Dendrochronology

[Benson Gray]

Does anyone have any experience with dendrochronology? The first link below has more details if you are not familiar with dating wood from tree rings. This might be a way to help date some of the very early canoes. It can be done with musical instruments as described at https://violin-dendrochronology.com/ so a huge amount of wood is not always required. The second link describes the use with old barns but they generally have much larger sizes of wood to work with. The last link indicates that the cost can be "about $2,000 per analysis" so it is not inexpensive. Thoughts?

Benson

Dendrochronology - Wikipedia

en.wikipedia.org

Eastern Barn Consultants

Eastern Barn Consultants is a cultural resources company that specializes in documentation, interpretation and construction dates of eastern North American eighteenth and nineteenth century barns.

easternbarns.com

How dendrochronology reveals the truth about historic homes

Every year, more tourists come to New England, and Rhode Island in particular, for its rich, long history. Getting that history right involves a science called "dendrochronology", microscopically studying the wood in historic structures to better determine when they were built. Caption: NBC 10's...

turnto10.com

 

[patrick corry]

Interesting links Benson. Deserving of further study. The Eastern Barn Consultants are sort of in my back yard... and, I have an old Pennsylvania German bank barn where I do my canoe work/fun! Thanks for posting this.

 

[Dan Miller]

My folks had a dendrochronologic study on their circa 1750s house. The core was about 1/4" in diameter and 6" or so long. They had several cores done, but only one or two were conclusive (and helped confirm the date the house was built. The core is taken on a timber with a waney edge towards the pith - the waney edge is required to know when the tree was harvested (e.g. no growth rings were removed in squaring the timber). The method also requires regional reference trees with which to establish a connection. The reference tree is harvested at a known date, so that the age of the tree is known and the rings from a core can be cross-matched.

I took a quick look at the violin aging page, but it isn't clear how the establish the reference to know when the wood was harvested. Being radially split, at least the growth rings can be easily analyzed.

I suspect there are not enough bits in a canoe to offer up a decent size sample, and there may not be any references available.

 

[Benson Gray]

Well, this rabbit hole has turned out to be deeper than most. The article at the first link below describes the use of digital photographs to date a violin. The second and third list organizations that work in this space. Now we just need a very old canoe with unusually wide planking and a few thousand dollars to see if this will work.

Benson

Dendrochronology – Studying Tree Rings to Learn about an Antique Violin | Historic Jamestowne

Visit the real thing at Historic Jamestowne, explore the actual location and active archaeological dig, Jamestown Rediscovery, home of the first successful English settlement.

historicjamestowne.org

Oxford Tree-Ring Laboratory - Dendrochronology

Oxford Tree-Ring Laboratory - Dendrochronology of Historic Building and Archaeological timbers

www.dendrochronology.com

Tree Consulting | Cross Timbers Dendro | United States

Providing clients a better understanding of their trees. Curious about what trees you have and how old they are? Consulting services include tree-ring dating, species composition, and other forest measurements.

www.dendrotech.net

 

[patrick corry]

Not that I have a spare "few thousand dollars", but what is considered unusually wide planking? This 18' Whistle Wing has 6" sheer planks.

 

[Benson Gray]

what is considered unusually wide planking? This 18' Whistle Wing has 6" sheer planks.

This is a good thought and six inch planking could be enough but quarter sawn would show more of the annual grain pattern. It might also be nice to start with an older canoe.

Benson

 

[Benson Gray]

One of the struggles with this technique is getting good dated reference sources. There are a few old canoes with likely dates that may be able to help. The link below describes one that was probably made in 1901. It has a roughly five inch plank that is quarter sawn as shown in the picture below. It is slightly curved which isn't ideal but might be a good start. Does anyone else want to share a similar picture and details? Thanks,

Benson

Thread 'A canoe from the Indian Old Town Canoe Company'

Nov 4, 2013

The pictures here show an Indian Old Town canoe with serial number 201. There are no build records that go back this far but it is probably circa 1901 when this company started advertising. This was the first form of the organization that eventually became the Old Town Canoe Company on January 23rd, 1903 as described at http://forums.wcha.org/showthread.php?10647 previously. The name plate is a non-ferrous metal which may have been plated originally. It appears to be a GG model based on the current 35.5 inch width and 18 foot length. The center thwart is missing and was held on...

• Benson Gray
• Replies: 36
• Forum: Canoe Photo Index

 

[ALCEDO ATTHIS]

why not trying to ask the question on AI ? in France sending picture is not avaible now ... the new toy of the world and it's free ...

 

[Benson Gray]

why not trying to ask the question on AI

My limited experience with AI indicates that it can occasionally help with general questions (like the previous message that you deleted) but has limited utility with very specific ones like this.

Benson

 

[1905Gerrish]

Not that I have a spare "few thousand dollars", but what is considered unusually wide planking? This 18' Whistle Wing has 6" sheer planks. View attachment 57972View attachment 57973

That is certainly wide planking. The early White I am restoring currently has some that is 8.5 inches. The widest I've ever seen.

 

[Benson Gray]

The early White I am restoring currently has some that is 8.5 inches.

Can you send a picture of the planking like the one of the Indian Old Town above? I may be able to match it up and show the relative difference in years if there is an overlap in the patterns. Thanks,

Benson

 

[1905Gerrish]

Sure thing Benson. This should do!

 

[Benson Gray]

Zach has provided some additional images with more detail and Chris Pearson has offered to take pictures of his oldest canoes as well. The paper about the Natural disturbance and stand structure of old-growth northern white-cedar (Thuja occidentalis) forests, northern Maine, USA at the link below probably indicates the best source of information about the northern white-cedar that was commonly used for the planking on these canoes. The primary author also teaches a course on dendrochronology at the University of Maine so I have sent him a message asking if he has any suggestions about how to best proceed.

Benson

Natural disturbance and stand structure of old-growth northern white-cedar (Thuja occidentalis) forests, northern Maine, USA

Natural disturbance histories and stand structures derived from old-growth forests are increasingly used to guide forest management prescriptions. Alt…

www.sciencedirect.com

 

[Benson Gray]

Progress is being made. I've been directed to Bill Flynt who has lots of experience using dendrochronology to date old houses and is interested in helping to see if this can work for canoes. The current investigation is focused on finding a way to get a very high resolution image for him to work with. I took the cover off my scanner and tried using some pillows on a thwart to push it into the hull as shown below. The laptop was balanced on a step ladder for the 15 minutes it took to scan. This produced a 2400 dot-per-inch image but the focus was terrible so that probably won't be the solution.

The next tests involved a camera on a tripod with either a flash or ordinary lighting. This had much better focus but less resolution. The flash tended to wash things out so that probably won't work either. The next alternative would be to remove the planking so he can study it under a microscope. This could work for canoes that are being restored but would not help with most other canoes. Small steps,

Benson

 

[pklonowski]

To reduce and possibly eliminate the flash/lighting glare, try using a Diffuser, sort of like a lampshade. Another way might be to use a reflector. Anything that makes the light less directly aimed at the subject should help...

 

[Benson Gray]

try using a Diffuser

That is a good suggestion. I suspect that the next issue might be that my antique digital camera may not be able to capture enough pixels as shown below. Thanks,

Benson

 

[Benson Gray]

It has been a valiant effort but the answer to the original question seems to be no, it is not likely that dendrochronology can be used to date the varnished planking of a restored wooden canoe. It appears that the sanding and varnish work on the interior of a wooden canoe are not quite up to the standards of an antique violin. The two pictures below show the rings from my canoe under a microscope and an example of the quality that is commonly required.

This concept might work for a canoe that is being restored which has an unusually wide quarter sawn plank with good grain. The plank will need to be sanded down to a 600 grit, and either photographed or delivered to someone like Bill Flynt to analyze. A one-to-two-inch-long piece is all that would be required. A very high-resolution scan or photograph of the plank's grain might also work. This still might not produce useful results if the plank happened to come from the center of an unusually old log. Bill has kindly offered to do a pilot project pro bono to see if it can work, but future projects are likely to cost over a thousand dollars depending on numbers of suitable samples. Let me know if you want to proceed with a project like this. Thanks,

Benson

 

[Benson Gray]

There is a happy postscript to this story. Rollin Thurlow kindly offered a small section of planking from a Thatcher in his collection. Thatcher lived from 1840 to 1914 and his canoe business in Bangor lasted from about 1896 to around 1923. Very little additional information is available about Thatcher's canoe business.

The trick is finding a wide quartersawn plank with more than sixty rings and shipping about two inches of it off to be analyzed. Rollin found one and Bill Flynt has analyzed it. The picture and Bill's report below summarize his results.

Benson

I cut off a 1" piece and sanded up the end grain, and also sanded the side of the plank to see if I could polish to the clarity I would need either to measure it under the microscope or scan it to be measured via the program CooRecorder. Turns out I had to continue to sand the quarter sawn plank side with 800 and then 1500 grit paper to get the grain to be clear enough (it could use even a bit more sanding). I have attached a scan of the piece I sanded (I tried coating a portion of it with tung oil to see if it would enhance the grain). I scanned it at 1200 dpi, the highest resolution my scanner is capable of).

I then measured the sample rings on both the end grain sample (PLKEG) and the quarter sawn sample (PLKQS) and ran some tests. As you can see on the other two attachments when I compared the end grain sample to the 2-sample group it is clear that the quarter sawn sample appears to have two additional rings towards the bark edge. When I changed the overlap (lag) from 10 to 2, it is quite clear that the two samples align well with each other up until the extra last two rings (as should be expected considering they both come from the same piece of wood).

When the samples were compared to a variety of northern white cedar dated masters supplied by Shawn Fraver, only two revealed significant alignment with specific dates. The test against the master Shawn identified as HOW_THOC_BEST (which I truncated at 1928 so as to not have excessive 20th century data confusing things) displays the strongest alignments (though the correlation coefficients - the numbers in the "Corr" column adjacent to the 870/872 numbers in the first column, are not overly strong- in the .40+- range) . As can be seen in both the 10-year lag test and the 2-year lag test, the quarter sawn sample aligns with 1872 while the edge grain sample aligns with 1870 (the "add" number, 870, is added to the last year of growth which I established as 1000 when setting up the measuring parameters). While the two year discrepancy may seem odd considering it is the same piece of wood, the explanation has to do with the grain not running absolutely parallel with the edge of the wood. The edge grained sample actually has a partial last ring which I did not measure, thus the true last ring is only one year earlier than the ring on the quarter sawn sample. And where the quarter sawn sample was measured there is an additional ring at the plank edge, due to the previously mentioned slightly angled rings.

What this information can tell us is that the canoe from which this plank came from was built at some point after 1872. How many rings are missing to the waney (bark) edge is unknown, thus we cannot narrow down the construction date further.

This little project does reveal that, if you are able to access relatively flat canoe planks from the exterior, sand them sufficiently, and scan the piece, it is possible to use dendrochronology to date the growing period of the sample. If repairs are being made and pieces of plank are available, these are also potential candidates for study. As I have mentioned previously, the critical requirements for such testing are quarter sawn planks with ring counts above 60 that are of a species for which there are dated regional masters.

I would like to thank Shawn Fraver for getting me involved in this experiment and supplying the white cedar masters he has developed, and Shawn's colleague Camilla Seirup for her willingness to attempt to measure the initial photograph you supplied (several times, while battling Covid no less) using CooRecorder and then forwarding me the data.