Protecting ships against shipworms and fouling during the Industrial Revolution era

Abstract

Metallic sheathing of ships’ hulls was one of the major advances in shipping technology during the late eighteenth and early nineteenth centuries. Both public and private actors in Britain’s naval-industrial complex played major roles in the development of techniques that had both military and civil uses. Evidence from Lloyd’ Registers shows how various sheathing materials were adopted by merchant shipowners between the 1770s and 1850s. In the aggregate wood gave way to copper, then to yellow metal and, to a lesser extent, zinc. Metallic sheathing was almost universally adopted in the East India, slave and Caribbean trades and somewhat later became widespread in Mediterranean and North Atlantic shipping as well as on early wooden steamships. Another sample from Lloyd’s Registers shows when in their working lives ships were sheathed and how often the sheathing had to be replaced.

Keywords:

• sheathing
• copper
• yellow metal
• shipping
• fouling
• diffusion

Metallic sheathing of ships’ hulls was one of the major advances in shipping technology during the late eighteenth and early nineteenth centuries. Although attempts to use copper, lead and other metals to protect vessels against shipworm had a long history, dating back as far as the Greeks, the practice only diffused widely during the Industrial Revolution era.¹ Shipworm was the common name for several species of wood-eating molluscs that, in the right environmental conditions, could do sufficient damage to ships and other wooden structures, such as dikes, to make them structurally unsound.² The oxidation of metallic sheathing was toxic to these molluscs, thus reducing the need for ship maintenance and prolonging ship lives. An incidental benefit of this technology was preventing plants and other molluscs from adhering to ships’ hulls. Cleaner hulls made ships faster and more maneuverable as well as further reducing downtime for maintenance.

Metallic sheathing had profound effects on some trades. It reduced the cost of shipping between Europe and Asia by a third, largely through savings in capital and maintenance costs as ships made more frequent voyages over longer lifetimes.³ By shortening the voyage time sufficiently to reduce the chance of the crew coming down with scurvy, it also allowed ships to sail to Asia without a stopover at the Cape.⁴ In the slave trade, copper sheathing, by increasing ship speed, contributed to a significant fall in mortality during the Middle Passage and probably also allowed slavers to bring their human cargo to market in better condition.⁵ Another indicator of its value is that in 1809 the Navy’s Transport Board was willing to pay 23–25 shillings per ship ton per month to hire coppered ships, but only 19–21 shillings for ones that were sheathed with wood.⁶

Various aspects of sheathing technology have been capably dealt with by maritime historians as well as by marine archaeologists, for whom surviving remnants of metal sheathing have played an important part in their analysis of shipwrecks.⁷ The British navy’s experiments with copper sheathing from the 1760s and its initial widespread adoption in the late 1770s and early 1780s have been thoroughly studied.⁸ So, too, has the initial transfer of the technology to France and its adoption by the French navy.⁹ As for the merchant navy, Harris and Rees have examined its use in Britain during the 1780s and 1790s and van Duivenvoorde has studied the use of both wooden and metallic sheathing by the Dutch East India Company.¹⁰ Most of this existing work has focused on sheathing with copper in the last decades of the eighteenth century and, in particular, on its use by navies.

Here we look at the range of sheathing techniques in use from the mid-eighteenth to the mid-nineteenth century and concentrate on their adoption by the merchant navy. We begin with wooden sheathing, the main technique in use before the 1780s and carry the story forward to the 1850s when the construction of iron ships started to shift the nature of solutions to fouling from sheathing to coatings.¹¹ During the early nineteenth century copper gave way to yellow metal, a copper alloy, and to a lesser extent, to zinc. We also focus on the users of sheathing, tracing out when the different techniques were adopted and in which trades they were used by drawing on cross-section data from Lloyd’s Registers. A different, longitudinal sample from the Registers is used to see sheathing in the lifetime of ships, asking when ships were first sheathed and how often sheathing needed to be renewed. Through newspaper reports and advertisements, as well as other sources, we explore the processes of invention, testing and diffusion in ship sheathing.

We concentrate on developments in Britain because from the late eighteenth century most innovations were made there and metallic sheathing was adopted earlier and more widely by both its navy and its merchant fleet. This leading role owed much to both the availability of abundant sources of copper in Cornwall and north Wales and the country’s strong tradition in metallurgy. In the early 1800s Britain accounted for about two-thirds of European copper production and during the first half of the nineteenth century the Swansea area alone smelted over 40 per cent of the world’s copper.¹² Other countries generally bought metallic sheathing from Britain before indigenous manufacturing was later started. This was the case for the United States, where domestic sheathing producers only first appeared during the French and Revolutionary Wars when supplies from Britain became less reliable.¹³

This study of metallic sheathing contributes to our understanding of economic change in Britain during the Industrial Revolution era. Beyond showing another aspect of the technological dynamism of the country’s shipbuilding and shipping industries, it reinforces recent research that emphasises the importance of Britain’s eighteenth-century strength in metallurgy and metalworking.¹⁴ The extensive technological cooperation between the public and private sectors highlights an earlier incarnation of what Lloyd-Jones and Lewis have described as Britain’s ‘naval industrial complex’.¹⁵

Development of sheathing techniques

Metallic sheathing potentially solved two distinct problems. One was the damage done to wooden hulls by shipworm, which created a danger to vessels’ structural integrity. The other was fouling, the adherence of barnacles and seaweed to hulls that made the vessels slower and less maneuverable and increased maintenance costs.¹⁶ Prior to the introduction of metallic sheathing the standard protection against shipworm was sheathing with wood.¹⁷ Wood sheathing involved first coating the hull with a mixture of tar with hair, paper or felt, then nailing onto the hull a layer of half-inch pine or fir planks.¹⁸ Until the 1780s wooden sheathing was the predominant technology used to deal with shipworm, and it remained in use well into the nineteenth century. However, wooden sheathing did nothing to prevent fouling. Another method to deter shipworms, used into the seventeenth century, was charring the hull to create a layer of charcoal, which was then sealed with tar or pitch pine.¹⁹

Wooden sheathing needs to be distinguished from the practice of doubling, which involved reinforcing a ship’s hull with an extra layer of oak planking. This had been a common practice since at least the sixteenth century for vessels likely to encounter ice, notably whalers and ships trading to the Baltic and White Seas. The Dutch East India Company also double-planked its ships in the early seventeenth century.²⁰ Wooden sheathing, by contrast, typically made use of cheaper wood that would provide a meal for the shipworms before being replaced after a few years. As such, it also goes by the name of sacrificial planking.

Among metals, lead was the first to be used for sheathing ships. It had been employed by the ancients until late in the era of the Roman empire, but only reappeared in Europe from the sixteenth century when the Spanish used lead sheathing to protect ships bound for Mexico. Almost all wrecks of Spanish colonial ships that have been excavated in the Caribbean show evidence of lead sheathing until well into the eighteenth century.²¹ The Dutch East India Company sheathed some of its earliest ships with lead, but abandoned the practice after 1606.²² The English navy experimented with lead sheathing in the late seventeenth century. It proved to be too heavy and its presence accelerated the corrosion of iron fittings, with the result that the Admiralty abandoned lead sheathing in 1691.²³ It made a brief reappearance in the early nineteenth century when Thomas Norris, a Manchester manufacturer, patented a lead alloy in 1810. Several merchant ships tried it and in 1817 the Navy gave it a test.²⁴ In 1832, the brig Elizabeth, of Plymouth, was lead sheathed when it was put up for sale by auction.²⁵ As late as 1833, the Admiralty tested lead sheathing on the Success, with far from successful results: the lead sheets were fixed with iron nails, which then corroded, with 621 sheets falling off and the remaining 321 being ‘very foul’.²⁶

Copper was used to sheath the rudder, stems and sternposts of many Dutch East India Company ships from the early seventeenth century.²⁷ There is no evidence that Company sheathed entire hulls, and the copper sheathing seems to have been applied between the oak hull and the sacrificial planking, serving as a second defense against shipworm without the benefit of preventing fouling. Later publications do state that the hull of a Dutch West India Company ship was copper sheathed in the 1620s, but the practice lapsed until the late eighteenth century when the Dutch navy coppered some of its vessels from the late 1770s. It has been suggested that the Dutch East India Company experimented with sheathing hulls with copper in the 1740s, but there is no archaeological evidence indicating that it became a common practice.²⁸ The first evidence of a fully coppered Dutch East Indiaman dates from 1791.

During the eighteenth century, the British Admiralty began to experiment with copper sheathing, culminating in the Navy’s decision in 1779 to copper the entire fleet.²⁹ Doing so in the midst of war and for many ships unlikely to visit the tropics suggests that the Admiralty was more concerned with fouling than with shipworm. Ferreiro has argued that faster speed and better maneuverability due to coppering gave the British fleet certain tactical advantages during the American Revolutionary War.³⁰ But the decision to copper the fleet must have seemed premature when as it was soon realised that the proximity of copper and sea water led to the rapid corrosion of iron fittings, resulting in the foundering of several ships. However, the problem of galvanic interaction was quickly resolved; by 1784 copper alloy nails and bolts of sufficient strength had been developed.

A few private shipowners were also experimenting with copper sheathing before the Royal Navy’s decision in 1779. The 1776 volume of Lloyd’s Register recorded two Liverpool ships as sheathed with copper. The Little Will was one of fourteen slave ships owned by William James and the Integrity one of four owned by Robert Green.³¹ They were joined in the 1778 volume by four other vessels. Three were Liverpool ships shown as trading with Africa, Jamaica and New York. The other was a privateer based at London.³² These experiments did not seem to have proved convincing because in 1779 all of these vessels were either not present or not recorded as coppered in Lloyd’s Register. In the 1779 volume there were three other coppered vessels: two privateers and one ship bound for the Caribbean.

Subsequent development of copper sheathing involved improvements in the quality of the copper, in its manufacture into sheets and in its application to the hull. The copper needed to be quite pure so that it would corrode gradually and hence be effective against fouling. Contemporaries distinguished good and bad copper, with the latter leading to variable results.³³ The Navy routinely tested the copper supplied by different manufacturers and even required them to stamp sheets with the indications of the manufacturer and the date of manufacture.³⁴ In 1802, the captain of the Medusa reported on a Mr Bolton’s copper, installed, as was common in experiments, on one side of the ship: ‘The copper on the starboard side is extremely foul with long grass adhering to it in several places while that on the larboard side is perfectly clean, a difference in the space of 18 months, which in my opinion, clearly bespeaks the quality of the two metals.’³⁵ Similar tests were done on copper supplied by Mr Bennett in 1808 and John Williams in 1817.³⁶ In 1820s, a new process was developed for smelting very pure copper on a large scale.³⁷ The quality of sheathing metals, copper as well as copper alloys, improved largely through trial and error. Looking back in 1863, W.J. Hay, chemist and lecturer at the Royal Navy College, observed that:

Although in the earliest preparation of sheathing for the Navy the application of chemistry to the process of its manufacture was not well understood, yet what it was deficient of in science was in a great measure supplied by practical skill in refining and purifying the metal. And further, whilst the durable sheathing manufactured in those times was often alloyed with foreign elements, the more complete fusion to which the metal was subjected in the furnace brought the alloys into such a state of combination with the copper as to render it beneficial.³⁸

Methods for manufacturing sheathing were also improved. Sheathing came to be sold in different thicknesses, but in a standard sheet size of four feet long by 14 inches wide.³⁹ Thomas Williams, the ‘Copper King’, established the Greenfield rolling mills in North Wales to produce sheathing.⁴⁰ Swansea copper smelters also got into the business, with Vivian & Sons opening a mill at Hafod in 1819 and acquiring another close-by in 1822.⁴¹ The Navy began manufacturing its own sheathing in 1805 when it set up a metal mill at Portsmouth Dockyard, replaced in 1847 by one at Chatham Dockyard. At Portsmouth, experiments were conducted to compare soft-rolled and hard-rolled copper.⁴² After Waterloo, as the fleet was run down, the Navy’s mills mainly recycled used copper from warships.

The way in which sheathing was applied to the ships also changed. The dissolution of the copper through oxidisation depended on the speed of the water hitting it. As a result, it became the practice to vary the thickness of the copper applied to the hull, with thicker sheets being applied to the bow and near the water line.⁴³ Copper sheathing, like wooden, was also applied on top of various coatings, usually felt treated with tar. In 1816, the Navy tested William Wood’s patent adhesive, but found that the surface of the sheathing became irregular and led to excessive wear.⁴⁴ In the late 1830s, ‘Belfast Patent Felt’ was being commended to shipowners.⁴⁵

Alternatives to copper, which was expensive, continued to be investigated during the late eighteenth and early nineteenth century. In 1780 the Betsy, a London ship owned by Blackburn and bound for Barbados, was sheathed with tin.⁴⁶ In 1818, a Mr Collins proposed a composition of tin and copper to the Navy, which, after testing the alloy in various proportions, found that none could be effectively rolled out in sheets.⁴⁷ Another method was to cover the hull with large-headed nails, which rusted and congealed to form a metal shield.⁴⁸ This was not cheap either: in the early 1780s the application of almost nine tons of nails added £5 per ton to the cost of the Sulivan.⁴⁹ Over the next 50 years several patents were filed for various alternatives to copper. Besides Norris’s patent for a lead alloy, the others concerned an alloy of tin, zinc and lead, an alloy of zinc and copper, and the use of iron plated with zinc.⁵⁰ In 1824, the noted chemist Sir Humphrey Davy proposed that a very thin coating of zinc be applied in order to reduce corrosion of the copper. The Admiralty ordered a trial, but, unfortunately, Davy’s ‘protectors’ inhibited the anti-fouling properties of the copper and the Navy quickly abandoned the technique.⁵¹

In 1832, George Frederick Muntz, a Birmingham metal roller, took out a patent for a brass sheathing alloy composed of 60 per cent copper, 40 per cent zinc and a trace of iron.⁵² Initially called Muntz’s metal, it came to be commonly known as yellow metal and proved to be the first serious challenger to copper. In 1834, it was said to be ‘superior in durability and cleanliness to copper, besides affording greater facilities in working’ and was estimated to be 21 per cent cheaper than copper.⁵³ In July of that year, London shipowners were invited to examine the patent yellow metal sheathing on the City of Edinburgh steamer after it had been in use for nine months.⁵⁴ Michael Faraday, the noted chemist, was even commissioned by the patentees to test the new product against pure copper.⁵⁵ From 1834 onward ships for sale were being advertised as sheathed with Muntz’s patent metal.⁵⁶

Initially, Muntz seems to have manufactured the new sheathing himself in Birmingham. Then, in 1834, he entered into an agreement to share his patent with the London copper merchants Grenfell & Sons, with the latter taking care of production and sales and Muntz receiving a royalty of £2 per ton and half the profits. Large scale production of sheathing and bolts began in 1837 at Grenfell & Sons’ Upper Bank Works in Swansea.⁵⁷ In 1842, the Grenfells put an end to the partnership, but continued to make and sell the product while challenging the legitimacy of the patent, arguing that it was the same as an expired 1804 patent by a Mr Collins, though earlier they had defended the patent in several actions against other copper manufacturers. After the dissolution of the partnership, Muntz, whose patent had been confirmed, was producing sheathing at his French Walls Works in Birmingham as well as granting licenses for the production of yellow metal to the principal copper smelters in South Wales.⁵⁸ When the patent expired in 1846, the Privy Council decided not to grant an extension: ‘their lordships, taking the amount of the profits since the patent as £64,000, were bound to consider the sum sufficiently remunerative.’⁵⁹

Muntz was among several innovators in the sheathing market during the 1830s. In 1833 Patent Marine Metal, invented by Baron Wetterstedt, a Swede, and manufactured at Island Works, Limehouse, was tested on several ships at Liverpool. Analysis showed that it contained a considerable portion of lead.⁶⁰ Experience showed that with exposure to sea water, it became harder and prone to crack.⁶¹ In 1834, Vivian & Sons, a Swansea copper smelter, proposed bronze sheathing, which had been tried by the French Navy in 1829. The Navy tested it on a Falmouth packet, but it made little headway with the Admiralty or anyone else because it cost more than copper sheathing.⁶²

Zinc as a sheathing material came back into consideration from the 1830s. Sheathing with zinc had been patented in 1805 and subjected to various tests on merchant ships. Voyages to the Mediterranean and the South Seas found that the zinc corroded too rapidly. In 1816, the Navy concluded from this private sector experience that ‘this is a matter that may be properly left to mercantile interest and speculation without government running any risk in thus establishing a zinc manufactory… If the trials abroad or at home, are found to answer, it will probably soon introduce the use of zinc into the merchant services and the example may then be more safely followed in the navy.’⁶³

In the 1830s, zinc sheathing was promoted once again, this time by François-Dominique Mosselman, who was involved in the Vielle Montagne zinc mines and works, now in eastern Belgium but then in a tiny territory called Neutral Moresnet, jointly administered by Belgium and Prussia. The Nautical Magazine noted an early trial in 1834:

An experiment is about to be tried on the ‘Ant’, a vessel of one hundred and sixty-six tons, to be launched from Portsmouth Dock-yard, the last day of the month, by sheathing her bottom with Mossleman’s patent zinc. The sheets are about the thickness of a two-ounce sheet of copper, and are fastened to the bottom with nails of the same material. In every other respect the bottom is prepared in precisely the same manner as if it were to be coppered.⁶⁴

The cost of zinc sheathing was put at only a third to a half that of copper sheathing, but the Nautical Magazine cautioned that its ultimate advantage would depend on its durability.

Diffusion of sheathing techniques in aggregate

Sheathing of one sort or another helped prolong ship lives by fending off shipworms and make ships faster and more maneuverable by keeping their hulls clean. These benefitted shipowners directly, but also indirectly by making their ships more insurable. We know this because from the late 1760s the publishers of Lloyd’s Registers, a standard source of information for underwriters, kept careful track of whether a ship was sheathed. Sheathing was indicated by the letters ‘s’ for wood, ‘c’ for copper, ‘ym’ for yellow metal and ‘z’ for zinc. For some vessels, the date at which the sheathing was applied was also noted. Lloyd’s Register recorded sheathing assiduously, except in the mid-1830s when the original publication was still digesting its merger with a competing register and information on sheathing and other matters was often wanting. We can use this information from Lloyd’s Register to analyse the diffusion of different sheathing materials, both in the aggregate and in various trades.

The Registers recorded only a small share of the vessels involved in the coasting trade of the United Kingdom, but captured a large share of the British and foreign vessels involved in its foreign trade. Since relatively few coasters were sheathed, these shares will thus overstate use of sheathing in the U.K. merchant fleet as a whole. Even with these limitations, the information on sheathing in Lloyd’s Registers is far better than that for other countries and makes it possible to trace out the diffusion of the different sheathing techniques.

Figure 1 shows, at roughly five-year intervals, the share of all sailing vessels sheathed with wood or metal from 1776 to 1860 (early steamships will be discussed below). Until the early 1830s, this share remained stable at about 35 per cent. During the 1840s and 1850s, it was higher, between 40 and 50 per cent, and may have been increasing. It is possible that the increase in the share may be a statistical artefact, arising from a change in the composition of the ships recorded in Lloyd’s Registers after it merged with its rival publication in 1833. Or it might be a real increase in sheathing, perhaps as the result of the introduction of yellow metal, a cheaper alternative to copper, in the 1830s.

FIGURE 1. Share of all vessels sheathed with any material in Lloyd’s Registers (% of all vessels). Source: Lloyd’s Register database.

Although refined copper was a major input into sheathing, along with its manufacture into sheets and the labour needed to attach it to the ship, the price of copper does not provide much help in explaining the changes in the overall rate of sheathing. Although there were large fluctuations in the real price of copper (Figure 2⁶⁵⁶⁶), it fell only modestly from the late eighteenth century to the 1820s and 1830s. During the 1840s and 1850s, it rose by about a third, at the same time as the share of ships that were sheathed seems to have increased.

FIGURE 2. Real price of refined copper (1820–29 = 100). Notes and Sources: price of copper divided by a seven-year centred moving average of London wheat prices. Copper prices: Cordero and Tarring; Wheat prices: Solar and Klovland.

What the evidence of Lloyd’s Registers says about the way in which the use of different sheathing materials changed over time is shown in Figure 3. The application of wooden sheathing declined steadily over the period, but some ships still had wooden sheathing as late as the 1850s. Copper sheathing showed a steady rise until the mid-1830s when it began to give way to yellow metal. By 1850 yellow metal had effectively replaced copper. Zinc, which had a limited application as early as the 1820s, came to be used on about 5 per cent of all vessels in the 1850s.

FIGURE 3. Sheathing by material (% of all vessels). Source: Lloyd’s Register database.

From 1800 until 1830 about five per cent of all vessels were sheathed with both wood and metal, with the consequence that the percentages in Figure 3 may add up to more than 100. It is not clear whether this was a new practice in Britain from the late 1790s. Earlier volumes of Lloyd’s Register may simply not have recorded combined sheathing. The nature of this combined sheathing is also not clear. It may be that a layer of metal was attached to an existing layer of sacrificial planking. Or it may be that part of the hull was sheathed with wood and part with metal. From the 1840s, use of combined sheathing fell off to only about 2.5 per cent of all vessels.

Diffusion of sheathing techniques by trade

Shipworms were most active in tropical waters, though some species were probably indigenous to Europe. In Europe, infestations were associated with hot, dry weather and were infrequent. For example, they attacked dikes in the North Sea area in 1730, 1770, 1827, 1858 and 1859.⁶⁷ Hotter temperatures and increased salinity due to diminished river flow created ideal conditions for shipworms. It is tempting to see the adoption of copper sheathing by the Navy in the late 1770s as at least a partial consequence of increased damage done by shipworms earlier in the decade. Here we analyse when and to what extent different sheathing techniques were adopted by merchant shipowners operating in different trades.

Almost all entries in Lloyd’s Registers specify the ship’s use or destination. Most were destinations with more or less geographical specificity—for example, America, New England, Massachusetts, or Boston—and these locations have been grouped into regions. But some were uses—transport, privateer, collier—which have been included in the UK region. This information allows us to trace the sheathing by these various uses. In the first instance we analyse only sailing vessels.

As shown in Figure 4, there were three distinct levels of sheathing, taking all types of sheathing together. As might be expected, ships destined for tropical regions—Asia (including Australia) and Africa and the Caribbean (including South and Central America)—were almost all sheathed, with only a modest increase from 80 per cent sheathed in the late 1770s to 90–95 per cent from the late 1790s. Just under half of the ships bound for North America and the Mediterranean were sheathed in the late eighteenth and very early nineteenth century, and these shares increased after the French Wars. In the Mediterranean trade the share continued to rise to around 80 per cent, whilst that in the North Atlantic trade eventually levelled off at around 60 per cent.⁶⁸ In home and northern European waters (including the Baltic and White Seas), relatively few ships were sheathed, and many of these may have been ships that had previously been employed in trades for which sheathing was much more common. The share in home trade fell over the period, whilst that for Western Europe and the Baltic remained more or less constant at about 20 per cent. The minor peaks in the home and North Atlantic trades in 1779 reflected the large number of transport ships engaged by the Admiralty as well as a smaller number of privateers; these vessels were sheathed for speed. The fall after the Revolutionary and Napoleonic Wars probably reflected the much more limited use of coppered transport ships by the Navy.

FIGURE 4. Sheathing by trade: all sorts of sheathing (% of all sailing vessels). Source: Lloyd’s Register database.

Of the new techniques, copper sheathing, analysed by broad region, diffused most rapidly in the Asia and Africa and Caribbean trades (see Figure 5). By 1790, 80 per cent of English East Indiamen were coppered. In this trade, the Dutch and the Danes lagged, with the first Dutch East India Company ship sheathed with copper in 1791 and the first Danish in 1792.⁶⁹ Opponents of the technique in the Dutch Company worried about the cost of imported sheathing and about potential damage to the copper, particularly for ships using camels to reach Amsterdam harbour.⁷⁰ Some French East Indiamen were coppered in the 1780s, but the extent of the technique’s diffusion in France has not been studied.⁷¹

FIGURE 5. Diffusion of copper sheathing, by trade (% of all ships). Source: Lloyd’s Register database.

Grouping of the Africa and Caribbean trades together does conceal the very rapid adoption of the technique by slave traders. As shown in Figure 6, ships bound for Africa before abolition of the slave trade were coppered to the same extent as those to Asia. Only after the abolition of the slave trade in 1807 did the share of ships that went to Africa rejoin that of ships going directly to the Caribbean. Slave traders adopted copper sheathing because it helped them make faster passages, thus reducing mid-passage mortality and getting their captives to market in better condition.⁷² After abolition speed mattered less and protection from shipworm relatively more, so the needs for sheathing in the Africa and Caribbean trades became more similar.

FIGURE 6. Diffusion of copper sheathing: ships for Africa and West Indies (% of all ships). Source: Lloyd’s Register database.

The adoption of copper sheathing in the North American and Mediterranean trades took off after the French wars for reasons that are not apparent. Copper prices fell after the wars, but so, too, did all other prices, with the result that there was no significant fall in the relative price of copper (Figure 2). It may be that speed became a more salient consideration. In the American trade liner services to New York and other ports began in the late 1810s and 1820s. In the Mediterranean trade, importation of fresh fruit took off during this period.⁷³ Alternatively, shipowners may have needed greater protection from shipworm, perhaps because it was becoming more prevalent in the Mediterranean or because in the American trade more ships were bringing cotton directly from Gulf Coast ports such as Mobile and New Orleans.

In the home trade, the few ships that were sheathed before the end of the French Wars were sheathed with wood. Metal sheathing was adopted very slowly and rarely exceeded 10 per cent of all coasting vessels, and many of these may have been ships previously used in other trades. This may also have been the case in western and northern European waters, though here the share of metal sheathing reached about 20 per cent in the 1840s and 1850s. Speed may have been a motivation, particularly in passenger and mail services.

The diffusions of yellow metal and zinc sheathing, shown in Figures 7 and 8, produce no great surprises. The degree to which different trades adopted yellow metal sheathing corresponds closely to the extent to which they adopted copper sheathing. In most trades, the transition from copper to yellow metal had taken place by 1850. The adoption of zinc sheathing seems to have reached its peak in the mid-1850s. It was most extensively taken up in the Mediterranean trade and, to a lesser extent, in western and northern European waters, probably because zinc sheathing was more popular on the continent and may have shown up in the foreign ships listed in the Registers.

FIGURE 7. Diffusion of yellow metal sheathing, by trade (% of all ships). Sources: Lloyd’s Register database.

FIGURE 8. Diffusion of zinc sheathing, by trade (% of all ships). Source: Lloyd’s Register database.

Many steamships (not included in the above data) were sheathed with copper or yellow metal. For example, the London-based General Steam Navigation Company coppered many of its vessels, as did the Fife and Midlothian Ferry Trustees. Most wooden steamers listed in Lloyd’s Registers (unfortunately only a small share of all steamers) had metallic sheathing, but this may overstate the share (Table 1). Only a third of wooden steamers advertised for sale in 1840 were copper sheathed.⁷⁴ The extent to which steamships were coppered is rather surprising since most early steamers were either used locally as ferries or tugs, or served relatively short coastal routes. In neither case was shipworm likely to have been a major problem, so speed was probably the prime consideration. Local newspapers occasionally reported ferries from different companies racing against each other. Speed was also important for steamers carrying passengers, mail or livestock. Perhaps reduced downtime for maintenance may have been another factor.

TABLE 1. METALLIC SHEATHING OF STEAMERS LISTED IN LLOYD’S REGISTER.

		Sheathed (no)	Total (no)	Share (per cent)
1825		12	16	75
1830		79	110	72
1835	Incomplete data
1840		87	132	66
1845		70	113	62
1850	Wooden steamers only	34	57	60

Source: Lloyd’s Registers (London).

Some steamship owners were early adopters of Muntz’s innovation. In August 1834, when the steamer Irishman was launched at Liverpool, it was noted that ‘It is sheathed with that newly-invented patent yellow metal, which seems likely soon to supersede the use of copper altogether, being not only better adapted for this purpose but very considerably cheaper.’⁷⁵ In the same month, similar sentiments were expressed at the launch of a steamer in Glasgow.⁷⁶

Speed should also have been important for the packet service. When Lloyd’s Registers started listing the Falmouth packet vessels in 1813, all but three of the forty vessels which delivered mail to the Caribbean were copper sheathed. But it seems that sheathing the Falmouth packets may have been done more to deter shipworm, with the prevention of fouling and faster passages only a secondary consideration. On the shorter Channel and North Sea routes from Harwich, few vessels were coppered.

Sheathing in the business of shipping

Sheathing, especially with metal, was expensive. It was estimated that sheathing with copper cost four times as much as sheathing with wood, though this was perhaps an exaggeration.⁷⁷ For two merchant ships built in the 1820s and 1830s by the Hilhouse & Hill firm in Bristol, copper sheathing cost about £1 per ship ton.⁷⁸ Earlier, in the 1780s, the coppering of several large warships cost a bit less than £1 per ship ton.⁷⁹ The cost of coppering an East Indiaman in 1790 was about £0.67 per ship ton.⁸⁰ But, as a share of total building costs, coppering that East Indiaman amounted to only eight per cent. More generally, a cost of about £1 per ship ton can be compared to the average value of £15 put on new ships by Feinstein for the period from 1821 to 1860.⁸¹ This implies that coppering would have amounted to 6.7 per cent of the cost of a new ship, not an enormous amount but also not trivial.

We can ask various questions about the economics of sheathing using a longitudinal sample of evidence from Lloyd’s Registers. This sample includes all ships with names beginning with the letter ‘A’ that were built after 1774, that entered the Registers within two years of their construction and that were sheathed at some time during their appearance in the Registers. These 2330 ships were, on average, recorded as being sheathed with one or more materials, simultaneously or successively, for 10.5 years. There was no clear trend in this duration over the period from the 1770s to the 1850s.

Most ships were sheathed early in their working lives, 56 per cent within the first year and 72 per cent within the first two years. But there was a rump of ships that were sheathed later: about seven per cent were 10 years old or more at first sheathing. It is difficult to see any pattern among these late sheathings from the diverse destinations recorded in the Registers. Of the years during which these ships appeared in Lloyd’s Registers, about 15 per cent of their lives were spent before sheathing and another 15 per cent after sheathing. Most of the time, 70 per cent, they were sheathed. Almost half were sheathed during their entire history in the Registers.

The cost of sheathing may have been a relatively small share of initial construction costs, but sheathing needed to be periodically renewed, wooden sheathing because the shipworms had eaten too much of it, metallic sheathing because to be effective in deterring shipworms and preventing fouling, copper and other metals had to oxidise, hence the layer of sheathing was slowly worn away. We can get some idea about how frequently this needed to be done using the more limited set of observations for which Lloyd’s Registers recorded at least two dates at which sheathing was applied to a given ship.

Wooden sheathing lasted on average about five years, with over 80 per cent of observations between three and seven years. The number of years between copper sheathings fell over time. The modal interval fell from five years in the late eighteenth century to four between 1800 and 1829 and three between 1830 and 1860 (Figure 9). There was already concern in the 1820s that copper sheathing was proving less durable.⁸² In the 1850s James Napier, echoing the 1845 Report on Metals, observed that ‘it seems a general opinion that the sheathing, since its first introduction, has greatly deteriorated, and since these last thirty or forty years the rapid wear or waste in sheathing has become the rule and instances of long wear exceptions.’⁸³ Napier suggested that a possible explanation might be the change in the principal origins of the copper ore used for sheathing, from North Wales to Cornish to foreign, but thought it not conclusive and called for more research, noting that many other factors were involved in the corrosion of the copper, including the speed of the ship and the chemistry of the sea water. Modern research has shown that pure copper erodes too rapidly and that a small quantity of the right impurities gives the best results (Bingeman, 2018, p. 460). Another possible explanation for the reduction in durability over time may be that improved manufacturing methods reduced the width of the copper sheets, which then deteriorated faster.

FIGURE 9. Intervals between copper sheathing: changes over time (years). Source: Lloyd’s Register database.

As shown above, the yellow metal alloy began to displace pure copper from the 1830s onward. However, copper continued to be used, perhaps because it needed to be replaced somewhat less often (Figure 10). It appears that yellow metal sheathing was replaced somewhat sooner than pure copper sheathing, a paradoxical result because it has been argued that yellow metal lasted longer because it oxidised at a slower rate than pure copper.⁸⁴ A problem may have been that the yellow metal became more brittle.⁸⁵ The relatively short intervals between sheathing—two to four years—also turns out to be well below what some contemporaries thought to be the normal duration. For example, advertisements for zinc sheathing vaunted its longevity, saying that it would last six years, as against four for copper and five for yellow metal.⁸⁶

FIGURE 10. Intervals between sheathing: copper versus yellow metal (years). Source: Lloyd’s Register database.

Concluding remarks

The developments in sheathing illustrate Britain’s naval-industrial complex of the eighteenth and nineteenth centuries in action. The Admiralty played an important role in testing and diffusing new methods. Its role in the initial development of copper sheathing and of the copper alloy fittings needed to attach it is well known. It also tested new alloys developed by copper manufacturers and showed an early interest in Muntz’s metal. In 1834 the Admiralty experimented by sheathing one newly built packet vessel with yellow metal and a second with copper.⁸⁷ The 1845 Report on Metals summarised fifty years of tests conducted by the Navy on various aspects of sheathing. At the time of the report there were thirteen experiments in progress and six others ordered, but not yet in progress.⁸⁸

But the direction of innovation was not just one way. Metallurgists in the private sector searched for alloys or other metals that would be cheaper or more effective than near-pure copper. Mercantile shipowners were willing make their vessels available for testing new sheathing materials, including copper in the period before the Navy decided to copper the fleet. Both the Navy and entrepreneurs called upon leading scientists of the period, including Davy and Faraday, to advise on sheathing.

Once proved effective, both copper and yellow metal sheathing were rapidly adopted by British shipowners. They did so where it was worth the expense, in trades where ships would be exposed to environments propitious to shipworm or where speed was essential.

By the middle of the nineteenth century, the days of sheathing ships’ hulls were numbered. Iron ships, which started to be built in numbers from the 1840s, needed no protection from shipworm. But they did face the problem of fouling, which could slow them down significantly. One transitional solution was the composite ship: an iron hull covered by a layer of sacrificial planking protecting the iron from contact with a further layer of copper or yellow metal.⁸⁹ These composite, usually sailing, ships were built for speed, the other benefit of metallic sheathing, and were prominent in the China tea trade in the 1860s and 1870s. Few were built after 1870 because from the early 1860s effective anti-fouling coatings had started to become available. It had taken time to arrive at these coatings; from the mid-1830s to 1865 more than 300 anti-fouling compounds were patented.⁹⁰ Metallic sheathing did continue to be used on wooden sailing vessels in the later nineteenth century, but their numbers declined as the iron steamship became the workhorse of merchant shipping.

Acknowledgements

We heartily thank Sébastien Berthaut-Clarac, Gwenc’hlan Broudic, Roger Knight, Silvia Marzagalli, Louise Miskell, David Plouviez, Nicholas Rodger and Michael-W. Serruys for advice on various points. Larrie Ferreiro, Cormac Ó Gráda and Michael-W. Serruys kindly read and provided comments that greatly improved the article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Peter M. Solar

Peter M. Solar is Professor of Economics emeritus at the Vrije Universiteit Brussel and UCLouvain Saint-Louis Bruxelles. His research has focused on three main areas: the economic history of pre-famine Ireland, the European cotton and linen industries during the Industrial Revolution, and the history of UK shipping in the late eighteenth and early nineteenth centuries. His current projects include studies of British ship names from the thirteenth to nineteenth centuries, of the non-famine of 1799–1801 in Ireland, and of nominal wage rigidity in pre-industrial Europe.

Aidan Kane

Dr Aidan Kane is Lecturer in Economics at the University of Galway. His research interests are principally in Irish economic history, and in particular, the construction of historical datasets, mainly related to Irish public finance, from the 18th century to the present, and to Ireland’s 18th century international trade, using a range of web, programming, and relational database technologies. He also works on the evolution of the cotton spinning industry in late 18th and early 19th century Britain and on technological and industrial change in UK shipping during the late 18th and early 19th centuries using databases of the steamships built in Britain and Ireland between 1812 and 1860 and of sailing ships listed in Lloyd’s Registers from 1776 to 1860.

Notes

1 J.R. Steffy, Wooden Ship Building and the Interpretation of Shipwrecks (College Station, TX: Texas A&M University Press, 1994), pp. 42–59: 56.

2 M.-W. Serruys, ‘The Societal Effects of the Eighteenth-Century Shipworm Epidemic in the Austrian Netherlands (c. 1730–1760)’, Journal for the History of Environment and Society, 6 (2021), 95–127.

3 P.M. Solar, ‘Opening to the East: Shipping between Europe and Asia, 1770–1830’, Journal of Economic History, 73 (2013), 625–61.

4 P.M. Solar and L. Hens, ‘Ship Speeds during the Industrial Revolution: East India Company Ships, 1770–1828’, European Review of Economic History, 20 (2015), 66–78.

5 P.M. Solar and K. Rönnbäck, ‘Copper Sheathing and the British Slave Trade’, Economic History Review, 69 (2015), 806–29; N.J. Duquette and P.M. Solar, ‘Ship Crowding and Slave Mortality: Missing Observations or Incorrect Measurement?’ Journal of Economic History, 77 (2017), 1177–202.

6 National Archives MT 23/2, Transport Board circular, 10 April 1809.

7 M. Staniforth, ‘The Introduction and Use of Copper Sheathing—A History’, Bulletin of the Australian Institute for Maritime Archaeology, 9 (1985), 21–48; J.M. Bingeman, et al., ‘Copper and Other Sheathing in the Royal Navy’, International Journal of Nautical Archaeology, 29 (2000), 218–29; J.M. Bingeman, John M., ‘Copper and Muntz Metal Sheathing: a global update’, International Journal of Nautical Archaeology, 47 (2018), 460–71; W. van Duivenvoorde, ‘Use of Pine Sheathing on Dutch East India Company Ships’, in Between Continents: Proceedings of the Twelfth Symposium on Boat and Ship Archaeology, ed. by G. Nergis (Istanbul: Ege Yayinlari, 2012), pp. 241–51; W. van Duivenvoorde, ‘The Use of Copper and Lead Sheathing in VOC Shipbuilding’, International Journal of Nautical Archaeology, 44 (2015), 349–61; N.C. Ciarlo, ‘Industrialisation, Warfare, and Science: An Archaeological-Historical Insight into Technological Changes of Mid-18^th to Early 19^th-Century European Naval Ships’, International Journal of Nautical Archaeology, early view, 52 (2023), 1–33.

8 R. Knight, ‘The Introduction of Copper Sheathing into the Royal Navy, 1779–1786’, Mariner’s Mirror, 59 (1973), 299–309.

9 J.R. Harris, Industrial Espionage and Technology Transfer: Britain and France in the Eighteenth Century (Aldershot: Ashgate, 1998), ch. 12; S. Llinares, Marine, Propulsion et Technique: L’évolution du Système Technologique du Navire de Guerre Français au XVIIIe Siècle (Paris: Librairie de l’Inde Editeur, 1994), pp. 130–9; L.D. Ferreiro, ‘Développements et Avantages Tactiques du Doublage en Cuivre des Coques des Navires Français, Britanniques et Espagnols’, in Les Marines de la Guerre d’Indépendance Américaine (1763–1783) – tome 2 L’opérationnel Naval, ed. by O. Chaline, P. Bonnichon and C.-P. de Vergennes (Paris: Presses de l’université Paris Sorbonne, 2018), pp 37–65; D. Plouviez, ‘Entre ‘l’état et le Marché’: La Fonderie de Cuivre de Romilly-sur-Andelle et la Marine Française, 1780–1823’, Revue d’Histoire Maritime, 22–23 (2017), 157–74.

10 J.R. Harris, ‘Copper and Shipping in the Eighteenth Century’, Economic History Review, 2^nd ser., 19 (1966), 550–68; G. Rees, ‘Copper Sheathing: An Example of Technological Diffusion in the English Merchant Fleet’, Journal of Transport History, new ser., 1 (1971), 85–94; van Duivenvoorde, ‘Use of Pine Sheathing’; van Duivenvoorde, ‘Use of Copper and Lead Sheathing’.

11 Woods Hole Oceanographic Institution, Marine Fouling and its Prevention (Annapolis: United States Naval Institute, 1952); P. King, ‘The Development of Merchant Ship Composite Hull Construction in Britain, 1850–1880’, Mariner’s Mirror, 108 (2022), 439–61.

12 J.R. Harris, The Copper King: a Biography of Thomas Williams of Llanidan (Liverpool: Liverpool University Press, 1964), p. 127; C. Evans and O. Saunders, ‘A World of Copper: Globalizing the Industrial Revolution, 1830–70’, Journal of Global History, 10 (2015), 3–26, 8. On the British copper industry in the late eighteenth century more generally, see M. O’Sullivan, ‘Machines in the Hands of Capitalists: Power and Profit in Late Eighteenth-Century Cornish Copper Mines’, Past & Present, 260 (2023), 71–122.

13 M. Whiteman, Copper for America (New Brunswick: Rutgers University Press, 1971), pp. 51–6; R. Martello, ‘Paul Revere’s Last Ride: The Road to Rolling Copper’, Journal of the Early Republic, 20 (2000), 219–39; L.A. Norton, ‘Copper Sheathing, Industrial Espionage and an Eminent American Entrepreneur’, Coriolis, 9 (2019), 37–44.

14 M. Kelly, C Ó Gráda and P.M. Solar, ‘Safety at Sea during the Industrial Revolution’, Journal of Economic History, 81 (2021), 239–75; M. Kelly and C. Ó Gráda, ‘Connecting the Scientific and Industrial Revolutions: The Role of Practical Mathematics’, Journal of Economic History, 82 (2022), 841–73; M. Kelly, J. Mokyr and C. Ó Gráda, ‘The Mechanics of the Industrial Revolution’, Journal of Political Economy, 131 (2023), 59–94; P.M. Solar, O.B Dunn and A. Kane, ‘Shipping in the London Coal Trade, 1700–1860’, Economic History Review, early view (2023).

15 R. Lloyd-Jones and M.J. Lewis, ‘Armaments Firms, the State Procurement System, and the Naval Industrial Complex in Edwardian Britain’, Essays in Economic and Business History, 29 (2011), 23–39.

16 For the early history of anti-fouling methods, see Woods Hole, Marine Fouling, ch. 11.

17 van Duivenvoorde, ‘Use of Pine Sheathing’.

18 J.A. Goldenberg, Shipbuilding in Colonial America (Charlottesville, VI: University Press of Virginia, 1976).

19 A.W. Marr, ‘A Comprehensive Investigation of Lead Sheathing from the Emanuel Point Shipwrecks in Pensacola Bay, Florida’ (MA diss., University of West Florida, 2012).

20 W. Van Duivenvoorde, Dutch East India Company (VOC) Shipbuilding: The Archaeological Study of Batavia and Other Seventeenth-Century VOC Ships (College Station, TX: Texas A&M University Press, 2015), pp. 186–205.

21 Ibid.

22 van Duivenvoorde, ‘Use of Copper and Lead Sheathing’.

23 W. Petty, The New Invention of Mill’d Lead for Ship Sheathing, report for James Astwood of the Royal Admiralty, 1691. T. Hale, The New Invention of Mill’d Lead for the Sheathing of Ships, British patent no. 256 (13 August 1687).

24 Public Ledger 28 Dec 1816; National Archives (U.K.), ADM49/172, Committee on Metals, 1845, First Report (Copper) (hereinafter ‘Committee on Metals’).

25 Royal Cornwall Gazette 26 May 1832.

26 Committee of Metals, ff. 40.

27 van Duivenvoorde, ‘Use of Copper and Lead Sheathing’.

28 J.H.G. Gawronski, De Equipagie van de Hollandia en de Amsterdam: VOC-bedrijvigheid in 18de-eeuws Amsterdam (Amsterdam: Bataafsche Leeuw, 1996). At about this time the Ostend Company, also trading with East Asia, sheathed parts of hulls (K. Degryse, ‘De maritieme organisatie van de Oostendse Chinahandel (1718–1735)’, Mededelingen van de Koninklijke Belgische Academie, 24 (1976–1977) 19–57, pp. 38–39).

29 Knight ‘Introduction of Copper Sheathing’; R. Knight, ‘Early Attempts at Lead and Copper Sheathing’, Mariner’s Mirror, 62 (1976), 292–4; R. Cock, ‘‘The Finest Invention in the World’: The Royal Navy’s Early Trials of Copper Sheathing, 1708–1770’, Mariner’s Mirror, 87 (2001), 446–459.

30 Ferreiro, ‘Développements’.

31 Lloyd’s Register 1776; slavevoyages.org.

32 Lloyd’s Register 1778 (Arethusa, Britannia, Ellis and Gregson).

33 J.H. Harland, ‘Piet Heyn and the Early Use of Copper Sheathing’, Mariner’s Mirror, 62 (Feb 1976), 1–2.

34 Bingeman et al, ‘Copper and Other Sheathing’.

35 National Archive, ADM49/172, extract from a letter from Captain Gore, 19 Oct. 1802. See also the note about the copper supplied by a Mr Bennett in 1808.

36 National Archive, ADM49/172, Note about copper supplied by Mr Bennett, 1808; note on tests of copper sheats, 1817.

37 C. Flick, ‘Muntz metal and ship’s bottoms: The Industrial Career of G.F. Muntz’, Trans. Birmingham & Warwickshire Archaeological Soc, 87 (1975), 76, 69–88.

38 W.J. Hay, ‘On Copper and Other Sheathing for the Navy’, Transactions of the Royal Institution of Naval Architects, 4 (1863), 95, 79–98.

39 D.J. Souza, The Persistence of Sail in the Age of Steam: Underwater Archaeological Evidence from the Dry Tortugas (New York, NY: Plenum Press, 1998), p. 67.

40 Copper alloy tacks to attach sheathing were still being produced by craft methods, on which see N.C. Ciarlo, et al., ‘Craft Production of Large Quantities of Metal Artifacts at the Beginning of Indusrialization: Application of SEL-EDS and multivariate analysis on Sheathing Tacks from a British Transport Sunk in 1813’, Journal of Archaeological Science: Reports, 5 (2016), 263–75.

41 C. Evans and L. Miskell, Swansea Copper (Baltimore, MD: Johns Hopkins Press, 2020), p. 16.

42 Hay, ‘On Copper’, p. 81.

43 Harland, ‘Piet Heyn’, p. 1.

44 National Archives, ADM49/172, note on 1816 experiment on Marquis of Wellesley.

45 Vindicator 22 May 1839.

46 Lloyd’s Register, 1781.

47 National Archives, ADM49/172, note on experiments with composition of tin and copper.

48 Bingemann et al, ‘Copper and Other Sheathing’, pp. 219–20.

49 J. Sutton, The East India Company’s Maritime Service, 1746–1834 (Woodbridge: Boydell, Press, 2010), pp. 138, 152, n. 15. In the 1730s the Flemish used about 4,000 nails per square metre to protect a few dikes (Serruys, ‘Societal Effects’, p. 108).

50 London Journal, vol. 5, p. 289; Repertory, vol. 8, p. 397; vol. 14, p. 209.

51 Bury and Norwich Post 5 Jan. 1825; Western Times 3 Jan. 1829.

52 J.M. Bingeman and J. Dunlop have found brass clench bolts on the wreck of the East Indiaman Sir Edward Hughes, built in Bombay in 1788 (‘Bronze Fastenings Used on an 18^th-Century Ship Built for the East India Company’, International Journal of Nautical Archaeology, 52 (2023), 214-221). Their composition is somewhat different from that of Muntz metal. Although there were some patents filed for alloys of copper and zinc before the early 1830s, we know of no examples of sheathing, as against fastenings, made from brass before Muntz’s innovation.

53 North Devon Journal 6 Nov. 1834.

54 Morning Herald 22 July 1834.

55 Cambrian 25 Oct. 1834.

56 Public Ledger 29 Nov. 1834, 24 July 1835.

57 Public Ledger 19 June 1838.

58 Morning Herald 17 Dec. 1841; S. Hughes, Copperopolis: Landscapes of the Early Industrial Period in Swansea (Aberystwyth: Royal Commission on the Ancient and Historical Monuments of Wales, 2000), p. 62.

59 Birmingham Journal 8 Aug. 1846.

60 Cork Constitution 26 Jan. 1833.

61 Bell’s New Weekly Messenger 10 Mar. 1833.

62 Public Ledger 27 Oct. 1834.

63 National Archives, ADM49/172, note on proposal of Sebastien Chaulet for sheathing with zinc.

64 Nautical Magazine, Aug. 1834, p. 492.

65 H.G. Cordero and L.H. Tarring, Babylon to Birmingham (Charleston, SC: Quin Press, 1960).

66 P.M. Solar and J.T. Klovland, ‘New Series for Agricultural Prices in London, 1770–1914’, Economic History Review, 64 (2011), 72–87.

67 A. Sundberg, ‘Molluscan Explosion: The Dutch Shipworm Epidemic of the 1730s.’ Environment & Society Portal, Arcadia (2015), no. 14. (Munich, Germany: Rachel Carson Center for Environment and Society); L.C. Palm, ‘Achtergronden van het Paalwormenonderzoek, 1730–1870’, Tsch. Gesch. Gnk. Naturw. Wisk. Techn., 13 (1990), 88–101.

68 The destinations for which sheathing was common correspond to the exigencies of insurers. The Coal Trade Association, a mutual marine insurance association on the Tyne, required ships to be sheathed with wood or copper if they voyaged south of 40 degrees north or to the Mediterranean. Ships more than twelve years old going to North America were also to be sheathed (Rules and Conditions of the Coal Trade Association (South Shields: Alfred Johnson, 1839), p. 9).

69 van Duivenvoorde, ‘Use of Copper and Lead Sheathing’, p. 355; E. Gøbel, ‘The Danish Asiatic Company’s Voyages to China, 1732–1833’, Scandinavian Economic History Review, 27 (1979), p. 42. pp. 22–46.

70 I.G. Dillo, De nadagen van de Verenigde Oostindische Compagnie 1783–1795 (Amsterdam: De Baatafsche Leeuw, 1992), pp. 182–6.

71 J. Meyer, L’armament nantais dans le deuxième moitié du XVIIIe siècle (Paris: S.E.V.P.E.N., 1969), ch. 4.

72 Solar and Rönnbäck, ‘Copper Sheathing’.

73 D.M. Williams, ‘Growth, Market Shifts and Technological Change – The Citrus Trade to Britain in the Nineteenth Century’, in Maritime Food Transport, ed. by K. Friedland (Koln: Bohlauverlag, 1994), pp. 325–48.

74 Shipping and Mercantile Gazette 1840.

75 Belfast Newsletter 15 Aug. 1834.

76 Lancaster Gazette 23 Aug. 1834.

77 R. Cock, ‘The Cost of Re-coppering’, Mariner’s Mirror, 85 (1999), 93.

78 National Maritime Museum, Caird Library, HIL/8/1, 2, accounts for Orestes (1836) and Hector (1824).

79 B. Rosier, ‘The Costs of Re-coppering’, Mariner’s Mirror, 85 (1999), 350–1.

80 Cock, ‘Cost’, p. 93.

81 C.H. Feinstein, ‘Capital Formation in Great Britain’, in Cambridge Economic History of Europe, vol. 7, The Industrial Economies: Capital, Labour and Enterprise, Part 1: Britain, France, Germany and Scandinavia, ed. by P. Mathias and M.M. Postan (Cambridge: Cambridge University Press, 1978), pp. 63-5, pp. 28–96.

82 A. Jamieson, A Dictionary of Mechanical Science, Arts, Manufactures and Miscellaneous Knowledge, vol. 1 (London: Henry Fisher, Son & Co, 1829), p. 195.

83 J. Napier, ‘The Sheathing of Ships, &c’, The Engineer, 1 (1856), 107, 119, 131; Committee on Metals, ff. 10–11.

84 Flick, ‘Muntz Metal’, p. 74.

85 Committee on Metals, ff. 79–84.

86 Hay, ‘On Copper’, p. 91.

87 North Devon Journal 6 Nov. 1834.

88 Committee on Metals, ff. 96–101.

89 King, ‘Composite Hull’.

90 Marine Fouling, pp. 216–17.