Fig. 1.--THE SHEER-CRANE at Duff’s Wharf. _a a a_ are the

working-sheers, to the upper extremity of which the purchase-chain

_a_, _e_, _g_, is attached; from the hook marked _i_, the stone

_k_ is suspended by the sling-chain _i_, _k_, which was lengthened

or shortened according to the state of the tide. _b b_ are the

upright-sheers; _c c_ the diagonal or supporting sheers. Those last,

though acting as braces, had also a motion upon the connecting

block _d_ at the top, from which the pulley _e_ is suspended, and

over which the purchase-chain passes. This motion had the effect of

giving the stone a _kant_ inwards, when the working-sheers came to the

perpendicular, so as to lay it upon the waggon _f_, to be wheeled along

the railways, as will be understood by examining Plate XVIII. The crab

or winch machine _g 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 letters _h h_, will be seen more distinctly

the cast-iron bed, with the snugs or flanges for the reception of

the lower ends of the sheers _a a a_ and _b 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, marked _a_, _b_, _c_; the

palm-bolt _d d_; the shackle _e_. The spear-bolt _f_, 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 a_ is

the cargo upon deck; _b b_ is 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 c_ mark the fore

and after peaks, for containing warps, kedge-anchors, grapplings,

defenders, and other tackle; _d_ marks the position of the bits and

cross-tree to which a hook at _e_ was fixed, for attaching the end

of the mooring-chain; _f_ is 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 ring _g_,

to the lower swivel of the floating buoy _h_, and also with the

mushroom-anchor _i_ at 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 buoy _k_, with its

chain _l_, was connected at the ring accented _l´_ 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 buoy _h_. When at

their moorings, the small buoy _k_ was unhooked and stowed below, the

strong mooring-chain being now drawn through the hawse, or slit at

_f_, and the ring at _l´_ being simply laid into the hook at _e_.

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 page 144. 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 a_ is a section of the principal boat, measuring 22 feet in length

of keel, and equipped in her rigging after the manner technically

termed _Lateen-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 common _lug-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 page 412, and further described in Thomson’s Annals of

Philosophy, vol. viii. p. 58. In this diagram _b_ is the two-half boat,

stowed the one-half within the other, between the main and fore masts,

_c c_ the two halves about to be joined and used as one boat, _d d_

the stern view of these boats in a separated state, _e e_ the chatter

and catch-bolt for connecting the boats together, after the manner of

a ship’s rudder, _f f f f_ the bolt holes, by which the upper parts of

the boats are connected and held together.

PLATE XII.

WORK-YARD, LIGHT-KEEPER’s HOUSES, SEA-WALL AT ARBROATH, AND SEAMEN’s

PROTECTION-MEDAL.

[Illustration:

_PLAN of the HARBOUR and part of the TOWN of ABERBROTHOCK_

_PLANS & ELEVATION of the LIGHT KEEPERS HOUSES & SIGNAL TOWER_

_Drawn by D. Logan_

_Eng^d. by W. H. Lizars_

_PLATE XII._]

[Sidenote: 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 page 209.

PLATE XIII.

PLANS OF THE SEVERAL COURSES OF THE MASONRY OF THE LIGHT-HOUSE.

[Illustration:

_PLANS OF THE COURSES OF THE MASONRY OF THE BELL ROCK LIGHT HOUSE_

_Drawn by D. Logan._

_Eng^d. by W. H. Lizars_

_PLATE XIII._]

[Sidenote: 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 in Plate 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-house here delineated, extends to the height of the

entrance-door, as will be further understood by examining the section

in Plate 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 on _the gravity of

the materials_ that 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 of Plate 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 a_ represent 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 section Plate XVI.;

_b_ is a small stove placed in the stair-case; _c_ is 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; _d_ is 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.

of Plate 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 a_ represent the storm-shutters, which will be more

fully seen in Plate XIX. _b b_ are the outer glazed windows; _c c_

the inner glazed windows; _d_ the open trap-ladder, with its brass

hand-rail, leading to the light-room-store; _e e_ the cast-iron coal

magazine; _f f f f_ the water-cisterns, of cast-iron, lined with a

mixture of pitch and sand, and containing each 150 gallons; _g g g g_

the four cast-iron magazines, for containing the provision casks, and

various implements; _h h_ the 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 i_ is 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 examining Plate XVI.;

_k_ the cast-iron stage upon which the light-keepers stand when they

work the machinery for taking up the stores; _l l_ the cast-iron steps

leading to the stage _k_.

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 marked _a 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; _b_ is the trap-ladder, and

shews also the manhole, measuring 3 feet in its greatest length and 2

feet in breadth; _c_ the store-room door; _d d_ the 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, _a_ is the door leading to

the apartment below; _b_ the door leading to the trap-ladder of the

apartment above; _c c_ the oaken partitions, formed into lockers, which

shut off the stair from the apartment; _d_ is the cast-iron kitchen

range or fire-place, which stands free and unconnected with the walls,

forming a connected piece of pannelled work, extending from the floor

to the ceiling; _e_ is a strong cast-iron fender, and also a receptacle

for the ashes; _f f_ copper coal-boxes, formed into seats, on each side

of the fire-place; _g_ the cook’s table and locker; _h_ the handle of

the pump, by which water is raised from the provision-store or the

second floor below; _i i_ other 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; _a_ shews 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 b_ the 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 c_ lockers 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; _a_

is the cast-iron funnel leading from the kitchen-chimney; _b b_ the

oaken framed book-case; _c_ the 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. _a_ is the circular aperture

for the cast-iron smoke-tube leading from the kitchen-chimney; _b b_

is 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 c_ is the case of the revolving-machinery,

which gives motion to the Lights; _d d_ is the drum or barrel, with its

connecting wheels, on which the rope is coiled, from which the weight

is suspended; _e_ the position of 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 marked _f f_

shew 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 g_ the

bell-hammers with their cases; _h h_ the 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; _k_ the 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. _a_ is the smoke-tube

leading from the kitchen to the cupola; _b b b b_ the cast-iron grated

trimming-path, on which the light-keepers stand when they trim the

lamps; _c c_ the reflector-frame or chandelier, on which three tiers of

reflectors are ranged; _d_ the upright shaft; _f f_, &c. the position

of the fountains for the reflector-burners, _g g_ the position of the

shades of red-coloured glass, by which the light is distinguished; _h_

the iron trap-ladder communicating with the trimming-path.

PLATE XIV.

MOVEABLE BEAM CRANE.

[Illustration:

_MOVEABLE BEAM CRANE &c._

_Drawn by A. Slight_

_Eng^d. by A. Wilson_

_PLATE XIV._]

[Sidenote: Pl. XIV.]

Fig. 1. is an Elevation of the Crane. In cranes of the common

construction, the beam is a fixture, and is placed at right angles

to the upright-shaft; but in the machine represented in this Plate,

its attachment is at the lower extremity of the crane, where it is

moveable up and down upon a journal or bolt. This crane is therefore

termed a Moveable-beam-crane. The moveable property of the beam, in

so far as the writer knows, is new, and possesses the advantage of

laying any stone within its range perpendicularly on its site. This,

from the dove-tailed form of the stones at the Bell Rock, rendered

it essentially useful to this work, to which a crane of the ordinary

construction could hardly be said to be applicable. At the Edystone

Light-house this operation was performed by means of Triangular-sheers;

but, from the greater extent of the Bell Rock works, and their greater

depth in the water, such means must have rendered the process of

building extremely tedious.

In reference to this Figure, _a a a_ is the upright shaft of the crane;

_b b_ the cast-iron foot into which the lower journal of the shaft was

stepped; _c_ the cap into which the upper journal works, and into which

two of the hooks _d d_ of the four guy-ropes _x x x x_ were entered,

for commanding the top of the upright-shaft. From the immersed state of

these cranes, while the building was low in the water, a guard-plate

was introduced, and bolted to the cap, which laid hold of a collar

raised round the journal, to prevent the cap from being unshipped by

the waves; _e e_ is the moveable beam, formed and built of two strong

pieces of oak timber, connected in the centre by a serpentine row of

bolts. This beam was mounted at the upper and lower extremities with

strong cast-iron plates; _f_ marks the cast-iron sheers or cheeks,

fixed to the bottom of the upright shaft, into which the moveable beam

works upon the journal or bolt _g_.

In order to direct the strain of the main purchase-chain _h h h h h

h_ passing over the cheek pulley _i_ fixed upon the shaft, and to

prevent its effect from bringing home the moveable beam _e e_ to the

upright shaft, a martingale or tail-block _l_ is introduced and made

fast to the shaft at _m_. When the purchase-chain is not in action,

the block _l_ is suspended from the small chain at _n_, which prevents

it from falling too low, and thereby deranging the position of the

purchase-chain. That the beam may be made applicable to laying the

stone marked _k_, at the foot of the crane, or at the utmost reach of

the beam, a chain or purchase marked _o o o_, is introduced, which

also passes over a cheek-pulley _i_ on the opposite side of the shaft.

By this additional apparatus the beam is capable of being elevated

or depressed at pleasure. The handle marked _p p_, with its pinion

and connecting wheel _q q_, and larger wheel _r r_, together with

its intermediate pinion, form the main purchase, and exert a force

calculated at the rate of about 98 to 1. When a smaller weight was

to be lifted, and greater speed wanted, the handle was transferred

to the axle _s_, whose pinion being always in gear with the wheel _r

r_, produced an accelerated motion, with a power in the ratio of 20

to 1; at the same time, the handle _t t_, with its pinion in action

with the wheel _u u_, worked the beam _e e_, so as to lay a stone

perpendicularly with the greatest facility within any part of its range.

Fig. 2. is the cast-iron tripod, used as a prop to the moveable beam,

when applied as a lever, for lifting the crane; _a a a_ mark the

foot, _b_ the cross head, having a stud which works into a circular

hole perforated in the top of the tripod. By this simple apparatus,

the crane could be moved and shifted either perpendicularly or

horizontally, with a facility which added greatly to the conveniency of

the operations. When the tripod was applied to use, it was placed under

the heel-plate of the moveable beam marked _v_, and when rested upon

it, the beam became a lever of great power.

Fig. 3. is an Elevation of the Working-gear of the Moveable Beam-Crane.

_a a a_ is the upright-shaft, as in Fig. 2.; _b b_ the cast-iron foot;

_c_ the cap with its guard-plate; _d d_ guy-hooks for commanding the

top of the shaft; _f f_ the edges of the sheers or cheeks, for the

heel of the moveable beam; _g_ the bolt or journal on which the beam

is moveable; _h h_ the purchase-chain; _i i_ the cheek pulleys; _o o_

the moveable beam-chain; _p p_ the two main purchase-handles; _q q_

the smaller wheel of the main purchase; _r_ the greater wheel, with

the intermediate pinion _w_, connected with the axle _s_ of the wheel

_q q_. The handles and pinion _t t_ are connected with the wheel _u

u_, for working the moveable beam-purchase; _x_ is the drum or barrel

for the main purchase-chain; _y_ the barrel of the purchase-chain of

the moveable beam.

Fig. 4. is a Section, shewing the connection of the purchases for

working the beam, and lifting the weight: the axle _s_, of the lesser

wheel _q_, with its intermediate pinion _x_ of the main-purchase, work

through the eye or centre of the wheel _u u_, and barrel _y_ of the

beam-purchase. _x_ and _r_ refer to the corresponding letters in Fig. 3.

Fig. 5. is an Elevation of the Winch-machine. The machines, used for

the various purposes of landing the materials and raising them to

the top of the building, were framed or made of cast and malleable

iron. _a a a a_ are the cheek plates or frames in which the axles of

the machinery work. Those employed upon the Rock were fixed down by

means of spear-bolts, to four bats, as shewn at _b b_; but in other

situations they were fixed by straps of iron to beams of timber. The

cheeks _a a a a_ were connected by means of three strong bolts passing

through hollow tubes, which butted against the inner sides of the

cheeks and kept them in their places. The large wheel marked _c c_

measures 3 feet 3 inches in diameter, and the smaller wheel _d d_ is

2 feet 6 inches: these, with their respective pinions, of 6 inches in

diameter, exerted powers respectively of 20 to 1, and 98 to 1, being of

a size similar to the cranes; as one set of wheel and pinion patterns

were made to answer the several machines employed at the work. Letter

_e_ is one of the handles connected with its axle and pinions, which,

at pleasure, is made to work with a double or single purchase, by

simply slipping the axle out and into gear with the larger and smaller

wheels.

Fig. 6. is a Plan of the Winch-machine. _a a a a_ is the sole of the

frame, shewing the bat-holes for fixing it down; _c_ is the large, and

_d_ the small wheel, with its axle; _e e_ the handles, with their axle

and pinions _f f f_; letter _g_ is the barrel attached to the axle of

the large wheel, with part of the purchase-chain; _h h_ is the axle of

the small wheel and intermediate pinion; and _i i_ one of the hollow

pipes through which the bolts pass for connecting the two cheeks or

frame of the machine together.

Fig. 7. refers to a machine fixed to the walls of the Provision-store,

for raising the stores from the railways to the entrance-door, as

pointed out in Plate XVI. _a a a a_ a section of part of the walls of

the Provision-store, in which a hole _x x_ is perforated, and lined

with a copper tube, for the passage of the purchase-chain; _b_ is

the pulley, with its case, over which it works; _c c c_ is the frame

of the machine; and _d_ the handle, with its bevelled pinion. The

distinctive feature of this apparatus is the vertical motion of the

barrel, by which it receives and discharges the chain always at the

same point; the direction also of the chain may thus be altered almost

close to the barrel, which in this case was the chief desideratum. To

effect this purpose, the barrel is made to move vertically upon the

axle _f_, by means of a screw _y_, upon its lower end, which works

into a corresponding screw-rack _g_; in its operation, the wheel _h h_

is worked by the cylindrical upright-pinion of brass, marked _i_. The

two pairs of bevelled wheels, supported upon the small intermediate

frame _l_, are introduced, for applying a double or single purchase,

according to the load to be raised.

PLATE XV.

FOUNDATION-PIT, OR EXCAVATED SITE OF THE LIGHT-HOUSE.

[Illustration:

_FOUNDATION PIT OF THE LIGHTHOUSE._

_Drawn by J. Slight._

_Eng^d. by W. H. Lizars_

_PLATE XV._]

[Sidenote: Pl. XV.]

Fig. 1. is a Plan of the site of the Light-house, and of the ground

or _imperfect course_, in readiness for receiving the first _entire

course_ of the building, represented in Plate XIII. Fig. 1. The dark

shaded figures delineated upon the Plan in Plate XV. represent the

stones of the ground-course, consisting of 18 detached pieces, which

vary in their forms according to certain irregular holes in the Rock.

From the same cause, the stones of this imperfect course vary in

thickness from 6 to 18 inches. The situation of the Foundation-stone

will be seen from its having the year of our Lord 1808 cut upon it, as

noticed at page 237. The four exterior stones, which are cut somewhat

of a dove-tail form, are of a lighter shade being granite, while the

14 interior pieces, being of sandstone, are of a darker shade. The

dark shading on the northern side of the Plan represents merely the

shadow of the higher parts of the Rock round the excavated site of the

Light-house.

Fig. 2. is a Section of the Foundation-pit, upon the line A B, varying

in depth from 18 inches to 5 feet, representing also the dip or

inclination of the strata; while the dotted lines above show the form

of the lower part of the Light-house.

PLATE XVI.

ELEVATION AND SECTION OF THE LIGHT-HOUSE.

[Illustration:

_ELEVATION AND SECTION OF THE BELL ROCK LIGHT HOUSE._

_Drawn by D. Logan_

_Eng^d. by W. H. Lizars_

_PLATE XVI._]

[Sidenote: Plate XVI.]

Fig. 1. is an Elevation of the Light-house, with the brazen-ladder

leading up to the entrance-door. Part of the Rock and railways are

seen, on which several figures are at work, landing stones from a boat,

as at low-water of spring-tides. The small aperture bored through the

outward wall between the door and the window of the Light-room-store,

is for the passage of the chain for raising the stores, as described in

Fig. 7. Plate XIV. The two leaves of the entrance-door are shewn folded

back upon the walls. The first window above the door seen in this view

of the building, is that of the Light-room store; the second is one of

the bed-room windows; and the third is in the Library; immediately over

this are the cornice and balcony-rail, through which last is seen the

Light-room door, with the alarm bells on each side. Through the glazed

sashes, the reflectors are seen arranged upon the chandelier, connected

with the revolving apparatus. On a level with the lower part of the

cupola is the signal-ball. On the ensign-staff a flag is hoisted, with

a light-house in the field, used as a complimentary signal in the

service of the Northern Light-houses.

Fig. 2. is a Section of the Light-house, shewing parts of the Rock and

ground-course. _a a_ show part of the railways; _b_ the brazen ladder

leading to the entrance-door, which is marked _c_. In the central

part of the solid of the building is shewn the cylindrical drop-hole

_d d_, which passes through the centre-stones of each course, and

forms part of the range of the machinery-weight. On each side of the

drop-hole, throughout the solid, and walls of the stair-case, are seen

the stone-joggles _e e_, &c. as they occur in the several courses,

and were noticed in the description of Plate XIII. Figs. 1. and 2. At

the entrance-door a figure is represented receiving stores into the

house. Immediately behind him, one of the leaves of the inner door,

of brass, appears folded back into its recess in the wall, the upper

part being glazed with plate-glass, for the admission of light to the

stair-case. In continuation of the range of the machinery-weight above

alluded to, and extending between the solid and the ceiling of the

provision-store, a column of cast-iron, marked _x x_, passes up through

the well-hole of the stair. The provision store, with which the stone

stair communicates, is formed by a scarsement of the walls at the level

of letter _f_, on which the water-cisterns, lockers for provisions,

and coal magazine, are ranged. Over these a stage or platform of cast

iron is erected, on which a figure is seen at work at the machinery for

raising the stores from the railways to the entrance-door of the house.

The purchase-chain of this machine passes over the pully at _g_, as

described in Plate XIV. Fig. 7.

The next apartment in ascending the oaken trap-ladders leading

through the several apartment, is the Light-room-store, marked _h_,

occupied chiefly with 7 copper oil-cisterns, which are strengthened

with polished brass bars forming the front into pannels. This, and

the several apartments above are partitioned off from the stair with

a pannelled framing of oak. The kitchen _i_, over the store-room,

is chiefly occupied with the fire-place, (though not seen in this

section), which, with its cast-iron pipe or chimney ascending through

the different rooms to the cupola, stand free, or are not embedded in

the walls of the house. On the right-hand side of the kitchen a figure

is seen at the cook’s table and lockers; and on the left are seen the

oaken trap-ladder set close to the wall, and the lockers, by which it

is partitioned off from the apartments. A similar arrangement takes

place in the bed-room marked _h_, occupied chiefly with the oaken bed

frames, described in Fig. 6. Plate XIII. The apartment marked _l_ is

the Strangers’-room or Library, which contains a small collection

of books. The furniture is of oak timber, executed in Mr Trotter of

Edinburgh’s best style. The walls were painted by Mr Macdonald of

Arbroath, in handsomely decorated pannel-work; and from the dome an

antique bronze lamp is suspended. The upper apartment _m_ forms the

Light-room and Lantern, rendered fire-proof, as every thing is of

stone or metal, excepting a small oaken table and chair for the use

of the light-keeper on watch; accented _m´_ is the copper-ball, shown

as hoisted for the signal “All is Well.” The reflecting apparatus and

revolving machinery with which the Light-room is occupied, will fall to

be described under Plate XX.

PLATE XVII.

BALANCE-CRANE.

[Illustration:

_BALANCE-CRANE._

_Drawn by J. Slight_

_Eng^d. by A. Wilson_

_PLATE XVII._]

[Sidenote: Pl. XVII.]

Fig. 1. is an elevation of the Balance-Crane, constructed for building

the upper part of the Bell Rock Light-house, when the guy-ropes of the

Moveable Beam-crane, became “too taunt,” as sailors express it, or were

too near the perpendicular, thereby rendering the machine unstable.

To remedy this, the crane alluded to was kept in equilibrium by a

back-weight of cast-iron, so adapted as to counteract the varying load

upon the working arm or beam. The elevation here represented is the

same in principle with that used at the Bell Rock, but differs somewhat

in form, agreeably to more recent improvements made in order to adapt

it to the erection of the Carr Rock Beacon. _a a_ is the cast-iron foot

or socket, into which the upright central column _b b_ is stepped,

being a tube of cast-iron put together in convenient lengths, with

flush joints, after the manner of spiggot and faucet, fitted by turning

and boring. The centre column of this machine might have been carried

to any suitable or convenient height, by adding length to length, as

the building advanced, without once moving the foot; but at the Bell

Rock, not more than three lengths of from 6 to 9 feet were generally

in use. _c c_ represent a malleable iron cross-head, which was stepped

into the void of the central shaft or column, when the body of the

crane was to be elevated. This operation was accomplished simply by

hooking the main-purchase and traveller-chains into the eyes _c c_,

when the machinery of the crane was employed with great facility as

a locomotive power for lifting itself; _d_ is a stone supposed to

be suspended in the purchase-chain; and _e_ is the back-weight or

counterpoise, which, at pleasure, was moved horizontally along the

balance-beam marked _f_, consisting of two plates or bars of malleable

iron; _g_ is the working-beam, of similar construction; _h-h_, _h-h_,

_h_, _h_, are four of the eight main and secondary suspending ties

of malleable iron, applied from above, in order to leave the lower

part of the crane unobstructed. This afforded great conveniencey

particularly at the Carr Rock, and also at the erection of the Melville

Monument of Edinburgh, where the space for the workmen was extremely

circumscribed, the shaft of the column not being more than 10 feet 6

inches in diameter towards the top. The main ties _h-h_, _h-h_, at the

lower extremity, were made fast by the same bolt which passes through

the pulleys _f_ and _g_, while the upper ends were bolted into a

collar, which is seen clasping the central column at _i i_. This collar

is fitted with four friction-rollers, one of which is seen at _k_.

_l l_ shew two of the four principal rods or bars of malleable iron

for connecting the Crane, and answering the purpose of a king-post to

the ties _h-h_, _h-h_, of the frame-work; _m m_ mark two of the four

braces forming a connection between the main ties and arms or beams

of the crane. The cheeks _n n n_, which contain the train or series

of wheels of the crane, are of cast-iron. In the formation of these

cheeks they present as little obstruction to the workmen as possible,

while, at the same time, they embrace the various journals or axles of

the machinery. The upper part is connected by a square framed collar

of malleable iron, seen at Fig. 5. fitted with friction rollers, and,

like the collar above alluded to, works round the central column. This

lower collar is connected with the cheeks of the crane by studs passing

through them, and fixed by means of screw-nuts. The lower part of the

frame is in like manner connected with the upright shaft, by a collar,

which is moveable upon friction-balls of cast-iron, contained in a

circular race or chamber _o o_, a plan of which, shewing the balls,

is given at Fig. 3. The whole machine thus fitted, is supported upon

the central shaft by means of the cutter or spear-bolt _p_. The winch

handle marked _q_, is that with which the main-purchase chain _r_,

passing over the pulley _s_, is worked, from which the stone _d_ is

suspended. Connected with the main-purchase, a wheel, marked _w_, of

30 inches diameter, is worked by a pinion of 5 inches, mounted upon

the axle of the handle _q_, producing a power or force in the ratio of

18 to 1; this power may at pleasure be increased by throwing another

pinion on the same axle into gear with the wheel marked _n´_, of 16

inches diameter.

The handle _u u_ is connected with the main-traveller _s_,

balance-chain _v v v_, and their traveller _x_, to which the

back-weight _e_ is appended. The main-traveller wheel _y_ measuring 36

inches in diameter, with its pinion of 5 inches marked _u_, exerting

a power in the ratio of 21 to 1, serves to work the main-traveller.

On the same axle with the pinion _u_, is another pinion, working two

wheels, as seen in Fig. 4, which gives motion to the balance-traveller.

These two combinations of wheels are so arranged, that, by working the

small levers _m_ and _z_, they can with facility be thrown in and out

of gear, so as to work the traveller either together or separately. The

whole weight of the Balance-crane, here represented as resting upon the

oaken beams A A B, on one of the floors, weighed about three tons; but

the balance and working beams having latterly been made of malleable

iron, and the other parts of the machine considerably lightened, it did

not exceed more than two tons in weight when used at the Carr Rock.

Fig. 2. The cast-iron foot of the Crane is necessarily very ponderous,

and weighs about half a ton. The toes _a a a a_ extend about 5 feet;

_b b b b_ are the bat-holes for fixing it down, in case of its at

any time getting off the balance, but, in practice, these bats were

seldom applied. When the crane was supported over the void or central

holes left in the floors during the progress of the work, the toes

were clasped to the oaken beams A A B, formerly noticed, represented

as resting on one of the upper floors of the building, B, in Fig. 1.,

being a cross section of the lower beam, with its levelling-block; _c_,

the socket for the central column, or upright shaft, is 10 inches in

diameter at the upper side, and diminishes to 9 inches, that the column

may become fixed into it by the pressure of the machine.

Fig. 3. _o o_, in reference to Fig. 1., represents the collar-chamber,

filled with cast iron friction-balls, upon which the body of the

machine rested, and traversed horizontally with the greatest facility.

Fig. 4. is a perpendicular section taken across the cheeks and wheels

with a view to shew the train of the machine more fully. _a a_ is the

foot; _b b_ two lengths of the central column, or hollow cylinder,

with their spiggot and faucet joint in the middle, shewing also that

the metal is about an inch and a quarter in thickness; _c c_ the

cross-head, referred to in Fig. 1.; _i i_ the upper collar, shewing its

connection _l l_ with the king-posts or main rods; _n n_ the cast-iron

cheeks, with the lower collar, and the chamber for the friction-balls;

_o_ the cutter or spear-bolt, which supports the whole machine; _u u_

the traveller handles, the main-purchase handles not being embraced

in this section; _y y_ the wheels and pinion of the main traveller;

accented _y´ y´_ the wheel and pinion of the balance-traveller _x x_.

In the central part of this figure, the barrel or drum _x_ of the

traveller-chains is seen, and also the middle collar _x_, with its

friction rollers.

Fig. 5. is a plan of the body of the Crane, in reference to Fig. 1.

_b_ is a cross section of the central column, seen in connection with

the upper collar _d d_; with a stone suspended from the end of the

main-beam; _e e_ the back weight suspended from the balance-beam:

_f_ and _g_ the extremities of these two beams; _h´ h´ h´ h´_ four

horizontal braces, extending from the cast-iron cheeks to the middle of

the beam. Letters _n n n n_ the cast-iron cheeks of the body; _q q_ the

main purchase-handles; _r_ the main-purchase chain; _s_ its traveller;

_t t_ the traveller-chain; _u u_ the traveller handles; _v_ the balance

traveller-chain; _x_ its traveller; _w w_ the main-purchase wheels;

_y y_ the traveller wheels; _z_ the lever, for stopping the main

traveller-wheel.

Fig. 6. is a plan of the frame work of this machine: _b_ is the upright

column, with the upper malleable iron-collar, shewing its connection

with the king-posts _l l_ of Fig. 1.; _f_ and _g_ are the extremities

of the main-purchase and balance-beams; _m´ m´_ the horizontal rods

connecting with the main-ties; _h h_, &c. the main ties; _h´ h´_, &c.

the horizontal braces; _n n n n_ the cheeks or frame of the wheels and

machinery, with the two great bolts marked _n´ n´_, by which the frame

was principally connected; these bolts being passed also through the

interior ends of the balance and working beams.

PLATE XVIII.

GENERAL VIEW OF THE WORKS.

[Sidenote: Pl. XVIII.]

This Plate gives a Perspective view of the Works at the Bell Rock,

taken by Carse, at low-water of spring-tide, from on board the

Light-house Yacht, in the month of July 1810, at the distance of about

half a mile in a southern direction from the Rock, and is here reduced

from a picture in the possession of the writer. In the fore-ground a

boat is introduced, approaching the Rock with a party of strangers,

and another is leaving it, supposed to be receiving orders from a

figure on the Rock, who is pointing towards her. In the back-ground,

the shipping belonging to the work is introduced, viz. the Tender,

a Schooner, and the stone-vessels Smeaton and Patriot, with the

Floating-light. In the distance, the hills of Fife and Forfar are seen,

but the entrance to the Firth of Tay is intercepted by the beams of the

Beacon-house. Between the Light-house and Beacon, or in the direction

of the chain and stone suspended from the Wooden-bridge, the ruins

of the Abbey of Aberbrothwick are seen. The operation of landing the

stones with the sheer-crane at Duff’s Wharf, toward the right, is seen;

and also one of the moveable beam-cranes, in a working position, at

Pitmilly Wharf, on the left.

The principal lines of the railways, with waggons, and a variety of

operations which are in progress, form a very busy scene upon the Rock.

On the praam-boat’s deck, toward the left of the picture, Captain

Wilson, the landing-master, is represented with a speaking-trumpet in

his hand; and at the foot of the Beacon-house, Mr Francis Watt, foreman

mill-wright, is supposed to be giving directions about some operations.

On a level with the entrance-door of the Light-house, the bridge

of communication is situate, and four blocks of stone are seen, in

progress of being raised from the railways to the top of the building,

viz. one is suspended from the winch-machine upon the bridge, another

from the beam projecting out of the window of the Light-room store, a

third from the bed-room, and a fourth from the Balance-crane, which

last is about to be laid upon the parapet-wall of the Light-room. Here

the operations are going forward under the direction of Mr Peter Logan,

foreman builder. In the open gallery of the Beacon-house, Mr Dove,

the foreman smith, is seen at work, with the smoke of the respective

fires of the forge and cook-room. The tackle, distended in a diagonal

direction, from the balcony of the Light-house, to the mortar-gallery

of the Beacon, shews the mode of raising the mortar-buckets. The figure

on the small scaffold suspended from the balcony, shews the method of

pointing the walls with Roman cement.

PLATE XIX.

ENTRANCE-DOOR, WINDOWS, HINGES, AND THUNDER-ROD.

[Illustration:

_ENTRANCE DOOR, WINDOWS, HINGES AND THUNDER ROD._

_Drawn by J. Slight_

_Engraved by R. Scott_

_PLATE XIX._]

[Sidenote: Pl. XIX.]

Fig. 1. represents part of the outward wall A A A A, and entrance-door,

one leaf or half of which is open, and the other shut; _a_, one of the

handles for opening and shutting it, connected with a thumb-latch; _b

b_ the bolts for securing the door when shut; _c c c c_ the hinges;

_d d d d_ the brass guard-plates at top and bottom of the door, for

defending the timber. The door is framed of fir-wood, and measures 6

feet 4 inches in height in the clear, besides the brass-checks upon

which it shuts at top and bottom, which are of 2 inches in depth, as

shewn at _e_ in Fig. 1., and also by an end view in Fig. 2. The two

leaves form a common breadth of 2 feet 10 inches in the clear. A

cornice of brass is formed on the lintel of the door answerable to an

eaves-drop, in which a friction roller _h_ is placed, for the chain

of the crane, with which the stores are raised. The door, when shut,

finishes flush with the building, and is therefore of a circular form,

framed and double lined, the whole being put together with white-lead

paint: each leaf measures 5 inches in thickness at the hinge side, and

diminishes to 2½ inches at the meeting edges, as will be understood

by examining the section in Fig 3. When the leaves of the door are

thrown open, they are kept in their places by catch-hooks of brass, to

prevent gusts of wind from shutting them suddenly; _f_ shews a moveable

handle or piece of brass rail, within the passage, for laying hold of

in stepping off the brazen ladder to enter the house; _g_ shews the

upper extremity or highest step of the ladder, which terminates at the

sill of the door.

Fig. 2. shews the relative position of the outer and inner

entrance-doors, in which _a a a_ is an end view of the former; _b b b

b_ a front view of one of the leaves of the inner brass door; _e e_

the outer door check, faced with plates of brass; _f_ the moveable

handle or rail, for the greater conveniency of entering the threshold;

_g_ the termination and upper step of the brazen-ladder, attached to

the building, for communicating with the Rock. _h_, section of the

cornice and friction-roller. The passage being only 2 feet 10 inches

in breadth, the rails or moveable handles _f_, on each side, are made

to slide into brass sockets _i i_, sunk into the walls, and, like the

inner door, are flush with the wall when not at use. _k k_ the sockets

for the centre-pin hinge of the inner-door.

Fig. 3. is a cross section of one of the leaves of the entrance-door,

shewing the position of the brass-case of the hinge-bat, as it lies

in the building. A A part of the walls, B B part of the side-walls

of passage, C C part of the surface of the outward wall. _a a a a_ is

the brass-case, containing the Lewis-bat-tails or palm of the hinge,

(described in Plate XI. Fig. 3.); _b b b b_ the working-tails; _c c_

the outside lining; _d d_ the inside lining; _e e e_ the frame-work of

the door, with the bolts and nails connecting the hinges; _f_ the joint

of the hinge, shewing the journal pin-hole; _g_ the half-check joint of

the door.

Fig. 4. represents a front view of the door-hinges, lettered in

reference to Fig. 3. _a a a a_ is the brass box or case, which is built

into the wall for containing the palm-end of the Lewis-hinge; _b b_ is

the exterior or working tail, with its screw bolt and nail holes; _f f

f_ the double-joint and slip-pin.

Fig. 5. is a cross section of the Lewis-box on the line A B of Fig. 4.

with its dove-tail feathers; _a a a a_ shew the parts of the Lewis-bat

_b c d_, as it lies in the box, which is built into the wall.

Fig. 6. represents a longitudinal section of the box and palm of the

hinge, shewing its position, in reference to the cross section in

Fig. 5. _a a a a_ is the brass box; _b_ and _d_ are the dove-tailed

compartments of the palm; _c_ is the tongue or locking-piece; _e_ the

pin hole, perforated in the locking-piece, for drawing the parts of the

palm in the event of the joint wearing and requiring to be renewed;

_f f_ is the slip pin-hole in the other two parts of the palm of the

Lewis. The weight of one of the entire hinges of the door, with its

Lewis-tail and brass-box was 56 lb., and consequently the four sets for

the door weighed about 2 cwt.

Fig. 7. shews the elevation of one of the windows of the Light-house,

with part of the exterior wall marked A A A A; one-half of one of the

storm-shutters, marked _a a_, is closed, and the other marked _c c_,

is open; _b_ is a bar of brass, which folds across the window when

the shutters are closed, and is used as a stretcher, for preserving

them in their places when opened. It will be observed by comparing the

close shutter _a a_ with the open one _c c_, that they are double or

cross boarded; they are also fastened with hammered copper nails; _d_

is the clasp used as a handle, which also locks the shutter; _e e e e_

the ends of the dove-tailed hinges as they appear projecting through

the walls; _f f f f_ the working-tails of the hinge, forming at the

same time the guard-plate of the shutters, as described in Fig. 1.

Letter _g_, upon the open shutter, shews one of the brackets connected

with the stretching-bar _b_, for keeping them open, as will be better

understood by examining the following Figure.

Fig. 8. is a plan of one of the window-sills, and a section of one of

the storm-shutters, with part of the walls A A, shewing the position of

the Lewis-bat cases; _a_ and _c_, the storm-shutters in an open state;

_b_ the stretching-bar in its place, when the shutters are open; _e e_

the exterior ends of the Lewis-bats, with their cases _é é é é_, which

are built into the wall, and, together with the other parts of the

hinge, weigh about 28 lb., or 1 cwt. for each set, being one-half of

the weight of the door-hinges; _g g_ the brackets connected with the

stretching-bar; _h h_ the check in the wall for receiving the shutters;

_i i_ the stiles or framing of the outer-window, which opens in two

leaves; _k k k_ the framing and case of the inner window, which slides

up and down in one sash; _l l_ the balance-weight of the inner-window.

Fig. 9. is a perpendicular section of one of the windows, shewing the

triple mode of shutting them during stormy weather. A A a section of

a part of the walls. _a a_, the storm-shutter; _h h_ the check in the

building for its reception; _i i_ the frame of the outer-window; _k k_

the inner-window; _l_ the case into which the inner-window drops when

not in use.

Fig. 10. A A is a section of part of the thunder-rod and outward wall.

_a a_ shew part of the zones or bond-belts, noticed in Plate VII. Fig.

7., and Plate XVI. Fig. 2.; _b b_ the brass-bats let into the wall, for

attaching the thunder-rod with the screws _c c_, which vary from 2 to

3½ feet apart; _d d_ the thunder-rod, made of the best gun-metal,

and weighing at the rate of 7 lb. per lineal foot in the range of the

sea, or from the Rock to the entrance-door, and from thence to the

Light-room, at the rate of about 4 lb. per lineal foot; _e_ is the

joint technically termed Half-checking, by which the pieces, of about

7 feet in length, are connected by two screws at each joint, as shewn

in the section. This rod, which extends from the Light-room to the

Railways, forms an exterior Conductor, while another, which is not seen

here, is connected with the chimney, brazen ladder and railways, and

completes the interior conducting process.

PLATE XX.

BALCONY AND LIGHT-ROOM.

[Illustration:

_LIGHT-ROOM AND BALCONY._

_Drawn by W. Lorimer_

_Eng^d. by J. Moffat Edin^r._

_PLATE XX._]

[Sidenote: Pl. XX.]

Fig. 1. _a a_ represent the Balcony or walk round the exterior of the

Light-room; _b b_, &c. the brass bats, made in the form of the paw of

an animal, are used for supporting the balcony-rail; _c c_ the two

Alarm-Bells; _d d_ the hammers by which they are tolled, during the

continuance of foggy or stormy weather; _e e_ the case for defending

the levers which work the hammers; _f f f_ the stone parapet-wall of

the Light-room, of an octagon form on the outside, and circular within;

_g g g_ the cast-iron sill of the lantern; _h h_, &c. the angular

cast-iron pillars or mullions, formed by the junction of the contiguous

parts of two of the sash-frames; _i i_, &c. the smaller upright bars,

forming the astragals or principal divisions of the sash-frames; _k k_,

&c. the grated cast-iron trimming-path; _l_ the smoke-tube, leading

from the kitchen through the cupola or roof; _m_ the trap-ladder

leading from the light-room-floor to the trimming-path; _n n_ the

reflector frame or chandelier, on which are seen 8 of the reflectors

marked _o o_, &c. with their oil-fountains _p p_, &c. the whole being

framed or built upon the moveable upright-shaft _q_.

Fig. 2. is a section of the dome-roof of the library, the parapet-walls

of the light-room, the lantern and its cupola. _a a_ is the balcony,

shewing the position of the Alarm-Bells, and cast-iron rail; which

last is made in the form of meshes, with a massive coping of brass;

_f f_ the parapet-wall of the light-room; _g g_ the cast-iron sill of

the lantern; _h h_, &c. the angular pillars or mullions; _i i_, &c.

the astragals; _k k_ the grated trimming-path; _l l_ the smoke-tube

passing through the cupola; _n n_, &c. the reflector frame, on which

20 reflectors, marked _o o_, &c. with their fountains _p p_, &c. are

ranged; _q q_ the upright shaft upon which the reflector-frame is

built, and which is connected with the revolving-machinery; _r r_,

&c. the copper smoke-tubes from the respective reflectors; _s s_ the

cross-bars supporting the upright shaft at _t t_; and _u u_ a copper

receiver for any accidental drop from the upper or central ventilator

marked _v´ v´ v´_, while the letters _v v v v_ mark the exterior line

of the cupola; _w w_ the external cornice of the lantern, used as a

gutter or eaves-drop, from which the rain-water is conducted off the

roof in small pipes to the parapet-wall of the Light-room; _x x_ the

handles which the light-keepers lay hold of; and _y y_ the exterior

grated path on which they stand when cleaning the outside of the

windows; _z z z_ the steps fixed to the parapet of the Light-room and

lantern, by which they ascend to the cupola; _á á_ the copper-tube,

used as a flag-staff; _b´_ the signal-ball, hoisted daily at the

Light-house, between the hours of 9 and 10 o’clock in the morning, when

“All is Well:” The ropes for raising this ball pass over two pulleys

fixed in the top of the flag-staff, and are let down through the

interior of it: _c´ c´_ part of the cornice of the building, shewing

the mode of connecting the horizontal and perpendicular joints of the

Library-roof; _d´ d´_, &c. shew the zone or bond-belt worked in the

beds of the courses, as mentioned in the description of Plate VII. Fig.

7., Plate XVI. Fig. 2., and Plate XIX. Fig. 10.; _e´ e´_, &c. from the

enlargement of the scale, shews more distinctly than any of the other

diagrams, the mode in which the horizontal joggling of the joints of

the Light-room and other floors of the building is accomplished; _f´_

the door leading from the Light-room to the balcony; _g´ g´ g´_ the

case and machinery for causing the Reflecting-apparatus to revolve, so

as to distinguish this Light from others upon the coast; _h´ h´_, &c.

the connection-rods, with their various wheels of communication, for

changing the direction, and giving motion to the Bell-hammers; _i´ i´_,

&c. the brass tubes for supplying fresh air to the Light-room; _k´_

the Time-piece, set upon brackets fixed in the wall, for regulating

the Revolving-machinery, and for the direction of the light-keepers

in changing the day and night watches; _l´_ a bracket of cast-iron

attached to the machinery-case, for supporting the foot on which the

upright shaft works; _m´_ the bevelled wheels connected with the

interior machinery and upright shaft, which can be thrown out and into

gear at pleasure.

In describing the Reflecting-apparatus delineated in Fig. 3., we may

notice, that, agreeably to the laws of optics, almost inconceivable

effects are produced by the use of these specula, by which portions

of a sphere are illuminated, whose radii seem to be proportionate to

the elevation of the radiant point, and the particular state of the

atmosphere. Taking these conditions into view, the Revolving-light at

the Bell Rock has been seen, from an elevated position on the land, at

the distance of about 35 miles. According also to observations which

have been made upon Sumburgh-Head Light, in Shetland, which is elevated

about 300 feet above the medium level of the sea, it has been seen from

a ship’s deck at the distance of about 27 miles. Similar effects are

also expected to be produced with light refracted through glass-lenses.

These, it is believed, are about to be made trial of in the Tour de

Corduan, at the entrance of the Garonne, with what are termed Polygonal

Lenses, being one large lens, built or composed of a number of small

lenses, as suggested by Dr Brewster, in the Edinburgh Encyclopædia, in

the year 1811, under the article “Burning Glass.”

Fig. 3. _a a a_ represents one of the reflectors, measuring 25 inches

over the lips, in a finished state, as now in use at the Bell Rock and

Northern Light-houses in general. They consist of a circular sheet

of copper, measuring, when flat, 26¼ inches in diameter; weighing

11½ lb. on an average; and plated with silver in the proportion of

6 oz. to each pound avoirdupois of copper. These plates are formed

into the Parabolic curve by a very nice process of hammering, and

afterwards set into a bezil or ring of brass; _b_ is the lamp, being

an Argand-burner, with a circular wick, of about three-fourths of an

inch in diameter. If the parabolic figure of the reflector could be

constructed and its form preserved with perfect accuracy, the magnitude

of the flame of the lamp employed for its illumination would be of

less importance. From certain experiments now in progress, the writer

is in expectation that considerable improvements may be introduced,

in the construction of reflectors, and that additional modes of

distinguishing the Light-houses on the coast will be obtained. _c_ is

a cylindrical fountain of brass, which contains 24 oz. of oil, suitable

for the consumpt of the lamp for about 18 hours, or equal to its

expenditure during the longest night in Shetland. A great improvement

upon the Burner-apparatus has lately been introduced into the Northern

Lights, by affording the light-keeper an opportunity of cleaning the

reflector without the obstruction of the burner: the oil-pipe and

fountain of the burner is connected with the rectangular frame _d_,

and moveable in a perpendicular direction upon the guide-rods _e_ and

_f_, by which it can be let down and taken out of the reflector, by

simply turning the handle _g_, as will be more fully understood by

examining Fig. 5. In this way, the necessity of lifting the reflector,

or deranging its focus, is avoided. Although a properly trimmed lamp,

especially upon the Argand principle, does not emit smoke, yet the

heat and effluvia arising from it, are sufficient to oxydise or sully

the upper part of the reflector: an aperture of an elliptical form,

measuring about 2 inches by 3 inches, is therefore cut in the upper

part of the reflector, to which the copper-tube _h_ is attached. Letter

_i_, immediately behind the reflector, refers to a cross section of the

main-bar of the chandelier or frame on which the reflectors are ranged,

each being made to rest upon three knobs of brass, one of which, as

seen at _k k_, is soldered upon the brass band _l_, that clasps the

exterior of the reflector.

To distinguish the Bell Rock Light from others on the coast, as noticed

at page 401, it is made to revolve, and to exhibit periodically

a bright light of the natural appearance, alternating with a red

coloured light. This last effect is produced by means of shades of

red glass, one of which, represented at _m m_, is also set in a brass

bezil, and made to slide horizontally upon two rods marked _n n_, into

corresponding sockets, fixed upon the reflector-frame at _o_, so as

to enable the light-keeper to trim the lamp without entirely removing

the red coloured shade. In the present aspect of the shade, the rods

are drawn out to their full extent; but when set for use, the shade is

pushed in till its bezil and that of the reflector are within half an

inch of each other.

Fig. 4. is a section of the reflector _a a_, shewing the position of

the burner _b_, with the glass chimney accented _b´ b´_, and oil cup

_b_, or receiver for any drop that may fall from the lamp. The letters

_c_, _d_, _f_, and _g_, in reference to the corresponding letters in

Fig. 3., shew the oil-fountain in its place when the burner is in use.

Fig. 5. has reference to the apparatus for moving the burner up and

down, so as to admit freely of the reflector being cleaned. In the

present position, _c_, the fountain, is moved partly down; _d d_, &c.

shows the rectangular frame on which the burner is mounted; _e e_ the

elongated socket-guides; _f_ the rectangular guide-rod, connected with

the sockets on which the perforated check-handle _g_ slides; accented

_c´_ is a cross section of the oil-pipe, where it joins the valve of

the fountain.

Figs. 6, 7, and 8. These three diagrams represent a different mode

of withdrawing the burner from the reflector, for the conveniency of

cleaning it. In Figs. 3, 4, and 5., this is supposed to be done by a

perpendicular motion of the burner; but in Figs. 6, 7, and 8. it slides

horizontally. Fig. 8. is a horizontal section of the reflector _a a a_,

and its apparatus, the letters in which correspond with those of Figs.

3, 4, and 5. The advantages attending this mode, are the rendering of

the apparatus more steady, by its having two points of support upon the

bars _i i_ and _k k_; while its motion is more direct. The part of

the reflector cut out for the admission of the burner in this case,

being that which is partly intercepted by it, little of the reflecting

surface is thus lost; and this mode may therefore be considered an

improvement upon the perpendicular manner of lifting and lowering the

burner.

FRONTISPIECE.

[Sidenote: 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

the _maximum_ height 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 page 519, 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.

VIGNETTE OF SECOND TITLE-PAGE.

[Sidenote: 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 page 64., a _fac-simile_

of 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 page 419.

PLATE XXIII.

DESIGN FOR A LIGHT-HOUSE, SUGGESTED UPON VISITING THE WOLF ROCK SITUATE

EIGHT MILES _S. S. W._ FROM THE LAND’S-END.

[Illustration:

_SKETCHES OF A NEW DESIGN FOR A LIGHT HOUSE._

_Drawn by G. C. Scott_

_Eng^d. by J. Moffat Edin^r._

_PLATE XXIII._]

[Sidenote: 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’s _Architecture 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 page 423, 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 base _a b_, and its parallel _c 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

parallels _a b_, and _c 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 base _a

b_, measures 56 feet in diameter, and parallel _c 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

cubic feet; 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, marked _g g_, is perforated through the building,

for the admission of the purchase-chain. The thickness of the walls

immediately above the solid, marked _c c_, is 12 feet; at the top of

the stone staircase or level _e f_, they are 8 feet, and where the

walls are thinnest, as at _h i_, immediately under the cornice, they

measure 2 feet. _k k_ represents 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, marked _c c c c c c_, which become so many girths to

the course, superseding the necessity both of the dove-tailing system,

and of the cubic joggles described in Plate 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. Letter _d_

refers 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 in Plate 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 which

_a b_ is the foundation course, and, in reference to Fig 6., letters

_c 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.

DIRECTIONS TO THE BINDER.

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 Note

The following printed corrigenda have been incorporated into the text:

CORRIGENDA.

Page 90, line 10. _after_ matter _insert_ rested

---- 414, marginal note, _for_ April _read_ August

---- 516, line 38. -- one of the ---- the two

The 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-drift

ahead and a-head

aisler and aislar

alongside and along-side

Belider and Belidor

blacksmith and black-smith

brushwood and brush-wood

bucky and buckie

Burlington Bay and Burlington-Bay

cast iron and cast-iron

coalfish and coal-fish

coboose and co-boose

cofferdam and coffer-dam

conveniencey and conveniency

Copinsha and Copinsay

coxswain and coxwain

creeking and creaking

daylight and day-light

dovetail and dove-tail

forepeak and fore-peak

freestone and free-stone

halfpenny and half-penny

hawsehole and hawse-hole

Island Glass and Island-Glass

Kinghornness and Kinghorn-ness

Kinnaird Head and Kinnaird-Head

landmark and land-mark

lengthway and length-way

Lewis bat, Lewis batt, Lewis-bat and Lewis-batt

lighthouse and light-house

lightkeeper and light-keeper

lightroom and light-room

manhole and man-hole

millwright and mill-wright

Milnfield and Mylnefield

Mull of Kantire and Mull of Kintyre

oatmeal and oat-meal

overboard and over-board

praam boat, praam-boat and Praam-boat

railway and rail-way

Redhead and Red-head

relaid and re-laid

roadway and road-way

Rubislaw, Rubieslaw and Rubeslaw

Scottish and Scotish

shackle and shakle

shipboard and ship-board

shipmaster and ship-master

shipowner and ship-owner

shipwreck and ship-wreck

skylight and sky-light

staircase and stair-case

Start Point and Start-Point

storehouse and store-house

tie chain and tie-chain

torchlight and torch-light

topmast and top-mast

torchlight and torch-light

Traill and Trail

United Kingdom, United kingdom, and united kingdom

_vice versa_ and _vice versâ_

workshop and work-shop

workyard and work-yard