LLAGS or LAGGY Opposite to foggy but not misty. Last. 'Bags eye goo laggy' meaning 'let me go last.'
LAMP Equiment. Portable lighting used to illuminate the inside of a bottle oven during setting or drawing. Sometimes made of metal - specially designed and constructed - with a spout from which emerged a 'tow wick'. A thick oil known as torch oil was used to soak the wick which was set alight.
LAMP Hit hard in a fight.
LAID UP Poorly potter. Worse poorly than 'off side.' If the potter is really laid up then he might be 'bad in bed and woss up.'
LARM KILL BONK Dialect. Lime Kiln Bank. A very steep hill between Bucknall and Hanley, Stoke-on-Trent. Dodgy in the winter.
LAST BOTTLE OVEN FIRING Longton, Stoke-on-Trent, England. 1978. The last firing of a Potteries Bottle coal fired oven organised by Gladstone Pottery Museum and took place on the factory of Hudson and Middleton (Longton) Ltd. www.hudsonandmiddleton.co.uk/
See how it was done here>
|Author of the Potbank Dictionary, Terry Woolliscroft, baits a firemouth |
at the Last Bottle Oven Firing in the Potteries 1978.
Alfred Clough, who managed the firing, looks on.
BBC Radio Stoke Gallery of images here>
LATE WOOD Dialect. Lightwood. A residential area south of Longton, Stoke-on-Trent.
LATHE Equipment. Machine. Potting department.
LATHE TREADER Occupation. Potting department. Male or female. Uses legs to treddle and create rotary motion on the lathe.
LAVATORY Sanitaryware. The correct trade name for a washbasin. Not a toilet. A term not used so much today (1990s onward). In the very early days of sanitaryware manufacture a lavatory was sometimes called a table.
|Lavatory or Table 1960|
Now this is messy, complicated and a tad confusing, so bear with me! In the good old days, in the UK sanitaryware industry, sanitary pottery casters and warehouse packers, called a WASHBASIN a TABLE. But why? Well, in the late 1800s when large WASHBASINS were designed to stand on legs rather than a single column pedestal (as is common in the UK today, 2015) the washbasin looked like a TABLE. But actually, the correct word, in those days, for a WASHBASIN or TABLE was LAVATORY. The word LAVATORY is derived from the Latin word LAVARE, meaning 'to wash.' Nowadays, a TOILET is often mistakenly called a LAVATORY since this is regarded as polite. But technically, it is incorrect. Of course, while it would be correct to wash your hands in a LAVATORY or WASHBASIN or SINK (see below) it would be odd to wash your hands in a TOILET, or worse still, to do something 'exceptional' in a LAVATORY, WASHBASIN or SINK.
LAV or LAVVY Toilet | WC | Loo | Euphemism | John | Crapper | Dunny | Shit house | Karzy | Privy | Jackes | Ajakes | House of Office | Bog | Netty | Vin | Latrine | Facility | Throne | Thunderbox | Porcelain, Appointment with the | Porcelain, point percy at the | Pan |
"A useful contrivance, the purpose of which requires no explanation"
GEORGE JENNINGS, 1877 - English sanitary engineer and plumber who invented the first public flush toilets.
GEORGE JENNINGS, 1877 - English sanitary engineer and plumber who invented the first public flush toilets.
LAVVY FACTORY Where the most the most fundamental of pots are made, in The Potteries.
|Twyfords Cliffe Vale Factory 1920|
Converted to dwellings 2007 Shelton New Road, Stoke on Trent, England
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LAWN Equipment. Sliphouse. A sieve. Fine mesh or screen of up to 180s mesh used during the cleaning of pottery slip after blunging. Usually made of phosphor bronze. The vibrating mesh takes out the over-sized particles in the slip. Earthenware usually has a coarser mesh than bone china. The material left behind in the lawn is called knottings or knockings.
LAY ON BASIN Sanitaryware. Sometimes called the vessel basin. This basin is the simplest form of washbasin since it is designed to simply sit on top of a counter, on furniture or on a shelf. The basin has a central waste outlet and sometimes comes with no overflow. Taps are either fitted to the basin or are designed to be freestanding on the furniture. Lay-on or vessel basins can be described as “minimalist” and ultra-modern.
LEAD Material used during the process. Glaze making.
LEAD GLAZE Material. Lead glaze is a glaze in which lead oxide (a metal ore) is the main fluxing agent; included to reduce the melting point of the glaze. Lead glaze matures at relatively low temperatures and produces high gloss and brilliance but must always be fired in an oxidising atmosphere if its is not to darken during firing. Lead has been used to make glass for more than 3,000 years. About 2,000 years ago potters adapted it to make glaze suitable for pottery
LEADLESS GLAZE Material. Glaze which contains no lead. Generally glazes which fuse at kiln temperatures above 1250°C in order to get the required gloss. No so satisfactory as leaded glazes they tend to be less brilliant when used and fired under the same conditions.
LEAN CLAY Component of pottery body recipe. A clay with very low plasticity. The opposite is fat clay. Lean clay which is deficient in plasticity is difficult to handle and work. Lean clays can be more desirable in some circumstances since they tend to have a lower shrinkage.
LEATHER HARD Partially dried clay where all the wet to dry shrinkage is mostly complete. Sometimes called cheese hard. Soft-leather-hard ideal for forming, joining, thick slip-decorating. Medium-leather-hard good for thin slip-decorating, joining, incising, carving, piercing. Hard-leather-hard good for thin slip-decorating, carving, scraping.
LIGGER Dialect. Liar.
LIME Material. Mineral. A white caustic alkaline substance consisting of calcium oxide, obtained by heating limestone.
LINE Decoration to the edge of flatware or holloware.
LINER Occupation. Mainly female. Decorating shop. Paints narrow lines in pottery enamel colour, gold, or platinum and other materials on tableware and ornamental wares as part of their decoration.
|Royal Doulton tableware in the pattern called Anthea.|
The 'line' decoration is created by lining in Platinum.
LINER Equipment. Tool. Decorating department. A pencil (potters name for a small painting brush) with the bristles special chamfered to allow lining in colour or gold.
LINING Process. Application of a narrow line of ceramic colour to the edge of a piece of pottery to form part of its decoration. Lining should not be confused with banding which is the application of a wider band of colour, or with gilding which is lining in gold.
LIQUID GOLD Material used during the decorating process. Decoration. Applied gold which is comparitively inexpensive since it doesn't need burnishing to brightness. Sometimes called bright gold. The term ''liquid'' is intended to distinguish it from the more expensive "best'gold", which is the true precious metal dissolved in a medium which, when fired away, leaves behind the pure mineral gold affixed to the ware. Liquid gold is really a substitute, and therefore has not the life and durability of the best or burnished gold.
LITHARGE Material used during the process. PbO. Also called Lead Monoxide, Lead Oxide, Plumbous Oxide & Yellow oxide. A yellowish or reddish, odorless, heavy, earthy, water-insoluble, solid, used chiefly in the manufacture of Lead Stabilizers (Lead Steareates), pottery, lead glass, paints, enamels, and inks.
LITHOGRAPHIC TRANSFER See below
LITHOGRAPH or LITHO Used to apply designs to glost or biscuit ware. Most usually glost ware. Alternative names are "transfer print" or "decal". But transfer printing is actually an entirely different process. The litho comprises three layers: 1) the backing paper on which the design is printed by screen printing or lithography, 2) the colour (image) layer which comprises the decorative design; 3) the cover coat, a clear or tinted protective layer which holds the colour in place as it is removed from the backing paper and place on the ware. This cover coat burns away in the firing process. Lithos may be used for onglaze decoration or inglaze decoration.
LITHOGRAPHY Process. Decorating department. The application of decorative 'lithos' (known as 'water slide' at the Spode factory) to the piece. Coloured patterns are printed onto special paper to created lithographs. Each litho is soaked in water before it is slid off the paper and carefully applied it to the item. This is delicate work - all air bubbles must be removed and the litho must be free of creases and in exactly the right position. Any mistakes and the item is ruined.
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LITHOGRAPHER Occupation. Decorating department. The male or female who applies lithos to glost pottery.
|Lithographer. Spode factory in Stoke-on-Trent, England. 1990|
LITTLERS BLUE Colour. Rich royal blue.
LIVERING Pottery body problem, but not a fault since a pot hasn't yet been created. Livering in slip appears like jelly. The surface of the slip looks like wet liver. Caused by incorrect defloculation.
LOBBY Food for the hungry potter. A delicious and nourishing and thin but lumpy soup full of carrots, parsnips, potatoes, onions and mate (meat). The meat may be lamb if you live in the north of The Potteries and beef (bayf or bafe) if you live in the south. Also containing dumplings, sometimes but not always. Perhaps. It depends on the chef!
|The Potters' CookBook |
Compiled by Hannah Staton in 1977
Drawings by Bill Morris Printed by KeatesLtd., Hanley, Stoke on Trent
LONDON SINK Domestic sink manufactured from fireclay with a similar shape to a Belfast sink, but this time without an overflow.
|London Sink. No overflow. 1934|
LONG FLAME COAL High bituminous coal, have a high quantity of gaseous ingredients which enable flames to reach the height of the inside of a bottle oven. Pottery districts were located on coalfields where this type of Black Band coal was plentiful.
LONKTON A potters' pronunciation for LONGTON. The southern most town of the six towns (not Arnold Bennett's five towns) which make up The Potteries of Stoke-on-Trent.
LOO Sanitaryware. Toilet , not Lavatory. Several theories exist about the origin of this word but the most popular, is that it is derived from the cry of 'gardyloo' - from the French regardez l'eau meaning 'watch out for the water'. The warning was shouted when a full chamber-pot was emptied from upstairs into the street below, showing passers by with all sorts of, erm, stuff.
LOOKED OVER Process. In the greehouse. Inspection of green ware to look for faults, blemishes, imperfections in the green clay product.
LOOKER OVERER Occupation. The person who does the looking over . (!) See above
LOOP LINE The rail track which before The Beeching Cuts of the 1960s connected the main towns of Stoke-on-Trent, Staffordshire, England. The Potteries Loop Line was a railway line that ran through the heart of Stoke. It was built by the North Staffordshire Railway off its main line (nowadays referred to as the Manchester branch of the West Coast Main Line via Stoke). It was opened in many short sections due to the cost of railway construction during the 1870s. The line throughout was sanctioned but the NSR felt that the line would be unimportant enough to abandon part way though its construction. This upset residents of the towns through which the line was planned to pass and they eventually petitioned parliament to force the completion of the route.
LOW CUP A low,height, wide , cup much favoured in hot countries.
LOW SOL GLAZE Material used in the process. Low Solubility Glaze. Defined by the Pottery Health Regulations as a glaze which does not release more than 5% of it's dry weight of soluble lead, when subjected to a specified test using hydrochloric acid.
LOSSOCK or LOZERK or LOZZUCK Dialect. After a hard day a well deserved rest, but usually slouching and unsupported laziness.
LUMP Faulty pottery. So bad that it is worse than seconds. Or even worst seconds (1751) or thirds.
Massively faulty. Worse than WORSER SECONDS. Or even THIRDS. This is almost, but not quite, the lowest quality of ware that leaves any potbank, and usually it is ware that has just managed to escape being deliberately smashed. Whilst there may have been possibilities in some china shops of disposing of SECONDS, or even THIRDS the risk of dealing in LUMP is "too great to be incurred lightheartedly." Top-end, high-grade potbanks see to it that LUMP is sent to the shraff tip, "in spite of the fact that enquiries were freely received from the poorer districts or export for mixed grades of lump." Usually, about 100 years later, lump re-appears on TV shows as 'rare and valuable.' That’s irony!
Here is the full classification of faults in a potbank:
- BEST - First quality pottery. Good ware. Sometimes called FIRSTS. But there is no such thing as a perfect pot since every piece will always have some sort of slight blemish - this is the very nature of pottery.
- BEST SECOND - Not bad enough to be a SECOND and not good enough to be best.
- SECONDS - Imperfect pottery. Not BEST and not THIRDS or LUMP! Slightly blemished or faulty and sold at a slight discount.
- WORST SECONDS - Sometimes called WORSER SECONDS. Slightly more imperfect than SECONDS. Then there was a DEGREE WORSER which was worse than WORST SECONDS. Or even WORSER WORSER. But not THIRDS, just yet.
- THIRDS - This signifies that the ware is well below the usual BEST standard, and not even good enough to fall within the description of SECONDS. But better than LUMP. The ware was/is still marketable, however, and was sold to hawkers or market stall holders for sale on the 'stones'. Badly twisted ware, crooked holloware, nipped ware and whirler plates fall into this category.
- LUMP - see above
- PITCHER Worse than lump. To be thrown away. Broken. Useless. But strangely saleable, at a price, in some quarters!
LUMPING Process. The first bait. Adding coal to the feeble fire at the start of the firing process in a bottle oven.
LUSTRE Type of applied decoration. Metallic. From the Middle East before 900 AD. Develops in a reducing (low in oxygen) atmosphere.
LUSTREWARE Pottery with a rich iridescent sheen used as a decorative effect, achieved by depositing a thin film of metal derived from metallic salts mixed with the glaze on the surface and firing in a reducing (low-oxygen) atmosphere. Ruby lustre, derived from copper sulphate, is the most common but other colours including gold, green and blue can be achieved through the use of different metal salts.
LUTEING The process of joining two halves of a press moulded holloware piece. Joining two clay surfaces together with slip.
LUTING Process. 18th century word for sticking up. Joining unfired parts of a vessel using slip as the "adhesive."
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MMAGNUM CUP or JUMBO CUP Very large bowl-like cup with handle.
MAIOLICA Type of pottery. Earthenware with opaque white glaze and coloured overglaze decoration. Not to be confused with majolica.
MAJOLICA Type of pottery with a particular recipe and requiring particular firing conditions. Originally tin glazed earthenware decorated with on-glaze colours. Used more loosely in the 19th Century to describe earthenware decorated with with bright opaque coloured glazes. First introduced by Minton in 1851 at London's Great Exhibition. Fired at high temperature.
MAKER Occupation. Potting department. A caster who makes really large and heavy clay products such as fireclay sinks or urinals.
MANGLE Machine. Potting dept. Type of drying cupboard for clay ware.
MAN OF FIRE One of Stoke's most impressive statues. Designed by the London sculptor David Wynne. He spent some time in the Potteries looking for inspiration and he said "..it hit me that the sculpture must have something to do with the great fires which dominate the life of the Potteries...." The statue is made of anodised aluminium. 35 feet high and 28 feet wide, it weighs 1.25 tons.
|Man of Fire|
MAO-DUP Clogged , as in drain, if you pour slip down it!
MARD Dialect. Spoilt! Male or female. Child or adult. Completely over 'fussed'. Nesh?
MARD ARSE Dialect. Very spoilt person. Lazy. Man flu? Nesh? A mard arse is easily sneeped!
MARRA Dialect. Potters word. Friend, buddy - a term of endearment. (Word courtesy of Stephen Knapper, 9 March 2014).
MARRED See Mard. Also spoilt by a surface blemish or firecrack, perhaps.
MARRED Disfigured. Spoilt. Spoiled.
MARL Material used during the process. Saggar marl.
MAR LOWAL Take clay out of the ground in huge quantities and what do you end up with ? Yes, a mar lowl.
Marl Hole - short documentary -don't go near the marl hole
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MAR LADY Dialect. The wife (or girlfriend). 'Er in doors.' Term of endearment.
MAR MATE Dialect. The friend. But not that love or hate it food substance which is spread on toast.
MAR WEE Dialect. Potteries born and bred lad done good!
Robbie Williams, a Stokie, My Way
MASHIN Dialect. Courting. Going out. Dating.
MASON Occupation. Works in a fireclay factory mason's shop. Uses hammer and chisel, drills, mechanical saws and other cutting tools to shape large pieces of fireclay pottery. In the case of gentlemen's urinals the mason cut and shaped huge backslabs of fireclay to create a long, joined urinal range.
MASONS IRONSTONE Type of pottery first patented in 1813. A particular recipe and requiring particular firing conditions. Particular to Masons Pottery factory, Hanley. But manufactured also by other potters.
MASTER MOULD Equipment. Potting department. Sometimes called a Block Mould. The first mould created from the model. Precious and must be preserved.
MATCHER Occupation. Warehouse. Usually a lady, but men did it too. The matcher would ensure that the pattern or colour of all the products in one complete a dinnerset or teaset would match each other. Particularly important for very large and expensive services.
MATCHING Process. Warehouse. The process of ensuring that the decoration employed on the individual pieces in a set (dinnerset or tea set) match each other.
MATCHINGS Some specialist companies have been set up to offer a matchings service. They sell odd pots which customers may buy to complete their dinner or tea services which may have had a piece broken in use. These companies do well by selling over the internet.
MATE Dialect. Meat. Filling in a pace. "Pace a mate." Not mar mate.
MATT GLAZE Type of glaze. Dull surface with no glossy shine. Used frequently by art potters. Josiah Wedgwood used it from the early 1930s.
MATURING Process. Like ageing, storing clay for a considerable period to allow it to homogenise. Moisture content will even out through the mass during ageing.
MATURING TEMPERATURE The temperature at which the body and the glaze develop to the required properties of colour, hardness, density, etc. of the pottery.
MATURING POINT Firing point (a combination of temperature and 'soak' time) at which the body or glaze reaches it's desired condition of colour, hardness, density, etc.
MAWL or MAU or MOW Equipment. The special tool used by a Saggar Maker and a Saggar Makers Bottom Knocker to flatten saggar clay into a slab. Like a large wooden mallet. Oak. Kept in submerged in water when not in use to stop saggar marl sticking to it during use.
|Two lads on a potbank with a mawl, mau or mow|
MAYTHERED Dialect. Emotion. Upset. Worked up over a situation. See Myther.
MAIZE EARLS Dialect. Infectious spots on potters. Highly infectious viral illness. Causes a range of symptoms including fever, coughing and distinctive red-brown spots.
MAZ BLUE or MAZARINE BLUE Royal blue, in intensity. Onglaze or underglaze. Based on Cobalt Oxide and flux.
MEDFEATHERS Part of a Bottle Oven. The brickwork used in building the flues and mouths in the oven. The dividing wall between two flues. Medfeathers, which form the flues and support the oven bottoms, are built four bricks high. Bricks used are firebrick and usually flat backs. They may sometimes be tapered and sometimes notched. Also known as Midfeathers.
MELDON STONE Component of pottery body recipe. Low quality China Stone. Cornish.
MEMORY Clay is said to have a memory. After the first fire, clay sometimes show signs of its processing prior to firing. It appears to have a memory. This is mostly caused by the orientation of the clay particles during the making process. In sanitaryware manufacture a well known problem is called slip-meet. The piece looks perfect before firing but after firing a distinct bulge appears at the point where the poured slip meets to create the full cast.
METAL MARK Glaze fault. Silver cutlery or other soft metal will leave a thin smear of metal on pottery if the glaze is minutely pitted. This pitting may be inherent or may arrived over a period through constant use.
METAL RELEASE A problem which pottery can suffer from. Toxic materials, mainly metals, being released from glazes into drink and foodstuffs. Lead and cadmium are the metals of greatest concern, although testing can be extended to include others. Regulations have existed since the late 1960s to protect consumers. Monitoring the level of metal release from glazed ware should form part of the Quality Control procedures of all reputable producers.
METAMERISM The phenomenon which occurs when colours appear to change when viewed in different types of light. So coloured objects might match perfectly in one light source (for example in fluorescent light) but not in another (say, incandescent or candle light.)
MICA Material. A waste product in china clay (kaolin) extraction. A shiny silicate mineral with a layered flakey structure, found as minute scales in granite and other rocks.
MICROLITE Brand name for shower trays produced in a fine fireclay. Twyfords and maybe others. Contains a grog of molochite.
MIDFEATHERS See medfeathers - directly above.
MIDDEN Dump. Pile of waste, sometimes human excreta. Smelly! A mound or deposit containing shells, animal bones, and other refuse that indicates the site of a human settlement.
MIDDLEPORT POTTERY BURLEIGH WARE Trade name for a product from Burgess and Leigh Ltd., Middleport Pottery, by the canal, Middleport, near Burslem, Stoke-on-Trent
MILL or MILL HOUSE A department in the potbank. In the sliphouse. Where the potting process starts and where the raw materials required in the ceramic body recipe are prepared. Flint is calcined and ground to fine particle size. China stone is ground. Bone is calcined and ground. When prepared, the raw materials are stored and constantly stirred in slop form, with water, to prevent them settling out, in arks.
|The Mill House|
MILLER Occupation. Sliphouse. Usually male since it is heavy work. Operates the machinery which grinds and mills the component materials of the pottery body to a fine particle size.
MILLING Process. Crushing and grinding component pottery recipe materials to a fine powder. Usually with water.
MINTON OVEN Type of bottle oven. Downdraught. Patented by T W Minton No 1709 May 1873.
MITHERED Past tense of Mither. Dialect. A worry. 'Dunna mither me, arm ow rate, duck!' Also Mayther. Or myther.
MOCHA CUP Small sized cup. Coffee cup
MOCHA WARE Pottery ware of the late 18th through the early 20th centuries, ornamented with colored glaze worked into branch-like patterns by drops of a diffusing agent applied while the glaze is still wet.
|Mocha type ware excavated from the Spode Factory site|
MODEL The original 3D design of the pot. The pot could be as small as a teacup or as big as a toilet.
MODELLING Process. Potting department. Creating a model using clay or Plaster of Paris. Also sometimes wax or alabaster. And for very large pieces (Eg: sanitaryware) the model may be created in high denisty foam or even wood.
Clay modelling: Before the pottery article can be produced from a mould it has first to be modelled from a mass of clay, which is gradually built up by adding or removing clay with the fingers or with wooden tools until the desired shape is realised. From the original model, block and case moulds are made, and from these working plaster moulds which have to be frequently renewed. Modelling for the pottery industry is a comparatively slow, delicate and costly.
THE MODELLING PROCESS
A SERIES OF POSITIVES AND NEGATIVES
master block -
master case +
working block -
working case +
working mould -
clay piece +
master block -
master case +
working block -
working case +
working mould -
clay piece +
MODELLER Occupation. Very skilled. Highly paid. Male or female. The person who interprets the designer's drawings and creates a 3-D model of the piece in either clay or plaster. Since clay shrinks during drying and firing, the modeller has to be highly skilled to expand the size of the model, by as much as 10 or 12%, so that the finished size is a true representation of the original design.
MODELLERS' TURNING TOOLS See diagram. The tools include the Borer and Frog
MOLOCHITE Material. The grog ingredient in the Microlite (fine fireclay) shower trays. Molochite is a hard abrasion resistant alumino silicate produced by the calcination of specially selected kaolins. Molochite is made by firing raw low-iron kaolin to very high temperatures to bring about maximum conversion of the clay crystal to crystalline mullite (usually 95%+). The latter has high mechanical stability and resistance to thermal shock. Many thanks to Simon Howard for suggesting this word. March 2016
MONITOR Name of the high pressure water hose used to blast china clay from the sides of deep open china clay pits in Cornwall and Devon, England.
MONKEY ARM Equipment. Found on jolleying and jiggering machines in the clay end.
MONKEY MUCK Material used during the process. Sanitaryware casting. Congealed slip. Used to stick two separate pieces of clay together to form one piece. This is clay slip squeezed from an icing bag onto the rim of a still-damp clay WC prior to the flushing rim and top of the WC being placed into position. The slip is the 'glue' which holds the base and the top together prior to glazing and firing (once-fired vitreous china).
MONTMORILLONITE Material. Clay such as bentonite. Results from the breakdown of airborne volcanic ash. The finest particle-size of all clays. Very high shrinkage, and generally used only as an additive to clay bodies or glazes.
MOONSTONE Type of glaze with a particular recipe and requiring particular firing conditions. Matt white surface finish. Particular to Josiah Wedgwood.
MOORSTONE Early name for Cornish Stone. Component of pottery body recipe. Same as china stone. In the UK it is found in the St.Stephen's and St.Denis districts of the St.Austell granite mass, Cornwall, South West England.
MOPPIT Moth. As opposed to WOPPIT which is a wasp.
MORED EAT ITE Knocked the saggar marl out with a mawl (pronounced mow).
MORTAR Material. Used for joining structural brickwork. May be cement mortar or Lime mortar or a mix of the two.
MORTED WARE or MORTING Pottery body fault. Well known in the days of bottle oven firing. Caused by partially dried clay pieces re-absorbing moisture before the fire. If this happens thin layers of partially re-hydrated clay when in contact with layers of dehydrated clay, flake off. Particular problem in once fired clay-glazed product.
MOTTLING Type of decoration. Sponged on or applied by roller. By hand.
MOULD The essential potter's tool for the shaping of pottery by slip casting, jiggering, jolleying or plastic clay pressing. The type of Plaster of Paris used depends on the type of mould being created or formed. The shape of the mould - whether in the positive or negative state - depended on the stage of the mould making process. In pottery manufacture the working mould was made from light and very porous Plaster of Paris.
THE STAGES IN CREATING A WORKING MOULD
Negative BLOCK, the Master Mould, formed from the model
Positive CASE, similar to the original model, but formed from the BLOCK
Negative WORKING MOULD formed from the CASE
The positive CAST PIECE
MOULD MAKER Occupation. Potting department. Usually a man who created working moulds from cases.
MOULDMAKING Process. Potting department. Creating the working mould from which pottery holloware can be cast or jiggered, or pottery flatware can be jolleyed. There are several different stages in the mouldmaking process.
- Modelling A model of the desired finished piece is created in plastic clay or in Plaster of Paris. Different shapes and sizes can be modelled for holloware (jugs, teapots, cups vases, bowls etc), flatware (plates and saucers etc) and figurines. This prototype model needs to be larger ( as much as 12% larger) than the envisaged fired or finished size of the final product so as to allow for the shrinkage of the clay during drying and firing.
- Blocking The process of producing the first or master mould. This is a precious mould and needs to be well protected and preserved since often the original model will be destroyed during the blocking process. The block can be a simple one-part mould such as for a cup for a jolley machine or a multi-part mould for casting a figurine or teapot.
- Casing The process of making the replica of the original model using the block. The block can be 'cased' in either a hard plaster or a silicone rubber, again this maybe a simple one part case or a complicated multi-part case. Cases must be stored in pristine condition, so that new working moulds may be perfectly formed from them as the old working moulds wear out.
- Mouldmaking working moulds From the case, the required amount of working moulds can be produced. The plaster used is lighter and less dense than that for the block and case. It is also highly porous so that water can be absorbed from the clay slip during the casting process. Once a working mould has been made, it must be dried out completely before use. Working moulds have a limited lifespan will last only for between 60 and 80 castings. After that time the surface of the Plaster of Paris deteriorates and the fine details and seams of the mould become worn.
MOULD MAKER'S SIZE A fluid made from soft soap melted into hot water. The subsequent solution is spread with a sponge onto the surface of the mouldmaker's case to ease the removal of the set plaster mould from the case. A bit like spreading butter onto the surface of a baking tin to allow the baked cake to be removed easily.
MOULD RUNNER Occupation. A man or a boy and sometimes a girl employed in old pottery factories. He ran between the maker (the potter) and the drying room, carrying moulds filled with clay to be dried, and returning with empty moulds for filling. Exhausting work.
From Clayhanger - Arnold Bennett - describing the work of the mouldrunner; the details seem to have been taken from 'When I was a Child' by "An Old Potter" (C. Shaw) first published in 1903 which is a wondereful first hand account of someone working as a child in the pottery industry.
"At the age of seven, his education being complete, he was summoned into the world...
Darius was first taken to work by his mother. It was the winter of 1835, January. The next morning, at half-past five, Darius began his career in earnest. He was ‘mould-runner’ to a ‘muffin-maker,’ a muffin being not a comestible but a small plate, fashioned by its maker on a mould.
The business of Darius was to run as hard as he could with the mould, and a newly, created plate adhering thereto, into the drying-stove. This ‘stove’ was a room lined with shelves, and having a red-hot stove and stove-pipe in the middle. As no man of seven could reach the upper shelves, a pair of steps was provided for Darius, and up these he had to scamper.
Each mould with its plate had to be leaned carefully against the wall and if the soft clay of a new-born plate was damaged, Darius was knocked down. The atmosphere outside the stove was chill, but owing to the heat of the stove, Darius was obliged to work half naked. His sweat ran down his cheeks, and down his chest, and down his back, making white channels, and lastly it soaked his hair.
Darius reached home at a quarter to nine, having eaten nothing but bread all day. Somehow he had lapsed into the child again. His mother took him on her knee, and wrapped her sacking apron round his ragged clothes, and cried over him and cried into his supper of porridge, and undressed him and put him to bed. But he could not sleep easily because he was afraid of being late the next morning."
MOULD STORE Potting department.
MOWED Dialect. Mould. Used to create a pot.
MOWED RUNNER Dialect. Occupation. Mould runner. Occupation. A man or a boy and sometimes a girl employed in old pottery factories. He ran between the maker (the potter) and the drying room, carrying moulds filled with clay to be dried, and returning with empty moulds for filling.
MOWING IN Process. Maturing new clay to make it more homogeneous.
MOW OUT or MAU OUT Dialect Saggar making. Bashing a lump of saggar marl with a mow or mau to create a flat slab of clay for use as a saggar bottom.
MOUTH Part of a Bottle Oven. The firemouth. On average, eight firemouths were built into the oven. It was here that coal was baited, set alight, to raise the temperature in the oven to between 1000°C and 1250°C ( sometimes as high as 1400°C) to fire the ware.
MUCKER Friend. Mate. Buddy.
MUFFLE KILN Type of Bottle Oven. Usually for a decorating fire - enamels. Built in such a way that the harmful gases of combustion, or the main heat source, are kept away from the ware in the setting. In this coal-fired kiln the flames did not directly enter the firing chamber as in downdraught and updraught ovens but were led around the outside of the chamber by a series of flues. In this way the delicate decorated colours were protected. The firemouths were kept separate from the kiln chamber.
A muffle kiln was a lot smaller than the other types of bottle oven and temperatures reached were lower at around 850ºC. This temperature made the decorated colours permanent (without firing, the colours would easily rub off or wash off) and did not need as high a temperature as the biscuit and glost. Also used for firing fireclay glost. More types of bottle oven here>
|Bottle Oven - muffle kiln |
Cross section diagram and external view of an oven at Gladstone Pottery Museum, Longton
drawing and photo: Terry Woolliscroft
MUFFIN (American) Small domed spongy cake made with eggs and baking powder.
MUFFIN (English) Small leavened bread. Beloved by the English aristocracy particularly in the early 20th Century and served in a Muffin Dish. "In Victorian clubs the ‘correct manner’ of serving the humble mufﬁn seems to have attained almost the signiﬁcance of a religious ceremonial, if not actually a sacrament. Sir Clough Williams-Ellis, creator of Portmeirion, now in his nineties, recently recalled how in his youth "muffins would come in their heated covered silver dish along with salt cellar, china tea, cream and folded napkin, and be set down at my elbow by a club waiter still in the livery of the Regency, knee-breeches, silk stockings and buckled shoes . . . and all for no more than a shilling." From Good Things in England, 1932, by Florence White.
MUFFIN DISH Not to be confused with the small plate.
MUFFIN Pottery plate measuring 5 or 6 inches in diameter.
MULBERY Material. Colour. A mixed shade of blue, derived from a cobalt base, but lighter and greyer than the ordinary underglaze blue, or cobalt blue. Mulberry is sometimes described as Canton Blue.
MULLITE Material. Clay mineral. Refractory. Aluminium silicate, produced artificially during various melting and firing processes.
MULTI OUTLET Sanitaryware. A multi-outlet WC is the term given to a WC which can be connected and used in all drain configurations. The horizontal outlet from the WC is configured so that it can be installed, with appropriate plastic connectors, to ‘S trap’, ‘P trap’, and ‘bottom outlet’ situations.
Many thanks go to Kath and Paul Holdway for help with this description - November 2010
|Murray Curvex Machine|
MURRAY CURVEX“In 1950 Guy Murray (d.1955) was invited by with the Spode company, then under the Copeland family ownership, to develop/invent mechanised printing. Murray urged the project to be conducted in great secrecy and a code name was used at Spode in relation to all aspects of the project. He also confined research and experiments to a permanently locked room at Spode.
The invention was based on the bat printing process and the first major breakthrough replaced the bat with a gelatine pad of circular parabolic shape. This pad had to be resilient enough to flatten itself when pressed down on and engraved copper plate then revert to its original shape when raised off; and then had to adapt to shapes of the curves of a plate fired to the biscuit stage (i.e. underglaze printing).
The first wares, when fired, revealed a problem that all the pattern fired away and disappeared. It was found that the oil-based colour, of the type used with underglaze transfer printing, was not compatible with gelatine. No suitable medium was then available. It was touch and go whether to continue as no solution could immediately be found.
Two of the Spode’s young directors won the day keeping the project going and used a retired chemist as a consultant. He produced a few colours which withstood the firing. Later two ceramic manufacturers made further developments. The ‘up and down’ movement of the machine was to be controlled by compressed air.
By late 1953 the basic problems were solved. The concept of the 18th century flat engraved copper was retained in conjunction with the gelatine pad. The Murray Curvex printing process reduced labour costs and improved productivity. Its use became industry wide with further developments over the next 50 years. It was still in use, with further refinements and the ability to printed in several colours (multi-bump machine) at Spode towards the end of production and closure of the company in 2009.
Murray proved difficult to work with and failed to acknowledge both individual contributions to the invention and of the Spode company, who had initiated the project and facilitated it on their factory site. The first patent application was in 1951 but instead of celebrations there were problems as Murray had not informed the Spode company of these patent applications in his own name. This was a hard lesson for the Spode company to learn. They never had the rights to this important invention to which they had contributed so much in investment of initiation of the project, their expertise, staff, research, time, facilities and costs. However it should be recognised that this important invention of mechanised printing used industry-wide was invented at Spode.
Here is an image of the later version of Murray Curvex known as 'multi-bump' here>
MUSHROOM Part of a bottle oven. Piece of specially moulded saggar marl to fill the well hole.
MUSSEL GOLD An older form of prepared gold for pottery decoration. Gold leaf is rubbed with sugar (or honey) and salt to make a paste. This was then washed free of soluble material and then stored in mussel shells.
MYTHER Dialect. A worry. 'Dunna myther me, arm ow rate, duck!' Also has the spelling of Mither or Mayther. You could also say "Dunna Wereet thee sen!"