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Re: [ITRDBFOR] Burnt wood


Chronological Thread 
  • From: "Oliver Nelle" <oliver.nelle AT gmx.de>
  • To: peter.kuniholm AT gmail.com, "Sebastian Million" <sebastian.million AT yahoo.de>
  • Cc: "itrdbfor AT itrdbfor.org" <itrdbfor AT itrdbfor.org>, "Björn Gunnarson" <bjorn.gunnarson AT natgeo.su.se>
  • Subject: Re: [ITRDBFOR] Burnt wood
  • Date: Tue, 29 Aug 2017 18:21:31 +0200

Dear Björn,
in anthracology (charcoal research) it is common to use a ring light which
gives a straight, evenly distributed light resulting in good black/light
contrast. Then you will see ring boundaries clearly and be able to measure
them.
best
Oliver

Gesendet mit der GMX iPhone App

Am 29.08.17 um 13:58 schrieb
peter.kuniholm AT gmail.com

> We have measured thousands of pieces of charcoal. The most effective way of
> seeing the ring boundaries was to use a pair of goose-neck lights, aiming
> them so that the latewood appears silver, against which the black
> crosshairs of the microscope may easily be seen.
>
> Sent from my iPhone
>
> > On Aug 29, 2017, at 7:06 AM, Sebastian Million
> > <sebi279 AT yahoo.de>
> > wrote:
> >
> > Dear Björn,
> >
> > we also work with archaeological burt wood.
> > Do you measure with a time table or on-screen on a scanned image?
> >
> > If you measure with a time table, try to change the angle of the light
> > source(s).
> >
> > Best regards,
> > Sebastian
> >
> >
> > Björn Gunnarson
> > <bjorn.gunnarson AT natgeo.su.se>
> > schrieb am 11:20 Dienstag, 29.August 2017:
> >
> >
> > Dear forum,
> >
> > I currently working on an archeological project trying to date (or making
> > a float) on burnt oak incorporated into a wall structure of stone (from
> > ca 500 AD). The wall has been burnt down and the only thing that is left
> > is bits and pieces of a wooden structure. The oak Is quite well preserved
> > with visible rings if I cut the piece into disks with a bandsaw. The
> > problem is even if a I see the rings, I have real problems to see the
> > boundary in a microscope (because it’s all black) so I need to increase
> > the contrast somehow? What I usually do with disks is to cut a radii
> > with a razor blade and then rub chalk on the cut radius with my finger.
> > This gives a very good results.
> >
> > The problem is If use the same method here I just mix charcoal powder
> > (that from the sample) and mix it with chalk, making it all very messy.
> >
> > Is there anyone that have ideas or have experience working with burnt
> > pieces of wood?
> >
> >
> > Regards
> > Björn
> > ________________________________
> > Björn Gunnarson, ass. prof.
> > Stockholm Tree Ring Laboratory
> > Dept of Physical Geography
> > Climate Science and Quaternary Geology
> > Stockholm University
> > SE-106 91 Stockholm
> > http://www.su.se/profiles/bgunn
> > http://www.natgeo.su.se/english/climate-science-and-quaternary-geology-research-unit/stockholm-tree-ring-laboratory
> >
> >
> >
> >
> > with burnt pieces of wood?
> >
> >



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