Minton Patent Ovens, Part 1: Patents

As part of our ongoing updates we’ve just added a new batch of digitised records to our themed searches, including a large number from the Mintons Patent Ovens section of the catalogue. We were curious to find out more about these special ovens and this portion of the collection is chock-full of information about them, from specifications and plans to marketing and correspondence. In this post – the first of a short series on the Patent Ovens – we thought we’d take a closer look at the patent behind the name…

As well as the ornate letters patent used as the feature image for this post the Mintons Patent Ovens section also contains the “Specification of Thomas William Minton. Ovens for Firing Pottery &c” (SD 1705/MS957), a detailed explanation of the patent itself. It declares that the nature of this invention is “to improve the construction of ovens for firing pottery, glass, and other substances” and exhaustively describes the various features of this new type of oven, referencing a number of enclosed drawings to do so. Thankfully the document also includes a more general explanation of the differences between the previous style of oven and the new ovens built to this specification:

In the ovens previously in use the fuel is burnt… by which arrangement the greatest portion of the heat radiating from the coke… has no other effect than to heat the surrounding brickwork without any direct action on the ware to be baked.

In the improved oven… the heat from the coke or the gases has a more direct effect on the saggars containing the ware with which it comes into contact; thus a considerable reduction in the quantity of fuel required… is realised. Besides, by the addition of a second chamber on the top of the oven use can be made of the heat that might escape from the lower part… avoiding besides the necessity of surrounding the ovens by a second building called hovel. In this way economy of space and money is effected.

A slightly more condensed version of the information present in the specification can also be found in a copy extract from Spon’s Encyclopaedia of Industrial Arts (SD 1705/MS989), including a short list of the claimed advantages for the Patent Oven:

1. Saving of space by doing away with the external hovel as well as the projecting fireplaces.
2. Saving of fuel.
3. Complete combustion of the fuel, and consequent prevention of nuisance.*

These documents help us understand what makes a Minton Patent Oven different – and what the benefits of this new “improved” oven were said to be – but to shed light on the genesis of the Patent Oven we can turn to SD 1705/MS992, a rather strained letter from Léon Arnoux to an unnamed individual obviously involved with the company at a high level. In it Arnoux effectively identifies himself as the man behind the Patent Oven:

When I went to Bournemouth last winter Mr Campbell told me these few words that if I could find some plan to reduce the quantity of coal for firing pottery he would help me to make a good thing of it.

and that he expects that – “if I do not mistake” – the improvements realised by the Patent Oven will save Minton up to 4000 tons of coal a year. Arnoux also makes clear in this letter that these sorts of benefits for the company were his primary concern but that if the Patent Oven is to be sold to other factories – something we’ll touch on in a future post – he would “expect a share in the profits”. This situation had obviously been previously misconstrued!

In our next post we’ll dive into the plans and drawings found in this section to find out what Patent Ovens look like – you definitely deserve some Folio-Friday-esque imagery after this rather text-heavy introduction!

* SD 1705/MS982 includes a note that a copy of this document was given to “the Commissioners of the Smoke Abatement Exhibition” so we assume that “nuisance” in this context means smoke and pollution.