Sign in to follow this  
Guy_Gallo

Dendrochronology Testing

Recommended Posts

I agree with Manfio. The likelihood that you would have a violin that would justify testing is very small, and an expert could tell you whether that likelihood is nonexistent or not. What maker do you think you have?

Share this post


Link to post
Share on other sites

I know the fiddle in question may not be worthy of doing the dendro test. I would seek more advice before doing it. I was just curious how much such a test runs, and who in the states does it (reputably). How big a deal is it?

The fiddle in question has gotten a range of age "guesses" from various players/makers/dealers -- none "experts of the level of Beare or the late Jacques Francais -- from 1780 to 1890. It has confused just about everyone who's seen it. And may just be a clever Frankenviolin composite.

Just thought if the test could clearly say "The tree was felled in 1870," then I could narrow where to look. And if was felled in 1770, I would have that much more credibility when I went to an expert to help place it into a region/school/maker.

Share this post


Link to post
Share on other sites

I think you have to narrow it down to a region (the region where the tree grew, that is) before you can ask the dendrochronologists for a date, because they use different reference chronologies for different regions. Also, I think that while spruce works well for this type of dating, maple does not. So, if you have a composite, at best you'll only be able to date the top.

Share this post


Link to post
Share on other sites

I personally know two of "my" violin makers who use (or have used) very old wood for their "modern" instruments instruments. Henry Meissner would make regular trips to Europe looking for old wood to use - and Fernando Solar Gonzalez told me that he had bought an old convent the central supporting vertical beam of which had been the main mast of a galleon (ship) - good spruce for tops that he claimed he used throughout his career.

Dendrochronology would tell nothing about the age of their instruments.

Andy

Share this post


Link to post
Share on other sites

Hello Falstaff,I know it may seem like a long time ago, but if you

still have your violin and would like a dendrochronology test

doneon it, you can send me some good jpgs of each half and i may be

able to date the wood for you. It's not a prerequisite knowing

wherethe wood is from as modern computers can whizz through

thousands of sequences of data in a matter of seconds.I am

experimenting with dating wood directly from the pc screen and I am

getting pretty good results, so as I said, send it off and I'll

have a look at it.Peter Ratcliff theamaticollection.com

Share this post


Link to post
Share on other sites

Talking about Dendro,has anyone read that Strad article on Cremonese wood in the July issue.

Ive noticed they are now using the results in auction catalogues over here in the U.K ,supposedly pinpointing instruments down to the same logs amongst different makers.Interesting but im not completely convinced.

There is a German place i saw on the internet that will age wood for you for around 100 euros,but they need a sample or preferably two from different areas.They use some sort of carbon dating i believe.

Share this post


Link to post
Share on other sites

quote:


Originally posted by:
Ratcliffiddles

if you would like a dendrochronology test

done on it, you can send me some good jpgs of each half and i may be

able to date the wood for you.

Is that offer a general invitation?

How good a quality photo do you need?

May PM you.

Share this post


Link to post
Share on other sites

Hello fiddlecollector.

There is very stong dendro evidence that some individual makers(very few) used wood from the same log. I have personal experience of four violins by the same Italian maker displaying almost identical grain pattern and made within a five year period.

Peter

Share this post


Link to post
Share on other sites

Hello Omobono,

Well, I am developing my already extensive database, and jpgs are only "adequate", but have given surprisingly good results so far.

I don't promise anything, but, and especially if you have "good" stuff, I will try to do it. Any Strad owners out there, get in touch!

Peter

Share this post


Link to post
Share on other sites

quote:


Originally posted by:
Ratcliffiddles

Hello fiddlecollector.

There is very stong dendro evidence that some individual makers(very few) used wood from the same log. I have personal experience of four violins by the same Italian maker displaying almost identical grain pattern and made within a five year period.

Peter

Hi Peter ,yes i have no problem with that,but these latest results are talking of T values ,with anything over a value of 5 bearing a possible relationship to another piece of wood. The best matches having values around 10. But some of the makers mentioned ,i doubt used the same wood.

Maybe John Topham who posts on here and was involved in the article can clear up some of this.

Share this post


Link to post
Share on other sites

Hello fiddlecollector,

T values are one thing, and together with an essential graphical comparison of the data, one can then make a pretty good assessment of the relationship between the various pieces of wood. You can have two pieces of wood from let's say Mittenwald, with a t value of 12 or sometimes more, which are evidently not from the same tree when compared graphically. On the other hand, a front, evidentally book matched, sometime only reaches a t value of 7 or 8, but will show up graphically as matching perfectly well.

Peter

Share this post


Link to post
Share on other sites

"I am experimenting with dating wood directly from the pc screen and I am getting pretty good results"

How do you know that you are getting "good results"?

Do you have wood samples that you are positive grew at a certain period of time, and are confirming them blindly using dendro?

Just curious....

" You can have two pieces of wood from let's say Mittenwald, with a t value of 12 or sometimes more, which are evidently not from the same tree when compared graphically."

What if the tree was off-center?

A billet from one side of the tree would display graining--for example--with 24 grains-per-inch, and the other side of the tree might have a 10 GPI count...

Both billets from the same tree, yet radically different...

Share this post


Link to post
Share on other sites

Hello Tonewoods,

Most of your points have been dealt with extremely thoroughly in the past by Derek Mc C. and John Topham, so I won't repeat to much unless ou want me to.

The reason I know I am getting "good results" is that I have tested dozens of violins with my regular optical equipment and subsequently repeated the process wih jpgs on screen for the same instuments, getting the same results and getting extremely good graphical correlation.

If the tree was off center, as is often the case, the results will almost certainly be correct, repeating some of my colleagues comments, it is the relationship between the rings overall and not ring widths that matter. If one side of the tree has wider rings and the other narrow ones because of the slant of the hill where it grew, the relative ring width pattern will be similar and that will show up both statistically in a program and graphically. So the billets may look different, but really, I can assure you, they will match each other.

Regarding wood samples that grew positively somewhere, there is an extensive database of stuff collected in various regions of the Alps (and everywhere else for that matters) by trained tree people over the last few decades which forms part of the basis for dating wood and together with instrument data, after four & half years of measuring, (blindly or not) I am starting to get a general picture of what was going on then with wood use.

Peter

Share this post


Link to post
Share on other sites

How close can a dendrochronological analysis get to the actual felling date of a sruce tree used for a violin? Or to put it another way, typically how close is the outside edge of the table to the bark? Or is there no 'typical'?

Andrew

Share this post


Link to post
Share on other sites

Hello rudall,

There is no general rule, but more often than not, Classical Italian violins, incl. Strads, Del Gesu, other Cremonese, Venetians etc.. produce a dendro date relatively close to the label date. To name drop, I'll mention a 1721 Strad with a dendro date of 1711, another from 1719 with 1710 dendro date, and occasionally even closer dates are met with. We have to assume in those cases that the tree was felled near to those dendro dates, and that Strad was pretty good at doing middle joints, therefore losing but a few outer growth rings.

On the other hand, a George Panormo of 1824 revealed a dendro date of 1733. This gap between the two dates is not unusual on English instruments, both from the eighteenth and nineteenth century in my experience.

Sometime the structure of the wood can lead to speculation as to the felling date, but as the last ring isn't actually present, it is only conjecture.

Peter

Share this post


Link to post
Share on other sites

On your web page you state:

"The present success rate in dating spruce from the table of an instrument is in the region of 60 to 70%."

That's a pretty low success rate in my eyes. Is that an accuracy percentage for a defined timeframe (such as...within 5 years)? I know I am missing something here.

Share this post


Link to post
Share on other sites

"On the other hand, a George Panormo of 1824 revealed a dendro date of 1733. This gap between the two dates is not unusual on English instruments, both from the eighteenth and nineteenth century in my experience. "

Fungusing, and thus the discarding of the sapwood--a fairly common occurance--would possibly help to explain this...

Share this post


Link to post
Share on other sites

"How close is the outside edge of the table to the bark?"

The proper question to ask is: "How close is the center joint of the table to the bark?," because the outside edge is toward the center of the tree. Some wood from the outside of the tree will allways be lost in planing the billet to make the center joint.

Share this post


Link to post
Share on other sites

Hello Dean,

Actually, I thought 60% success rate was pretty good. When I get a date, I get a date, it is not within five, ten or any other number of years, it is the actual date when the last growth ring present on the violin was growing. The rate of success will I suppose and trust, increase as time goes by. When a date is not found, the data is stored and used in future analysis and might, in time reveal the correct date.

Peter

Share this post


Link to post
Share on other sites

quote:


Originally posted by:
Brad_Dorsey

The proper question to ask is: "How close is the center joint of the table to the bark?,"

Silly me.

Share this post


Link to post
Share on other sites

OK Peter,

I think I have it.

It's close to a coin toss that you will get a date but....if you get a date it's near 100% accurate. The lack of a date is not a fault in the method but a current deficiency in the data pool. Am I getting close?

Dean

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.