Cornish Stamping Mills

A comprehensive, but by no means exhaustive, survey of Cornish documentation revealed at least 149 stamping mills which were built before 1700. This number of mills must represent a minimum figure, Since many were probably never documented and the documentation for others has been lost. A wide variety of document types were examined and Leases, Sales, Conveyances, Assignments, Manor Rentals, Estate Maps, Stannary documentation (particularly details of bounding) and parish perambulations all proved especially useful. The documented stamping mills are listed in Table II and Figure 3.8 indicates their distribution throughout the county.

The distribution map shows that the majority of mills were in the three western stannaries. The stamping mills were primarily concerned with crushing lode-tin and thus they were necessarily situated in close proximity to the cassiterite lodes, and the scarcity of these [p. 24] in the east, compared with the west, accounts for the observed skewed distribution. The tin output from the eastern stannaries was predominantly from alluvial and eluvial deposits, and hence did not require stamping prior to dressing. Figure 3.9, which illustrates the distribution of known mines and openworks is, as expected, very similar to that for stamping mills, thus confirming the close correlation between lode works and stamping mills. In all, it is possible to identify six separate clusters of mills, these being from east to west:

Tregrehan; Polgooth (in Blackmore); St. Agnes (in Tywarnhaile); St.Day-Creegbrawse, Tolgus and Porkellis (in Penwith and Kerrier).

These probably represent the major tin ore production centres of the early industry, and for further archaeological investigation of stamping, these areas could well prove fruitful for future research. The failure of fieldwork on Foweymore, to reveal a large number of mills can certainly now be readily explained as a consequence of a scarcity of lode tin which needed stamping. Thus there was probably never more than a handful serving the entire stannary, and their shortage in the archaeological record, although lamentable, can now be explained.

The majority of the early documented mills belonged to the seventeenth century. This is probably a reflection of improved documentation and the increase in mining at the expense of streamworking. Sadly, the bulk of the evidence only records the existence of a site and there are few or no details of its character. There are, however, a few welcome exceptions, with for example:

1. Stephen Hickes of Truro (a gentleman with substantial interests in tinworks, C.R.O. DD.EN. 1591) obtaining a lease in 1666 from Sir James Smyth, of Chelsea, knight, to build a stamping mill at Poldice and erect buddles, frames and prepare places for laying of tin and tinstuff in a § acre plot immediately next to the mill (R.I.C. SALV II).
2. In 1691, the sale of the moeity of two stamping mills and a pair of associated tinwork bounds to Thomas Carlyon of St. Austell, records the existence of ‘mill places, buddles, races, waters and leats’ (C.R.O. DD.CN. 2527).
3. The most comprehensive insight into the character of an individual stamping mill is provided by a series of accounts from the mill at Harvenna [SW 8958]. A complete copy of the Accounts is included below because they are a particularly valuable source of information regarding many aspects of stamping:

A number of particularly significant points emerge from these accounts, and these are:

1. The weight of the stamp heads was about 56 lbs. and they could be purchased locally from the nearby village.
2. The leats serving the mill were maintained by the tinners, but because this item of expenditure only appears on one occasion it was not possible to ascertain whether this was a regular commitment.
3. A carpenter was employed. This person probably maintained the machinery, much of which was made of wood.
4. The cost of stamping included hire of the mill itself at 6s per week plus an additional payment of Is for every 10 seames of ore which were stamped. According to Pryce, (1778, 326) a seame is:

‘a horse load, viz. two small sacks of black Tin’

and weighed about 315 lb. Thus in March 1688 Philip Thomas et al stamped 1,575 cwt of ore, Jn Pooll et al stamped 844 cwt, and in 1692 Henry Blake stamped 1,395 cwt whilst John Williams stamped only 84 cwt.

1. The machinery needed greasing, presumably to reduce friction.
2. The lifters, tapets and toungs were made at the mill, rather than being purchased from elsewhere.
3. The mortar box grate was pierced at the mill. This presumably allowed the tinners to choose the size of the holes which they considered most compatible with the nature of the ore being crushed.
4. The tinners asked for credit until the next coinage (when they would have received payment for their tin). This indicates that these adventurers shared the cash-flow problems of many tinners [p. 60] but that credit was sometimes given is indicated by John Blakes debt of 2s 6d.
5. Another useful source of information regarding stamping mills is the Enys business ledger of tin loans for the period 1691-98 (C.R.O. DD.EN. 1031). During 1692-3 this document records the sale of 33 stamp heads in 13 separate transactions. Significantly, on ten occasions the stamp heads were sold in groups of three. This would strongly suggest that the seventeenth century stamping mills were of the triple head variety. The remaining three heads were sold singly at significantly lower prices (eg. 3s 3d instead of £2 ls 7d for three), suggesting that they were much smaller than the others because the cost of stamps varied according to their weight. The implication of this difference is that there may have been small single headed stamping mills in existence at this time. However, further research is needed to confirm this suggestion.

The Enys document also contains details of accounts relating to stamping mills in the St. Agnes area, and the most comprehensive, is that for Moses Carter’s stamps at Port Chapell [SW 6949]. This Gives details of the items of expenditure contracted by this mill.These include:

                                                                          £     s   d

‘one bulling shovell                                          00:01:00

2 bowls                                                             00:04:00

2 grates                                                            00:03:00

3 stamp heads                                                02:02:08

3 lifters                                                            00:08:00

1 shovel                                                           00:02:00

2 shovell staves                                               00:00:04

New frames                                                     05:15:00

payd ye loss in Wheal Coates                        00:04:08’

This last item suggests that Moses Carter had a financial interest in the nearby Wheal Coates and that because the mine had returned a loss he was required to make a payment to cover it. It is likely that at least some of the ore from this mine was crushed in Moses’ stamps.

Ownership of stamping mills seems to have been largely limited to the wealthy. These people often leased their mills to tinners or yeomen, with for example:

1. The Little Stamps at Porthkellis were leased by the Enys’s for a rent of 50s. per annum in 167] (C.R.O. EN. f.45).
2. In 1673, Sir Joseph Tredinham leased ‘a pair of stamps called Carbous Stamps in St. Hilary parish’ to John James, junior, yeoman HEND. 2.92).
3. In 1626, Joane Bray rented a stamping mill on the Manor of Tolcarne, in Gwennap, for 8s. 4d. per annum (HEND. 23.145).
4. In 1/00, Simon Tregea leased two stamping mills in Church Town Coombe, St. Agnes, from John Nance of Trengoffe (C.R.O. DD.CN. 2526).

The form of lease agreement between the landowners and the tinners provide a useful insight into the legal relationship and responsibilities of the two parties, and often give at least an impression of the characters of individual sites. A good example of this type of lease, is that relating to the mill called “Little Stamps” at Porkellis [SW 6832]. This lease was drawn up in May 1694 between Samuell Enys (landowner) and William Gundry (tinner), and its more significant conditions are worth consideration:

‘That he the said William Gundry his Executs Adins + Assignes or some or one of them shall and will keepe + constantly mainteyne ten men and boyes att worke att the Ball of Porkellis aforesd and buddles there dureing the said Tearme of five yeares. And that he and they shall and will from tyme to tyme keepe and mainteyne cotihers in the leat + leates belonging to the said stamping mill that the casualtyes which now are or which hereafter shall be laid down there on the lands of Porkellis aforesd and Lizarea may not be wasted or carried away with the water into any other psons lands att his + theire owne costs and charges. And that all psons that now doe or that hereafter dureing the said Tearme shall adventure in the said Ball shall stampe accordinge to the customs or usuage of the said Ball and be well and kindly used. And that he or they shall not take or cause to be taken any mony reward or other consideration for the stamping save only the leaveings. And that he and they shall be att discharge + defray the third pte of all costs and charges in cleansening riddeing maintaineing + repaireing all such flood hatches headweares banks rivers watercourses leates bridges and wayes as now doe belonge or apperteyne to the watercourses in the lands of Boswen Lizerea + Tolcarne dureing the said tearme. And that he and they shall + will from time to time during the said tearme hereby granted pay or cause to be paid unto the said Samuell Enys … the full and just farme of all tyn which he or they shall stampe att the mill aforesd according to the conditions of the Sett of the Ball and also the sixth pte to farme of all the Tayles + leaveings as shall be brought out of the lands of any other pson or psons + stamped att the mill aforesaid. And that he and they shall + will repair susteyne uphold and mainteyne the sd stamping mill herby granted as well in wales wheeles axelltrees + upstanders as in all other things whatsoever thereunto belonging or apperteyning in goods and needfull repaire att his + their own proper costs + charges dureing the said tearme and in the end thereof leave the same well and sufficiently repaired upheld and mainteyned (the stamping heads only excepted). And that he and they shall and will permitt and suffer the sd Samuell Enys … from tyme to tyme dureing the said tearme to take + dispose of the water ariseing in Lizerea to carry + convey the same unto the stamping mill or mills of the sd Samuell Enys on Lizerea aforesaid called the Higher Stamps Cross Hole shall be Sett att any time or times dureing the said tearme that then itt shall and may be lawfull to and for the holder + holders of the said stamps called the Higher Stamps + Cross Hole aforesaid to carrye + stampe such tyn stuffe as they shall breake or cause to be broaken in the aforesd Ball att the stamping mills last mentioned’ (R.I.C. EN. 111).

A number of important points are raised by this document and should be emphasised:

1. William Gundry employed ‘ten men and boyes’. It is not clear whether these workers were involved exclusively in either mining or processing, but it is possible to ascertain the total size of Gundry’s operation. This consisted of a small tinwork served by a nearby stamping mill, both of which were leased separately to Gundry by the same landowner. The stamping mill crushed only cassiterite from the leaseholders leased tinwork.
2. Gundry was responsible for maintaining the leat serving the mill.
3. Gundry had to ensure that the waste from the mill did not enter the river. This was probably achieved by the use of slime pits.
4. Gundry had to pay only a third of the maintenance of certain facilities, the cost being shared with two other mills called “Middle Stamps” and “South Stamps” (R.I.C. EN. 109 and 110).
5. In addition to a yearly rent of £3, a percentage of the tin produced had also to be paid to the landowner.
6. Gundry was responsible for maintaining the mill.
7. The landowner reserved the right to take some of the water in the leat serving Gundry’s stamps, should the need arise. This particular clause may have caused problems for Gundry if this option was taken up at a time of drought. It was of course in the interests of the landowner to ensure that there was sufficient water for all his stamps or else the financial return would have been much reduced, since a percentage of his income was directly related to the output from the mills.

Whetter’s examination of seventeenth century probate inventories has confirmed that the majority of mills were owned mainly by landowners and merchants (Whetter, J., 1974, 70). Thus, in the second half of the century, of 23 owners identified, 15 had estates worth over £50 and only 2 were worth under £20. More specifically, Richard Remfry’s estate valued at £1,435 5s, in 1668, included implements of husbandry, tin stamps and an estate at Tolgus (Michell, F., 1978, 17). Mill ownership was, however, not solely confined to the upper classes, and, for example, in 1628 Walter Carlyon of St. Blazey, yeoman, possessed a mill under West Park (C.R.O. DD.CN. 2526).

In the seventeenth century many of the landowners ensured that their own mills were used by the adventurers by granting setts only on condition that the tin ore was crushed at the lords mill. Thus, for example, in granting the setts at Porthkellis Wartha in 1626, the Enys’ almost guaranteed that the adventurers would use their stamping mills by the introduction of two separate clauses:

‘3 That noeman carry away any work to dress without the licence of the Said Landlord his heires and Assignes uppon payne of forfeiture of the Said workes unto the Said Landlord

4 That every compa handling a quantitie of work wrought to the Vallew of one hundred Seames and the Stamps aforesd or any of them want work shall carry and Stamp the same as aforesaid at Such times as the Landlord shall appoynt uppon three days warninge or Shall loose the same work by them wrought soe refusinge’ (C.R.O. DD.EN. 509).

The fourth clause of this sett agreement is especially interesting since it would have enabled the Enys’ to maximise the use of their mills by staggering the arrival of the tin ore and this would have prevented delays at the especially busy times before the coinages. A second example of this practise, in 1628, involved John Hodge of St. Austell, yeoman, who was granted a licence to search for tin on Walter Carlyon’s lands in Tregrehan, agreeing :

‘to stamp all tin found by him at Walter Carlyons stamping mill under the West Park, as the same may be there conveniently done in a reasonable time and at an indifferent price’ (C.R.O. DD.CN. 2526).

Finally, in 1697, Anthony Coode was granted a sett to:

‘digg worke and serach for Tynn … at Harvenna’ (SW 8958) on condition that he:

‘stamp and dresse all such Tynn Stuffe as shall be gotten + found | in + upon the Ennises att the Stamping Mill of the sd Jonathan Rashleigh … if the sd mill be then in condition + fitt soe to stamp the same att the usuall rate att the sd mill accustomed’ (C.R.O. DD.R. 4775/1).

In conclusion, the stamping mills were generally owned by the wealthier elements within the industry and the tin ore crushed was either from works on their own land or their own tinworks managed by their employees. Mining was, of course, compared to streaming, a capital intensive operation and thus it is only expected that those who could afford to finance a mine could also possess the necessary stamping mills. It is thus, perhaps, surprising that so many tinners are recorded as only having leased stamps. The most likely explanation of this situation is that the landowners, would not sell land for the building of stamps and instead preferred to lease it, as this would have ensured a constant income. The tinners, likewise, would have preferred this option, Since all tinworks have a limited lifespan and the stamps with associated land would have been nearly impossible to sell at the cessation of work. In addition, by leasing, they would have done away with the necessity of making a comparatively large capital investment in land, this after all was the policy regarding the works themselves. The tinners did not purchase the land, containing the lode, but rather paid a percentage of the tin ore raised. The practise of leasing mills and plots of land for dressing purposes is thus consistent with the nature of mining.

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