I have found very little evidence that wood turners used continuous rotation lathes prior to 1600, though pewterers and other metalworkers clearly did. In 1550 a lawsuit was brought against "old Peverell" because the noise from his "tornyng whele" was annoying his neighbors; but it is unclear if Peverell was a wood turner. The lack of continuous rotation lathes may have been due to the higher cost, the adequacy of pole lathes, or it may have related to guild restrictions. In urban areas such as London, guilds (or companies) restricted the tools and techniques that a craftsman could use. Even so, there were numerous disputes over who was entitled to use a lathe, and efforts to settle the dispute through company charters met with limited success.(10) Among rural craftsmen, restrictions were less stringent and individuals were more at liberty to practice multiple trades (or at least use their tools).(11) Among those craftsmen who observed guild restrictions, the work of a turner was marked by round mortises and tenons, pegged or wedged in place.(12) The cutting of square mortises and tenons was reserved for joiners, who might contract out the turning for a piece or, if skirting the restrictions, hire a turner to work in his shop or simply turn it himself.

The lathe is an ancient tool, dating at least to the Egyptians and, "known and used in Assyria, Greece, the Roman and Byzantine Empires."(1) The earliest depiction of a lathe comes from a Ptolemaic tomb painting(2) . Primarily a tool of tradesmen known as "turners" or "throwers" (the term "bodgers" came later), the lathe was also used by pulley makers, seal makers, wheelwrights, chairmakers, joiners, pewterers, bell founders, and others. Early evidence of wood turning in England dates from the 4th to the 7th century(3), and by 1180 there appears to have been a turner's guild established in Cologne, Germany(4).

There are several reasons why this simple machine has been in use for thousands of years. From a practical point of view, the lathe can easily produce truly round objects, invaluable in making wheels for carts and parts for mills and pumps. Turned spindles can also be easily assembled into complex objects such as chairs, beds, tables, etc. This same machine also simplifies the making of woodenware for eating, drinking, and storage. From a more aesthetic perspective, turning can create a sort of surface decoration impossible to achieve by hand alone. The combination of mechanical simplicity, versatility, and decorative appeal has made turning a steadily practiced trade throughout European culture.

The idea of the lathe is simple: a piece of wood is made to turn on an axis while a sharp tool cuts or scrapes the wood into a desired shape. In the 17th century, Joseph Moxon described it as,

    Any substance, be it Wood, Ivory, Brass, etc., pitcht steddy upon two points (as on an Axis), and moved about on that Axis, also describes a Circle concentric to the Axis; And an Edge-Tool, set steddy to that part of that Aforesaid Substance that is nearest the Axis, will in a Circumvolution of that Substance, cut off all the parts of Substance that lies further off the Axis and make the outside of that Substance also Concentrick to the Axis... This is a brief Collection, and indeed the whole Summ of Turning...(5).

One of the earliest reliable references to lathes is Theophilus' "On Divers Arts," probably written in the 11th century by a metalworker named Roger of Helmarshausen. In this treatise, he mentioned two lathes. The first is a hand-cranked lathe for turned heavy bell cores. The other is a pewterer's lathe, which he describes as "set up in the same way as the one on which platters and other wooden vessels are turned.(6)" This lathe is pulled by "a boy," presumably pulling back and forth on a cord wrapped around the piece being worked. Such reciprocol motion is charactistic of most early lathes, particularly those used in woodworking.

Turner, from the "Mendel Housebook," c. 1436.

Medieval European turners favored a design called a "spring pole" lathe. In this form, a frame, usually of sufficient height for the turner to stand, holds the piece being turned between two upright posts (called poppets or puppets) on sharp metal points (called centers). One end of a cord is attached overhead to a pole or similar "springy" mechanism to provide recoil. The cord is then wrapped around the piece to be turned and attached to a foot treadle. The turner cuts on the down stroke, and then lets the spring pole power the return motion. Later variations of the design incorporated a lever arm so the spring pole could be mounted to the base of the frame instead of overhead, or replaced the pole entirely with a bow mounted on upright posts.

A turner and some of his wares, from the "Book of Trades," 1568.

The spring pole design proved versatile. It could be made light and portable, important to craftsmen who might travel to where raw materials were plentiful. It was relatively easy to build and required few parts that the turner could not himself make. There are drawbacks to this elegant design however, such as relatively slow turning speeds and limitations on the size and weight of the object that could be turned. Yet despite these limitations, the spring pole lathe would remain popular well into the 19th century among chair makers and other traditional crafts.

One of the most detailed illustrations of a possible lathe appears in the late 15th century Medieval Housebook of Wolfegg Castle. Unlike the lighter designs seen elsewhere, this frame is heavy, low, and includes a large adjustment screw of the sort seen in later lathes (perhaps the earliest example of a screw used in a workbench). It's similarity to a carver's bench illustrated in a 16th century woodcut by Hans Sebald Beham suggests that this style of frame was shared by both turners and carvers.

The majority of lathes illustrated throughout the Medieval period are spring pole lathes, though not all. An important advancement to lathe design was to convert the reciprocal "back and forth" motion of the pole lathe to a continuous rotation. Such an arrangement allows for faster turning speeds, enables longer and heavier objects to be turned, and makes more efficient use of the turner's labor. It also allows for the use of a flywheel, a mechanism that stores energy and provides a consistent speed and torque during the return stroke of the treadle. There was probably little incentive for wood turners to invest in this relatively complex and expensive technology, but other trades (such as pewterers and bell makers) had need of just such abilities.

The basic knowledge of how to transfer reciprocal motion to rotary motion was known through much of the Middle Ages. Water-driven saw mills used cranks and connecting arms to transfer a wheel's rotary motion to a reciprocating sash saw(7). However, such engineering is complex and requires more engineering skill and capital investment than the more traditional spring pole design. It also usually requires specialized parts, such as cranks and bearings. It is unclear when continuous rotation lathes first came into use, but the earliest illustrated examples of these rotary mechanics being applied specifically to a lathe appear in the sketchbooks of Leonardo da Vinci.(8)

In the late 15th century, da Vinci drew three simple machines together on a page. The first is clearly a lathe that uses the flywheel, though only for inertia; the treadle is connected directly to a cranked drive shaft and thus would turn only as fast as the operator could pump. The second is a sash saw driven by a flywheel. In the third, da Vinci depicts a treadle attached to another flywheel, but this one uses a drive belt connected to a smaller pulley to step up the speed. This arrangement allows for much faster turning speed and a less frantic pace for the operator. The function isn't exactly clear, but it resembles a gem cutter's wheel illustrated later in the 16th century. It is not clear if da Vinci's lathe is for woodturning or for use in metal working.

It is likely that da Vinci did not wholly invent the designs he drew, but rather sketched or improved on existing mechanics that he observed; da Vinci's sketches went largely unknown until long after the flywheel treadle lathe was documentably in use(9). Continuous rotation lathes appear to be common by 1568 when Jost Amman's "Book of Trades" illustrated pewterers and bell makers using great wheel lathes to turn their wares. Almost exactly the same lathes are illustrated 200 years later in Denis Diderot's encyclopedia of trades and industries.

Pewterer, using a Great Wheel lathe turned

by an assistant, from the "Book of Trades," 1568.

A variety of woods were used by medieval turners. Artifacts from Saxon and Anglo-Scandinavian finds in York (ca. 990-1000 A.D.) show that maple, alder, and ash were common, with yew, boxwood and even Scots Pine used on occasion(17). Each type of wood had its strengths and faults. Leon Battista Alberti wrote in the 15th century, "If they needed to produce slender forms on the lathe, the ancients would use the beech, the mulberry, or the turpentine tree, but most especially the box tree, which is the densest of all and extremely suitable for turning; while for very fine pieces ebony was used."(18) For furniture, favored woods included ash, walnut, beech, hornbeam, and fruitwoods. Oak, highly popular for joined furniture, doesn't turn well due to its relatively open grain but was still used when need or fashion required. For woodenware, woods such as sycamore and maple were preferred because they did not impart a flavor to food and beverages, though yew and ash artifacts have also been found.(19)

In general, medieval turners worked largely in unseasoned ("green") wood. Spring pole lathes work well with green wood, which is relatively soft and cuts easily. A skilled turner with a sharp chisel can remove shavings in long ribbons while the wood fibers are still soft and pliable. However, working in green wood presents problems of its own, especially when making hollow objects such as bowls and cups. As the wood dries, it will tend to shrink across the grain. Round objects will tend to become oval and crack as the outside tries to shrink faster than the greener interior. The shrinkage can be used to advantage in joinery however, letting a greener mortise shrink around a drier tenon, locking it fast into place. As turners often contracted for other trades, it is likely that the parts they turned green were seasoned by the time they were used by the joiner or chairmaker.(20)

Turners did not work exclusively in green wood however. Leon Battista Alberti wrote in the 15th century of, "immersing timber in water and leaving it covered in mud for a period of thirty days, especially if it is to be used for turning; they say that it will accelerate the curing process and make the wood easier to manage, whatever the intended purpose."(21) Curing wood provides the craftsman with a more stable medium, less prone to warping and cracking, but also one more likely to dull or chip his tools.

Bibliography

Alberti, Leon Battista (Rykwert, Joseph; Leach, Neil; and Tavernor, Robert, translators). On the Art of Building in Ten Books. The MIT Press, Cambridge, 1996. Includes a rare period discussion of the use of different types of woods.

Amman, Jost. The Book of Trades [Standebuch]. Dover Publications, Inc., New York, 1973. Excellent illustrations of numerous trades from the mid-16th century.

Chinnery, Victor. Oak Furniture, the British Tradition. Antique Collectors' Club Ltd, Suffolk, England, 1979. Both scholarly and readable, one of the useful references for the period furniture-maker.

Christoph Graf zu Waldburg Wolfegg. Venus and Mars, The World of the Medieval Housebook. Prestel-Verlag, Munich, 1998. Rare early examples of technical illustration.

Evan-Thomas, Owen. Domestic Utensils of Wood, XVIth to XIXth Century. EP Publishing Limited, 1973. Not a scholarly work, but contains useful illustrations of household goods.

Gies, Frances and Gies, Joseph. Cathedral, Forge, and Waterwheel, Technology and Invention in the Middle Ages. Harper Collins, New York, 1994. An accessible, if occasionally flawed, summary of medieval technology.

Gloag, John. A Social History of Furniture Design, from B.C. 1300 to A.D. 1960. Bonanza Books, New York, 1966. Good overview of furniture development.

Hodges, Henry. Technology in the Ancient World. Barnes and Noble, 1992. A dated reference, but with occasionally useful references.

Mercer, Eric. Furniture, 700-1700. Weidenfeld and Nicholson, London, 1969. Useful reference illustrations; his commentary is not always well supported.

Morris, Carole. "Aspects of Anglo-Saxon and Anglo-Scandinavian Lathe-Turning." Woodworking Techniques before A.D. 1500: Papers presented to a Symposium at Greenwich in September, 1980, together with edited discussion (McGrail, Sean, ed.). National Maritime Musuem, Greenwich, Archaeological Series No. 7, BAR International Series 129, 1982. Useful archaeological references, though the author does not appear to be well versed in woodworking.

Muendel, John. "The Mountain Men of the Casentino during the Late Middle Ages." Science and Technology in Medieval Society (Long, Pamela, ed.). Annals of the New York Academy of Sciences, Volume 441, April 19, 1985. Interesting essay on medieval technology.

Theophilus. On Divers Arts. Hawthorne, John G. and Smith, Cyril Stanley, translators. Dover Publications, New York, 1979. An important early reference on painting, glasswork, and metalwork.

Underhill, Roy. The Woodwright's Shop. UNC-TV, University of North Carolina Center for Public Television, Research Triangle Park, NC. 1999. An excellent introduction to traditional woodworking skills.

Notes

1. Gloag, p.12.

2. Hodges, pg. 187.

3. Morris, p. 245.

4. Mercer, p. 85.

5. Chinnery (Cited quote from W.A. Thorpe, "The Prosody of the Turner", Antique Collector, December 1952), p. 83.

6. Theophilus, p. 180.

7. Muendel, p. 55.

8. Gies, p. 259.

9. Gies, pp. 254-260.

10. Chinnery, pp. 85-86.

11. Chinnery, pp. 26, 45-48.

12. Chinnery, p. 89.

13. Chinnery, p. 93.

14. Gloag, p. 89.

15. Chinnery, p. 81.

16. Evan-Thomas, p. 1.

17. Morris, p. 243.

18. Alberti, p. 45.

19. Chinnery, p. 84.

20. Chinnery, p. 85.

21. 21.Alberti, p. 41.