SOME PRELIMINARY THOUGHTS ON STYLISTIC CHANGES TO 16th & 17th CENTURY COPPER ALLOY KETTLES
William Fitzgerald
(Permission given by William Fitzgerald to reproduce on this web site)
Introduction
With the realization of the temporal and cultural sensitivity of the humble glass trade bead has come a chronological saviour that should lead to a better understanding of the economic and social events of the tumultuous 16th and 17th centuries. There seems to be an unfortunate trend to ignore the temporal precision that has been provided by glass beads, and consequently there have been a number of controversial areas of research which would be seen in a totally different light if there was a firmer grasp of chronology and reality. Unfortunately, there has been a tendency to reconstruct culture without first establishing chronological control.
Glass beads have provided a temporal framework from which stylistic changes in other, less frequently recovered artifact classes can be identified. Implementing a slightly modified version of the glass bead sequence pioneered by Ian Kenyon ( 1969), I would like to present trends that would seem to be apparent in two of the more notable European introductions of the 16th and 17th centuries: the copper alloy kettle and the iron axe. In combination with.; the distinctive glass bead assemblages it will become evident that there were, as would be expected, constellations of artifact types which might be considered as characteristic of particular European suppliers. Those associations will not be presented here, I simply hope to illustrate the ease with which artifact histories can be reconstructed once there is a reliable chronology to work with.
Copper Alloy Kettles
While kettles from Glass Bead Period I (GBPl) sites exhibit some variability, they are generally homogeneous and distinctive in comparison to kettle varieties from later sites. The dramatic shift in the style of kettles seems to parallel the increased use of lower-priced brasses immediately after the end of GBP I.
By definition, pure coppers contain a minimum of 99.3% copper. The addition of other elements in various amounts and combinations produces a variety of alloys with different properties and potential uses. Generally the alloys tend to be harder, less malleable and less corrodible than true coppers. The particular value of coppers are that they possess almost unlimited capacities for being. cold-worked while the alloys tend to be harder and more brittle as the copper content decreases. Perhaps this tensile property is reflected in the abundance of Native manufactured ornamental goods fashioned from metal that scratches reddish-orange --a characteristic of copper and high copper content alloys. With decreasing copper content the alloys scratch yellow. Recent spectroscopic analyses indicate that a copper alloy that scratches reddish-orange is pure copper or an alloy with greater than 98% copper. In this study the dichotomy between "reddish-orange" and "yellow" can be confidently correlated with "copper" and "brass" respectively. What I hope to demonstrate is that there is a temporal shift in .the predominance of high copper content alloys to lower priced brasses, and that this was a consequence of intentional commercial considerations developing out of the newly established fur trade.
As mentioned previously, true coppers are at least 99.3% pure. High copper alloys (96.0 -99.3% copper) contain cadmium, beryllium, chromium or iron to give. greater strength than copper. Brasses (an alloy of copper and zinc) can consist of anywhere from 61.4 -97.3% copper with the remainder being zinc. Brasses with between 10 -20% zinc and 80 -90% copper are gold in colour and tend to be used primarily for ornamental purposes, while brasses consisting of 40- 60% zinc and 40- 60% copper are more yellow in colour and tend to be difficult to cold-work. Furthermore, in acidic water this brass combination tends to corrode. Heavily encrusted artefacts found on sites are likely to be one of these high zinc brasses.
Other major brasses include leaded brasses and tin brasses. Leaded brasses contain 32 -39% zinc and 1 -3% lead added to copper. While the inclusion of lead improves the ability to cut the material, lead does not mix well with copper and consequently reduces its strength and durability. Tin brasses are marked by a .5 -2% addition of tin to the copper and zinc mixture. Tin adds tensile strength and corrosion resistance, and consequently this alloy can be cold-worked.
While brasses are used in application where some characteristic of copper is desired to be improved, a major reason brasses tend to be utilized is that they can be produced at lower costs {Wilkins and Bunn 1943: 27). During the 18th century, of kettles made from tin, copper, and brass, the latter type of kettle was considered the most inexpensive (Stone 1974). The rudimentary, but generally effective scratch test on kettle fragments recovered from sites, has revealed a temporal trend toward the extensive utilization of brasses, indicating a decrease in the inclusion of copper (Table 1 ). This presumably was a cost-saving development that is mirrored in the variety of kettle imported after GBP1. As was the case with glass beads, once the French developed a domestic industrial base during the reign of Henry V (Nef 1964) to produce goods which could be used in the fur trade, there was a reduced need to import quality goods from other European manufacturing centres. A wide range of less expensive and inferior quality goods appear to flood the post-1600 market.
The most notable impression about kettles recovered from sites of this era is the amount of work that would have gone into this elaborate variety of kettle (Figures 1-7). If the number of kettles, and indirectly the amount of non-ferrous metal scrap, is any indication, the quantity traded to Natives was not that great. Quite probably the cost to the French to manufacture or import this style of kettle was prohibitive.
Material
Of the sixteen kettles and two pails of this distinctive style that have been examined, all but two are manufactured from a copper alloy that scratches "reddish- orange", indicating a very high copper content. The other two scratched "yellow", indicating that they were an alloy with a considerably lower content of copper (Table 2). This style of kettle was fabricated from high grade coppers which would have been more expensive than lower content copper alloys. Also, the metal of these kettles tended to be thicker ( >1mm) than subsequent varieties.
Construction Technique and Kettle Shape
Since high. copper content alloys are easily cold-worked, all of these specimens were likely formed by the battery method. Evidence for this is the consistent ball-peening pattern which starts at the centre of the base of the kettle, and radiates in a spiral towards the basal edge. The pattern proceeds in horizontal parallel rows up the side of the kettle. The regularity and compression of the peening suggests superior craftmanship, especially when compared to the randomness evidenced on later kettles.
Generally, the bases of these kettles are slightly convex. The largest kettle from Northport exhibited a 35mm difference between the depth at the edge and at the centre of the kettle. The smaller Northport kettle and the Gaetan basin possessed flatter bottoms.
All kettles had outward-sloping sides. The degree of outflaring varied: the largest Northport kettle expanded by 20mm over 220mm of height, .while the Grimsby kettle flared more notably - 70mm over 290mm. The most notable difference in this style of kettle was observed in the basal configuration. While all but the smallest of the Micmac kettles from Northport have slightly outflaring bases, the Grimsby and Gaetan Kettles, and the aforementioned Northport specimen, possessed a rounded curvature in the transition from kettle side to base.
Diagnostic of this variety of kettle is the configuration of the rim. The upper edge of the kettle was folded outward, perpendicular to the kettle wall. A portion of the end of the out-turned rim was then tightly folded underneath. The resulting width of the horizontal shelf is generally consistent (17 to 22mm) for all but the smallest Northport kettle, which had a 10mm shelf width. Around the interior edges of the rims were oblique, closely-spaced incisions. generally, these incisions were observed at a frequency of about two per centimetre. There is no apparent functional purpose for this feature, and if it is ornamental it cannot be definitely determined whether its presence was a European or Native addition. The regularity of the pattern and its presence on sites of diverse ethnicity would suggest the former; however, it might have' been intended to imitate the spruce-root rim lashing on birch bark bowls.
Rim Support Bands and Bail Attachment This feature epitomizes the qualitative and presumable cost differences between this style of kettle and subsequent varieties. To strengthen the rim of the kettle two bands (in the sample 15 were iron and 2 were copper) were riveted to the kettle beneath the horizontal shelf. t; Incorporated into each support band was a bail attachment. The copper Northporf attachment ,differed by having a strip of copper looped by hammering in order to form the bail attachment (Figure 3).
The maximum width of the iron bands were between 40 and 50mm, generally tapering down towards the ends of the straps. W hen possible to measure, the bands were approximately 5mm thick. With the exception of the copper attachment, the Northport iron support bands completely encircled the kettle rim. Of the four Hopps kettles that had intact banding" two kettles exhibited similar support while the other two only partially encircled the rim, reinforcing about 50% of the circumference. The three kettles from Ontario sites exhibited only partial encirclement, again reinforcing about 50% of the kettle's rim.
Bail Varieties
Three styles of hooks have been observed on kettle handles. The simplest variety involved the bending of the ends of a square iron rod at right angles to the handle. The two other styles are variants of U-shaped hooks. These were manufactured from rectangularly-shaped iron rods of approximately 10 by 20mm in cross section. The ends of one of the variants were formed into a near circular, open-ended hook, with the points either inflaring or outflaring. The more intricate U-shaped variety consisted of an elongated hook. Instead of ending in a point, the iron band continued outward as a rectangular flange perpendicular to the orientation of the hook.
Summary
The manufacturing extravagances exhibited in all aspects of these distinctive kettles --high copper content, intricate cold-working technique, elaborate rim and interior decoration, iron band rim support and bail attachment, ornate handles --would seem incongruous within an economic situation that was attempting to maximize returns from the fur trade. The intricacies of the kettle's manufacture, not the least being the detailed craftsmanship of both copper and iron workers, would not have made the utilization of these goods as trade items profitable for either Europeans or Natives. If too much was asked there would be little Native desire, but if the kettle's European value was not sought then there would be little reason to include these Items.
Clearly kettles were in demand. \The only alternative was to manufacture kettles more rapidly and inexpensively. This appears to have been done after GBP 1 when this variety of kettle faded from the archaeological record. The worn example from GBP2 dated Grave 11 at the Grimsby cemetery is the only currently known post-GBP 1 example (Figure 8). It was replaced by more rudimentary varieties, evidently geared for the fur trade market (Figure 9).
Glass Bead Periods 2 and 3 Kettles
As suggested by the increase in the use of low copper content alloys, there was an attempt during this period to reduce raw material (costs by decreasing the utilization of high copper content alloys (Table 3). As well, jess time was spent on hammering sheets into shape, for the ball peening patterns tended to be sparse and irregular. It must be remembered, however, that these brasses could not be as readily cold-worked, so it cannot be confidently stated that this less rigourous hammering process was a result of the lower quality of the material, an attempt .to reduce manufacturing time, or both. Many kettles from GBP2 and GBP3 burials commonly have the bottom of the kettles missing or separated, a feature that has often been interpreted as the ritualistic killing of the kettle. Equally plausible, the brittleness of brasses when cold-worked may have led to stress breaks at the kettle base, decreasing the life-span of the article.
The formation of the rim was simpler on kettles of this era. Instead of a folded over horizontal shelf, the lip was simply rolled, either to the inside or exterior. Occasionally the lip was folded over a thin iron ring to add support to the rim.
Another manufacturing procedure that would result in a dramatic reduction in production time and material expenditure was in the style and nature of the bail attachments. The elaborate forged iron support band/bail attachment combination present on GBP 1 kettles was eliminated with a simplification or complete absence of a rim support system on later kettles. Bail attachments also became exceedingly simplified. Lennox (1981: 322-324) has identified two main classes of these later lugs. Basically, they were pieces of copper or brass sheet metal, perhaps salvaged" from the initial formation of the kettle, then cut, bent, pierced and riveted to the kettle. The folded-leaf class consisted of one or more rectangular pieces. of sheet metal folded in half over the kettle rim. In some instances (Alonso), the piece is not folded over the rim, which would provide even less support. Generally two, but occasionally one hole was punched for the rivets and another above the rim for the bail. The loose-leaf class consisted of one of several pieces of sheet metal on either side of the rim riveted together in a similar fashion. Also, a hole for the bail was punched. The corners of the lug above the rim tended to be folded or snipped whereas the basal corners tended to be left unaltered. The bails also tended to be simplified. Instead of the forged rectangular bands, the bails from GBP2 and GBP3 sites tend to be formed from rim rods simply hooked at the ends.
Summary
The attempts to manufacture kettles at a reduced output of time and expense are quite evident. With the intensification of the fur trade, the iron-banded high copper content kettle typical of the ca. 1580-1600 era was too expensive to either manufacture or import. The decrease in the quality of workmanship and the materials used resulted in an inferior product -- but one that was clearly important in the trade inventory.