Glossary A-F

Here, in this glossary, is an alphabetical list of terms used in the firing of a traditional Potteries Bottle Oven. For definitions of more general terms used in a traditional Potbank click here>

The Last Bottle Oven Firing in The Potteries 1978

BOTTLE OVEN GLOSSARY

These words have been collected during a lifetime in potbanks. Some are specific to a particular factory, others are more general. Some vary from potbank to potbank and from Tunstall in the north to Longton in the south. Some are technical, and some feature the very special dialect of The Potteries. Some words are being lost as potbanks close or manufacturing methods change.

A

ARCH BUNGS Part of a bottle oven. Those bungs of saggars which were placed between the bag walls in the oven. These were usually the first saggars to be placed in the oven. The cod placer had to ensure that the bungs in these arches were 'run up' correctly. Arch bungs were usually tied to the crown of the oven and to the sticklers by scotches to prevent the bungs from toppling.

ARCHES Part of a bottle oven. The area between bags.

ARSE The inside bottom of a saggar. Made by a Saggar Makers Bottom Knocker.



ARM OH RATE DUCK Dialect reply to "Adoo ow at?" Or if the respondent wasn't feeling too well he might say that he was "bad in bed an woss up."

ASH Material. Could be the useless waste material found in the ash pit of a bottle oven after firing.

ASH HOLE The ash pit underneath the firemouth in an oven. Also a Potteries dialect word. "S Hole is simply a dialect way of saying ash hole [found in coal fires in domestic premises] rather than a specifically industrial word." Many thanks to Brian Jones for this update 18 March 2016 

ASH PIT The space under the firebars which collects the ash falling from the burnt coal in the firemouth. Sometimes called the essole and sometimes the well. The ashpit is scraped out at intervals and the ash discarded.


B


BAG Part of a bottle oven. A small firebrick chimney found directly above the firemouth on the inside of a potter's biscuit or glost bottle oven. Separates the combustion space from the stacked ware space. Prevents hots spots among the pots nearest the fire. The photo below shows three bags.  In a 'usual' large bottle oven there would be eight bags, situated above the eight firemouths.

Three bags and the pipe bung in one of the ovens at
Gladstone Pottery Museum, Stoke-on-Trent, England.  September 2013

BAITING Process during firing. Periodic stoking of the oven. Pouring coal onto the fire in each of the mouths of an oven during firing. A careful operation so as not to disturb the fuel bed. Follows lumping (the first loading of coal in the firemouths at the start of the firing cycle) and was carried out regularly and equally at each mouth to ensure even firing in the four quarters of the oven. Up to one and a half hundredweight of coal could be use at one baiting at one mouth. (A full firemouth in a smallish oven would take a total of 4 cwts) A sitter up and the fireman would use up to 20 tons of coal during the firing of a large bottle oven.

Preparing the fuel bed in the firemouth at the Last Bottle Oven Firing, Gladstone Pottery Museum 1978
The Last Bottle Oven Firing, Gladstone Pottery Museum 1978.
The Author with a No.8 British Standard Shovel
Wife and sister in the Background

Baiting at the Last Bottle Oven Firing. 1978
Fred Greasley and Alfred Clough

BAITING PLATE The bottom ledge of the cast iron frame which surrounds a bottle oven mouth and against which the firedoors can be slammed tight.

BAITING POKER Equipment. Used during firing. A tool of the fireman's trade. About six feet long and 1 inch diameter steel or iron rod. Used to keep the firebed under control during firing. Also used as a device to detect condensation in the oven during baiting.


Baiting Poker

BANNERING Process. Ovens department. A job for the saggar maker. Involved the use of a small metal or wooden tool to true up the rim of an unfired saggar to ensure that it lay in one true horizontal plane. Bungs of saggars in a bottle oven can reach up to 20 feet in height and should stack as close to the vertical as possible. It was therefore an important job to ensure that the rims and bottoms of freshly made saggars were perfectly flat.

Bannering in the saggar making shop
11th Sept 1900

BANJO Kiln Furniture. A saggar. Particular shape. Mainly for glost firing. Ideal for a double row of dottled muffins.

BASIN SAGGAR Kiln furniture. A saggar. Particular shape used for small holloware.

BASS Poor coal.  Not good for using to fire an potters oven.

BAT Equipment. Kiln furniture. A saggar marl or refractory flat clay shelf on which pottery ware is placed during firing. Also: in The Last Bottle Oven Firing 1978 bats were used instead if hillers to top of bungs of saggars.

BAT also known as a  PLATE or a SHARD. Equipment. Used in the saggar making shop. Large flat metal sheet pierced with holes of about 2" diameter. Used by the saggar maker's bottom knocker to transfer the recently made saggar bottom onto a whirler prior to the saggar maker constructing of the sides of the saggar.

BATING Another spelling found in the literature for BAITING (stoking the oven during firing).

BAT WASH Coating of refractory material applied in slurry form to kiln furniture or saggars to stop ware sticking to it during firing. It is regarded as good practice to use a batt wash coating on the upper surface of shelves only. No other kiln furniture needs to be treated. Over a period of time, some ‘plucking’ or flaking of the batt wash may occur and this can be retouched without the need to completely recoat the shelves.


Church batter


BATTER The description of the slope given to the shape of the brickwork of the hovel of a bottle oven. Batters can be stepped or flat. Church batter is curved and real bottle shaped. Straight batter is truly conical.The oven used in The Last Bottle Oven Firing 1978 had a straight batter. 

BATTER HEAD A pottery placer. All placers have their birthday on Shrove Tuesday.

BATTER RULE Equipment. Used by a bottle oven builder as a measuring device. Used to give the required slope on the hovel. Sort of a protractor. (Mountford, kiln builder)

BEANS Lumps of coal of a particular dimension.

BEDDER Occupation. Ovens department. Placer who beds flatware in a bed of ground silica sand for earthenware, calcined and ground flint or alumina powder for china. ( Not in The Last Bottle Oven Firing 1978 since it was a glost firing)

BEET Dialect. See baiting.

BET Past tense of BAIT

BISCUIT Biscuit ware is pottery which has been fired once, but is not yet glazed. Biscuit ware feels dry and coarse, just like the baked crisp unlevened bread of the same name.  Biscuit is the fired clay piece with sufficient strength to allow it to be stored, glazed or decorated and fired again.  Jasper and Parian wares are left purposely in their 'biscuit' state, unglazed, but they are of a particular ceramic recipe called stoneware which is particularly strong and non-porous. Earthenware biscuit is porous. Biscuit firing temperature? Earthenware around 1100°C to 1150°C, Bone China around 1200°C to 1250°C.  Note: The Last Bottle Oven Firing 1978 was a glost firing.

BISCUIT FIRING The first firing of the body in a multiple firing process, and before decorating of glazing. Note: The Last Bottle Oven Firing 1978 was a glost firing.

BITSTONE Material. Ovens department. Saggar making. A foundation of rough crushed calcined flint chips spread in the bottom of glost saggars to allow the placing of holloware directly on the saggar base without the need for stilts or spurs or saddles.

BOARD Equipment. Wareboard. Used in most departments of a potbank. About 6 feet long, 9 inches wide and 1 inch deep. Made of good quality pine. Simply a board or plank with rounded corners to carry ware about the potbank. Carried on one shoulder and supported with one hand, requiring some balancing skills and a lot of confidence.

BONT Essential part of the construction of bottle oven. Iron hoops used to brace and support the brickwork of a bottle oven. The wrought iron straps which encircle the potter's bottle oven. Tightened on to the walls of the oven to the brickwork greater strength and resistance to warping during firing.Usually bonts are three eighths of an inch thick and from 3 to 8 inches deep. Made of several sections, each section being attached to its neighbour by a hook and eye arrangement. Bonts are usually placed at 1 to 2 feet intervals up the wall sides of the oven but often extra bonts are used near the shoulder of the oven to support the crown.
Bonts or Bontings
Wrought iron bands around the oven to keep it in shape


BONTINGS Part of a bottle oven. Another name for bont.

BOTTLE OVEN

"The most notable feature of The Potteries skyline and nobody knew how they got there." Prominent until about the 1960s when they started being pulled down following the introduction of the Clean Air Act. A type of intermittent kiln for firing pottery. Coal fired using local long-flamed coal. Oil has also been used to fire bottle ovens.


Bottle ovens at Gladstone Pottery Museum >

A bottle-shaped structure, built from brick, in which pottery was fired. It consists of two main parts, an outer and an inner.

In the most basic oven, the updraught, the outer, which is the bottle shaped part, is known as the hovel. This could be up to 70 feet high. The hovel acted as a chimney taking away the smoke, creating draught and protecting the oven inside from the weather and uneven draughts.


The inner part is the oven proper. It is a round structure with a domed roof, the crown, and its walls are approximately 1 foot thick. Iron bands, known as bonts, run right round the circular oven about 12" apart to strengthen it as it expands and contracts during firing. A doorway, the clammins, just large enough for a man with a saggar on his head to pass through, is built into the oven surrounded by a stout iron frame. 

Around the base are firemouths - the exact number depends on the size of the oven - in which fires were lit for the firing. Inside the oven, over each firemouth, is a bag which carries some of the heat from the fire into the oven, like a small chimney. 


Flues underneath the floor of the oven leading from each firemouth distribute the heat throughout the inside. In the centre of the oven floor is the well hole.


Pottery may need to be fired several times during its manufacture and different ovens were needed for each type of firing so, depending on the output of each factory, a single works could have anything from one to 25 ovens. 


Within a factory, ovens were not situated to any set plan. They may have been grouped around a cobbled yard or in a row. Sometimes they were built in to the workshops with the upper part of the hovel protruding through the roof. The stack of such ovens was usually built on the shoulder of the oven itself.


No two bottle ovens alike; each had an individual shape. But they do fall into four main types.


  •    Updraught
  •    Downdraught
  •    Muffle
  •    Calcining
Within each type there are sub types more here> at the Potteries Bottle Oven website

There were/are many other types of oven such as two-tier ovens with an upper and lower chamber, salt-glaze ovens, frit kilns, beehive brick kilns and lime kilns.

BOTTLE KILN Same as bottle oven. But not quite!  The word 'oven' usually meant the biscuit or glost firing ovens and the word 'kiln' usually meant the enamel firing kiln, hardening-on kiln or calcining kilnBut usage did vary from factory to factory, so its complicated and difficult to be precise.

BOTTOM CLAY Type of saggar marl. Made with a higher concentration of grog to make the clay a little stronger at the bottom of the saggar than the side clay.

BOTTOM KNOCKING Process. Ovens department. During saggar making. Flattening a ball of saggar clay into a bat using a mawl to knock the clay into a former made from a ring of iron.  The bat of clay is used for the bottom of a saggar.

Saggar making - bottom knocking
Bottom knocking



BOWL PINS Kiln furniture.

BRITISH STANDARD SHOVEL BS 3388:2004 Forks, shovels and spades. Alfred Clough always said that a No.8 shovel is "comfy" to use during the baiting process (shovelling coal onto the firemouth of an oven). He regarded the larger No.10 shovel as "too clumsy."

BROADBACK Type of fireclay or refractory brick. Used in the construction of a pottery bottle oven. Measuring "a brick and a half" and used in the oven bottoms, resting on the medfeathers. (Alfred Clough quote. Feb 1978)

BULLERS RINGS BOX


Bullers ring being measured

BULLERS RINGS Equipment. Used during firing. Pyrometric device used to measure the heatwork (the combined effect of both time and temperature) when firing materials inside the oven. Bullers rings do not measure temperature but show how well the fire has progressed, the intention being to visually communicate intensity of fire within the ware. Flat and hollow centered (a bit like a big giant Polo mint).A gauge is used to measure the fired ring. Various grades of ring, each of slightly different compositions, are available to cover all firing conditions and temperatures.



BULL NOSED Particular shape of brick used during the building of a bottle oven to provide a decoration at the very top of neck of the oven's stack. Also called pig nosed.

Bull nose bricks decorate the top of the bottle oven


BUNG Vertical piles of almost anything on a potbank are called bungs. Most often applied to a pile of saggars in the bottle oven, or a pile of ware in the warehouse. In a pile of saggars in the oven ready for firing the the top rim of each saggar has a wad or roll of wad clay to give each saggar a firm seat on the one below.  The wad also sealed the saggar to prevent the products of combustion entering and spoiling the ware it contained.


Bungs of saggars in the bottle oven, just placed


C

CANT Bottom outside edge of a saggar. Should be rounded to help the saggar resist thermal and mechanical shock during firing and rough handling.

CHARACTER JUG Similar to a toby jug but usually just head and shoulders and definitely no knees on show! Why?  Because only Toby Jugs show knees! Royal Doulton Character Jugs were fired in The Last Bottle Oven Firing 1978.

Royal Doulton Character Jug

CHECKERS Part of a Bottle Oven>. Refractory brick (the size of a standard building brick) placed in above the firebars in the ashpit of a bottle oven's firemouth to retain the coal.

CHURCH BATTER Description of the shape of a bottle oven. Actually very curvy and bottle shaped. (Mountford, kiln builder).

Twyfords Cliffe Vale - Church batter
Photo: Virtue, London  Date: 1900


CIRCS A particular shape of brick used in the construction of the bottle oven chimney. Circs are curved bricks and they form the circular top of the oven chimney. (Mountford - kiln builder).

CLAMMINS Part of a bottle oven. Sometimes called clammings. The brickwork created to seal the entrance to a bottle oven before and during firing. Sometimes known 'clammins arch.' Bricked up and sealed before firing and knocked down again after the fire to gain entrance to the fired ware. The clammins are built two bricks thick with the lowest trial hole at about the same height of the bags. The clammins fill the wicket>

Clammins - bricked-up entrance to the oven.
Seen here being bricked up prior to firing 1978

CLEARING Process. Emptying a fired bottle oven. Taking out the fired pieces and passing them on to the next process - usually in the warehouse.

CLINKER Lumps of fused ash formed from coal burning during a bottle oven firing and found in the ash pit and mouths of the oven. Clinker can form over the firebars during the fire and particularly if small pieces of coal or slack are used. This clinker will prevent a sufficient draught for the fire. This clinker needs to be punched out but this allows cold air into the kiln and this, in turn, retards the firing. Lets face it - clinker is bad news for a potter.

CLOGS Clumpy footwear with a wooden sole and leather tops and laces. The wooden sole was protected with nailed-on metal bands. Uncomfortable but healthy.

Woolliscroft Potbank Dictionary
Clogs - last used in the Last Bottle Oven Firing 1978  here>

COAL Material used in the Pottery making process.  Fuel. Stuff of The Potteries. Florence Nuts. Used in the Last Bottle Oven Firing more>  Combustible black rock carbonized plant matter found mainly in underground seams. Interestingly 'young people' are unaware of its significance - or even how to light it!  The Last Bottle Oven Firing used coal:  more here>

Woolliscroft Potbank Dictionary
Coal


COD or COD PLACER Occupation. The foreman responsible for placing the bottle oven. Experienced and knowledgeable man who knows how and where the products should be placed in the oven to get the best fire.

COME UP Process. During the firing of a bottle oven, near the end when the temperature of the oven is reaching its peak, the fireman (or sitter up) will be careful to ensure that the temperature has "come up" correctly without dropping back at all.

COMMONITES Common size of saggar. Common height of about 8 inches. Alfred Clough, February 1978. It was possible to stack 3 dozen (36) cups in a 'commonite.'

CONE The chimney stack of a bottle oven.

CONE  - actually SEGER CONE Equipment. Pyrometric cone. Device for measuring the heat-work imparted to pottery pieces during the bottle oven firing. Pyramid-shaped. These devices are formulated from different mineral mixtures and numbered accordingly. They are placed in a kiln so they can be viewed during firing and when a cone begins to bend it is closely monitored and the firing is terminated when it reaches a specific position.

CORK Foundations of a bottle oven. All bottle ovens had to have a very firm foundation. 3 to 4 feet of earth should have been excavated from the plot of a new oven and the hole filled solidly with broken bricks. Smaller spaces between the bricks should have been filled in with shards and then fired sand used to smooth it all over as a basis for the brickwork of the oven. The cork was raised or domed as the start for the oven flues.

COVER Kiln furniture. Flat cover fits on the top of a crank. Protects ware from falling dirt and holds the pillars of the crank in position.

CRANK Equipment. Kiln furniture. Refractory support for flatware and tiles in glost and enamel firing. The flatware rests on replaceable pins which rest in sockets in the crank posts. The pins are so designed as to make minimal marks in the glazed surface.

Crank - kiln furniture


CRANKER Occupation. Ovens department. Assembler of kiln furniture for flatware glost placing. Usually female.

CROWN Part of a bottle oven. The domed roof of the oven interior.

CROWN DAMPER Equipment. Part of a bottle oven. A substantial hinged brick and iron flap operated by levers and pulleys from below to close or open the hole in the domed roof (or crown) of the oven.

Crown damper

D

DAMPERS Equipment. Essential part of a bottle oven to control how its works during firing. Crown damper and four quarter dampers. Flaps of iron and refractory (firebrick) bricks, hinged, which can be lowered or raised by means of a pulley system from ground level, to affect the draught in a bottle oven (and hence affect the firing conditions) during the firing cycle. Much of the control of the firing of the potters' bottle oven was achieved by the use of these dampers. The number of dampers varied from oven to oven, it all depended on the individual kiln builder and the manufacturers requirements. During the firing, the fireman would regulate the draught in any part of the oven by opening or closing the dampers.

DEAD COAL Material. Ovens department.  Coal for firing used in the bottle oven which has not yet been lit. Lumping coal, not baiting coal.

DONUT also known as a placer's roll. Made from rolled up stockings and worn under a cloth cap to help placers balance saggars on their heads when placing (loading) a bottle oven.

Donut or Placer's Roll
Photo: courtesy of Nerys Williams of Gladstone Pottery Museum


DOTTLING Process. Not to be confused with rearingPlacing or setting glazed pottery flatware, which has been dipped in glaze, into refractory of fireclay thimbles in a saggar. 'Best ware' was dottled. 'General current ware' was reared.



DOWNDRAUGHT Type of Bottle Oven. This type of oven is a more complex type of oven than the simple updraught oven. This type of oven was a development of the early 20th Century industry to make more efficient use of the firing fuel (coal). The hot gasses pass through the setting of saggars not once but twice, theoretically making the most of the heat from the fires.  From the firemouths the intensely hot gases flow upwards to the crown then descend through the setting and are then drawn out through the flues in the floor of the oven. This type of oven was used for both biscuit and glost ware. More here> at The Potteries Bottle Oven website.  The oven used in The Last Bottle Oven Firing 1978 was an Updraught Oven.

DRAW or DRAWING Process. Emptying a bottle oven (or other type of oven) after it has been fired.

DRAW TIN Equipment. Used around the bottle oven.

DRESSING IRON Equipment. Ovens department. Stout bar of metal about 9 inches long and usually sharpened at each end, like a chisel, used for knocking wads off the top rim of previously-used glost saggars. The dressing iron was also used as a lever to level up a bung of saggars in the oven.

DROP ARCHES Part of a bottle oven. Forming the roof of a firemouth.

DRUM Equipment. A wooden former used in saggar making to form the basic shape of the saggar.

DUMP Kiln furniture. Spacer or support for big pieces, or for refractory shelves.

Dump

DUMP Term used in saggar making. A lump of clay ready to 'mau out' into a saggar's bottom. 4 or 5 pounds in weight of saggar marl is used for a saggar's bottom. A flat D-shaped tool called a grafter was used to slice a flat piece of saggar marl from the dump, before use.


E

EASING AIR  In a bottle oven kiln. (more to come).

ESS Dialect. Found in an essole.

ESSOLE  Potter's name for the ash pit underneath the firemouth in an oven. Same as S Hole. Also Potteries dialect word. "S Hole is simply a dialect way of saying ash hole [found in coal fires in domestic premises] rather than a specifically industrial word." Many thanks to Brian Jones for this update 18 March 2016  



F

FEATHERS Brickwork in the base of the bottle oven, forming the flues.

FINISHING FIREMAN Occupation. Some potbanks would employ three men to fire a bottle oven. The Fireman - he was in charge and responsible for the whole firing cycle.  The Sitter Up - he took over responsibility during the night hours. And The Finishing Fireman - he saw to it that there were no problems once the peak temperature had been reached and the correct soak time had been concluded.  He would ensure the fires burnt out completely OK.

FIRE and FIRING Process at the heart of ceramics and making pots. A time/temperature process. Applying high temperature over a period of time to convert soft and fragile raw clay into a hard and brittle ceramic material. Firing also used to mature glaze. The conversion of clay to pot by fire.

FIREBARS Part of a bottle oven. Found in the bottom of the firemouth. Used to support the burning coals but allow ash to fall through into the ashpit below.

FIREBED Part of a bottle oven. The seat of the fire. Burning coal on the firebars.

FIREBOX Part of a bottle oven. Another name for firemouth or mouth

FIREBRICKS Part of a bottle oven. Refractory bricks made from fireclay and used in the construction of the oven. Various shapes of firebrick were manufactured by specialist producers. Different names were given for the different shapes of brick. Eg: Oven bottoms, flatbacks, arch bricks, bull heads, split, wristers, knuckles, bag bricks.

FIREDOOR Part of a bottle oven.

Firedoors open on a bottle oven being fired

FIREHOLE Part of a bottle oven. Same as firemouth

FIREMAN Occupation. Maybe the most responsible job on the potbank. He controlled and supervised the firing of the bottle oven. He took over the completion of the firing from the sitter up after around 20 hours.

"Our fireman was a red eyed, bloody-minded, unshaven, uncouth old drunk who could fire ovens as perfectly as the baker. On the night in question he lay down on 20 tons of best cobbles, freshly delivered from Florence Colliery, and died." From FIRING THE BISCUIT BOTTLE OVEN
By John A T Duncan FFARCS. More here>


FIREMOUTH Part of a bottle oven. Openings around the base of a bottle oven in which the fires were lit (lumped and baited).

Firemouth

FIRING Process. At it most basic level, firing is the process of heating a clay (or recipe of clays and minerals) to a temperature sufficient to fuse the particles together.  Heat treatment of ceramics in an oven to mature the clay body or glazed biscuit ware. Irreversible - physical and chemical changes take place in the pottery during firing.

FIRING CYCLE The time taken from the start of the firing process to the finish and cooling.

FIRING RANGE The best range of temperatures at which a particular pottery body recipe will achieve its best fire.

FIRING SCHEDULE  An often-overlooked aspect of the ceramic process and yet is very important, since it relates so directly to glaze quality and body maturity. The rate of rise of the temperature in the kiln, the soaking time and the cooling off. When firing is very fast, optimisation of every stage of the fire is critical. In slower firing the need to plan and adhere to firing schedules is less.

FLATWARE Plates, saucers, flat dishes. Shallow articles. Actually flat ware (apart from the rim!) Usually made on a plaster mould fixed to a revolving jigger. The mould forms the face to the piece. The back of the piece is formed by the metal profile tool which is lowered onto the clay bat on the mould.

FLUES Part of a bottle oven. System of brick channels found underneath the domed floor of the bottle oven. Connect the fire in the oven mouths to the central well hole. Also flues may be of two types in the same oven - down draught flues carry exhaust gases. The middle flue goes from the mouth to the centre well hole and is built 4 bricks high. The cross bricks are 3 bricks high. The number of side flues between mouths vary according to the ideas of the kiln builder (between three and five). The more flues the better in the oven bottom, provided that the construction is not weakened.

FORE BUNG The last bung of saggars to be set in before the oven entrance (wicket)  before the clammins were bricked up and sealed.

FRAME FILLER Occupation. Ovens department. Male apprentice Saggar Makers Bottom Knocker, and worked alongside him. This apprentice flattened a mass of saggar marl to produce a large rectangle of clay on a special bench, edges with a shallow frame of metal, about 3/4 " deep. Slices of saggar marl clay were taken from the frame to wrap around the side of a drum (the mould) to make the side of a saggar.

FUEL BED Part of a bottle oven. In the oven mouth.  Where the coal burns at its most intense.




Go to Glossary G-O here>