DSC_0174

Gräsbobågen utlagd på ett bord i februari 2012 (Foto Niclas Björck).

Gräsbobågen utlagd på ett bord i februari 2012 (Foto Niclas Björck).

Gräsbobågen utlagd på ett bord i februari 2012 (Foto Niclas Björck).

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  • Uploaded on: 5 april, 2012

1 Responses to “DSC_0174”


  • Tuukka Kumpulainen

    Niclas,

    Thank you for the reply. I’ll further the discussion a bit.

    The Gräsbo find is certainly very much like a bow. However, interpreting it as a back laminate of a two-wood bow is loaded with uncertainty. A back laminate capable of taking the tension strain in a two-wood bow can take the tension strain in a selfbow, or a bow made from one piece of wood, in this case the ‘back laminate’. So how to tell if the Gräsbo find is a back laminate of a two-wood bow instead of a Neolithic selfbow made from an unusual material?

    A bow-like artifact with a clearly-flattened inner surface might seem to indicate a laminate structure. However, many archaeological and ethnographical selfbows from around the world exhibit markedly flat belly surfaces. Surface treatment of a back laminate is no basis for distinction, except in the following:

    Roughly 25 cm from the left end of the artifact in the picture, there is a substantial bump on the upper surface, indicating a large knot. A similar, smaller bump appears on the same limb approximately 5 cm from the end, on the opposite side of the artifact. This is a strong counter-indicator for the two-wood bow hypothesis, because the gluing surfaces of the back and belly laminates of this type of bows need to fit precisely together throughout their length for the construction to work. However, on selfbows, knots such as here present no problems.

    The Gräsbo find seems thick for a back laminate, although it is hard to tell from the picture. Archaeological and ethnographical back laminates of two-wood bows range from roughly 3 mm to around 15 mm maximum thickness, the latter number being a rare high end. The thicker back laminates are mostly in bows that are narrow and thick in cross-section, but the Gräsbo find is very wide, as wide as the wide, flat, Late Viking Age two-wood bow find of Vibby, Sweden. As Ragnar Insulander commented on his reconstructions of the Vibby and the Jokkmokk finds, paraphrasing: “with back laminates thicker than the 3 – 5 mm used, the bows would have been impossible to even string”.

    That the Gräsbo find is perhaps unusually thin for a selfbow, is to be expected by the low strength of the wood used. Thin cross-sections lower the strains in a wooden bow, enabling low-strength woods to work where they would promptly break if left typically thick, as in the Stone Age elm bows of Scandinavia.

    The picture shows that both ends of the Gräsbo artifact are missing, so there’s no telling if it had nock grooves at the limb ends or not. If the ends were intact and didn’t have nocks, or had nocks that were non-functional as is, the back laminate hypothesis would strengthen, although an unfinished selfbow might look just the same.

    Back laminates of two-wood bows do not have the distinctive grooving evident in most archaeological belly laminates from Fennoscandia and absent on selfbows, so no ID help there.

    Surface markings indicating an outer wrapping are common on archeological finds of two-wood bows, and typical of late historical bows of this type. However, selfbows were sometimes wrapped with birchbark, as well, as on the Mesolithic bow fragments from Nizhnyi Veretye, in northwestern Russia. A wrapped bow find may be laminate or self.

    For the reason alone that the Gräsbo find is *five times* older than the next oldest two-wood bow find from Fennoscandia, there needs to be substantial, weighty evidence of it being a back laminate of a two-wood bow before any conclusions are made. The bow from Korekawa, Japan, scarcely applies here, as it is a geographically isolated find made from a completely different type of raw material (split bamboo slats), and even it is a millennium younger than the Gräsbo find.

    As they say, extraordinary claims require extraordinary evidence.

    On the face of it, it seems the Gräsbo find is a Neolithic selfbow, perhaps a low-weight, large-scale weapon of a young or infirm person.

    Tuukka Kumpulainen
    University of Turku
    Finland

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