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The History of the British Coal Industry: Volume 1: Before 1700Towards the Age of Coal$

John Hatcher

Print publication date: 1993

Print ISBN-13: 9780198282822

Published to Oxford Scholarship Online: October 2011

DOI: 10.1093/acprof:oso/9780198282822.001.0001

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(p.557) Appendix A Weights and Measures

(p.557) Appendix A Weights and Measures

The History of the British Coal Industry: Volume 1: Before 1700
Oxford University Press

Coal is not a commodity [which] would pay its charge of a minute, nice admeasurement

Charles Montagu, 1699

The description and definition of the variety of weights and measures used in the medieval and early modern coal trade might at first sight appear to be a routine task requiring patience, perseverance, accuracy, and attention to detail in greater quantities than insight, powers of analysis, and imagination. Such a judgement would be quite erroneous. It would be tedious to attempt to convey a full appreciation of the labyrinthine complexities and the essential intangibility of this seemingly substantive topic, or of the succession of uncertainties, incongruities, and blatant contradictions that await any researcher who seeks to produce, from the measures used for coal, a set of consistent and logical relationships. Yet the portents are clearly in evidence for any aspiring historical metrologist to observe. Eloquent testimony to the difficulty of the task is furnished by the long succession of researchers, from Green in 1866 to Dendy (1902), Nef (1932), Mott (1962) and Dietz (1986), who have begun their expositions by pointing out the errors and misunderstandings of their predecessors. Moreover, immersion in the sources reveals that contemporary experts in the coal trade were at times scarcely less bewildered by the manifold measures in use, and the relationships which they bore to each other, than the historians who followed centuries after.

Many of the contributory agents of this doubt and confusion soon become apparent to the student. There is the baffling variety of measures in use, of which chaldrons, tens, keels, weys, tons, metts, vats, quarters, bushels, corves, scoops, rooks, dozens, works, fothers, and loads (cart-, wain-, waggon-, and, horse-) are but a small selection. Nor was a chaldron simply a chaldron. There were land chaldrons and sea chaldrons. Nor was a land chaldron simply a land chaldron, or a sea chaldron a sea chaldron. In the north-east each colliery using the chaldron as a measure of output, sale, or transport had its own standard of capacity. Newcastle sea chaldrons differed from London chaldrons, which in turn differed from those on the Forth, or in Lancashire or Hull. Nor were such measures necessarily constant over time. The Newcastle sea chaldron of the fourteenth and fifteenth centuries was very different from that of the seventeenth century, while the local land measures of individual collieries had a tendency to alter with (p.558) the terms of leases, the capacities of the containers filled by the hewers, or the capacities of the vehicles by which the coal was conveyed from the pit. Colliery chaldrons carried in wains or waggons to the staithes were the basis upon which royalties were calculated for payment to the landlord, but they had to be converted into sea chaldrons when they were carried by keels to the shipmasters and when coal was assessed for the payment of customs duty. Such a conversion constituted ‘making out,’ and according to Charles Montagu all the ‘coal professors’ believed that because 30 ‘led’ chaldrons made 40 sea chaldrons a ‘led’ chaldron made out at 25 per cent, ‘grounded on 10 being the fourth part of 40’. Whereas, he proclaimed gleefully, it was really one-third!1

Coal was repeatedly transferred from container to container on its journey from colliery to consumer, and each of these had its own customary capacity. Yet, even when the precise dimensions of the container are known, there can be no certainty how much coal it carried. First because the coal in the containers was heaped, and second because coal is not homogeneous and does not have a uniform ratio of weight to volume. Even when in identical condition coal varies greatly in density, and of course it can exist in varying degrees of size and wetness, and varying states of purity. Therefore the amounts of coal contained in identical receptacles can differ widely in weight. But the practice of heaping is of no less significance, for the amount of coal in the cone, which formed the heap of measures of identical capacity when level, varied greatly according to the shape of the container and whether it was wide or narrow, deep or shallow.2 Therefore, in order to calculate the amount of coal in a heaped measure, or to compare one heaped measure with another, it is essential to know not merely the capacity of the measures, usually defined by the number of gallons of water they held, but their precise shape and dimensions. A failure to comprehend these two fundamental truths has led many into making false comparisons and conversions.

Coal, in keeping with many other commodities, was almost invariably measured by volume rather than by weight, and its measures were defined, when they were defined at all, in bushels, quarters, gallons, pints, and suchlike. With the exception of Scottish coal, which was customed by the ton in London, it was not until the act of 1694 that coal was first required to be measured by weight rather than volume. Even then, however, measurement by weight was only for Northumberland and Durham coal destined for shipment, and when this coal reached its port of destination it was duly measured by volume. The reason for the universal dependence upon volume rather than weight was simply that for most commodities it was far easier and cheaper to (p.559) administer. Weighing a low-value, high-bulk commodity like coal was, with the exception of utilizing the keel, impractical. Even measuring by volume was a time-consuming and relatively expensive process. Contemporaries therefore invariably dealt in volumes: the annual vend of Newcastle was reckoned in Newcastle chaldrons, the production of a midlands colliery in loads or rooks, the purchases of a London household in London chaldrons, quarters, bushels, or pecks. Yet, it is now customary to measure by weight, and in order to be intelligible medieval and early modern volumes need to be converted into tons.

Herein lies the rub, For, as the authorities increasingly came to appreciate, there was no single standard of conversion of weight to volume or vice versa. In the final analysis it is not possible to tell precisely what a particular chaldron of Newcastle coal weighed, even when it was in exact accordance with the act of 1678 and defined in terms of ‘the bowl-tub of Newcastle containing two and twenty gallons and a pottle Winchester measure, and being seven and twenty inches diameter upon the top from outside to outside and no more, and allowing one and twenty bowls of coals to be measured by such bowl-tub by heap measure to each chalder and no more’. To discover its weight one would need to know the density of the coal, its moisture content, and the dimensions of each lump. No doubt this is why sixteen years later Parliament, having defined the Newcastle chaldron by volume, sought also to define it by weight. But inevitably, since there was no constant relationship between weight and volume, the statute of 1694 merely substituted one for the other.3 These are basic facts of nature, but an appreciation of them can help to explain much of the confusion of contemporaries and historians alike on metrological matters.

The following commentaries are not intended to provide a comprehensive guide to the measures used in the coal industry and trade. When local and customary measures have been converted into tons in the tables and text of this book, the methods employed have been noted there. A lengthy discourse on the size of the load, chaldron, or corf in each of the collieries which used it as a measure would be inappropriate as well as inconclusive. Instead the intention has been to provide some general information on the most common measures. The exceptions are the Newcastle and the London chaldrons, which dominated the coal trade and which have warranted extended discussion.

i. The chaldron

The chaldron, also known as the chalder, was an ancient measure used for coal from at least the thirteenth century. It was, however, little more than a generic name given to a large quantity of coal; it was not standardized, and there were very many widely differing regional and local chaldron measures. Two were of prime importance: the Newcastle chaldron and the London chaldron. The Newcastle chaldron was the measure for all coal shipped from the ports of Northumberland and Durham coastwise and overseas; and the London (p.560) chaldron became the standardized wholesale measure for coal throughout virtually the whole of the east and south of England and, eventually, also on the western seaboard.

The quest to discover the weight of the Newcastle chaldron during the medieval and early modern centuries has proven to be a Herculean task for historians, for it is beset with obstacles, traps, and false clues. J. U. Nef assumed that, although the London chaldron remained stable in weight throughout the sixteenth and seventeenth centuries, the weight of the Newcastle chaldron was altered repeatedly. He maintained that it weighed 2,000 lb. in 1421, and that ‘thereafter its weight was continually increased by the traders, in their efforts to reduce the burden of taxes on coal, until 1678, when the weight was fixed by statute at 52 2 1 cwt., to be increased in 1694, by another statute, to 53 cwt.’. Nef established to his own satisfaction a series of dates when the weight of the chaldron was known, namely 18 cwt. in 1421, c.40 cwt. in 1616, c. 52 cwt. in the period 1636–40, and 52.5–53 cwt. in the period 1678–94, and, ‘for want of a better method’ he postulated that the weight of the chaldron increased at a constant rate between these dates.4 It was on the basis of these series of estimates that Nef converted the data that he was able to collect on the numbers of chaldrons shipped from Tyneside into tons, and arrived at his subsequently discredited conclusion that In less than a century and a quarter, shipments from Newcastle multiplied nearly nineteenfold, while imports at London multiplied more than thirtyfold’.5 In the persistent and at times heated debate which has surrounded Nef’s quantitative estimates of the growth of the east coast coal trade, the crucial issue of the changing rates at which he converted chaldrons into tons has scarcely been raised.

In 1962, however, R. A. Mott published two articles in which he attempted to correct Nef’s estimates.6 Mott argued that in 1368 the Newcastle and London chaldrons were identical at around 17 cwt., and that the statutory increase in the capacity of the bushel in 1497 pushed both chaldrons up to c.21 cwt. In 1530, he goes on, the Newcastle chaldron was doubled in size, and at about the same time the London chaldron was increased to 1.33 tons, at which weight it was to remain until it was abandoned as a measure in 1832. Mott put the date of the final change in the weight of the Newcastle chaldron at 1635, when it rose from 42 to 52.5 cwt. Thus although there is broad agreement between Nef and Mott that the Newcastle chaldron became c.52 cwt. in the 1630s, Nef would see this as a result of a gradual increase in size over many decades, while Mott would see it occurring at a stroke. The most recent examination of the capacity of the Newcastle chaldron was published in 1986 by B. Dietz.7 Dietz concluded that the chaldron was constant before 1695, and he is therefore at considerable variance with both Nef and Mott. In a reworking of the data for both shipments from the north-east and the weight of the (p.561) London and Newcastle chaldrons, Dietz follows Nef and Mott in believing that the former remained fixed at 1.3 tons from an early date, but for the latter, before 1694, he adopts a compromise figure of 42 cwt.

The Newcastle chaldron

In most forms of historical research it is advisable to proceed from the known to the unknown, rather than vice versa, and in the pursuit of the chaldron it is essential. Accordingly we must begin with the statutes of 1678 and 1694, which were entitled ‘An Act for the Admeasurement of Keels and Boats carrying Coals’ and ‘An Act for the better Admeasurement of Keels and Keel-Boats in the Port of Newcastle and the Members thereunto belonging’ respectively. As their titles suggest both pieces of legislation were primarily concerned with regulating the size of the loads which keels carried to seagoing ships higher up the estuary. For the keel-load was used to determine the amount of customs and other duties which were payable and the amount of coal of which the shipmaster was taking delivery. The quantity which the keel carried was indicated by nails, which were driven into the vessels at successive intervals at the watermark as they lay in the water. The 1678 statute attempted to define the chaldron by volume, and required that nails be driven in at chaldron intervals after twenty-one bowls of coal of carefully specified dimensions had been thrown into the keel; while that of 1694 attempted to define the chaldron by weight and required that the nails be driven in at 53 cwt. intervals, according to ‘a dead weight of lead or iron or otherwise’.

The first measuring and nailing of the keels was therefore a crucial exercise, for it determined the dimensions of all the subsequent cargoes which they carried. Although it had been the accepted method of gauging shipments since early times, it could never be more than rough and ready, as the repeated concern with the achievement of greater accuracy, expressed from the late fourteenth century onwards, amply demonstrates.8 The procedure lent itself to manifold ‘Frauds, deceits and abuses…to the diminution of His Majesty’s customs and the damage and prejudice of the sellers and buyers of coals’, which could be practised both during measurement and in subsequent use, such as the heaping of coal in the middle of the keel so that more could be loaded before the water reached the nail, and the illicit removal and repositioning of nails. It was also an unavoidably inaccurate form of measurement in choppy water. But, perhaps most important of all, the capacity of all subsequent loads was dependent upon the nature and condition of the coal which had been used when the keel was first measured.

As has been noted, the statute of 1678 prescribed that the chaldron used for shipping coals from all north-eastern ports should consist of 21 heaped bowls, each bowl to be 27 in. in diameter and 22 gallons and a pottle Winchester (p.562) measure in capacity. It was further specified that each wain used to fill the keels should carry 7 heaped bowls and each cart 3 heaped bowls and 1 bushel, and that there were to be 3 wain-loads or 6 cart-loads to each chaldron, and no more. Care was also taken to specify that the coal used for measuring keels should be newly wrought and led to the staithe within three months of the ‘Admeasurement’, and that one-half used in the measuring should be wet and one-half dry. Just prior to the statute, in 1676, exact and even more detailed dimensions of the ‘sealed bowl-tub’ were sworn to in Newcastle by various collectors of customs, coal-meters, and the keeper of the bowl-tub, and their findings are contained in a document of hitherto unrecognized significance.9 The bowl the officials found in use measured 26 in. from outside to outside across the top, and 24 in. on the inside; the diameter of the bowl across the inside at the bottom was 25 in., and the depth at the middle was 11 2 1 in. and at the side 11 4 1 in. It held 22 gallons and 1 pint by liquid measure, though it was previously thought to hold 22 gallons and a pottle. Fortunately, one of the inquisitors, Anthony Isaacson, then proceeded to calculate the weight of coal which it would hold when heaped. First he filled it with dry coals and having deducted the weight of the bowl found that it held 2 cwt. 13 lb.; he then repeated the process using wet coals and found that it weighed 3 cwt. 1 lb., a massive 42 per cent more. Taking half dry and half wet coals would produce a chaldron weighing 53 cwt. 91 lb. Isaacson concluded his calculations by remarking that in such matters there ‘is no certain rule’.

It was right that he should be so circumspect. For a contemporaneous memorandum presented to Giles Dunstar, one of the General Surveyors of customs, claimed that although identical bowls were used in Sunderland and Newcastle, and 21 bowls went into each chaldron, half wet and half dry, ‘exactly as is now practised’, a chaldron at Sunderland was bigger than a chaldron at Newcastle. This the memorandum evidenced by stating that the same ship which could take in but 20 chaldrons at Sunderland, could take in 25, and sometimes 26 and 27, at Newcastle. Likewise the ‘20 chalder from Sunderland will make out at London 44 and 45, when 20 chalder from Newcastle will make but at London 31, 32, 33’. This ‘knotty question’, the memorandum goes on to relate, was due to a variety of factors, including the construction and working conditions of the keels of the two ports: which gave easier measure as time passed in Sunderland but worse measure in Newcastle; the differing state of the coal used in the measuring: which was newly dug, hard and round, and water resistant in Newcastle, and old, weathered coal which soaked up the water in Sunderland; and the contrasting qualities of the coal produced in the two regions: namely, hard and heavy, bad mixed with good, on Tyneside, and free and light on Wearside.10

(p.563) This memorandum thus stresses a crucial element often neglected by those who have studied the dimensions of the chaldron. Whereas keels were initially measured with chaldrons of carefully regulated volumes, thereafter they were loaded for shipping in accordance with the weight of the coal used for the first measuring. Which is to say, as much coal was thrown into the keel as was necessary to bring it up to the appropriate nails, rather than as much coal as was necessary to match the volume of the original coal. Thus, since coal of varying densities, size, and moisture content was shipped, so the volumes required to load the keel up to the conventional 8-chaldron marker inevitably differed, even though the statute might be rigorously adhered to. Moderately damp small coals from Tyneside have been found to be 10 per cent heavier than large dry lumps, and differences in the specific gravity of bituminous coals can affect the space-weight ratios by a similar margin.11

Not everything in this memorandum should be accepted at face value, however, for there was intense rivalry between the two northern coal ports, with Newcastle extremely resentful of the exemption of their neighbours from the 1s. per chaldron customs duty on coastwise shipments. But many of the issues it raises were real enough, and no doubt similar reasoning led to the adoption of weight rather than volume as the standard in 1694. The provisions of the 1694 statute were simple, the keel was to be marked according to 53 cwt. chaldrons rather than 21-bowl chaldrons, and those wains and carts which were used to load coal directly into keels were to be marked to contain 17 2 1 cwt. and 8 4 3 cwt. respectively.

In the light of Dr Dietz’s conclusions our first task must be to consider whether the 1694 statute ordered an increase in the size of the Newcastle chaldron by around a quarter. The answer must be firmly negative. As Anthony Isaacson noted in 1676, when he conducted his experiments using the precise volumes specified in the 1674 statute, a chaldron of half dry and half wet coal weighed 53.8 cwt. Furthermore, neither the content of the statute of 1694, nor the proceedings in Parliament which preceded it, give any indication that the intention was to increase dramatically the size of the chaldron. On the contrary the stated intention was to maintain better its prescribed proportions. The 1694 statute draws attention to the new forms of frauds and deceits which were diminishing the king’s customs revenues and, of course, these could only occur through the shipping of chaldrons of excessive size. Indeed the prosecutions which had been brought in the years preceding 1694 were against those who had moved the nails in keels so as to give excess measure as a bribe to shipmasters. These and other frauds and deceits the statute of 1694 hoped to stamp out, as the title states, by ‘the better Admeasurement of keels and keel-boats’. Moreover, there is no indication whatsoever in the voluminous contemporary records of the north-eastern coal industry and trade of this time that the chaldron had been changed in size, and even a much smaller increase than 25 (p.564) per cent would have had repercussions which could be expected to have featured somewhere in the broad spectrum of contemporary records available to us. Nor is there any detectable sympathetic movement in either the price of a Newcastle chaldron, the number of chaldrons carried by vessels visiting the Tyne and the Wear, or the total numbers of chaldrons shipped, each of which one would have expected as an inevitable corollary of such an enlargement. It may therefore be safely concluded that the chaldron was not increased in size in 1694, and the same would appear to be true in 1678. Indeed both statutes are best explained in the context of the need to restrain the size of the chaldrons shipped from the north-east during gluts of coal and the proliferation of discounts and incentives to shipmasters.

The key to the size of the Newcastle chaldron lies in the bowl. That the statute of 1678 did not introduce the chaldron of 21 bowls is shown by a petition of 1663 from Newcastle coal-owners which speaks of ‘21 bowls to the chalder being the measure now established by law to ships’. Contemporaneous documents in the same collection also predicate a Newcastle chaldron one and three-quarters to twice as large as a London chaldron, which, since the latter can be shown to have remained fixed in size, strongly suggests that the former was of the order of 53 cwt.12 Proceeding backwards in time, we find confirmation in the State Papers of 1638 of a 21-bowl chaldron then in use, and an Exchequer commission of inquiry into measures in the coal trade in 1616 found that the ‘water-bowl’ of Newcastle contained 22 gallons within the wood, and that 21 of these bowls ‘being ringed and heaped’ made a Newcastle water chaldron, ‘by which all manners of coals that are sold and shipped to be transported out of the port of Newcastle or any of the members or creeks thereof into the ports beyond the seas or elsewhere’.13 Thus the only change in the volume of a chaldron between 1616 and 1678 would appear to have been a contraction in the capacity of the bowl by a pint or a pottle (half-gallon), which constituted just 0.5–1.1 per cent, and was well within the margins of error of construction of the bowl or of changes occurring in its use. Moreover, experts in 1624 and 1618 worked on the premiss that the Newcastle chaldron was approximately double the size of the London chaldron.14 Therefore, contrary to what has hitherto been claimed, there is no reason to believe that the volume of the standard Newcastle chaldron changed significantly during the course of the seventeenth century.

When we pass backwards beyond 1600 our task becomes more difficult and our conclusions must be more tentative. Yet the depositions of witnesses to the Exchequer commission of 1616 testified that the bowl was a customary measure that had been in use ‘for sundry years’, and among all the profusion of documentation on coal and the coal trade in the sixteenth century a single direct reference to a change in the size of the standard chaldron has yet to be (p.565) discovered. What is more, in the second half of the century there were a series of well-recorded and tenacious inquiries into such closely related matters as the rising price of coal and the customs duties payable on shipments. Any change in the size of the measure used in the north-east would have been of direct relevance, but in none of the inquiries does any of the protagonists or witnesses raise the slightest suggestion that this had happened.15

None the less, although we can confirm the stability of volume of the standard Newcastle chaldron back to the 1570s, there is conclusive evidence from the fourteenth and fifteenth centuries that a substantially smaller sea chaldron was then in use. For example, the statute of 1421 sought to restrict the capacity of the measured keel to 20 chaldrons, whereas keels in the seventeenth century carried only 8–12 chaldrons.16 References abound to the 20-chaldron keel in the later Middle Ages, but if each chaldron then was of the capacity of 53 cwt, they would have been carrying more than 50 tons. Such a proposition strains the bounds of credibility, for not only would keels of such burthen have been twice as large as later keels, they would have been as large, if not larger, than the sea-going craft of the time. The satisfyingly detailed account of the purchase of coal at Winlaton in 1366 for the king’s building works in Windsor Castle throws considerable further light, for when delivered to London the 604 chaldrons purchased at Winlaton which had survived the voyage, the rest having been lost at sea, made just 561 4 3 chaldrons by London measure. That the Winlaton chaldrons were the same measure as those referred to in the 1421 statute and elsewhere is indicated by the fact that 20 of them were carried in each of the keels which ferried them from the colliery along the Tyne to the ships.17

Further specific information is available on chaldron sizes in the accounts of the bishop of Durham’s mines at Whickham in the later fifteenth century.18 We are told in the accounts of the 1450s and 1460s that the land chaldron, used to measure production, was 4 quarters, that the sea chaldron was 6 quarters and 4 bushels, and that each keel contained 18–20 chaldron or 30 fothers. At the Moyr pit at Whickham at the close of the century, 16 chaldrons ‘by pit measure’ equalled 12 chaldrons ‘by water measure’, 20 water chaldrons made a keel-load, and 1 water chaldron was equivalent to 1 3 2 fothers. The coal was transported from the pits to the water in fother units, and, as later, we can be certain that a fother was a wain-load. The reported relationship between fothers and keels on the one hand and chaldrons on the other is thus again seriously at odds with that of the seventeenth century, when we know their (p.566) dimensions. If the wain-load/fother was approximately the same as it was to be later, then the water chaldron would have been 26 to 29 cwt. In the seventeenth century a keel was capable of carrying around 27 to 32 tons; in the later fifteenth century, at 20 water chaldrons to a full load, keels would have carried 26 to 29 tons. Once again it is far more likely that chaldrons were around half the size of later chaldrons, than that wains and keels in the later Middle Ages were twice as large as they were to be in the seventeenth century.

Such reasoning is further substantiated by the numbers of chaldrons carried by ships engaging in the coastal and overseas coal trade. A series of Newcastle customs accounts from 1377 to 1391 reveals average shipments of between 43 and 46 chaldrons, with a few ships carrying in excess of 100 chaldrons. When in 1465–6 we next have data, the average shipment had risen to 50 chaldrons. Such average shipments, if chaldrons weighed over 50 cwt. each, would have been of the order of 115 to 130 tons, with the largest ships carrying 250 tons or more. Once again this is far too high to have been possible. It is generally thought that the vast majority of ships engaging in the east coast and North Sea trades in the later Middle Ages were of less than 50 tons burthen. At Yarmouth in 1513, for example, only 36 vessels out of the 157 registered were over 50 tons, and the average was a mere 39 tons.19 Conclusively, in the opening decades of the sixteenth century, when a good spread of Newcastle Chamberlains’ accounts and royal customs records are available, the average coal shipment was not 50 chaldrons but only 20.20 Indeed, it was not until the seventeenth century that the average number of Newcastle chaldrons per ship began to exceed 20. If late medieval chaldrons weighed around 25 cwt, instead of over 50 cwt., however, the burthens of the ships which carried them would have been a more plausible 60 tons, which would also be compatible with the thesis that the size of ships engaged in the east coast trade declined in the late fifteenth and early sixteenth centuries.21

All this evidence, and much more besides, points indisputably towards a medieval sea chaldron of far smaller capacity than that in use from the sixteenth century. By the time of the earliest available Newcastle Chamberlains’ account of 1505–6 and the first sixteenth-century royal customs accounts, a Newcastle chaldron of approximately double the size of that used for shipments in the Middle Ages was in use, and thereafter it appears to have remained approximately stable, There is no direct indication in the records of the early and mid-sixteenth century, any more than there is in those of the later sixteenth- or seventeenth-century, that the standard measurements were subsequently (p.567) changed. Indeed the testimony of customs accounts, royal and local, with their details of cargo sizes and duty paid, and the pattern of wholesale and retail prices both in the north-east and at the points of consumption, all indicate stability in the units by which coal was transported and traded.

In conclusion, the amplitude of the variations between standard chaldrons and the actual chaldrons which were shipped must be stressed again. To those inconsistencies which inevitably flowed from the methods of measuring and the qualities of coal must be added the overmeasure which was illicitly given by sellers in order to connive in the evasion of customs duties and encourage shipmasters to buy when trade was slack. For these reasons the chaldrons shipped from the north-east could not have had a set volume or weight or a fixed conversion ratio into London chaldrons, even though the standard measurement was not altered. It is perhaps significant that the statutes of 1678 and 1694, which were seeking to limit the size of the chaldrons which were shipped, were introduced in a time of recurring glut, stagnant or falling prices, and massive allowances of gift-coals to shipmasters.22 On the other hand, it is likely that the average size of chaldrons shipped from Tyneside in periods when demand threatened to outrun supply, as from time to time around the turn of the sixteenth and seventeenth centuries, conformed much more closely to the standard. Indeed it was claimed in 1600 that the wain which had for ‘time out of mind’ carried 8 bowls was now carrying scarcely 723.

For these reasons previous assumptions of the changing size of the Newcastle chaldron cannot be sustained. A case cannot be upheld for either a progressive rise in the size of the Newcastle chaldron over the sixteenth and seventeenth centuries, or for a substantial increase in the seventeenth century following upon a long period of stability. While the size of chaldrons shipped from Tyneside and Wearside undoubtedly varied significantly in both weight and volume, these variations took the form of oscillations, fluctuations, and deviations rather than trends. As such it would be impractical to attempt to incorporate them formally into our statistical descriptions of the coal trade. Accordingly a weight of 25 cwt. has been adopted for the chaldron used for shipping coal from the north-east in the Middle Ages, and 53 cwt. for the Newcastle chaldron of the sixteenth and seventeenth centuries.

The London chaldron

Throughout the Middle Ages and the sixteenth and seventeenth centuries the London chaldron was a volumetric measure, with no fixed weight. The capacity of the chaldron was defined many times, and it can be shown to have remained fixed from at least as early as the mid-sixteenth century at 48 Winchester bushels. This capacity was arrived at by defining the chaldron as constituting 36 heaped coal bushels, with the heap constituting an additional third. According to the statute of 1664/5 ‘all sorts of coals commonly called (p.568) seacoals brought into the River of Thames and sold, shall be sold by the chaldron containing thirty six bushels heaped up, and according to the bushel sealed for that purpose at Guildhall in London’. More detail is forthcoming from the report of a committee appointed by Common Council in 1676 to consider the measures for sea coals, and in particular complaints by coal-merchants that the Guildhall bushel was not lawful and that it did not accord with the ‘fatt’ anciently used for measuring coal when it was offloaded from ships. The committee found all to be well, and concluded that ‘in the said trial we found the said bushel to agree and answer the dimensions of the said fatt, the said fatt heaped with coals containing nine of the said bushels heaped with seacoals agreeing as near as art can make them’. The significance of the standard bushel residing at Guildhall rather than at the Exchequer was that it was a special coal bushel, and when measured by the committee it was found to contain 8 gallons and 1 quart of water, rather than the 8 gallons of the Winchester bushel.24

A number of references survive of the total volume of coal comprised by 4 heaped vats or 36 heaped bushels. In 1616 the Exchequer commission of inquiry found by experiment that a London chaldron contained 396 gallons of coal. William Gilpin, estates steward of Sir John Lowther, claimed in 1698 that the ‘London chaldron exactly’ was used to measure coal shipped from Whitehaven, that the bags or sacks used there contained 3 Winchesters (24 gallons), and that 16 such sacks produced a chaldron of the same size as 36 heaped coal bushels did in London. He also added that in London ‘the heap reckoned one third of the strike’. The total volume of coal in the Cumberland chaldron was therefore 384 gallons, just 3 per cent less than the Exchequer commissioners had computed in London over eighty years before.25

A number of attempts were made at the turn of the seventeenth and eighteenth centuries, in a new spirit of enquiry, to weigh the coal which constituted such a volume. In 1698 William Gilpin weighed a sack of Whitehaven coal and ‘found it very near 1 C. 3 quarters, that is 196 lb.’, which would have resulted in a London chaldron of 28 cwt. This was exactly the weight found by a committee of the House of Lords, which conducted a series of experiments in 1703. When Sir Robert Southwell had conducted a similar experiment for the Royal Society in 1675, the coal he used weighed just under 29.5 cwt, and in 1697 Sir Charles Montagu, using Derwent coal, found that a London chaldron weighed 29 cwt. So novel did Montagu think his experiment, that he instructed his cousin to keep it ‘from all flesh living’.26 The close degree of agreement produced by these trials, a range of only 5 per cent, suggests that coals of very similar densities were used in them. A series of authoritative estimates made (p.569) between 1793 and 1847 produced London chaldrons ranging in weight from 26.5 cwt. to 28.462 cwt.27 Throughout this book London chaldrons have been taken to weigh 28 cwt.

ii. Notes on some common units of production and sale

The following notes are not definitive, nor are they intended as a comprehensive guide to the multitude of measures in use before the eighteenth century. Such a task would, in any event, be scarcely attainable, since although the names of measures were often widely disseminated, their capacities varied widely between collieries and localities. Many errors in the past have stemmed from the assumption that the precise information which had been obtained from one colliery on the size of the corf, chaldron, load, ten, etc., could be applied to the corves, chaldrons, loads, tens, etc. of other collieries. Discussions of the dimensions of particular measures are contained in the text and the footnotes, and may be consulted via the index. Lists and attempted definitions of the weights and measures used in the coal industry and trade are to be found in various works.28

Corves, bowls, and baskets

The containers used to convey coal from the face to the surface were naturally also often used to compute the output of collieries. They were also the units commonly adopted in the piece-rate agreements of hewers and putters. As might be expected the dimensions of the corf, bowl, or basket varied widely from colliery to colliery, and were dependent upon local working conditions and custom. Within each colliery, however, strict procedures were taken to keep them of uniform size.


Coal was very frequently sold in loads. The size of the load was variable and depended upon the capacity of the vehicles or horses used to carry the coal from the colliery. There was no standardization between collieries, although standard loads were often introduced in towns, as part of attempts by urban authorities to regulate the dimensions of the weights and measures of commodities sold within their jurisdictions. In the collieries the load was usually defined in terms of the number of corves or baskets of coal which it contained. Information concerning the precise size of the load in use in any particular colliery is only rarely available, but it is invariably obvious from the context whether reference is being made to a horse-load or a cart- or wain-load. A wain-load often approximated to a fother or a ton, and was rarely much larger. On Tyneside the wain-load for leading coal to the staithes was defined as 17.5 (p.570) cwt. In Coventry the city corporation decreed that a ‘wain load is to contain in measure being orderly and sufficiently stacked up to one full ell square in height, breadth and length, according to the usual manner heretofore used at other coalmines within the county of Warwick and the county of Coventry’.29 At 45 in. to the ell such a quantity of coal might be expected to weigh just over one ton. Horses were generally capable of carrying 2–2.5 cwt., though the weight could vary according to the breeds of horses and the terrain they had to traverse.


The rook was widely used as a measure of production and sales in the midlands’ coalfields. It was based on the corf or basket in which coal was hauled to the surface, and therefore varied from colliery to colliery. We have two contemporaneous definitions: at Wollaton c.1610 a rook was defined as containing 18 ‘corve-fulls’, and measuring ‘2 yards and a quarter high, and one yard square, close stacked’, while at nearby Strelley in 1612 a rook was said to contain 13 ‘corve-fulls’ and to be ‘two yards high and a yard and a quarter square by measure’.30 Such quantities of coal would be likely to have weighed between one and two tons. That the rook did contain more than a ton of coal, and more than most wains and carts could transport, is suggested by the sale of coal by collieries in ‘three quarters’ of a rook, also called a load, as well as in rooks.


The ten was a north-eastern measure. It has been the subject of much confusion, largely because of the failure to recognize that there were three distinct tens: the production of coal was often measured by ‘getting tens’; coal carried from the colliery to the river was frequently measured in ‘led tens’, and the ‘vending ten’ was used for the sale and shipping of coal. That the ‘vending ten’ was quite simply ten Newcastle sea chaldrons can be demonstrated from innumerable sources, and poses few problems. The tens used to measure the quantities of coal that were dug or led to the Tyne were, however, highly variable and depended upon the receptacles in which the coal was raised and the vehicles in which it was carried. Thus on the earl of Northumberland’s estates at Whitley colliery in the 1670s and 1680s, 16 scores of corves made a getting ten and 40 fothers (wain-loads) made a led ten, while at Whorlton Moor colliery in the same decades the getting ten consisted of 21 scores of corves and the led ten contained 60 fothers.31 Led tens were generally appreciably larger than vending tens, often making 13–15 Newcastle chaldrons. The process of conversion was termed ‘making out’.

(p.571) Weys

The wey was in general use in South Wales, and occasionally also in other west coast ports. There are good reasons for believing that the seventeenth-century Glamorgan wey contained approximately 5 tons. There were 4 weys to a last.


(1) NeUL Montagu, Montagu to Baker 17/8/97.

(2) A report into London measures in 1800 produced drawings of a coal bushel and a coal vat, with movable triangular bows or handles across the tops to determine the height and form of the heap. It was claimed that if the height of the heap were undefined it could allow with ease 10 bushels in the place of 9 (Smith 1961, 362–3).

(3) Statutes of the Realm, 30 Charles II, c. 8; 6 and 7 William and Mary c. 10.

(4) Nef 1932, ii. 368–70.

(5) Ibid., i. 20–1.

(6) Mott 1962a, 1962b.

(7) Dietz 1986.

(8) Statutes of the Realm, 9 Henry V, 1 c. 10; CPR 1381–5, 499; CPR 1389–92, 30; CPR 1416–22, 394; CPR 1452–61, 608.

(9) NuRO Society of Antiquaries, ZAN M12/C23.6.

(10) LCA NCB Swillington, memorandum to Giles Dunstar. See also PRO C.30/24/7/596; BoL Rawlinson A.241, fos. 79–82.

(11) Dietz 1986, 284–5.

(12) PRO C.30/24/7/597.

(13) CSPD 1637–8, 347; PRO E. 178/4934.

(14) BoL Rawlinson, C. 784, fo. 1; Moller thesis 1933, 522 n.

(15) See e.g. the long-running dispute between the City of London and Newcastle aldermen and coal-owners (BL Lansdowne 65(11); Harleian 6850(39); Dendy (ed.), Hostmen, 5–7), and the voluminous records generated by the succession of disputes following the granting of the Hostmen’s Charter and the imposition of the Queen’s shilling (see above, Ch. 15(i)).

(16) See above, Ch. 13(iii).

(17) Taylor 1858, 208–9.

(18) DUDP Church Commission box 79.

(19) Blake 1967, 17–20; Scammell 1961, 332–41; Burwash 1947, 145–90.

(20) TWRO 543/212; PRO E. 122/108/12, 109/1; Scammell 1961, 333.

(21) Scammell 1961 argues convincingly for a decrease in the average tonnage of east coast ships at the end of the Middle Ages, but his assumption that the size of the chaldron did not change between the mid-15th cent, and the later 16th cent, leads him to overstate the scale of the decrease.

(22) See above Ch. 15 (ii).

(23) Dendy (ed.), Hostmen, 38–9.

(24) Statutes of the Realm, 16 and 17 Charles II, c. 2; Smith 1961, 361–2.

(25) PRO E. 178/4934; Hainsworth (ed.), Sir John Lowther, 578.

(26) Hainsworth (ed.), Sir John Lowther, 585; HMC House of Lords, v. 239–40; NeUL Montagu, Montagu to Baker 29/7/97; Birch 1756–7, iii. 207–10.

(27) Green well 1888, 17.

(28) Flinn 1984, 416–2; Nef 1932, ii. 367–78; Rees 1968, i. 129–32.

(29) White thesis 1969, 196.

(30) HMC Middleton, 170, 175; HMC Rutland, iv. 484.

(31) DN Syon Cx 2a (1); 4b (1,2).