Age of Invention: All Fired Up

The mystifying, centuries-long failure of the coal briquette

You’re reading Age of Invention, my newsletter on the causes of the British Industrial Revolution and the history of innovation, which goes out to over 42,000 people. To stay tuned and support the project, subscribe here:

Previously, we looked at the many English attempts from the 1570s through to the 1630s to invent a smokeless kiln for drying malt — the main ingredient of ale and beer. This post was supposed to be the next part of that story, when we’d look at the technology that ended up being used instead: the smokeless coal, or specifically coal baked into coke. It was not only to usher in a revolutionary change in the drying of malt, which was a huge deal even on its own terms, but also in the smelting of metals, especially iron. I was supposed to first briefly introduce another method of how to remove the smoke from coal, spend a few paragraphs on why that didn’t work out, and then switch to a much longer discussion of the origins of coke. But it turned out that the first, failed method was so interesting, and its failure so repeatedly mystifying to contemporaries, that it ended up deserving a post of its own.

To explain, we need to see things from the vantage point of the 1580s, when we find the first recorded attempts in England to develop the smokeless coal. There were at least two main ways to go about it. One was to try to remove its soot-inducing, sulphurous impurities, which we’ll come back to another time when I set out the story of coke. But the other, much older, and more tried-and-tested method was to add a material to counteract them. At Europe’s greatest coal-mining region in the sixteenth century, near Liège in present-day Belgium, the locals there had long crushed the coal into a dust and mixed it with some wettened loamy soil or mud, working it into balls or briquettes before leaving them to dry, creating a fuel that burned more regularly and completely, releasing far less soot.

What follows is, effectively, the untold story of the coal briquette — and a solution to the centuries-old mystery of why it failed to catch on.

The Secrets of Signior Romero

The person who tried to bring these coal balls or briquettes to London was one Nicolas Romero — a name that has been almost entirely and undeservedly forgotten. Indeed, the one other historian to have ever noticed a handful of his achievements was unable to find his first name. And so I get the pleasure of being able to give a few glimpses of his remarkable story for the first time in over four hundred years.

Nicolas Romero seems to have originally hailed from the Spanish Habsburg possessions in Italy, most probably Naples. He was personally acquainted with Cardinal Granvelle, who was the regent in Naples from 1570 to 1575, and may have been involved in the Spanish attack on Tunis in 1573-4, where he picked up some siege techniques used by the Ottoman Turks. Romero then moved to Spanish-ruled Milan, where he was apparently the close confidant of one “Dr Sirnige” or “Dr Siring” (as it sounded to an English ear), who received a hefty reward for discovering a “defensative” or preventative treatment against a plague that killed some 15% of the city’s population in 1576-8. Then Romero appears to have gone to the Low Countries, much of which was in outright revolt against Spain, where he picked up the details of how coal balls were made at Liège.

There, astonishingly, he suddenly switched sides. Perhaps having fallen afoul of the Inquisition, or perhaps having converted to Protestantism, from some point in the 1580s he was only ever involved with the manifold enemies of Spain. He moved to England, even partaking — and I suspect investing — in its unsuccessful invasion of Spanish-ruled Portugal in 1589, where he was captured and held in “a very cruel prison” for ten months until managing to escape.

Somehow making his way back to London, Romero there befriended the barrister, alchemy enthusiast, and wannabe inventor Hugh Plat. It was via Plat, who plied all of his acquaintances for their technological know-how, and recorded his sources in his manuscripts, that Romero introduced various innovations to England.

Romero told him of how mere bags of linen or canvas, when filled with whatever dirt or sand was to hand, could be used to instantly create a “musket-proof” trench — in essence, the modern sandbag — which had been used by the Turkish army in their successful siege of La Goleta near Tunis. Plat saw a wider potential too, hoping to use these sandbags in reclaiming land from both marsh and sea.

In 1593, when a deadly plague gripped London, Romero gave Plat the recipe of Dr Sirnige’s defensative pills, as used in Milan, and together with the apothecary John Clarke they produced and distributed hundreds of them, including to Queen Elizabeth I and her entire Privy Council, apparently with great success. Clarke published their case notes under the boastful title The Trumpet of Apollo Sounding out the Sweet Blast of Recovery in 1602, though it was a little premature. Just a year later plague returned to London with a vengeance.

Most enduringly of all, Romero told Plat the details of making pasta, which Plat then made and marketed as a cheap and long-lasting food for the English armed forces. What Plat called his “macaroni” even won plaudits from Sir Francis Drake, and in 1594 he published the first known depiction of a pasta extruder. To Nicolas Romero, then — a name never mentioned by even specialist historians — belongs the considerable distinction of introducing the English to pasta. He is the patron saint of “Spag Bol” (if you are Italian, and do not wish to suffer a heart-attack, under no circumstances should you look up this term).

Romero was full of other ideas too. Romero gave Plat his methods for preserving wine, chestnuts, butter, turnips, and quince. He revealed to him the principle behind the diving bell; how to make a metal rotisserie oven; how to catch crayfish; how to engrave glass; how to make vellum paper translucent; how to keep snow from melting over the course of a year by storing it underground; and how a few drops of sulphuric acid might be added to a ship’s water supply to keep it fresh for longer. Along with various recipes for Italian salads, and how to make smoke grenades, he even told him how to raise water using atmospheric pressure — perhaps the earliest record in England of what would eventually be developed into the steam engine. In papers seized by the government from the soldier Sir Thomas Arundel, who was arrested for being a Catholic in 1597, are mentions not just of Romero’s sandbag “trench”, but “also his bridge, his boat to go without wind or sail, and his device against horsemen” — which according to Plat’s manuscripts was a kind of rest for muskets that could also serve as a pike.

Throughout the 1590s, Plat tried to commercialise some of Romero’s inventions, including a method to replace the expensive copper vessels for boiling water for home-brewing with a supposedly more efficient tub made of treated wood; some kind of light, portable water pump; and the Liège-style coal balls or briquettes. But with little success. By 1594 Romero was running low on money and had given up on trying to make it in England, having apparently passed up various opportunities to serve some German princes. So he left Plat in London to keep trying to sell his inventions, while he himself went to Holland to become an engineer in the service of Count Maurice of Nassau, who was fighting to free the Netherlands from Spanish rule.

While in the Netherlands Romero patented his water pump and the wooden boiling tub — an invention apparently “very much needed in the present time of cities under siege”, for whom fuel supplies were scarce. And having gained Count Maurice’s trust and backing, he wrote to one of Elizabeth I’s favourites, the Earl of Essex, in a fresh bid to get the two inventions, along with the coal balls, patented in England. Naturally, Hugh Plat served as his go-between.

Despite such allies, however, they once again failed. Romero would patent more inventions in the Netherlands in 1598 — a means of reducing the friction on the axles of carts and carriages, and a winch for more easily lifting heavy items like anchors and cannon — but he wasn’t to get a patent in England until ten years later in 1608. Just months before Plat’s death, Romero with one James Jackson, presumably an investor, was finally granted an English patent for some kind of universally-applicable method of saving fuel. Unfortunately, the wording of the patent gives no indication whatsoever of what it involved.

I’ve traced no further record of Romero — if anyone is familiar with German, Dutch, Italian or Spanish sources and has ever come across the name, please do get in touch — but along with introducing the English to pasta and sandbags and inoculating Londoners against the plague, his smokeless coal balls were remarkably resistant to being adopted, and not for want of trying. After a demonstration organised by Plat at some point in 1591-3 before the Lord Mayor and Aldermen of London, the coal ball was the talk of the town — “hot in every man’s mouth for a while”, as Plat put it — prompting the great and the good to visit his house “in whole troops” just to see it for themselves. Yet this failed to attract the reward he hoped for, to be able to reveal the secret to the world. After all, given that making the coal balls simply involved crushing up cheap coal and mixing it with mere wettened dirt, if Plat and Romero weren’t paid up-front, or if they didn’t receive a monopoly patent from the Queen, then the technique was so easily copied that neither of them would receive a penny should the word get out.

Undeterred, Plat lauded the coal balls among his most valuable secrets in the pamphlets and books he published in 1593, 1594, and 1595, continuing to call for a patron to purchase the method from him, and so release it to the benefit all. To the rich and powerful, he argued, its eradication of coal’s smoke should have been worth the investment alone, ensuring that their fine houses and palaces would no longer be besmirched with soot. But he also appealed to their charity and public-spiritedness. The poor, he argued, would save at least a third of the money they usually spent on coals, at a time when deadly plague, a run of especially poor grain harvests, and war with Spain had all combined to make fuel more expensive than ever before. The coal balls would, he argued, even give the poor the jobs they needed to be able to afford fuel in the first place — especially veterans of the war, who despite having lost their legs, might work the crushed coal and wet loam with their hands “according to the manner and making of snowballs”. All Plat asked, given the huge effect the invention would have on the country, was but a fraction of the gain.

Plat was ambitious about the size of that fraction. In his 1595 pamphlet he suggested that between the fuel-saving wooden boiling tub, the fuel-saving coal balls, and a fuel-saving method for making saltpetre — the crucial ingredient in gunpowder — the best way to reward him for revealing all these secrets would be to levy a general tax on the whole population, conceiving of it as a proportion of the fuel everyone would save. Underlying this ambition, however, was an anxiety. The boiling tub was designed for people’s private home-brewing, rather than for the breweries selling beer and ale to the public, and the coal balls could be easily made by poor people using common materials within the privacy of their own homes. So even if Plat were to receive a patent for them, it would be almost impossible to enforce.

As for simply being paid up-front, it was clear that money was too tight. He had already been promoting the secret for years, and noble or charitable patron had been forthcoming, while thanks to the war against Spain the finances of the government were already under severe strain. A new tax thus seemed the only way to capture at least some of the gain to the inventors, as well as setting a precedent, he argued, to incentivise both himself and others to reveal still more useful secrets, and so “enrich and beautify this little island with their admirable and most profitable inventions.”

Plat’s ambitious proposal failed to convince. The following year he was lampooned in a tract by Sir John Harrington, who in addition to promoting his own invention of a flushing toilet, unwisely took the opportunity to analogise, with excrement, many of the perceived corruptions of Elizabeth I’s court. Harrington sarcastically offered Plat assistance in his petitions for a tax to pay for the coal balls. Speculating that the secret ingredients must be urine and cow-dung, Harrington promised that if Plat played the game right and sold a half share of the patent to some powerful royal favourite, then “though it should poison all the town with the ill savour”, his oppressive monopoly on coal balls would nonetheless “be suffered”.

In 1596, Plat hit back in a pamphlet of his own, writing smugly that those in power were ignoring “the malice both of viperous tongues as also of slanderous pens”, and begging his audience to wait a little longer for the secret, because his petitions did “as yet attend some courtly favours”. But he was once again to be disappointed, and in 1603 — over a decade after having first demonstrated them, and having lost all hope of reward — he finally released the secret, publishing all the details of how to make the coal balls, along with helpful tips on how to judge the quality of coals offered for sale, how to most efficiently arrange the balls or briquettes when making a fire, and even describing a range of premium coal balls of his own devising, involving even more additives like charcoal and sawdust.

Plat’s coal ball fire, as illustrated in 1603

It’s unclear how many copies Plat printed, but it cannot have been many, as the fact he revealed the secret was soon entirely forgotten. A quarter of a century later, in 1628, one Richard Gosling was to advertise near-identical coal balls, citing Plat as the original inventor, but as one who had “kept this jewel secret, and so preserved it”. Gosling did make a few small changes to its form, sometimes lengthening the balls “into rolls like to a weaver’s shuttle”, and sometimes casting the mixture of coal and wet loam into the elongated triangular shape of a Toblerone box using moulds. Plat’s round coal balls, he claimed, had been best suited to boiling, whereas his longer briquettes were equally suited to roasting as well. But Plat must have turned in his grave at the lie that it was Gosling, and not he, who had first condescended “to show it to the whole world; who of his mere love, without coveting of a patent, has for the good of the poor and rich showed it at full in ample manner to give all content and comfort.”

Nonetheless, even Gosling’s pretensions seem to have fallen on deaf ears. In 1644, by which time Gosling was dead, one of his executors again advertised the details of how to make coal balls to the public. Suggesting that “had he lived, he might have put it to the press”, the executor was apparently entirely unaware that Gosling had already done so sixteen years before, and he made no mention of Plat at all. And even this was soon forgotten. Another twenty-two years later, in 1666, a physician named Theodore de Vaux read a short paper to the recently-established Royal Society on how coal balls were made, which was in fact an abridged version of Plat’s 1603 tract, copying from it almost word-for-word (it’s unclear whether he divulged his source, and so whether Plat was yet again turning in his grave).

Despite being presented to the country’s scientific establishment, however, the method of making coal balls appears to have failed to stick yet again. Eight years on, in 1674, the coal balls were being advertised in a pamphlet as “a new experiment lately found out”, and under the headline “good news for the poor”. The anonymous author noted how they had even been adopted by “several eminent victuallers and coffee-houses” in the city centre, but this cannot have lasted long: by 1716, the coal balls were again being promoted as a novelty, this time by the playwright and failed entrepreneur Aaron Hill, who had travelled widely and probably seen them for himself at Liège.

When Coals Fail to Catch

But the coal balls still wouldn’t stick — not just for the whole of the seventeenth century, but for the eighteenth, nineteenth, and well into the twentieth as well. Twenty-five years on from Hill, in 1741, the journal of the Royal Society published a fresh account of how coal balls were made. The author, a landed gentleman named William Hanbury, of Kelmarsh near Northampton, had apparently first seen them himself at Liège. He provided some coal balls for the Royal Society’s own hearths at Crane Court, and even demonstrated them at the house of the Speaker of the House of Commons. But the balls were to be advertised to the public as a novelty yet again in 1754; again in 1764, when Hanbury’s article was reprinted in full; and again in 1796.

We might, at this point, begin to wonder if the coal balls actually worked as advertised. Aaron Hill claimed in 1716 that “for pleasure, for heat, for long burning, and cleanliness, one bushel of this is worth two of sea-coal”. He was certainly exaggerating its efficiency, but over the centuries pretty much every author said something similar, noting how the addition of mud not only reduced coal’s soot, but made coal last much longer in terms of the heat it gave out.

Not everyone could believe it. The French scientist Gabriel François Venel claimed in the 1770s to have put the Liège-style coal balls to the test. Despite his “researches and experiments”, the only advantages he could see were in providing a way to use up coal dust that would otherwise have been wasted, and in not needing to stir the fire so often, adding dismissively that perhaps coal balls didn’t blacken one’s fingers as much as handling raw coal. Venel wondered whether the idea of their smoke-reducing quality and superior efficiency had been put about as a mere marketing ploy, so as to inure a sceptical populace to the very idea of burning coal.

Yet Venel was motivated to find fault. He wrote to persuade the people of southern France to adopt raw coal in their hearths, and took every opportunity to dismiss any notion that coal had any downsides at all. Many of his own claims were grossly exaggerated, and it undermined his case to admit that coal could be improved. Despite claiming to have conducted experiments, he didn’t report how he conducted them, or any measurement of results, most likely allowing theory to mislead him. Knowing that mud didn’t combust, he simply couldn’t see any way, in theory, that adding it would do anything to augment the combustion of coal.

Yet against Venel, who spent most of his life in southern France and cannot have had much everyday experience with coal, stand dozens of experiments by those who used coal all the time. Plat’s demonstrations in the 1590s had impressed coal-burning Londoners, and Hanbury in the 1740s had managed to convince the coal-burning fellows of the Royal Society, England’s premier scientific society. Indeed, the person to advertise coal balls in 1796 — and to resolve the seeming paradox of how they could give out more heat than raw coal — was none other than Benjamin Thompson, Count Rumford, one of the most important scientists to investigate heat in the eighteenth century, and a founding figure of thermodynamics.

To Rumford, the superior efficiency of coal balls was firmly empirically proven, having “been found by long experience”, and would only “appear extraordinary to those who have not considered the subject with some attention”. (Had Venel still been alive, he’d have felt that burn.) Rumford’s key insight was that ordinary coal was actually extremely inefficient, because much of it literally went up in smoke: “the enormous waste of fuel in London may be estimated by the vast dark cloud which continually hangs over that great metropolis, and frequently overshadows the whole country, far and wide; for this dense cloud is certainly composed almost entirely of unconsumed coal.” So what the coal balls did was to trap the fuel where it was actually useful, in the hearth. The added mud bound the particles of coal dust, preventing them from escaping up the chimney half-burnt, and so forcing them to burn completely and give off all their heat where it could actually be enjoyed. Coal balls were more efficient precisely because they produced less soot and smoke.

So we have considerable evidence that coal balls worked. Rumford even wondered if they might be improved by adding sawdust, much like Plat, almost two hundred years earlier, had actually tried. Indeed, when Rumford helped found the Royal Institution a few years later with the aim to apply science in the service of the poor, one of its fourteen founding research strands was to perfect the coal ball by “ascertaining the effects of mixing clay, etc. with coal dust and cinders in forming fire-balls and combustible cakes”.

With such high praise, the failure of Londoners to adopt coal balls was soon becoming something of a mystery. “It is surprising”, wrote one author in 1767, “that some work of this kind is not undertaken in the neighbourhood of London”. It was still “surprising” to another in 1789, and to yet another in 1828. The lack of adoption was not because of ignorance, as the knowledge of how to make coal balls became both widespread and in a sense latent — a technique lying embedded among the population at large, re-emerging whenever the situation seemed to call for it. In a letter to the London Evening Standard in 1867, a correspondent had no doubt that they would already “be inundated with letters when the hard frost sets in pointing out how [coal balls] can be made with coal dust and clay”.

In the early nineteenth century there was even a spate of patents taken out in Britain, continental Europe, and the United States to cover coal balls “made, with very trifling modifications, of the same simple materials.” Plat, having repeatedly failed to patent the method, must by the 1840s have not had a chance to stop spinning in his grave. As one writer sardonically put it: “notwithstanding the extreme antiquity and publicity of the custom among people at all times and all countries, there have not been wanting persons … to assert the originality of their re-invention”.

This was not entirely fair. There were some significant changes in the additives used as binding agents, and the process of forming the balls became considerably more mechanised. Using increasingly sophisticated compressing machines, the manufacture of coal balls became a major industry in the 1860s in Belgium and France — perhaps one of the reasons that we now almost exclusively use the French word briquette, rather than calling them balls. After they were displayed at the 1867 Exposition Universelle in Paris — one of the early World’s Fairs — an English observer called the mechanically-made briquette “one of the most important of modern inventions”. He was especially impressed by the progress made in Austria, where the binding agency of mud — which had traditionally taken up at least a third to a half of the balls, and left a lot of ash — had been replaced by taking up just 1% of the mixture with the residue from manufacturing starch, a substance “practically almost valueless for other purposes”.

Yet despite these processes being introduced in Britain too — major briquette factories were erected in the 1840s in both Sunderland and southern Wales — they still failed to find a market in London, and even in much of England. By the 1870s, of the 230,000 tons that they were producing each year, over 90% was instead being exported, and even into the twentieth century had failed to catch on, with the technique of making coal balls still occasionally resurfacing in the newspapers as a novel top tip for household thrift. As a Daily Express headline put it in 1920, “Coal Balls Save Coal Bills”. In 1942, with the country embroiled in the Second World War, the papers even called on the population to make their coals go further as part of their patriotic duty.

A Coal Ball Conundrum

So why did the coal ball keep failing to catch on in London? Ironically it was Plat who gives us a hint, by having recommended the manufacture of coal balls as a means to provide gainful employment for thousands of wounded veterans. Although he extolled this as a benefit, it also shows that coal balls required a great deal of extra labour to make. And as such, they would have been at their most attractive to Londoners at times of both severe fuel scarcity and high unemployment. It was when the poor were faced with rising fuel bills and struggling to find work that it made most sense for them to spend their hours of enforced idleness making coal balls, stretching their fuel reserves as far as they could. And with widespread unemployment causing the cost of any added labour to fall, it was also when coal balls were at their cheapest for the rich to buy.

The conditions of high unemployment and fuel scarcity were most usually met when England fought a war, leaving wounded veterans in its wake and mobilising swarms of enemy privateers to disrupt the supply of coal shipped down the coast from London to Newcastle. Indeed, the technique for making coal balls tended to pop up at precisely those times: in 1593-1603 when England fought Spain; in 1628 during the next conflict, this time against both Spain and France; in 1644 during the Civil War, after Parliament had banned the buying of coals from Royalist-held Newcastle, which was then besieged by the Scots; in 1666 during war with the Dutch; and in 1674 at the end of the next war with the Dutch.

Thereafter, with the British Navy increasingly dominant, the risk that privateers would disrupt London’s coal supplies seems to have receded. But the crucial conditions could still be brought about by extreme weather. When Aaron Hill promoted coal balls in 1716, there had been such a cold winter that the river Thames froze over. The demand for coal for heating must have been exceptionally high. When Hanbury demonstrated coal balls to the Royal Society in 1741 it was after the Thames had frozen over again in one of the coldest winters in centuries. Hanbury’s account was reprinted in full in 1764 on the grounds that “our daily papers are continually full of complaints of the high price of coals”, which a parliamentary inquiry discovered was the result of some “tempestuous and rainy seasons” having prevented the arrival of the coal ships.

Even in the late nineteenth and and early twentieth centuries, when coal in Britain had become super-abundant, there could be supply-disrupting events of such magnitude as to prompt the coal ball to be recommended again. In early 1873 it was owing to the coal miners of Britain going on strike for higher pay, resulting in what the newspapers dubbed the “coal famine”. Its consequences were so severe for ordinary people, both in terms of heating their homes and bringing all their workplaces to a standstill, that the failure of the mine owners and unions to reach a compromise was labelled a “treason against the supreme law of human society”. The periodic advertisement of coal ball recipes in the newspapers throughout the 1920s and 30s seems to have also corresponded to whenever the miners threatened to strike, or actually did, while in the early 1940s it was because coal supplies had become disrupted by the Second World War.

How to make coal balls, as illustrated in 1926 by the Sunday Mirror

Apart from being promoted and perhaps adopted during these specific crises, however, the coal ball just wouldn’t catch on. When coal was relatively cheap, it wasn’t wasn’t worth all the extra effort of making it go further, especially compared to the other items the poor had to stretch like food or drink or clothes. The only major appeal of coal balls became their lack of smoke, which could appeal to only the more discerning and wealthier consumers who could afford the extra cost. Yet even in this, coal balls were inferior to other smokeless fuels like charcoal, not least because they often still reeked of sulphur. And as for when unemployment was low, labour was in such high demand, and could command such high wages, that it made the coal balls all the more expensive to make, pricing them out of the market completely.

When a Penny Saved is Not a Penny Got

This would, you would hope, largely explain the mystery. But you might have spotted a rather important snag, as coal balls had also of course been used for centuries right next to the coal mines of Liège, one of the most coal-abundant places in sixteenth- and seventeenth-century Europe. Indeed, coal balls were the preferred fuel in many other coal-mining regions too. Visitors to Aachen in the mid-eighteenth century (then usually known as Aix-en-Chapelle) reported that the locals gave the coal balls “so much the preference to coal alone that, though the town is surrounded with collieries [coal mines], they burn in all their best rooms no other fuel.” In Ireland, close to the inland coal mines of Leinster, coal balls were in the early nineteenth century said to be “the principal fuel of every class of persons”. Even as late as the 1940s, with the disruptions to global coal supplies brought on by the Second World War, the Leinster newspapers reported on the resurgence of coal balls as an “old yet familiar substitute for coal”, albeit “perhaps a novelty to the younger generation, especially those in towns and cities”.

And they were not just a phenomenon beyond Britain. In the 1760s, coal balls were said to have already been in use near the coal mines of southern Wales for centuries, to the great mystification of visitors: “in a country abounding with coal pits, where there is no scarcity of any sort of fuel, one would not expect to meet with this economical preparation”. One English visitor supposed that the seemingly irrational practice of making them had originated centuries earlier, before the coal mines were discovered, commenting that “it proves how tenacious countries are of once-adopted customs”. Most others thought it simply reflected the Welsh national character, which included a marked propensity to scrimp: “nobody understands better than a Welshman”, explained one visitor, “the tenor of the old adage ‘a penny saved is a penny got’”.

Yet there was nothing peculiarly Welsh about the practice, because coal balls were also long used in many of the coal-producing regions of England, too. In the 1760s, coal balls were said to be in use near the coal mines of Brislington, just east of Bristol — a custom that had apparently started thirty or forty years earlier. And in the 1810s, up in the Pennine mountain range separating Cumbria and Northumberland, coal balls were reportedly in use near the many coal outcrops at Alston Moor and Cross Fell, and had probably been in use there for centuries.

So if it wasn’t the peculiar character of the southern Welsh, or of the inhabitants of Leinster, Liège or Aachen, what explains the use of coal balls where coal was at its most abundant? The answer, I think, lies in the fact that not all coal is the same. One thing that all of these regions had in common was that they produced a particularly pure, hard, rock-like coal known as anthracite, then usually called “stone coal”. As I noted in previous posts, anthracite was so smokeless as to be the highest-quality fuel used in drying malt, and had always been a luxury fuel in people’s homes. When Londoners imported coal from as far away as Wales or Scotland, rather than from Newcastle, they were importing the very largest and highest-grade coals for the parlours and bedrooms of the rich, as an alternative to smokeless, expensive charcoal.

What this meant, however, is that those who lived in the regions where anthracite was mined, or who were even the miners themselves, were priced out of being able to buy the good stuff, outbid by the needs of industry and by the wants of the wealthy in distant lands. What the locals burned instead were the much cheaper by-products of mining anthracite: the tiny shards, flakes, and fragments that chipped away from the larger coal rocks, or which in some places were only ever present in the ground in that form. In the mines of the Pennines, for example, the lower coal seams were already made up of small brittle flakes that immediately crumbled “to powder when exposed to the air”. This coal dust, or coal slack, was known in Liège and Aachen as clute or clutin; in the north of England as crow-, craw-, or crop coal, being typically found on exposed outcrops; and in Wales, Ireland, and the west of England as culm (although, confusingly, culm was also sometimes the name given to Welsh coals in general when sent outside of Wales). At Mt Billingen in Sweden, the dust was also known as kolm, which was later discovered to be rich in radium and uranium — their culm balls, if they made them, must have really glowed.

There was often some industrial demand for culm, as with the other smaller sizes of coal: for burning limestone into lime, evaporating seawater into salt, and sometimes for the use of blacksmiths. But such demand was usually limited to the immediate locality or at best to any nearby coastlines, because unlike larger chunks of coal, which were expensive to transport even at the best of times given their high weight per value, culm dust also needed to be barrelled up before any major journeys, to stop it all from blowing away in the wind. This perhaps explains why most of the coal-ball-using regions were to be found far inland. Without an easy way export it, and without immediate access to the sea for making salt, for the coal mines of Aachen, Leinster, Liège, and the Pennines, culm would have been almost entirely wasted had it not been used in the homes of the local population. And to be burned in the home, it actually needed to be worked up into balls with dirt or clay, because as mere dust it could not be burned in a fire-grate at all.

Indeed, much like the anthracite rock from which it had chipped, culm was in general very difficult to set alight. Working it up into coal balls helped somewhat, by spreading the particles of coal dust amongst the clay and increasing the fuel’s surface area to the fire. But even then, it often took such a great heat, made with so much other fuel, that people often took great pains to avoid the cost of starting coal-ball fires by preventing them from ever going out at all. The Welsh built their coal-ball fires with a hollow in the top, to help draw air through the bottom of the grate below; before going to bed, they would cover it over with a ball of damp coal dust, so that the fire continued to smoulder throughout the night until it was uncovered in the morning again and sprang back to life. Carefully replenishing the balls as needed, many Welsh homes reportedly kept their fires burning continuously for decades.

And there were even advantages to the mines of using up the culm. As the English report on the 1867 Exposition Universelle put it, coal dust had “formed an encumbrance rather than a source of gain to the proprietors of coal mines”, and warned that “its introduction into the English coal districts can hardly be postponed any longer.” Coal dust had, in other words, become so plentiful, valueless, and even inconvenient, that mine owners should have been paying to have it made up into balls and briquettes just to have it taken away.

There was a crucial difference, then, between the fuels available where coals were dug, and the fuels on offer where they were sent. Londoners received only the most expensive and largest coals that Newcastle, Wales, or Scotland had to offer — the kinds of coals could bear the cost of transportation for hundreds of miles by sea. For Londoners to work these into balls involved either sweeping up the miniscule amounts of culm or coal dust that were shed from the coals piled up in their cellars or on the city’s wharves, or else to take the effort to break their large coals — which had specifically been sold to them at high prices for their largeness — down to dust. Plat in 1603 had recommended taking a bushel of the “best” coal, strewing it on a paved floor, and breaking it down with mallets. Aaron Hill in 1716 had even recommended that better-off Londoners invest in buying a small mill made of iron, to be kept in their cellars for their servants to grind their coals to dust. But to have done so was not only in itself costly, but fundamentally misunderstood the market for coal. It would have been the equivalent of buying rare books just to pulp them for use as toilet paper — something that might make sense during a particularly severe shortage, but never, ever else.

To those who lived in the coal-producing regions, however, where so much of the coal was already dust, and extremely cheap, it made perfect sense to use it at home while exporting the larger coals elsewhere for a much higher price. In fact, the larger the gap in price between local culm and exported coal, the more likely it was that coal balls would be used in the region as fuel: the greater the gap, the more it would cover the costs of mixing the culm with additives and working it into shapes, while still leaving the resulting balls or briquettes much cheaper than ordinary coal. As one writer astutely put it in the 1880s, when commenting on the mechanised mass-manufacture of various patented coal briquettes and their continued failure to break into the British market, they could “be financially successful only so long as there is sufficient difference between the prices of dust and best coal to cover the entire cost of manufacture, with the requisite profits”. The reason that even the British-made briquettes sold 90% of their tonnage abroad was, quite simply, that ordinary coal was so abundant in Britain that its price was too low for the briquettes to compete, while coal in other countries was relatively scarce.

Even in coal-producing regions, if the gap between the prices of culm and coal became too narrow, then the coal-ball-using locals might switch to using ordinary coal instead. This probably explains why the balls eventually went out of use in even Leinster and Wales, as coal in general became increasingly abundant, and why I’ve not been able to find any evidence of coal balls being widely used along the coast of Scotland’s Firth of Forth, and hardly at all in Newcastle.

The smaller and cheaper Scottish coals and their dust, which were often mined right by the coast, had since the sixteenth century been used for making salt practically on the spot. And as for Newcastle coals, they were generally much softer and more bituminous, with relatively little dust being produced except on the few outcrops of crow coal. For most locals the price difference between the crow coal dust and ordinary coal seems to have been so small that they simply used the ordinary coal, with only the very poor resorting to making coal balls: the only mention that I’ve been able to find is a 1750s account of how coal balls had “been long practised by the wretched inhabitants of the coasts of Cumberland and Northumberland: they roll a ball of clay in the small coal which is found on the surface of their declivities … but as they have no better fuel to kindle the ball and keep it glowing, it is a poor succedaneum [substitute] for sea coal, and the fires thus made are scarce worthy of the name” — exactly the same problem that the Welsh had in lighting their culm. It seems that the narrower the gap in price between the culm and coal, the more restricted the use of coal balls, until they were made exclusively by those who experienced the same kinds of conditions that prompted coal balls to be popularised in places like London: those who could hardly afford fuel at all and had too many hours of enforced idleness to spare.

Far from being an irrational economy, as English visitors to Wales had supposed, the relative prices of culm and coal explained all. But there was, at one vital technological juncture, a point at which the coal ball might have had a heyday.

Simon Says “Smelt Iron”

In 1612, just nine years after Plat published the secret recipe for making coal balls, a patent was granted to one Simon Sturtevant for smelting iron ore with coal rather than charcoal. Although Sturtevant published a rather vague treatise describing the process, it sounds a lot like he tried to use an alternative form of coal ball to achieve his aim.

Back in 1606, Sturtevant had had great success in applying a kind of mechanical crushing and compressing machine, which he dubbed his “lenicke instrument”, to the mass-manufacture of earthen water-pipes. The courtier tasked by the king with assessing it, Sir Thomas Chaloner, was an experienced backer of other innovators, and after two years reported that Sturtevant’s machine could “easily cast 700 or 8000 yards in one day [I’m not sure which is the typo] as just and even as a printer prints his letters”, compared to just 40 yards a day when made by hand. Sturtevant could apparently even make his pipes at just a tenth of the cost per yard compared to pipes of lead. Chaloner reported that the person responsible for the king’s buildings was very eager to buy them, and I suspect that he did, for a few years later Sturtevant made almost two thousand yards of earthen pipe for the Earl of Salisbury’s gardens at Hatfield Park, quoting him — for everything including the manufacture, trench-digging, pipe-laying, joint-soldering, trench re-filling, and 18-mile delivery overland from his factory at Highbury — even less than the shockingly low price of manufacture that Chaloner had reported.

Encouraged by this success, and probably having heard of Plat’s coal balls — Chaloner was one of Plat’s acquaintances, telling him how to make a camera obscura, a man-powered paddlewheel boat, and various alchemical secrets — Sturtevant then claimed that his lenicke instrument could prepare coal for smelting iron, saying that it would be used “for the tempering, stamping, and comixing of seacoal or stone coal, that a kind of substance being there made of them like unto paste or tempered clay, the pressmould may form and transfigure that claylike substance into hollow pipe coal as it does earthen pipes”. He was proposing the mechanised mass-manufacture of a kind of tubular coal briquette, or “pipe coal”.

Sturtevant claimed that his method would make coal just like charcoal. Singling out Scottish coal as most fit for making metals for its lack of sulphur, but noting that it “consumes at once”, rather than being “lasting and durable”, he claimed he would make coal burn with charcoal’s steady, high heat — much as making it into coal balls would. He claimed he would remove coal’s “nocive”, or noxious properties compared to charcoal — much as making it into coal balls would take away the soot and smoke. And, he claimed, his method would involve coal’s “addition and infusion” with charcoal’s beneficial properties — just as making coal balls involved infusing it with loam or clay.

But for all that working coal into briquettes could make it burn like charcoal, Sturtevant failed to change its all-important chemistry. For all that he removed its visible soot or smoke, the coal’s invisible fumes would still have been far too high in sulphur and other impurities to smelt a usable iron. Whereas economics had banished the coal ball from the capital’s domestic hearths, it was physics that prevented it from revolutionising one of the country’s most important industries. For that task, as we’ll see in a future post, only coke could be king.

If you’d like to support my work, you can upgrade to a paid subscription here:

[P.S. I’ll be adding the dozens of footnote references to the web version of this post over the next few days]