I originally only transcribed the last entry of these, as a relatively accurate account of the early history of Portland cement as early as 1904. However, the whole exchange of letters is interesting, if only to show that little has changed in terms of the adherance of the various factions to their own anhistoric narratives.
The essence of the controversy over Joseph Aspdin concerns whether the product that he made, called Portland cement, and patented in 1824, was only a quick-setting hydraulic lime, as made in many versions at the time, or whether it was a modern slow-setting high-strength cement such as we call Portland cement today. Hard evidence one way or the other is almost totally lacking, and the matter has remained controversial throughout nearly two centuries. The matter was further complicated by a confusion among many writers between the work of Joseph Aspdin and that of his son, William - a confusion which the latter did his best to encourage.
The following transcribes a sequence of letters that appeared in the Yorkshire Post and Leeds Intelligencer, in 1904. It is believed to be out of copyright. An initial proposal to raise a monument to Joseph Aspdin, the inventor of Portland cement, is challenged because the product he made was not the important modern product. The question remains unresolved by the end of the exchange. Although I. C. Johnson is mentioned tangentially by Redgrave in the second letter, his claim to all the credit for modern cement had not yet been propagated. When he later made this specious claim, the lack of any consensus about the role of the Aspdins allowed it to be accepted without challenge. Presumably due to this muddying of the waters, no memorial to Joseph Aspdin was raised, and it was not until 1924 - the centenary of Aspdin's patent - that a memorial plaque was finally installed in Leeds Town Hall, paid for by the American Portland Cement Association.
The first letter was from Joseph Thomas Pullon (b 6/8/1850, Stanley, WR: d 3/1927, Leeds, WR) who was a Leeds engineer, much given to very long sentences. He started as an apprentice at Manning Wardle & Co locomotive engineers, and from 1871-1878 spent much of his time abroad on railway construction projects. He then set up as a consultant in London, but continued working largely overseas.
Monday 8 February 1904, p 9: JOSEPH ASPDIN, THE INVENTOR PORTLAND CEMENT.
To the Editor of The Yorkshire Post.
Sir.—On the centenary of Dr Joseph Priestley (Note 1), which is being so justly commemorated, both in Leeds and elsewhere, in memory of so distinguished a Yorkshireman (Note 2), philosopher, and scientist, but who, after all, was not a native of Leeds, allow me to call the attention of my fellow-townsmen, and especially engineers and others of kindred constructive industries, to the name, almost forgotten, of a genius whose invention has received world-wide application, and has rendered possible the construction of colossal engineering and architectural works all over the world during the last 60 years, who was native of Leeds, but who has received no recognition at all. I refer to Joseph Aspdin, the inventor of Portland cement.
The readers of The Yorkshire Weekly Post may have noticed an interesting article during October last on this subject, written by my friend, Mr B. H. Thwaite, A.M.I.C.E., of Westminster, which well worthy of perusal (Note 3).
I feel strongly that some effort should be made to provide some fitting memorial to Aspdin, whose invention is being utilised to a greater and wider extent day by day, not only in Europe and America, but over the whole of the globe, and the great utility of which in so many different classes of construction renders the name of Aspdin worthy to be remembered with those of Smeaton, Watt, Stephenson, Symington, Faraday, and the rest of the roll of celebrated Englishmen, whose work has so completely changed the conditions of life for the better during the past century.
An effort is being inaugurated with this view, which I trust will result successfully in perpetuating the memory of a worthy Yorkshireman, a Leeds man, and a great benefactor of the human race. I shall be glad to receive correspondence on this subject from any of your interested readers.—Yours, etc.,
J. T. Pullon, A.M.I.C.E., M.Am.I.M.E.
75, Victoria Road, Headingley, February 6.
The next letter, perhaps solicited by Pullon, is from Benjamin Howarth Thwaite (b 7/1855 Brighouse, WR: d 2/5/1908 Windsor, Berks). Thwaite was a civil engineer, concerning himself with gas generation, electric power and gas engines. He collaborated with Ransome in his attempt to construct a rotary kiln.
Saturday 20 February 1904, p 12: THE PROPOSED ASPDIN MEMORIAL.
To the Editor of The Yorkshire Post.
Sir,—It is certain that if the measure of the value of Joseph Aspdin's work could be adequately appreciated, his name would be for ever associated with those of the great heroes of practical science whose labour and results illuminated the last century. Among all the famous sons of Leeds, none more thoroughly deserve (sic) some form of plastic or memorial recognition, and in honouring Joseph Aspdin's name, Leeds men will honour their city, and doing so will honour themselves.
Any one who understands the practical science of cement-making, can easily appreciate (Note 15) the indomitable patience, the vexatious trials, and the personal and family sacrifices involved in the years of work intervening between the date of the conception of the idea—1813— and the year 1824, when Aspdin applied for his patent. This actual patent document, I am given to understand, is in the possession of Aspdin's grandson, now living near Leeds (Note 16).
This work of development, which formed the prelude to the patent of 1824, can only be understood when the contemporary knowledge of practical and industrial science is taken into consideration, and it known that the work was done at a time following on the period of the Napoleonic Wars, when it would be impossible (Note 17) for Joseph Aspdin, the Leeds bricklayer and mason, to have heard or learnt what the French chemists had done or were doing in the direction of cement-making, and in attempting to discover the secret hidden in the cemented joints of old Roman structures (Note 18).
From my own experiments in collaboration with the late Frederick Ransom, A.Inst.C.E., in producing Portland cement in a rotating type of furnace (Note 19), I am satisfied that Joseph Aspdin's long years of experimentation after 1813 are traceable to the difficulty he would find in securing the high degree of heat necessary to completely expel the carbon dioxide (Note 20), and only when he succeeded in constructing a kiln that would enable him to continuously produce the genuine Portland cement clinker, was he able to make the slow setting cement, or what Candlot, the French authority, defined in 1891 as un ciment à prise lente (Note 21).
I am satisfied that Joseph Aspdin, in his early experiments, extending from 1813 to 1824, had produced intermittently the genuine Portland cement clinker, but the production of a perfect uniformity of cementitious product would be the difficulty (Note 22), and it is to Aspdin's great credit that he struggled on through long years until he obtained the result that satisfied the great civil engineers of the railway era, including among them Brunel, who employed Aspdin's cement in the construction of the Thames Tunnel, commenced in 1825 (Note 23). Had this Aspdin's cement been of the quick-setting, non-vitrified or irregular quality, its treacherous character would have been discovered as far back as seventy years ago (Note 24). As my article in The Yorkshire Weekly Post of October 15, 1903, explained, not only did Aspdin's cement satisfy our great constructional engineers of the early 19th century, but satisfied Sir Robert Peel, who was greatly impressed with its high quality and national importance (Note 25).
It is pleasant to realise that some foreigners, even Germans, are sufficiently magnanimous to admit that Britishers have done something in practical and constructional science and invention. For instance, Herr Becker, in his work Erfahrungen über den Portland Cement, published in 1853, gives Aspdin the honour that belongs to him as the inventor and perfecter of the process of manufacturing Portland cement. M. Candlot, the French authority, in work on Ciments, published in Paris in 1891, does practically the same; and Professor Busing in his work on Der Portland Cement, published in Berlin in 1899, gives credit to Aspdin for employing the high temperatures necessary to produce Portland cement clinker (bei sehr hoher temperatur einen vorzuglichen hydraulischen Kalk zu erzeugen welchen er Portland Cement nannte) (Note 26).
Fourteen years ago the Italian authority Cardi, in his work on Esperimente sulle Cement, gives England the credit for producing cement a lente presa.
Had French cement manufacturers believed they could justly claim the credit of the invention for one of their own countrymen, they would have named it after Vicat, but Aspdin's cement is known all over the world by the name Portland cement. Q.E.D. (Note 27)
The justice of Aspdin's right to the credit of the invention and the commercial perfection its manufacture can be found in most of the great engineering constructional works produced in the Victorian Era. Aspdin's cement, all along, has been the true Portland cement. Samples of under-burnt material may have been sold, and applied to artistic and other irresponsible applications, but I am confident not with the sanction of Joseph Aspdin.
I sincerely trust that the natives of Leeds will see that the genius who produced the cement that rivals that of old Rome will do justice to themselves and their city by perpetuating his name in a suitable manner in some conspicuous position in the good old town.—Yours, etc.,
B. H. Thwaite,
29, Great George Street, Westminster, London, Feb 18.
The final letter (of those I have found) was a relatively well-informed summary of the facts, making clear that a sceptical view of Joseph Aspdin's contribution was already well-established in 1904.
Wednesday 2 March 1904, p 5: JOSEPH ASPDIN AND PORTLAND CEMENT.
To the Editor of The Yorkshire Post.
Sir, — The following facts may be of interest in reference to recent correspondence in your paper on the subject of a proposed Aspdin Memorial (Note 28).
In the year 1756, the important action of clays in natural or artificial conjunction with carbonate of lime in the production of hydraulic or water resisting cement was first demonstrated by Smeaton, and utilised by him in the construction of the original Eddystone Lighthouse. (Note 29)
The principle was afterwards applied experimentally by Mr. Vicat, in France, in 1818, and further developed by Pasley and Frost in this country about the year 1826.
Sir C. W. Pasley is said have been the first to use Medway clay in the manufacture of hydraulic cement at Chatham, and very shortly afterwards Frost started the manufacture on a commercial scale at Greenhithe, Kent, on the actual site of the present well-known works associated with Messrs. White.
The patent specification of Joseph Aspdin, the bricklayer, of Leeds, is dated December 15th, 1824, but was clearly anticipated in 1810 by patents granted to Edgar Dobbs, of Southwark, and also in 1818 by a patent granted to Maurice St. Leger, of Camberwell. In all these patents the claim relates to the manufacture of cement by a suitable mixture of lime or carbonate of lime with clay or other substances containing alumina and silica; the mixture being afterwards burnt in kilns and ground to powder.
It is, however, certain that neither Joseph Aspdin nor his predecessors attempted to burn the mixed materials to the point of vitrefaction (sic) - an essential feature in the manufacture of what is now known as Portland cement. This appears to have been first adopted by a son of Joseph Aspdin (Note 30), who about 1828-39 (Note 31) was engaged at the works known as Robins's, at Northfleet, in Kent, now the property of the Associated Portland Cement Manufacturers (Limited); at these works the kilns erected by the younger Aspdin are still in existence (Note 32). The materials used were the local chalk and alluvial clay still employed in the neighbourhood by the largest makers Portland cement.
At an early stage the manufacture as carried on at Northfleet was developed and improved upon (Note 33) by Messrs. White, the successors of Frost at Greenhithe, and by Messrs. Francis, at Cliffe, and Hilton and Anderson, on the Medway.
So far as Joseph Aspdin is concerned, apart from the name "Portland cement," which he adopted in his specification from a fancied resemblance of the cement to Portland stone, he can only be said to have worked somewhat crudely on the lines of his predecessor and contemporaries, and the material which he produced was simple an artificially manufactured hydraulic lime.
We may, however, be content in recognising that Portland cement is essentially an English invention, which has been developed to the degree of excellence now attained by the best makers in the country and locality of its origin.
The memorial of its founders may be seen in the great constructive works of the last half-century throughout all parts of the world, and that its pioneers are still abreast of the times is evidenced by the fact that the most extensive modern plant in Europe is now in operation at White's works at Greenhithe, where Frost made his experiments, and in close proximity to the old kilns of Robins's works, where Portland cement was first produced on a commercial scale.—Yours, etc.,
W. Illingworth. (Note 34)
Popplewell's Chambers, 9. Market Street, Bradford, March 1.
Note 1. Of course, Doctor not of Philosophy but of Divinity.
Note 2. He was born at Birstall, near Batley, 10 km from Leeds.
Note 3. Thwaite's article reiterated the biographical details given by Spackman in his 1895 1st edition.
Note 4. W. A. Becker, Erfahrungen über den Portland-Cement, 1853 - apparently the earliest treatise on the subject.
Note 5. It was in the Yorkshire Weekly Post.
Note 6. In a sense, the lack of details is the most persuasive evidence. Joseph Aspdin was most probably not remarked upon because he was unremarkable.
Note 7. This is untrue: the Aspdin operation was always very small, and others - notably Frost and Francis - were much larger.
Note 8. In fact, Pasley was not greatly aware of anything - as late as 1847, he was saying that there were only three "artificial cement" makers in England - one Portland cement, one making a selenitic cement and one making a Blue Lias lime. In fact there were many others. So Pasley's impressions don't add much to our knowledge.
Note 9. This is, of course, nonsense. Pasley always maintained that clinkered material should be thrown away. He perhaps means Frost's plant, which much later began making Portland cement.
Note 10. I haven't been able to find out who he was.
Note 11. One might wonder whether a world without Portland cement would be more challenging than a world without oxygen. But this is an engineer's view.
Note 12. This gratuitous diversion is complete nonsense. The original product was called Portland cement long before this, and the product used at Portland was William's.
Note 13. What is "a sufficient degree"? Aspdin's patent doesn't specify other than to say that all the CO2 should be expelled, which could be accomplished at 1000°C, well below the temperature needed to make alite. And J. T. Pullon certainly doesn't know!
Note 14. Which one? One small snippet of information that has emerged since 1904 is the fact that Aspdin had at least three separate plant sites in Wakefield, and "modern" Portland cement wasn't made at any of them until after Joseph's retirement. The assumption that the final, Ings Road site was the "original" misled all the early writers.
Note 15. When he says "appreciate", he means "imagine", since there is no evidence for the trials and sacrifices suggested, all of which seem to be the product of a romantic imagination.
Note 16. This might have been William Altona Aspdin, Wiliiam's son.
Note 17. Note the subjunctive: this is unwarrented supposition. In fact, Frost, who was in exactly the same business, set up his plant having first visited Vicat's plant.
Note 18. Needless to say, Roman cement was in no way related to Portland cement.
Note 19. Collaboration with Ransome was scarcely a qualification, since Ransome's lack of understanding of cement was the main cause of the total failure of his project.
Note 20. This is clear evidence of his lack of expertise. It was thought by the likes of Ransome that failure to get a Portland cement product was due to incomplete decarbonation of the mix. In fact, the temperature needed to make Portland cement is the temperature above which alite is formed, which is much higher than that needed for decarbonation.
Note 21. "a slow-setting cement"
Note 22. The suggestion that it was variability that caused the delay in perfecting Portland cement is, once again, pure fantasy. Such issues were presumably resolved by the time the patent was obtained in 1824. But the patent does not even specify the composition of the mix, let alone set any standard for its uniformity.
Note 23. Claims of approval by the great and the good emanate entirely from promotional pamphlets produced by William Aspdin in the 1840s. The most prominent claim - that Portland cement was used in the construction of the Thames Tunnel - is completely bogus, since the materials used in that project were meticulously accounted for, and no such cement is mentioned. Other claims are no more likely to be true.
Note 24. Here we have a circular argument, delivered once again in the subjunctive. If, as was probably the case, Portland cement was not used at all for prestige projects, then its treacherous character (or lack of it) is a moot point.
Note 25. This is another of William Aspdin's claims. It had been suggested that, because of depletion of septaria for strategically important Roman cement, a tax ought to be placed upon it. William Aspdin said he wrote to Peel, saying that this was unnecessary, since a superior alternative to Roman cement had been developed. Peel, he said, replied approvingly, and the threat of a tax was lifted. There is no evidence that this actually happened.
Note 26. This is a quite blatent falsehood, presumably relying on an assumed inability of the average Yorkshire Post reader to translate the German. The full sentence was: Erst Joseph Aspdin, einem Maurer zu Leeds, gelang es, nach langjährigen Versuchen im Jahre 1824 durch Brennen einer bestimmten Mischung von gelöschtem Kalk und Ton bei sehr hoher Hitze einen vorzüglichen hydraulischen Kalk zu erzeugen, welchen er Portland-Cement nannte, weil der erhärtete Cement dem in England vielfach zu Bauten verwendeten, sehr geschätzten Portlandstein inbezug auf Farbe und Festigkeit gleichkommen sollte. This translates as "First Joseph Aspdin, a bricklayer of Leeds, by burning a certain mixture of slaked lime and clay at very high temperature, succeeded after many years of experiments in 1824 in making an excellent hydraulic lime, which he called Portland cement, because the hardened cement resembled in colour and hardness the much-valued Portland stone used in England for many purposes." So he doesn't mention clinker at all, and calls it (rightly!) a hydraulic lime!
Appeals to foreign writers of this sort don't usually help, since their historical knowledge is limited to having read the historical accounts produced by British writers, particularly Reid, who visited Aspdin's Ings Road plant, noted the tall kilns capable of high temperature, and mistakenly assumed that this was the original plant. A few of the German writers may have had direct contact with William Aspdin, but any conversation with him, it must by now be clear, would not have left them any the wiser.
Note 27. This is a valid point, but the cement that French cement manufacturers came to know and grudgingly love was William's, and not Joseph's.
Note 28. The Joseph Aspdin memorial in question did not materialise. A bronze plaque was placed in Leeds Town Hall in October, 1924 (the centenary of his patent) by the American Portland Cement Association, and in November 1938, a plaque was placed at St John's Church, Wakefield (his burial place).
Note 29. It was in fact the third: the present one is the fourth.
Note 30. i.e. William.
Note 31. These dates are badly wrong. He was only in Kent between 1842 and 1851.
Note 32. William Aspdin built eight or nine bottle kilns at Northfleet during the five short years (1846-1851) that he was there. The kiln bank was subsequently extended westward, to a total of twelve kilns. These were abandoned in 1887, but remained, in ruinous state, well into the twentieth century. The site was eventually redeveloped, and all but the last-built were demolished.
Note 33. Whether Whites or the others "improved upon" Aspdin's cement at the time is questionable, since tests at the time showed no significant systematic difference between the various suppliers' products. Obviously, all cements improved in quality over subsequent years. The other two manufacturers mentioned were also part of the APCM combine.
Note 34. I don't know who W. Illingworth was, but it's a fair bet that he had shares in APCM.