Nineteenth Century Glass Making Devices

Historical: Keith Cummings describes some mechanical devices for Hot Glass forming used at Royal Brierley Hill in the late nineteenth century.

This information relates to a specific group of glass forming devices, which date from the last two decades of the nineteenth century and which were used in the manufacture of products by Royal Brierley Crystal during this rich and fruitful Swansong of High Victoriana. Their survival is, at least in part, accidental, having been stored in a forgotten loft, but in broader terms they are representative of similar devices which were in use world-wide during the same period.

1850 - 1900 saw the erosion of much of the raison-d'etre for factories that produced by traditional skill based methods. Factories like Royal Brierley Crystal, Thomas Webb and Richardsons in the Stourbridge area of the West Midlands found themselves, by the 1870's left with the production of high quality lead crystal stemware and decorative domestic items. The need to channel all of their competitive energies through these commercial outlets resulted in a proliferation of high Victorian form, colour and surface decoration in rich, complex and sometimes bizarre combinations. Labour costs, even the highly skilled labour of the glassblowers, were a relatively low element in the overall manufacturing equation. Adding visual value to an object that was going to be marketed for its novelty and decorative function within a domestic interior could best be achieved by extending its making time at the furnace. Decoration after this, though cold processes like, cutting and engraving or those that required re-firing like enamelling were, by comparison expensive.

The combination and interaction of these factors caused, for a short time, an outburst of invention, and the devices illustrated stem from and are representative of this. An important factor in their development were the in-house engineering shops that were an essential part of the hand made glass factory and whose role was to manufacture and maintain moulds and forming devices. This was especially true of experimental items constructed from wood and brass for prototyping prior to their manufacture in permanent form.

When I worked for Whitefriars Glass Company in the early 1960's they still ran an excellent engineering shop, which facilitated the development of Geoffrey Baxter's famous textured vases. The early test moulds, which I helped him with were constructed from bark, hob nails etc prior to being produced in cast iron. This direct link between designer and glass was an essential part of the creative process, especially in the period when designers had no direct contact with the material and had to communicate everything through unambiguous drawings.

Most of the devices illustrated here are not moulds in the strict sense of the word; they were designed to distort the blown glass after its preliminary forming and before it became a solid. Sometimes, as with rim forms, this required reheating to restore flexibility to the glass, but the principle of partial shaping remained constant. In doing this these devices exploit one of the most characteristic qualities of glass as it transforms from liquid to solid; its elasticity in its intermediate stages. The peculiar nature of glass as a super cooled liquid and the way in which it changes slowly from liquid to solid has been the basis of most glass forming processes. The way that hot glass creates a skin at its surface as its primary response to a loss of heat is paramount. Without this it would have been impossible to form it in any of the ways which have been developed over its five thousand year history. These devices particularly exploit the mobility of soft glass held in a state of equilibrium by the stiffer surface skin.

In commercial terms the prime function of these devices was to add value to objects by adding an extra decorative dimension at minimum cost and effort. This decoration was, with the exception of John Northwood's thread distorter, achieved through the manipulation of either the wall of the bubble or the rim of an opened form. They were designed to be operated by simple hand movements, the lifting and depression of an outside metal ring or the shutting and opening of flaps. Such operations were carried out by the most junior members of the glassmaking team, the boy who also carried the finished item into the lehr. Moulds that could be foot operated by the glassblowers were called, appropriately 'mechanical boys' although none of these fall all into this category.

It is particularly remarkable that the moulds made from wood and brass rod and wire should have survived. These were clearly prototype moulds and designed to last only for the production of a couple of items.

As a group they represent a way of thinking that allowed thought to become action within a short time through a direct link from design to material. It is ironic that this last great flowering of creativity within the traditional glasshouses occurred precisely at the point when they lost their central place in the production of glass items for everyday use. The development of machines capable of producing sheet glass or bottles automatically narrowed the relevance of manual processes.

However, the survival of such skill-based activities into the 21st century and their redefinition through the worldwide craft movement make an interest in such objects more than merely academic. The devices fall into six distinct categories and are described below with images.

Edge Crimpers - Items 1 - 10

Designed to distort the edge of an opened blown from, usually destined to become a light fitting for gas or oil. After puntying the bubble would be opened, sheared and reheated to make the rim area soft prior to its positioning in the device.

* The glass would be distorted both by the lower projections and the movement of upper projections placed counter to them. This is a simple concept but one capable of enormous variation through the design and spacing of the projections. The variety of crimped edges on light fittings of the period are ample evidence of this.

* It seems that these were called 'bolivers' in the Stourbridge area. This could be an anglised version of a French word.

Item 1 Lighting Boliver - closed Cast iron with adjustable centre boss and distorting fins. The robust iron frame ensured that such a device could be used for decades, and the fact that the centre and distorting fins could be varied in shape and number allowed its use to be changed.   Item 3 Lighting Boliver Two part iron mechanism with one side open. The principle is the same as 1 the central shaping boss and fins can be varied at will.   Item 5 Dish and Base. Stevens and Williams 1880's. Two items with walls and rims distorted by similar devices. Item 7 Test Crimper 1880's Made from wood and brass in the workshop at Royal Brierley Crystal this rare object was only intended to last for a few uses, either to make a one-off piece or, more likely, to try out a design in glass before going to the expense of a cast-iron version like 8. It is hinged and in two parts with the upper part split. One side is raised to show the upper and lower rod. Item 9 Decorative items, Stourbridge 1880.

Item 2 Lighting Boliver - open Showing the opening ratchet mechanism and three way split. Item 4 Boliver 3 in operation Both sides are open to allow removal of the shaped glass.   Item 6 Dish in cranberry glass with rim and applied collar, both heavily distorted. Stourbridge 1880's. Item 8 Cast-Iron Crimper 1880's A cast iron crimper with two-part operation and no flexibility of design, all of the fins are part of the casting. Item 10 Decorative items, Stourbridge 1880's Jug and plate with crimped body and edges. Two items distorted by crimping devices, the jug as a blown bubble and the plate after it was puntied and opened.

Hand held Crimpers - Items 11 and 12

These are small 'bolivers' designed to be held in the hand and used to distort the rims of small trumpet shaped objects (like baskets in epergnés). These particular ones do not show any evidence of actual use and may have even been unsuccessful prototypes. I hope not, for I find them extremely beautiful in their own right.

Dip Moulds - Items 13 to 18

Moulds designed to import a partial pattern of variations of thickness in the wall of an initial glass bubble. Once imprinted the glass is further inflated either freely or into a mould. The final items retain a pattern within the glass wall. The simplest of these moulds are called 'dip moulds', which describe the way in which the glass is given its pattern by being dipped straight in and out of them while more complex, patterns or forms are achieved by splitting and hingeing the moulds.

Although this is a simple and fast technique it generates a number of variants depending on how the patterned gather is made into a finished item. This includes leaving the pattern raised on the surface (by freeblowing), forcing into the interior as an optic pattern (by mould blowing) or by reheating the surface extrusions of a sensitive striking glass, creating a pattern of different colour within the same glass. Simple dip moulds had been used for centuries, particularly to create depressions in the glass, which became rows of bubbles when gathered over, but the more complex versions and uses were a particularly nineteenth century development. In North America, Amelung used dip moulds to create his famous range of bottles partly to cover contaminated glass due to a lack of sophisticated glassmaking skills .

Items 17& 18

These illustrate the complexity of some patters and the way in which the moulds vary in size and numbers of sections depending on requirements. This indicates their wide use as a design tool.

Rock Crystal devices - Items 19 to 23

These devices were designed to distort lead crystal paraisons by inflation through a brass cage. The glass would remain unmarked where it pushed through retaining its optical brightness. The mould was opened and shut by means of an outside ring.

The resulting object had a regular pattern within its profile similar to and inspired by Renaissance rock crystal carved vessels, hence the marketing name.

John Northwoods combing device - Items 24 to 27

Although the creation of a surface pattern through the distortion of a row of horizontal glass threads with a metal spike had been known since Egyptian times, this was the first attempt to mechanise it.

A blown glass cylinder which has had a surface covered with regular horizontal threads is placed in the device where a number of saw toothed vertical blades engage with the still soft glass. These blades are moved up by means of the large wheel under the device, combing the threads into zigzag patterns. This cylinder is removed from the device, reheated, blown, shaped, puntied and opened. This device is characteristic of Northwood who was a major creative presence in the Stourbridge area. It was fairly complex, required a high degree of control to operate, particularly in terms of the presentation of the glass at the right temperature for operation. In many ways it epitomises the late Victorian search for increasingly novel decorative systems particularly when used with coloured threads and unusual glasses that changed colour when heated.

Miscellaneous Items

These two items are separate from the main thrust of this article but are included out of interest because they come from the same source.

All of the objects illustrated came from the premises of Royal Brierley Crystal. Most date clearly from the 1880's although, it is hard to be precise about some items. I am grateful to the Board and Directors of Royal Brierley Crystal for their help and permission to publish. Glass objects 9.10.15.16.26.27 are all in the Glass Museum at Broadfield house, Kingswinford. I am also grateful for their help and permission. All photographs by David Jones.

This article is a special version of information included in, A History of Glassforming by Keith Cummings - published by A & C Black & University of Pennsylvania.

Professor Keith Cummings is Reader in Research at the University of Wolverhampton.