above alluded to. For the same reason, a joint was formed in the perch or middle of the frame atd. The trucks or wheelse e e ewere of cast-iron, measuring 15 inches in diameter. These waggons were always left upon the Rock, being simply turned upside down, or off their wheels, in a particular part, and were seldom moved by the sea, as they weighed about 2 cwt. each.

Fig. 17. The ten diagrams, markeda,b,c,d,e,f,g,h,i, andk, are a set of moulds for one course of the solid part of the building, by which the stones were cut and prepared in the work-yard previous to their being shipped for the Rock. The application and connection of these diagrams will be better understood by examining the courses of the building inPlate XIII.

Fig. 18. a Trainer or Rule, framed of timber, applied by the builders, for ascertaining the exact position of the stones of the respective courses.ais the eye or socket on which it was fitted to a steady-pin placed exactly in the centre. This rule was used chiefly for ascertaining the radiating direction of the stones, from the centre towards the circumference, being laid agreeably to corresponding notches and lines marked upon their upper-beds, so as to preserve band throughout the work, and prevent difficulty with the closing or finishing stones.

Fig. 19. is a perpendicular section of the carpenter’s jack, used with much advantage for shifting and turning the stones in the work-yard. The case of this machine was made of elm, and strongly bound at the ends with iron. It measured 4 feet in height, its greatest breadth 12 inches, and its thickness 6 inches.a ais the stock or case,b bthe rack, fashioned at the lower end somewhat like the claws of a carpenter’s hammer. The upper end is of a forked form, both ends being conveniently applicable to the varied positions of the stones;canddare the wheel and pinion work;ethe handle by which the machinery is worked, affording a purchase or mechanical advantage in the ratio of about 64 to 1.

Fig. 20. is a plan of the useful machine called The Woolwich Sling-Cart, applicable to transporting large blocks of stone suspended between the wheels by means of a Lewis-batt. When a stone was of considerable length, it became necessary to employ a chain to steady it at the farther end, the application of which will be seen in this and the following figure.a a a arepresent the shafts and body of the cart,b b b bthe wheels,c cthe handles passing between the spokes of the wheels, by which the machinery is worked for lifting the stone. The dotted lined d d drepresents a plan of a stone in its state of suspension,e e ethe wheel and pinion work,fthe barrel or cylinder on which the chain turns as the stone is raised;g gis the tail-beam with its chainh h, and steady-pini.

Fig. 21. represents the sling-cart in its working state, with letters corresponding to Fig. 20. Here the Bell Rock carter, and his horse, are shown, already noticed in the description of Plate VI., page498.

Apparatus connected with the Bell Rock Works.Drawn by G. C. ScottEngd. by W. Miller.PLATE XI.

Apparatus connected with the Bell Rock Works.

Drawn by G. C. Scott

Engd. by W. Miller.

PLATE XI.

Pl. XI.

Fig. 1.—The Sheer-Craneat Duff’s Wharf.a a aare the working-sheers, to the upper extremity of which the purchase-chaina,e,g, is attached; from the hook markedi, the stonekis suspended by the sling-chaini,k, which was lengthened or shortened according to the state of the tide.b bare the upright-sheers;c cthe diagonal or supporting sheers. Those last, though acting as braces, hadalso a motion upon the connecting blockdat the top, from which the pulleyeis suspended, and over which the purchase-chain passes. This motion had the effect of giving the stone akantinwards, when the working-sheers came to the perpendicular, so as to lay it upon the waggonf, to be wheeled along the railways, as will be understood by examiningPlate XVIII.The crab or winch machineg g, fixed upon the Rock at one side of the railway, with batts and spear-bolts, was worked with a less or greater purchase, according to the weight of the stone to be lifted. The large wheel measuring 3 feet 3 inches in diameter, formed the single purchase, and the smaller wheel of 2 feet 6 inches, with its pinion of 6 inches, when connected with the former by an intermediate pinion, formed the greater purchase, exerting a power in the one case in the ratio of about 20 to 1, and in the other of 98 to 1.

Fig. 2. is a front view of the machine described above, with corresponding letters. At lettersh h, will be seen more distinctly the cast-iron bed, with the snugs or flanges for the reception of the lower ends of the sheersa a aandb b b b, with their journal-bolts. This apparatus, along with the other parts of the works, have been modelled for preservation.

Fig. 3. represents one of the malleable iron Lewis-batts, with which the stones were lifted from stage to stage, after leaving the hands of the stone-cutter. This useful implement consists of six members, viz. the palm, which is in three pieces, markeda,b,c; the palm-boltd d; the shacklee. The spear-boltf, for preventing the palm-bolt from drawing, was seldom used in practice.

Fig. 4. is a section of one of the praam-boats, shewing her cargo on deck, and more particularly the form and application of the mushroom-anchor and chain-moorings of the Bell Rock craft.a ais the cargo upon deck;b bis the hold or compartment under deck, calculated to contain a sufficient number of empty casks, for floating her, in the event of receiving injury at the rock.c cmark the fore and after peaks, for containing warps, kedge-anchors, grapplings, defenders, and other tackle;dmarks the position of the bits and cross-tree to which a hook atewas fixed, for attaching the end of the mooring-chain;fis the slit in the stem, answerable to a hawse-hole, through which the mooring-chain passed almost on a level with the deep water-line, and was ultimately fixed by the ringg, to the lower swivel of the floating buoyh, and also with the mushroom-anchoriat the bottom, connected with a length of chain extending to about twice the depth of the water.

The detached diagram towards the stern of the praam-boat, consisting of a mushroom-anchor, a larger and smaller floating buoy, with their respective chains, represent the state of the moorings while the praam-boats were employed at the Rock. The small buoyk, with its chainl, was connected at the ring accentedl´to the hawser-chain of the praam. When she was unmoored, this small buoy prevented the end of the chain from sinking. In this manner the praams were conveniently disengaged, or attached to the large buoyh. When at their moorings, the small buoykwas unhooked and stowed below, the strong mooring-chain being now drawn through the hawse, or slit atf, and the ring atl´being simply laid into the hook ate.

Fig. 5. is a perspective view of the sloop Smeaton at her moorings, delivering a cargo of stones, with one of the praam-boats along-side. In the back ground, the Light-house is seen partly built, together with the Beacon-house. Two of the three figures shewn on the deck, near the mast, are working the winch-machine of the ship in raising a stone from the hold, while the figure, in a lying posture, is holding-on the end of the tackle-fall, as described at page144. A stone is seen in the main hatch of the ship, suspended from the end of a short boom nearly at right angles to the mast. The figure near the companion or cabin-stair is working one of the guy-tackles. On the praam’s deck, part of a cargo may be seen, and the figure towards her stern is laying hold of the stone, suspended in the tackle, to guide it to its birth, while the other contiguous figure is working an opposite guy-tackle. To avoid confusion, only five figures are here introduced. The praam-boat is understood to be lashed head and stern to the ship, having three or four large wooden defenders slung between them, to prevent the vessels from injuring each other with the undulating motion of the sea. The Smeaton’s sails are handed, and the main and gaff-booms braced to one side, to give room upon deck, in bringing the stones out of the hold. The only peculiarities about the fitting of the Smeaton, were her large main hatch, for the conveniency of loading and discharging; her winch-machine was pretty powerful, exerting a force in the ratio of about 20 to 1, independently of the purchase-tackle; her cargo was also carried upon a temporary platform laid in the hold.

Fig. 6. is a perspective view of the smith’s forge, which was partly fixed with batts upon the Rock; and also of the Foundation-pit, with a number of figures pumping water from the excavated site of the Light-house. The pumps for this purpose were laid in an inclined direction, made of a square form, and very simple in their construction; the pump-spear with its leathern valve, being worked by the artificers, who laid hold of a rope attached to the end of it. In the back ground of this diagram, the Floating-light is seen as if through the haze of the atmosphere.

Fig. 7. represents an Attending-boat, occasionally used during the summer months for visiting the Rock, and relieving the light-keepers.a ais a section of the principal boat, measuring 22 feet in length of keel, and equipped in her rigging after the manner technically termedLateen-sails, which were originally introduced into use on the Firth of Forth by Mr Thomas Bruce of Grangemuir. These sails are considered more safe than the commonlug-sail, from their greatest breadth being carried very low on the mast. But the chief peculiarity of this boat is the launch or “two-half boat” of Mr James Bruce, which she carries, for more conveniently communicating with the Rock, as alluded to at page412, and further described in Thomson’s Annals of Philosophy, vol. viii. p. 58. In this diagrambis the two-half boat, stowed the one-half within the other, between the main and fore masts,c cthe two halves about to be joined and used as one boat,d dthe stern view of these boats in a separated state,e ethe chatter and catch-bolt for connecting the boats together, after the manner of a ship’s rudder,f f f fthe bolt holes, by which the upper parts of the boats are connected and held together.

PLAN of the HARBOUR and part of the TOWN of ABERBROTHOCKPLANS & ELEVATION of the LIGHT KEEPERS HOUSES & SIGNAL TOWERDrawn by D. LoganEngd. by W. H. LizarsPLATE XII.

PLAN of the HARBOUR and part of the TOWN of ABERBROTHOCK

PLANS & ELEVATION of the LIGHT KEEPERS HOUSES & SIGNAL TOWER

Drawn by D. Logan

Engd. by W. H. Lizars

PLATE XII.

Pl. XII.

Work-Yard.—The left-hand side of this Plate is occupied with a plan of the harbour of Arbroath, shewing the relative positions of the Bell Rock work-yard and light-keepers’ houses.

Light-Keepers’ Houses.—The other side of the Plate is occupied with a plan and elevation of the light-keepers’ houses; but as the apartments are respectively marked, it seems unnecessary to enter farther into particulars, than to notice that each family has three rooms, with other conveniencies. Connected with this establishment, there is also a signal-room at the top of the tower, represented in the elevation, where a five-feet achromatic telescope is placed upon a stand. On the roof a flag-staff is erected, and here the signals made by the light-keepers at the Rock are watched and repeated. On the opposite side of the small court formed by these buildings, there is a range of houses for stores, and accommodation for the seamen belonging to the Bell Rock Tender. The whole occupies a piece of ground extending to about one-third of an acre. While the works were in progress, the large telescope was placed at one of the attic-room windows of Provost Balfour’s house, which commands a view of the Rock, as may be observed from the Plate.

Sea-Wall.—The diagram laid down on the left of the light-keeper’s houses, represents a section of the wall erected for the protection of the property against the encroachment of the sea. It extends to about 100 feet, and consists of a face-wall of stone from Mylnefield quarry, backed with Arbroath stone, and a granite pavement along its seaward base.

Protection Medal.—The diagram in the central part of this Plate represents the obverse and reverse of the seamen’s protection medal, described at page209.

PLANS of the COURSES of the MASONRY of the BELL ROCK LIGHT HOUSEDrawn by D. Logan.Engd. by W. H. LizarsPLATE XIII.

PLANS of the COURSES of the MASONRY of the BELL ROCK LIGHT HOUSE

Drawn by D. Logan.

Engd. by W. H. Lizars

PLATE XIII.

Pl. XIII.

As the ground or imperfect course of the building could not be ascertained till towards the second year’s work, when the site of the Light-house was excavated, this course is represented inPlate XV.

Fig. 1. Plate XIII., is the first entire course, which measures 42 feet in diameter. The dove-tailed method of connecting the solid part of the Light-househere delineated, extends to the height of the entrance-door, as will be further understood by examining the section inPlate XVI.The outward stones of this course are of a lighter shade, being intended to represent the granite blocks, while the central part of a darker shade, represents the sandstone. The thirteen small square or cubical stones in the Plan of this course, shew the upper sides of the joggles, sunk half into the one course, and penetrating half into the superincumbent one, acting as so many steady-pins, calculated to guard against any force tending to affect the fabric horizontally. By tracing the bounding-lines of the stones, from the centre to the circumference, it will be observed, that the whole are connected by means of a system of attachments technically termed Dove-tailing, by which the stones may be said to hook laterally into one another, forming a vertical bond of connection; but it is onthe gravity of the materialsthat the chief dependence is placed for the stability of the fabric. The small circular dots, of which there are four in the centre-stone, and two in each of the others, shew the position of the oaken trenails, measuring 1¾ inch in diameter, and varying in length from 16 to 26 inches, so as to pass through the upper or last laid course, and penetrate 6 inches into the course immediately below. Besides these circular holes, others of an oblong form were cut in the joints, as will also be observed from the Figure. These last were for the reception of wooden wedges, driven in pairs perpendicularly into the joints of the stones, with a view to bring the dove-tailed parts to a uniform bearing, before the joints were grouted with mortar; the bond throughout the building being carefully preserved, by placing the perpendicular joints over the middle of the stones immediately below, being what is technically termed “Breaking-band,”—a system universally attended to in good masonry.

Fig. 2. represents the upper side of the 27th course, or first of the Stair-case, which measures 6 feet 4 inches in diameter within walls, and 19 feet 8 inches over walls. This course is elevated 32 feet 8 inches above the Rock at the foundation of the first stone, as will be seen in the section ofPlate XVI.Here the granite casing is discontinued, and sandstone only is in future used. It will be observed, that the same system of dove-tailing is attended to in the stair-case as in the solid: this unavoidably occasioned the working of the stones into very awkward forms, and required the utmost precaution in landing them on the Rock with safety.

The parts of this course which are not shaded, shew the plan of the entrance-door, passage, and circular void of the stair, crossed by the radiating lines of the steps, as also the form of some of the stones of the top of the solid.a arepresent the base of a column of cast-iron, which renders the drop-hole for the machinery continuous from the floor of the oil-store down to the level of the passage, and so through the centre of the solid, as shewn in the sectionPlate XVI.;bis a small stove placed in the stair-case;cis the position of the Inner door, of brass, as shewn in Fig. 2.Plate XIX., the upper part of which is glazed with plate-glass, to preserve the light of the stair-case;dis the position of the entrance-door, which is fashioned agreeably to the circular form of the building, and is strongly bound with the brass-hinges, as also shewn in Figs. 1. and 2. ofPlate XIX.

Fig. 3. is the 39th course of the building, and first of the provision-store, and is 45 feet 11 inches above the foundation. This apartment measures 11 feet 9 inches in diameter within walls, and 18 feet over walls. From the floor to the roof the height is 8 feet 7 inches. Here the dove-tailed system, excepting at the end joints, and in the centre stones of the floors, was laid aside. At this level another system of connecting the courses was adopted, by means of a zone or belt, which was raised or worked upon the upper bed of the stones, and fitted to a corresponding groove in the course laid immediately above, as may be seen by tracing the diagrams representing the habitable parts of the house. This zone or belt, together with the horizontal plan of the floors, form the chief distinctive differences between the Designs of the Edystone and Bell Rock.

Fig. 3. The parts in this Figure which are not shaded represent the two windows of this apartment with the landing at the top of the stone stair-case.a arepresent the storm-shutters, which will be more fully seen inPlate XIX.b bare the outer glazed windows;c cthe inner glazed windows;dthe open trap-ladder, with its brass hand-rail, leading to the light-room-store;e ethe cast-iron coal magazine;f f f fthe water-cisterns, of cast-iron, lined with a mixture of pitch and sand, and containing each 150 gallons;g g g gthe four cast-iron magazines, for containing the provision casks, and various implements;h hthe machinery, placed on a level with the top of the water-cisterns, for raising the stores from the entrance-door of the building to the Light-house;i iis the hole perforated through the wall for the passage of the chain for lifting the stores, the operation of which will be better understood by examiningPlate XVI.;kthe cast-iron stage upon which the light-keepers stand when they work the machinery for taking up the stores;l lthe cast-iron steps leading to the stagek.

Fig. 4. is a plan of the floor of the light-room store, being the 48th course, which is 55 feet 10 inches above the foundation. This apartment, within walls, measures 11 feet 10 inches, over walls 16 feet 10 inches, and its height is 8 feet 7 inches. The shaded part of the floor markeda a a a a a a, represents the copper oil-cisterns, coated with tin, calculated to contain one whole year’s stock of oil, or about 1100 gallons. This apartment being chiefly occupied with these cisterns, there is only one window in it;bis the trap-ladder, and shews also the manhole, measuring 3 feet in its greatest length and 2 feet in breadth;cthe store-room door;d dthe position of the oaken pannelled partitions, which separate and inclose the store-room from the stair.

Fig. 5. being the kitchen floor, forms the 57th course, which is elevated 65 feet 8 inches above the foundation. This apartment measures 11 feet 11 inches in diameter, over all 16 feet, and its walls are 8 feet 9 inches in height. This room, in the position of its windows, manhole, and trap-ladder, is similar to what has already been described in reference to Figs. 3. and 4. In Fig. 5,ais the door leading to the apartment below;bthe door leading to the trap-ladder of the apartment above;c cthe oaken partitions, formed into lockers, which shut off the stair from the apartment;dis the cast-iron kitchen range or fire-place, which stands free and unconnectedwith the walls, forming a connected piece of pannelled work, extending from the floor to the ceiling;eis a strong cast-iron fender, and also a receptacle for the ashes;f fcopper coal-boxes, formed into seats, on each side of the fire-place;gthe cook’s table and locker;hthe handle of the pump, by which water is raised from the provision-store or the second floor below;i iother lockers, also formed into seats.

Fig. 6. is the bed-room floor, or 66th course of the building, and is elevated 75 feet 8 inches above the foundation; it measures 11 feet 11½ inches in diameter, and over all 15 feet 6 inches; the walls are 9 feet in height. The windows, manhole, trap-ladder, doors, and oaken partition are similar to what have already been described in the floors below;ashews the position of the aperture for the cast-iron funnel leading from the kitchen-chimney through the several apartments to the cupola of the Light-house;b bthe bed-frames, forming two bed-places in breadth, which are three tiers in height, reaching from the floor to the roof, and capable of accommodating six persons;c clockers on each side of the beds, for the use of the four light-keepers.

Fig. 7. the next in order is the floor of the Strangers’-room or Library, being the 75th course of the building, which is 85 feet 11 inches above the foundation. The diameter of this floor is 12 feet, it measures 15 feet over walls, and the height of the roof, at the centre, is 11 feet 1 inch. The walls, windows, and other particulars of this apartment are nearly similar to those formerly described;ais the cast-iron funnel leading from the kitchen-chimney;b bthe oaken framed book-case;cthe tube through which the machinery-rope is conducted by the side of the walls of the several apartments, to the ceiling of the Provision-store.

Fig. 8. is the Light-room floor, or 86th course of the building, which is elevated 97 feet 9 inches above the foundation; within walls the floor measures 11 feet in diameter, over walls 13 feet 6 inches. The stones of the floor of this apartment, as will be observed, extend from the centre stone to the circumference of the balcony, varying from 7 feet to 7 feet 6 inches in length. The parapet-wall of the light-room, as will be seen from the Plate, has its outward face of an octagon form, but is worked circular within. In the several courses of the parapet, the principle of the zone or belt in the beds of the stones is still continued, and also the dove-tail of the end joints. The Light-room measures from the floor to the top of the stone work, or sole of the glazed sash-frames, 6 feet.ais the circular aperture for the cast-iron smoke-tube leading from the kitchen-chimney;b bis the manhole of this floor, having its landing towards the centre of the apartment, instead of being close to the wall, as in the several floors below. To have formed the length-way of the man-hole of this floor along the wall, would have occasioned the cutting of the stones in the dome-roof of the Library, in a manner hurtful to the strength of the building, which was conveniently avoided by introducing a platt in the ladder, instead of ascending more directly as by the trap-ladders of the floors below;c cis the case of the revolving-machinery, which gives motion to the Lights;d dis the drum or barrel, with its connecting wheels, on which the rope is coiled, from which the weight is suspended;ethe positionof the upright shaft for supporting the chandelier on which the reflectors are ranged, which is put in motion by its connecting train of machinery. The dotted lines markedf fshew the direction of the grooves cut in the floor for the horizontal shafts, which derive their motion from the machinery, and work the hammers of the two alarm-bells placed on the balcony;g gthe bell-hammers with their cases;h hthe bells, weighing each 5 cwt., which are tolled during the continuance of foggy or snowy weather;i i, &c. are the screwed batts of brass, forming the fixtures of the balcony-rail;kthe Light-room door communicating with the balcony, which measures in the clear 5 feet in height, and 1 foot 10 inches in breadth.

Fig. 9. is a plan of the Lantern, showing the position of the trimming-path, and reflector-frame. The height from the foundation to the sill of the sash-frame is 102 feet 6 inches, and from thence to the lining of the cupola 13 feet four inches.ais the smoke-tube leading from the kitchen to the cupola;b b b bthe cast-iron grated trimming-path, on which the light-keepers stand when they trim the lamps;c cthe reflector-frame or chandelier, on which three tiers of reflectors are ranged;dthe upright shaft;f f, &c. the position of the fountains for the reflector-burners,g gthe position of the shades of red-coloured glass, by which the light is distinguished;hthe iron trap-ladder communicating with the trimming-path.

Back to Index Next