Building stones, 11th-19th century

Bernard C. Worssam investigates the many types of building stone used in the construction of the Cathedral from the medieval times until Sir George Gilbert Scott’s restoration of the 1870s. Featured in The Friends of Rochester Cathedral Annual Report for 1994-1995.

Rochester Cathedral is built from a variety of types of stone, the lack of any natural source of high-quality building stone in the cathedral's immediate vicinity having, it would seem, been more than made up for by the situation of Rochester on the Medway estuary, which must have facilitated the import of stone from the earliest times.

This account is written in the form of an itinerary. A circuit is first made of the cathedral exterior, for the texture of building stones is best seen when the stone is in a clean, rain-washed condition, while it is only out-of-doors that weather-resistance, always an important property of building stones, can be assessed; marbles, which are polished, are best seen inside a building.

1. Exterior of nave, west front and Lady Chapel.

Some of the earliest masonry of the cathedral exterior is in the north wall of the have, easternmost three bays of the late eleventh to early twelfth century (the rest of the wall having been rebuilt in later periods, though in a similar style).' Also early is 'Gundulf's' tower. The early Norman nave wall bays are mainly of Kentish Rag rubble?, with a few flints and pieces of tufa and Roman brick. They have pilaster buttresses of Caen stone ashlar', a stone best seen on the cathedral west front. The Kentish Rag, or Ragstone*, would have been shipped down the Medway from Maidstone. It is a light grey, hard, finely glauconitic sandy limestone. Some blocks include patches of chert, a hard splintery stone, which like flint is a variety of amorphous (i.e. non-crystalline) silica. The flint itself Occurs as lines of nodules in chalk quarries. Chips of flint are stuck in the mortar

Plate I. In the east range of the cloister, a weathered twelfth-century column of onyx marble, showing undulate bedding.

Plate II. Flying buttress to wall of south choir aisle, by Gilbert Scott, 1875.

Kentish Rag with dressings of Chilmark stone.

seams of the nave wall, an eighteenth to early nineteenth century technique known as galleting.

"Gundulf's' tower? is in a plain Norman style. Its walls are of coursed rubble of Kentish Rag with wide mortar joints. The quoins of its north-west buttress are of squared blocks of tufa, a soft, porous stone formed at springs. Tufa was widely used in the early Norman period in north Kent. The north-east corner of the tower is supported by two massive buttresses, of the fourteenth century but conveniently described here. Their quoins are of a pale grey to deep yellow, very fine grained sandstone from the Hastings Beds of the Weald. The only other use of this stone in the cathedral was for the Anglo-Saxon carved 'Ringerike' stone, found in 1984 built into an interior wall of the west front south-west turret'. The stone may have come from near Tonbridge on the Medway, or equally likely, by sea from Fairlight, near Hastings (note 7, p.9).

On the way to the west front from the tower one sees a different type of sandstone in the massive piers of the Victorian cemetery gateway. Fine-grained and evenly bedded, this is in large blocks exactly 3ft. (0.9m) square. It is probably from the Coal Measures of Yorkshire.

Caen stone is much in evidence on the cathedral west front. Its distinguishing features are its pale yellow colour, lack of internal bedding, and fineness of grain. It is composed of calcium carbonate particles of less than 0.2mm diameter; scattered crystalline calcite grains glint in reflected light'°. The stone was imported into southern England on a very large scale in the twelfth century, and remained in use throughout the Middle Ages. The Victorians also made use of it. The west front was originally almost entirely of Caen stone, but in its 1889-96 restoration and partial rebuilding by John Loughborough Pearson" Weldon stone, an oolite from Lincolnshire, was brought into use 2. The limewash shelter-coat applied to the west front stonework after recent cleaning gives both Caen stone and Weldon stone a uniform vellow colouration, but the two can still be distinguished, the Caen stone blocks being pitted by weathering, and those of Weldon stone flat-surfaced, with lightly incised tooling, diagonal on walling, vertical on columns. The north-west turret was wholly rebuilt by Pearson, after it had already been rebuilt in Portland stone in the eighteenth century. The fine central doorway is nearly all of Caen stone, but with the outermost attached column on its south side, and all bases and plinths of columns, of Weldon stone. The shaft of the outer column on the north side is of onyx marble, an unusual stone better seen in the cloister. The Cathedral's great west window was reconstructed in 1825 in Bath stone'4. This stone, too, can be seen close-to in the cloister. Two statues in niches on either side of the doorway head, of bishops Gundulf and John of Canterbury, were placed there in 1894 by the Freemasons of Kent. The type of stone used was not recorded.

On the wav to the cloister one passes the south wall of the nave, refaced in the nineteenth century with Kentish Rag rubble and much re-used Caen stone. Three Portland stone lancet windows, replacements of larger late Medieval windows, are probably the work of Daniel Alexander in 180115, High above the nave wall rides the late-Medieval clerestory wall, its yellow Caen stonework enlivened with patches of red tiles, beneath a mainly Kentish Rag parapet (the north clerestory wall is similar).

The masons who built the Lady Chapel (possibly in course of completion in squared blocks of kernst Rag with some peroisone the maling n squared blocks of Kentish Rag, with some Caen stone and tufa, on a plinth a large blocks of Kentish Rag ashlar. A little above the plinth, running under the window sills, is a four-inch band of squared knapped flints; there is also a knapper flint facing to the upper parts of buttresses. The windows and buttresses seem

Plate III. The north face of the north-west transept, remodelled by Gilbert Scott

originally to have been of Caen stone, but much of the window stonework has been replaced, mass recesy by Monk's Park stone (a variety of Bath Ston has War Damage repairs in 1956-58'. Most of the buttress quoins were replaced in Portland stone in 1801 by Alexander, who also made good the 'flints in squares!?.

The Portland stone can be examined near ground level. It is an oolite composed of closely packed regular ooliths of 0.3mm diameter; some blocks include much shell detritus. It has proved durable enough, but its stark whitish colour gives a severe effect in combination with the Kentish Rag, which the softer yellow Caen stone would have avoided.

2. The Cloister

In the east range of the cloister, Caen stone was used for the Chapter House facade and for the blind arcading of the dormitory undercroft wall to the south.

Tim Tatton-Brown'8 has drawn attention to shafts of oolitic limestone that flank the three upper windows of the Chapter House, inside and out. Only five shafts remain of the original twelve. They are of a brownish yellow oolite with pronounced shelly streaks, which seems to match the stone of some columns in the crypt (see below).

To the south of the Chapter house, Caen stone blind arcading is backed by roughly coursed rubble stonework of Kentish Rag, tufa, flint and ironstone. Every stone is shown separately in measured drawings by John Atherton Bowen 8. Of particular interest are attached mid-twelfth century columns of Tournai Marble and onyx marble. The former, for example beside the Chapter House doorway, are in a sorry state after centuries of exterior weathering they were not intended to withstand. One has split along a well-marked flat bedding plane. The stone is a dark grey silty limestone from the Carboniferous of Tournai in Belgium - not a type of rock one would expect to find used as a marble', but where well-preserved, as in the twelfth-century font of Winchester Cathedral, or in column capitals from Lewes Priory, now in the Anne of Cleves Museum in Lewes, it takes an attractive glossy black polish. Two weathered onyx marble2 columns remain in the arcarding (see Plate I), and at the south end is one that is fresh-looking and highly polished. It was found lying in the cloister and is thought to have come from the west end of the cathedral, but has been polished and placed here so that the original appearance of the stone can be appreciated".

In the south-west corner of the cloister is the early-thirteenth century entrance to the monks' refectory, through which to the left can be seen a vaulted passage that was their lavatorium or wash room. The passage and the outer masonry of the doorway are of Reigate stone, a pale grey, slightly greenish, finely glauconitic and slightly micaceous sandstone from the Upper Greensand of Surrey. The stone is badly weathered. Purbeck Marble, also much corroded by weathering, is used for flanking columns and capitals, and for the inner, cusped arch of the doorway head. The stone is composed of closely packed shells of the small freshwater snail Viviparus22. It had great prestige as a decorative stone throughout the thirteenth century. Both it and Reigate stone are displayed to good affect inside the cathedral.

The cloister is the best place to see two types of building stone introduced in the nineteenth century - Bath stone, used for the south wall of the south-east transept by L. N. Cottingham in 1827-284, and Chilmark stone, in dressings of the south.

West transept and of a flying buttress to the south choir aisle, added by si George Gilbert Scott (Plate II). The Chilmark stone is a sandy limestone, pale grey with a slight greenish tinge, composed in about equal proportions of quad grains and rounded carbonate particles, all about 0.3mm in diameter. Manga the blocks show small-scale cross-bedding. The Bath stone is pale yellowish grey where rainwashed, and of a brownish-yellow 'gingery colour where sheltered. Typical of this stone are thin calcite veins, known to quarrymen as watermarks or 'snailcreep'. Its surface shows a honeycomb-like texture under the lens, where ooliths have fallen from their sockets in the harder crystalline calcite matrix. The weather-resistance of this Bath stone is better than that of the Chilmark stone, blocks of which are spalling at their edges.

Within the south-east transept wall is a range of windows at ground level, with surrounds of an oolite of a greyer colour than the Bath stone, and composed of close-set 0.3mm ooliths?. I am inclined to think it a variety of Lincolnshire Limestone, perhaps Ketton rather than Weldon stone - it is less shelly and its ooliths are more perfectly rounded than those of the Weldon stone on the west front. It has weathered well.

A loose boulder, about 1m in length, beside the path in the north-west corner of the cloister is worth mentioning, for this is a sarsen stone, a quartzite of clear quartz grains of 0.1 to 0.2mm diameter, cemented by crystalline quartz and extremely hard. Boulders like this are found sparsely, littering the surface of the North Downs, and were used for such prehistoric monuments as Kit's Coty.

Lastly, from the cloisters there is a good view of the cathedral tower. This was cased in Bath stone in 182627. It was again rebuilt in 1904-05 by C. Hodgson Fowler, who in 1903 proposed to use Weldon stone - 'same as used in restoration of the W. front by Mr. Pearson?8'.

3. Cathedral east end and north transepts

At the east end of the cathedral much of the stone work is soot-encrusted. The bay window and ashlar north wall of the Chapter Room, rebuilt by C. Hodgson Fowler, can be seen to be of Bath stone (yellow, with watermarks). The architect's specification, of 1906-07, stated that the new window and wall facing should be of 'old stone from the Tower, now lying at Mr. Foord's Acorn Wharf?.

The east wall of the presbytery is all Gilbert Scott restoration. He removed a large late-Medieval Perpendicular window and inserted the present upper tier of three lancets. Here and also on the north side of the choir, and around the north-east transept, walling is mainly Kentish Rag rubble, with some re-used tufa, and dressings are mainly of Chilmark stone (grey, with lamination, cross-bedding, slight blistering).

On the way to the north-west transept one passes 'Gundulf's' tower again (note the top of the mostly-buried Purbeck Marble plinth course of the fourteenth century north-east buttress, just showing above ground level at the buttress northwest corner), and through the Sextry or Deanery Gate archway (good quality fifteenth century Kentish Rag masonry).

The thirteenth century doorway into the north-west transept was originally apparently of Caen stone (surviving in its innermost arch) but has been much repaired with Chilmark stone. On each side of the doorway are two attached columns of a hard grey limestone with prominent calcite veins, which looks like a variety of Carboniferous Limestone. Tim Tatton-Brown suggests it may be Kilkenny 'marble, from Ireland, a stone used in the Westminster Abbey restoration by Sir G. Gilbert Scott.

Standing back, and with John Newman's account' as a guide, one can appreciate how Gilbert Scott, even though he followed its original design, must have transformed the north face of this transept (Plate III). All dressings are of Chilmark stone, except for the shafts of the blind arcading that embraces the lancer windows. But the effect of these elegant shafts is rather spoilt by their mis. matching stonework. In the lower tier, all eight shafts are of what looks from ground level like Bath stone, on grey Kilkenny 'marble' bases, while in the upper tier there is a mixture of the two, some shafts all Kilkenny limestone, others with either their upper or lower half Bath stone. On the west face of the transept all the column shafts (though not their bases) are apparently of Kilkenny limestone. The attached shafts around the octagonal pinnacles that surmount the corner buttresses of the transept seem to be of Bath stone"

4. The cathedral crypt

The earliest stonework of the cathedral interior is in the crypt, which is entered by an Early English doorway in the south choir aisle. The doorway surround is of a black snail-shell marble that has larger-sized shells than Purbeck Marble, and is a Large - 'Paludina' limestone from the Weald Clay formation", The walls of the western, early-Norman (probably1080's) two bays of the crypt are of tufa blocks with a thin plaster coating. The groin-vaulted roof is supported on two monolithic oolite columns with cushion capitals, and, around the walls, on half-columns of tufa blocks with capitals and bases of the same oolite. Of a pale vellowish grey colour, it is composed of closely packed ooliths of 0.5 to 0.6mm diameter, projecting in 'millet-seed' fashion on worn surfaces, and including a few oncoliths (composite ooliths) of 2mm diameter, in a finely granular (0.1 to 0.2mm) matrix. W. St. John Hope' described the columns as of

'white stone, perhaps from Barnack'. They are, however, certainly not of Barnack stone, which is a shelly oolite with a crystalline calcite matrix, and I am inclined to regard the stone as Marquise oolite, from near Boulogne". Marquise stone was employed in Canterbury and elsewhere in east Kent from Roman until early Norman times, after which export may have been prevented by silting-up of the little estuary which led from the quarries to the sea at Ambleteuse. The Rochester columns, if correctly identified, would provide the only known instance of the use of Marquise stone in England outside east Kent.

Between these columns and the rest of the crypt are two rectangular piers faced with ashlar stonework, comprising evenly-sized randomly alternating blocks of Caen stone (yellow) and Reigate stone (pale greenish grey). Around each pier, at the springing line of the roof vaults, is a torus (half-round) string course or impost of Large - 'Paludina' marble. Architecturally the piers are of a piece with the whole eastern part of the crypt, which dates from the 1190's, and throughout which a mixture of Caen and Reigate stone seems to have been used for walls and vault-ribs. The string course also continues throughout, and forms an abacus 10 free standing columns, is the aans ple it as of large m Paludina' marble, cus to most of the line of piers separating the transepts from the chapel, and in the chapel itself, it is of Purbeck Marble.

The stone of the later crypt columns is no less interesting than that of the early Norman ones. There are twenty free-standing columns, and against the crypt walls, a further 32 half-column responds (Plate IV). The columns and halt. columns (with some exceptions) are round and octagonal in alternate north. south rows. All, except for one or two of the half-columns, are monoliths.

In 1833 to 1840, when L. N. Cottingham was cathedral architect, four shafts (two in the north transept and two at the east end of the chapel) were replaced with grey Dartmoor(?) granite, and an uncertain number of other shafts and capitals with other types of stone, to an extent that a careful examination of the whole crypt would be needed, in order to determine how many of the columns may be of original late-twelfth century stone34 (Plate V).

Throughout much of the seventeenth and eighteenth centuries the crypt was derelict and open to the elements. Fires must have been lit against the walls, for some of the stonework is reddened as if burnt. Among the stonework affected is a half-column at the west end of the chapel north wall. This at least must precede the 1833-40 restoration. Like many other columns, it is a brownish-yellow, shelly oolitic limestone, with a crystalline calcite matrix, and shell detritus in 2 to 3cm wide streaks. Worn surfaces have a honey-comb-like appearance under a lens, as do those of the Combe Down stone used by Cottingham in the cloister. As a whole, however, the stone has more resemblance to that of the early twelfth-century attached columns beside window openings of the Chapter House, mentioned above. Both may be a variety of Bath stone, more shelly and without the 'watermarks' that characterise the Combe Down Oolite? (Plate V).

5. The cathedral interior

The stonework of the main part of the cathedral interior, above the crypt, calls for only brief description. The nave (mid-twelfth century) is of fine Caen stone ashlar36. The abrupt change to the Early-English style of its eastern-most two bays is quite obvious. Rather less obvious is the appearance, in the triforium arches of the easternmost of the Norman bays on each side of the nave, of a few blocks of Reigate among the Caen stone37

Mid-thirteenth century masonry (c. 1240-1255) is well displayed in the northwest transept, with walling, as in the crypt, a random mixture of squared blocks of Caen stone and Reigate stone, set off by splendid Purbeck marble shafts. Still more impressive, one may think, is the early-thirteenth century stonework of the choir crossing and the presbytery. There, again with John Newman's account as a guide, one can only marvel at what he describes as the coherence, the harmony, of these shafts, lancets, vaults, string courses, all wrought in simple Caen stone, Reigate stone, Purbeck Marble.

A few more observations need to be recorded: that large 'Paludina' marble was Arey or are baserval ons ref the Pur beck Marble columns in the presbytery and north-east transept, and for some of those in the south-east transept; it was also used for the central shaft of Bishop Merton's tomb in the north-east transept; that the carving of the Purbeck Marble corbels supporting attacted shafts in the choir is especially fine; and that the magnificent fourteenth century doorway of the Chapter Room is carved from reigate stone.

Bernard C. Worssam

For a detailed plan and description of the cathedral see J. Newman, The Buildings of England: West Kent and the Weald (Penguin Books) 2nd Ed. (1976, reprinted with corrections 1980). The standard work on the cathedral is by W. H. St. John Hope, 'The architectural history of the cathedral church and monastery of St.

Andrew at Rochester', Arch. Cant., 23 (1898), pp. 194-328. Also of great value is a 1994 account by Mrs. Diana Holbrook, R.I.B.A., entitled 'Rochester Cathedral: repair and restoration of the fabric 1540-1983', a copy of which has been lodged with the RIBA Library in Portland Place, London. Her project, undertaken for the Surveyor to the Fabric of Rochester Cathedral, and funded by research grants from the R.I.B.A and English Heritage, summarises a vast number of records, mostly in the Kent County archives, relating to post-Reformation building work up to the end of Emil Godfrey's incumbency as Cathedral Architect in 1983.

I am indebted to Tim Tatton-Brown for guidance on current views on construction dates of various parts of the cathedral, as well as for much other help in the preparation of this essay.

Bernard C., Worssam and Tim Tatton-Brown, 'Kentish Rag and other Kent building stones', Arch. Cant. 112 (for 1993), 1994, pp. 93-125.

Ashlar - masonry with flat-surfaced, squared stone blocks laid in regular courses.

Ragstone is commonly thought of as a hard stone suitable only for rough walling, as opposed to freestone, a stone which could be easily worked and carved. Later medieval particularly fifteenth-century) masons, however, ignoring this distinction, could produce finely carved Kentish Rag masonry. The fifteenth-century windows in this wall were originally of Kentish Rag, now partially replaced with other types of stone.

Limestones consist of calcium carbonate, CaCO, and a sandy limestone is one that contains detrital grains of quartz, the crystalline form of silica, SiO,. Glauconite is a dark green silicate mineral, occurring in grains usually 1mm or less in diameter throughout the Lower Greensand, the group of strata that includes the Kentish Rag.

At Rochester, it was the architect Daniel Alexander (in 1799 to 1804) who favoured galletting when walls were repointed, 'which is usual all over the southern parts of the County' (Diana Holbrook, note 1, p. 14).

According to Tim Tatton-Brown, '"Gundulf's" Tower', Friends of Rochester Cathedral: Report for 1990-91, pp. 7-12, it is probably of mid-twelfth century date.

See Allan Pentecost, 'British travertines: a review', Proc. Geologists' Assoc., 104

(1993), pp. 23-39, for an account of tufa (strictly Calcareous Tufa) occurrences, The alternative name travertine avoids confusion with volcanic tufa, a lithified volcanic ash. The mode of occurrence and Norman use of tufa in Kent was described in a thorough manner by the Revd. G. M. Livett, 'Early Norman churches in and near the Medway valley', Arch. Cant., 20 (1893), pp. 137-154.

Mary Covert, 'An exciting find', Friends of Rochester Cathedrall Report for 1988, pp. 10-11.

Calcite is a crystalline form of calcium carbonate. For identification of hantam stones, 3 is ready necessary to use a hand lens the type recoienended ital lighting conditions - one reason for starting to look at building stone guests, lets. or so ad lion magnitication, which is held close to the eye tand need suit building). These lenses are obtainable from opticians or photographie shape

1. Philip McAleer, 'The Cathedral West Front: form, function and fashian. of Rochester Cathedral: Report for 1990/91, pp. 23-35.

An oolite is a limestone composed of spherical grains, or solts.

of talcium

carbonate. The name comes from the Greek 'oon', meaning egg, and refers in the superficial resemblance that the stone bears to hard roe of fishes, Gefit form today in shallow tropical seas, as around the Bahamas and in the Persian Gulf. In the Jurassic period, northern Europe was positioned in tropical fatties and ooites were then deposited here.

Martin Care, 'From the Cathedral Surveyor', Friends of Rochester Cathedal Report for 1992/3, pp. 3-6.

Mary Covert, 'The Cottingham years at Rochester', ibid. for 1991/2, 00 6.11

Diana Holbrook (note 1), p. 81.

ibid., p. 107. ibid., p. 102.

Tim Tatton-Brown, 'The Chapter House and Dormitory facade at Rocheste Cathedral Priory', Friends of Rochester Cathedral: Report for 1993/4, op. 20.28

The term marble is used here in its original medieval and present-day commercial sense, for limestones capable of taking a polish. Geologically, the term is restricied to metamorphosed limestones, recrystallised under great heat and pressure deep in the earth's crust.

Not to be confused with onyx, which is a silica mineral, and as gemstone is related to agate and chalcedony. Onyx marble is a banded erystalline limestone deposited from solution at springs, and so strictly speaking is a variets of travertine. The onyx marble at Rochester probably came from a Med source, Italy or perhaps North Africa. Algeria is now one of the large producers; onyx marble from there was used in ancient Rome an Martin Caroe, see p. 4 of note 13. During the course of renovatit in 1894, a number of shafts of 'stalagmite', originally part of Norman arcading were found around and above the west doorway (Diana Holbrook, note 1, D 122).

Two species are present, Viviparus inflatus and V. cariniferus, according to W. I Arkell, 'The geology of the country around Weymouth, Swanage, Corfe and Lulworth', Mem. Geol. Surv. Gt Brit., (1947, reprinted 1978), p. 130 and fig. 29.

Mary Covert, see p. 10 of note 14, The stone supplied was recorded in a note of

18 March 1827 as 'Combe Downe 2,013ft (Diana Holbrook, note 1, p. 124):

From Chilmark, in the Vale of Wardour, Wiltshire, the stone used for Salishury Cathedral, but only used more widely than in southern Wiltshire and north Dorset after the coming of the railway. Geologically, the stone is of Portlandian age, deposited at the same time as Portland stone but 6okm or so to the north, in a different environment, and hence is of a different facies.

Like Portland stone, it is a 'grain-supported' oolite, as opposed to Bath stone which is 'matrix-supported'

The Revd. G. M. Livett, in 1889, 'Foundations of the Saxon Cathedral Church of Rochester', Arch. Cant., vol. 18, pp. 261-278, recorded that at the bottom of the foundations of the Saxon apse wall, just outside the present west front of the cathedral, a large 'sarsen' stone was found, embedded in the mortar. The stone, he added, 'is now in my garden'. The same volume of Archaeologia Cantiana gives his address as The Precinct, Rochester.

In 1826, 5,188ft of Combe Down stone was obtained for the tower rebuilding (Diana Holbrook, note 1, p. 145).

ibid., p. 153. When some minor repairs were needed in 1964, the stonemasons noted that Fowler's stone seemed to have surprisingly good weathering qualities.

They took it to be Clipsham stone, which they proceeded to use. ibid., p. 299.

Tim Tatton-Brown, see p. 9 of note 7.

No record apparently survives of Gilbert Scott's work on the north-west transept, apart from an undated drawing of its west face, signed by him and by G. White, in the Kent County archives at Strood. The drawing, at the scale of 4ft to 1 inch, shows the windows flanked by shafts labelled 'Purbeck' (Diana Holbrook, note 1, p. 237).

Large - 'Paludina' limestone occurs in a number of separate outcrops in the Weald Clay formation. In Kent the stone is known as Bethersden marble, and in Surrey and Sussex as Petworth Marble or Sussex Marble. The shells are hazelnut-sized, the species being Viviparus fluviorum. It is not known from which outcrop the stone used in Rochester Cathedral came, so perhaps it is best to call it Large

- 'Paludina' marble.

For a description of Marquise stone see B. C. Worssam and T. W. Tatton-Brown, The stone of the Reculver columns and the Reculver Cross' in D. Parsons (Ed.), Stone: quarrying and building in England AD 43-1525' Chichester: Phillimore/ RAI (1990), 00. 51-69.

A list of items of work carried out by W. Brisley includes: 'fixing Granite column; underpinning Old column Bases (24 august 1833); making Ashlar for Piers and Columns in Crypt; removing Caps of Pillars, fixing new ones; fixing new Granite pillars and caps (7 September 1833); ... 8 Portland Stone caps.; 3 circular and 5 octagonal; 8 Yorkshire stone ?forms moulded upper members, worked from very hard strong Stone (26 October 1833). And finally, in August 1840: 'cutting out old work; making good Brick and Rubble work in Crypt, digging out and removing rubble. Farley down bath stone 242ft; Double Firestone 77ft . .. building Rubble work, working columns, repairing Caps; repairing Brickwork, removing Rubble from Crypt'. (Diana Holbrook, note 1, p. 338). 'Yorkshire stone' might be sandstone or magnesian limestone; Farleigh Down is a variety of Bath stone; and Firestone is no doubt Reigate stone.

For the geology of Bath stone see G. W. Green and D. T. Donovan, The Great Oolite of the Bath area', Bulletin Geol. Surv. Gt Brit., 30 (1969), pp. 1-63.

I have not been able to confirm the report by John Newman (note 1, Addenda, p.

685) that the nave pier bases are of black marble.

Pointed out to me by Tim Tatton-Brown, and best seen on the south side of the nave. According to W. St. John Hope (note 1, p. 220), the triforium arches were originally open, and were closed by ashlar blocks with ornamental patterns and diapers later.

John Blair, The Limoges Enamel tomb of Bishop Walter de Merton', Friends of Rochester Cathedral: Report for 1993/4, pp. 28-33

Plate IV. Late twelfth-century columns of the crypt transepts.

(copyright Dr. Henry Teed)

Plate V. A column in the crypt north transept, with early nineteenth-century replacement capital and granite shaft. (copyright Dr.

Henry Teed)