James Neilson’s Hot Blast: Pierre Armand Dufrénoy and Lady Charlotte Guest – part 2

by Victoria Owens

In September 1836 advertisements for On the use of hot air in the Ironworks of England and Scotland […] appeared in the London newspapers. Published by the august firm of John Murray, it was a modest octavo, priced at 5s 6d. To all appearance, the English text was anonymous, the title page stating only that the work was ‘Translated from a report made to the director-general of mines in France, by M. Dufrénoy in 1834 [sic]’ without naming the translator. The entries in John Murray’s ledgers were equally uninformative about the origin of the English version, referring to the work only as ‘Hot Air (On the use of)’ with a caret mark adding the scribbled note ‘By M. Dufrénoy’. The illustrations, however, carry some mark of Lady Charlotte’s involvement. Murray’s publication re-cycles the engravings which had appeared in Dufrénoy’s Rapport, but with an addition. Examination of the English text reveals the initials ‘C.E.G.’ – Charlotte Elizabeth Guest – in her distinctive handwriting beside each picture, presumably as confirmation to the printer that the image is to be bound in with the text.

Illustration of the Dundivan Heating Apparatus from On the Use of Hot Air in the Iron Works of England and Scotland […] (London: John Murray, 1836). The initials ‘C.E.G’ and date ‘March 1836’ appear below the engraved diagram.
To remain anonymous may have been her choice. Not only were mid-nineteenth century publishers apt to view women writers dismissively – it was why the Bronte sisters took masculine pen-names – but her mother had been less than happy about her marriage. For all his acumen, the industrialist John Guest was not the husband she would have chosen for her daughter – she preferred Robert Plumer Ward, a barrister-cum-novelist, whose proposal Charlotte resolutely declined. Charlotte, what was more, had loved South Wales from her first sight of the ‘blazing furnaces’ of Dowlais and the ‘broad glare of the fires.’ By contrast, when Lady Lindsey visited in August 1834, she thought the Glamorganshire countryside ‘wild enough for banditti’ and likened the ironworks to ‘a den of thieves.’ It seems unlikely that she would have viewed her daughter’s work on the Rapport sur l’emploi de l’air chaud with much enthusiasm. Nevertheless, Charlotte’s achievement did not remain secret for long. In December 1836 the local newspaper jubilantly identified her as the translator of On the Use of Hot Air and carried a story full of praise for her disregard of all ‘temptations to indolence’ and ‘frivolities of fashion,’ and ready devotion of her ‘time and talents to useful […] works by which mankind may be benefitted, and the interests of Science advanced.’

Her book had a print run of only two hundred copies but in iron manufacturing circles, it sparked considerable interest. On 1 October 1836, when it had been out for less than a month, John Wilson, co-proprietor of the Clyde Ironworks and member of the syndicate which held the patent rights to the Hot Blast process, called on Lady Charlotte to request a copy of her translation. He was apparently ‘anxious to see [it], as he did not understand French.’

If it yielded little financial return, the engagement with Dufrénoy’s survey of the British iron trade nevertheless set the course of Charlotte’s future. It is no coincidence that in her journal entry for 26 September 1836 – just when the book went on sale – she should mention having ‘undertaken the office of Merthyr’s secretary, to write all his letters and keep them copied and arranged.’ It was, she thought, a ‘beginning in earnest’ for which she had ‘been training for some time.’ Her remarks were prescient indeed, for on John’s death in 1852, she succeeded him as head of the works, and would soon have to bring all her acuity to bear on resolving a strike. Disputes aside, commerce gave her immense satisfaction. ‘I am happy to see we are at the head of the iron trade,’ she wrote in April 1839. ‘Otherwise I could not take pride in my house in the City, and my works at Dowlais, and glory (playfully) in being (in some sort) a tradeswoman.’

James Neilson’s Hot Blast: Pierre Armand Dufrénoy and Lady Charlotte Guest – part 1

by Victoria Owens

Many thanks to Victoria Owens who provided the following fascinating article.

When James Beaumont Neilson, engineer of the Glasgow gas works, patented his ‘hot-blast’ of 1828 – the system of pre-heating air by passing it through a hot ‘vessel or receptacle’ before it entered the blast furnace – he was confident that it would save fuel and reduce costs. Encouraged by three Scots iron manufacturers – Colin Dunlop of Tollcross, Charles McIntosh of Crossbasket, and John Wilson of Dundyvan, all of whom acquired shares in his patent rights – Neilson conducted  experiments at the Clyde Ironworks which demonstrated that use of the hot blast could reduce fuel consumption by about a third. News of its merits spread fast. Not only did many English, Scots and Welsh ironmasters adopt Neilson’s system, but the French inspector of mines, Ours-Pierre-Armand Petit-Dufrénoy, (1792-1857), visited Britain to analyse the economic and metallurgical consequences of its application.

Ours-Pierre-Armand Petit-Dufrénoy

Dufrénoy’s Rapportsur l’emploi de l’air chaud dans les mines à fer de l’Ecosse et de l’Angleterre’ appeared in the 1833 issue of the French Annales des Mines. By chance, Edward Hutchins, nephew of Josiah John Guest of the Dowlais Iron Company, obtained a copy, in autumn 1834 and, recognising the British iron trade’s likely interest in its content, asked his uncle’s wife Charlotte to translate it into English.

The previous year, John Guest had married Lady Charlotte Bertie, daughter of the late ninth earl of Lindsey. An able linguist, she was fluent in Latin, Greek, Persian, Arabic and Hebrew. Soon after her marriage, she began to learn Welsh from the Revd. Evan Jenkins, Rector of Dowlais, and would in time publish a best-selling translation of the mediaeval Welsh story-cycle known as the Mabinogion. That she had a fair working knowledge of French goes without saying.

She started work on her translation of Dufrénoy’s article on 3 December 1834, while John Guest, MP for Merthyr Tydfil, was canvassing votes for the coming general election. She found the text ‘full of technicalities’ and foresaw that producing an English version would take a long time. Nevertheless, she continued throughout the following day, and calculated that by the evening, she had completed about a sixth of it. Here, to give some flavour of the task, is Dufrénoy’s description of Neilson’s methods:- ‘Dans la première experience,’ he writes

l’air fut chauffé dans une espèce de coffer rectangulaire en tôle de 10 pieds de long, sur 4 pieds he haut et 3 de large, semblable aux chaudières des machines à vapeur. L’air provenant de la machine soufflanteé tait introduit dans cette capacité, oùil s’échauffait avant de sa render dans le haut-fourneau. Malgré l’imperfection de ceprocédé, qui ne permit d’élever la temperature de l’air qu’a 200⁰ Fahrenheit (93.3 cent), on pouvait déjà pressentir que l’idée de M. Nielson était destinée à produire une revolution dans le travail du fer.

‘In the first experiment,’ offers Lady Charlotte, ‘the air was heated in a kind of rectangular box of sheet iron, ten feet long, four high and three wide, similar to the boilers of steam engines. The air proceeding from the blowing machine was introduced into this space, where it was heated, previous to being conveyed into the blast furnace. Notwithstanding the imperfection of this process, which did not admit of the air being heated above 200⁰ Fahr, it became immediately apparent that Mr Neilson’s idea was destined to produce a revolution in the manufacture of iron.’

If terms such as tôle [sheet metal] and chaudières [boilers] sent her to the dictionary, her rendition of the idiomatic phrase on pouvait  déjà pressentir, [literally, ‘one could already foresee’] as ‘it became immediately apparent…’ shows her ready command of the syntax.

Lady Charlotte Guest. Photo courtesy of Cyfarthfa Castle Museum & Art Gallery

First caught up in the excitement surrounding the election and, later, dismayed by an outbreak of cholera, Charlotte does not mention the hot blast again in her journal until February 1835. By this time, she and John and their infant daughter Maria were visiting Charlotte’s mother and step-father at their Lincolnshire home – Uffington House near Stamford. ‘Wet Day,’ Charlotte wrote on Friday 13 February; ‘Merthyr (her private name for her husband) […] corrected iron hot air [sic] for me.’

For all its brevity, her statement raises intriguing questions. That John Guest should have been interested in the observations of a highly qualified mining engineer from a rival nation upon the production process of every ironworks from Calder to Merthyr Tydfil by way of Monkland, Codnor and Wednesbury was understandable. Whether he also wished to explore Dufrénoy’s account in the hope of discovering some means of using the hot blast technique without having to pay Neilson royalties is a matter for speculation. The fact that on 12 March 1836 an injunction was issued against Guest and partners restraining them from infringement of Neilson’s patent suggests that by the time Lady Charlotte was translating the French treatise, the Dowlais Ironworks had already introduced the hot blast. In the event, John Guest, was quick to settle with Neilson and his fellow patentees, and pay the shilling-per-ton royalty on iron produced by their method.

Furthermore, Lady Charlotte’s reference to her husband’s ‘correction’ of her work, suggests that, rather than treat her translation of the treatise as a work of private reference, the two of them thought it deserved publication. Certainly the English edition of On the use of hot air includes a number of observations – each designated ‘Note by the Translator’ –which, to judge from their detailed knowledge of the ironworks and coal deposits of South Wales, are the work of an industry insider. The remark, for instance, that before they introduced the hot blast, both Guest at Dowlais and Samuel Homfray of the Penydarren ironworks were using raw coal rather than coke to fuel their furnaces evinces considerable local knowledge. Incidentally the concluding ‘Note by the Translator’ not only gives a complete overview of the hot blast apparatus in use respectively at Dundivan in Scotland and Pentwyn, Clydach and Dowlais in Wales but also appraises the efficiency of the system and the quality of the iron produced in each place. Dufrénoy includes no corresponding commentary and this state-of-the-art survey of British iron manufacture offers an authoritative epilogue to the English version of his treatise.

To be continued in the next post……

Thank you

A big thank you to everyone who has already made a donation to help this blog keep going. It costs roughly £200 a year to keep the site up and running, so all the donations are greatly appreciated.

If you would still like to make a donation – please use the Paypal application to the right.

Merthyr Memories: Cyfarthfa Park Swings

by Laura Bray (née Bevan)

Do you remember the Cyfarthfa Park swings?  Not those that are there now, which are but a pale shadow of their former incarnation, but those of the 1970s?

There were two sets of swings in the Park. The Bottom Swings, down by the Lake –  more or less where the miniature railway now runs – contained a wooden, boxed-in roundabout; the most amazing helter-skelter slide which was about half the size, at least to my childhood eyes, of those found in a fairground; and the “baby swings”, for small children.  There was also the paddling pool, usually empty of water, but I recall some hot summers where it was filled and crowded by children in varying states of undress, splashing, both themselves and those on the bank, watching. My main use for the paddling pool, however, was to cycle round the edge, where there was a band of differently coloured paving slabs and where we could see how fast you could go without going over the edge and into the painted blue depths of the dry abyss!

But for me, the main attraction was the Top Swings. These were just off the road between the Chalet where you could buy ice-cream, and the Quar Gate. They contained a six-seater iron rocking horse, which you could push until it banged against its metal supports; a spider’s web roundabout where, depending on how dizzy you wanted to get, you could push from the inside or the outside, then jump on the bars with your legs outstretched and spin till you couldn’t stand up; and a slide, not too high, but which people did seem to routinely fall off. And we ran up the steps to slide down the slide, or raced up the slide itself, turning round at the top to come back down again. In the hot summer of ’76, the metal on that slide burned the backs of your legs, and yet we came back for more.

There were swings there too – a set of cradle swings for small children and a set of normal swings where we raced to see who could swing the highest. Sometimes we would jump off mid-swing to land with a thud on the floor, and there was a kudos in letting go when the swing was high. Then we would run to the parallel bars and the staggered bars, where we could hang upside-down from our knees and see if we could touch the concrete beneath. Not for our generation the soft surfaces enjoyed by children today.

However, the star of the Top Swings was the Swinging Log. These have all but disappeared now but essentially this was a plank, suspended from an A-frame, on which there was space for four children seated. Two more stood, one at either end, and they were responsible for swinging it back and forth. Some of the boys could swing it so hard that the plank reached heights parallel with the top of the frame, 15 or so feet from the ground, moving at speed. How there were no injuries, I never know, either from falling off or from the risk of being knocked out if you stood too close to the swinging end. There were several near misses, but that was part of the fun.

A log swing similar to the one in Cyfarthfa Park

We would take our bikes and bump across the grass between the two sets of swings and then head home – hot and tired, with our hands smelling of rust and our trousers stained by grass. Those were the days indeed.

If anyone has any photographs of either of the playgrounds in Cyfarthfa Park, please let us know.