What's a Bottle Oven?

THE BOTTLE OVEN - THE DOMINANT AND CHARACTERISTIC FEATURE OF THE POTTERIES FOR OVER 250 YEARS

A huge, towering, brick-built, bottle-shaped structure, up to 70 feet (20 metres) high, once essential in the pottery-making process. The bottle shape could bet tall and thin or squat and fat. Short and thin or tall and fat!  Square or round. The shape depended on the use that the oven was designed for and the whim/experience of the builder, but all had a semblance of a bottle.

Potteries bottle ovens at Gladstone Pottery Museum, Longton, Stoke-on-Trent
Bottle ovens at Gladstone Pottery Museum
Photo: source unknown  Date: 1975

“THE ovens are the most important part of the potter’s plant, and it is on their successful management that the result of the business will largely depend. Good biscuit ware is absolutely necessary to make good glost ware and yet if the glost firing is not up to the mark the ware will be inferior, no matter how good the biscuit may have been.  It is on these processes that the ware depends for its solidity, brilliancy of appearance, and durability; and it matters little what care may have been bestowed in the potting, glazing, and decoration of the pieces if the firing is not satisfactory. It is in this department that more money is lost than in any other, and any time given up to the correction of defects, or to the lessening of breakage and loss in the ovens, is indeed well spent.”     Extract from: Notes on the Manufacture of Earthenware  by Ernest Albert Sandeman, 1901






The name 'bottle oven' was derived from their particular shape and not as a reference to the manufacture of bottles!

Some ovens were used for firing pottery to the biscuit and then the glost stages. These huge ovens could hold as many as 3000 dozen (36,000) pieces of pottery at a time.

Some, much smaller, were used for firing applied decoration to the ware to render it permanent. Smaller still were hardening on muffle kilns.

Some were used for calcining flint or bone for use as components of the pottery body recipe.

Some ovens were described by the way they operated - either as updraught or downdraught or muffle.

Some were described as 'oven-n-ovel' (oven and hovel, or more simply hovel oven) where the oven stands in the centre of the separate circular hovel which was, essentially, the chimney stack. These could be entirely free-standing or partially attached to an adjacent workshops, for instance, the placing or saggar shop.

Others were described as stack ovens where the oven and the bottle-shaped stack were built together. In this case, the bottle-shaped chimney stack was built straight onto the top of the shoulder of the oven. This type became part of the entire structure of the factory, with the stack rising through its roof.

Some ovens were a combination of both hovel oven and stack oven.

No two ovens were and are alike. More about oven types and shapes here>





"Some are prim and severe, spinsterish even, in line and appearance;  others peculiarly curvaceous. The immense heat of the firing distorted their swelling curves, great fissures and cracks appeared, drastic surgery was necessary to preserve them, the brickwork was renewed and their great bellies were strapped round with girdles of iron to save them from collapse."  From an essay by Reginald G. Haggar  here>






In 1939 there were about 2000 bottle ovens in The Potteries of Stoke-on-Trent (not 4000, which has been ignorantly suggested, elswhere)

In 2017 there are less than 50. Some have been restored to excellent condition yet others are just short of a heap of rubble. All are Listed Buildings.

Gladstone Pottery has five of those still in existence, and there are two next door at the Roslyn Works. So in a this very small area of Longton, the southern-most town of Stoke-on-Trent, there are seven magnificent bottle ovens - 15% of all those remaining in The Potteries. A very special place.

This grouping is unique, saved at the eleventh hour in 1970. more here>  

The Gladstone Pottery was restored and opened to the public as a museum officially on 24 April 1975 by The Duke of Gloucester. In the years since the museum opened its huge and magnificent ovens have undergone restoration and all five at Gladstone can be explored.

The people of the Potteries who lived and worked in these buildings invariably despise them. They created ill-health, terrible lung disease and early death. They filled the atmosphere of the area with thick black smoke and "golf ball-sized" smuts.  They ruined brickwork and paintwork and etched windows with the acid rain which they created.  They blackened churches and municipal buildings.






"Some of them were respected, others were feared, and some were absolutely hated and were known by rude names." From an essay by Sir George Wade here>






The remaining bottle ovens of The Potteries will never be fired again. The Clean Air Act of 1956 and their delicate condition prevent it. The remaining ovens of the The Potteries are all 'listed' buildings, yet that does not guarantee that they are safe from neglect, vandalism or collapse. (The oven in Town Road, Hanley collapsed in 2012)


Longton skyline with Gladstone Pottery circled photo: unknown source  date: 1953
Longton skyline with Gladstone Pottery circled
Photo: unknown source  Date: 1953




Simeon Shaw, in his History of the North Staffordshire Potteries, written in 1829, described the filth produced by bottle ovens

"The vast volumes of smoke and vapours from the ovens, entering the atmosphere, produced that dense white cloud, which from about eight o'clock till twelve on the Saturday morning, (the time of firing-up, as it is called,) so completely enveloped the whole of the interior of the town, as to cause persons often to run against each other; travellers to mistake the road and strangers have mentioned it as extremely disagreeable, and not unlike the smoke of Etna and Vesuvius."


Potteries bottle ovens and smoke in the landscape of Stoke-on-Trent
Bottle ovens and smoking chimneys in The Potteries landscape
Photo: source unknown  Date: Early 1950s




THE UPDRAUGHT HOVEL BOTTLE OVEN USED FOR FIRING POTTERY TO BISCUIT AND GLOST 

The hovel bottle oven: A bottle-shaped structure, built from brick, in which pottery was fired. It most commonly consisted of two main parts, an outer hovel and an inner oven.

The outer, which is the bottle shaped part, is known as the hovel. This could be up to 70 feet high, but never less than 60 feet according to the Borough of Hanley Works Committee Minutes – 14 February 1877. The hovel acted as a chimney taking away the smoke, creating an up-draught and protecting the oven inside from the weather and uneven draughts.

Potteries bottle ovens at Gladstone Pottery Museum, Longton, Stoke-on-Trent
Gladstone Pottery Museum - updraught bottle ovens in the cobbled yard
Photos: Phil Rowley  Date: 2015

There is a narrow gap between the hovel and its inner part which was called the oven.

The oven, proper, is a round, robust brick built structure with a domed roof, called the crown, and its walls are approximately 1 foot thick. Iron bands, known as bonts, run right round the circular oven at intervals, to strengthen it as it expands and contracts during firing.



...
Inside the hovel
The entrance to the oven is called the wicket. 
The black iron bands whcih strengthen the oven are called bonts
The image is of one of the ovens, open to the public, at Gladstone Pottery Museum, Longton, Stoke-on-Trent
360° picture provided by 360picture.uk


A doorway, called the wicket, was just large enough for a man with a saggar on his head to pass through (preferably without crouching) is built into the oven and 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 intense heat from the fire into the oven, like a small chimney.

...
Inside the oven. Bags, flues and blackened and charred walls.
Look up to the crown and crown damper, and out to the wicket.
The image is of one of the ovens, open to the public, at Gladstone Pottery Museum, Longton, Stoke-on-Trent
360° picture provided by 360picture.uk

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 up to 10 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, and up to 40 on very big factories (Spode, in Stoke, had 37 in 1843). Gladstone Pottery has five. At the Middleport Pottery of Burgess and Leigh, near Burslem, just one remains but at its height the factory had seven.

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




BOTTLE OVEN TYPES

No two bottle ovens were alike; each had an individual shape, character and method of firing. But all bottle ovens fall into four main types :
  • 1) Updraught
  • 2) Downdraught
  • 3) Muffle 
  • 4) Calcining
The Bottle Oven Survey of 1976 (organised by North Staffs Junior Chamber and Gladstone Pottery Museum) used this classification. more here>

Within the four main types some additional variations occur and these are described here>


MENTION OF BOTTLE OVENS IN PENNY MAGAZINE 1843

A day at The Staffordshire Potteries, May 1843, Page 201
Digitised by Google Books here>


DESCRIBING A 'POTWORKS' in the 1700s

Description extract 27 October 1767 for a site in Stoke rented by Spode & Tomlinson partnership:
'new erected hovell & three bays of building for the use & intention of a potwork…'


Description extract 29 February 1776 for the Spode site:
'pot works, pot ovens, pot houses, work houses, ware houses, compting house, barns, stables, cow house, marl bank, and out buildings to the same belonging ... adjoining Madeley's Meadow…'

Courtesy: Peter Roden research more here>


For definitions of unusual Potteries words go to The Potbank Dictionary here>