www.bueforum.no

Kviljo skrev:Kjenner ikke til noen slik analyse, men det kan godt eksistere likevel.
Det burde vært gjort, uansett.

Vet faktisk heller ikke om man har noe håndfast bevis for at man har utvunnet bjørketjære og bek i steinalderen? Det svarte man finner på piler og annet kan like godt være harpiks blandet med noe. Skulle gjerne sett nærmere på dette, men jeg tror en kjemisk analyse er det eneste som ville duge for å avgjøre det. Har ikke sett noe slikt heller, uten at jeg har lett særlig etter det.

Såvidt jeg forstod hadde de i etterkant funnet den andre halvdelen av "koggeret" noe som de mente vitnet om at det var et bue-kogger og ikke et pil-kogger.

The research centres on a new analysis of two samples of blackish-brown pitch discovered in a lignite open-mining pit in the foothills of the Harz mountains in Germany. Their geological location suggests they are more than 80,000 years old.

One of the pitch pieces bears the print of a finger and there are also imprints of a flint stone tool and wood, suggesting that the pitch had served as a sort of glue to secure a wooden shaft to a flint stone blade.

In the research, carried out at the Doerner-Institut in Munich, the scientists set out to discover the chemical composition of the pitch, its biological origins, and the amount of skill and ability needed to make it.

It had been thought that the pitch was made from melted pine resin. But although such resins could work as putty, they are not strong enough to work as glue.

When the researchers broke down the samples, they found that it was a birch pitch, which is far more difficult to make. Birch pitches can be produced only at temperatures of 300-400C (570-750F). At lower temperatures, no tar is produced, while higher temperatures destroy any tar that has formed.

Christian skrev:Opp ned og bak fram

men skikkelig stilig kogger 8) hvordan er det å sy i never?