Various dated objects

Last update 31 Oct 2013.
The Finnish sailing ship "Aimo"

In a snow storm in the middle of December 1898 the Finnish sailing ship "Aimo" failed in a tacking maneuver and sailed straight into the archipelago outside Nämdö and stranded on the skerries "Vitkobbarna". With the two ship's boats, the whole crew got safely to the nearby island of Rågskär. Eighteen soaking wet men doing a surprise visit in the early evening at the crofter's cottage!

The ship could not be saved. It was sold and the wood was used for building houses. Later the left-overs of the ship was used as an artillery target by the Swedish navy.

Tacking, a maneuver by which a sailing boat turns its bow through the wind (Wikipedia)

A four inch "slice" of the 8 by 11 inches thick stock.
At Långholmen, an island close to Runmarö (North of Nämdö), tradition says that part of a peer and part of a barn came from the Aimo ship.
The "slice" above has been ground to allow for a dendrochronological analysis.
Several radii have been measured (Aimo.rwl) and a mean value of that was analysed.

Litteratur:
Skärgårdsmuseets tidskrift Skärgård nr 19 Nov 1979, artikeln "Aimo" av Allan Gustafsson.
Om förlisningen, se Maj-Britt Eriksson, Notvarp i Nämdö 1979 eller ovanstående nummer av tidskriften.

The analysis was done with a collection of 37 members, each representing a mean value curve (in .d12 or .wid format) from an area in Sweden, Norway, Denmark, Estonia and Finland. The presumed Aimo sample was selected as the reference in CDendro and the command Test Towards reference was run from the collection.

The best matching results list like this:

 
                  T-    Over 
           Corr   Test   lap  Year 
all...     0.31   3.51   121   302   based on 37 members 
3EP281AV   0.50   6.24   121  1792   Estonia Est002 (EXTRATERR) 
BratPIr    0.43   4.92   107  1792   Mälardalen (Bråthen), questionable segments removed 
NKarelia   0.37   4.29   121  1690   North Karelia, Finland 
se_005Go   0.35   4.10   121  1792   Gotland, Lunds univ. (EXTRATERR) 
EXFin002   0.35   4.06   121  1769   Fin002 N.Finland (EXTRATERR) 
gud14      0.49   4.00    54  2017   Gudbrandsdalen, Norway 
SE006-La   0.34   3.98   121  1769   Lappland, Lund (EXTRATERR) 
East Sve   0.34   3.91   121  1792   East Svealand Aneby+Askersu+Bettna+Sissham+Saltsjöba 
NFinland   0.34   3.91   121  1769   Northern Finland 
swed304S   0.33   3.88   121  1792   Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910 
............ 
Year numbers occurring more than once: 
 1792   11 
 1769    3 
 1824    2 
 1913    2 
 1921    2 
 2010    2  
With the presumed Aimo sample provisionally dated to 1792 the matching of each member to that year could be analysed. With then only the best eigth members selected, I got: ... with corr >= 0.30 and with overlap >= 107 Results sorted according to decreasing correlation coefficient values.
                    T-  Over 
           Corr   Test   lap 
all...     0.45   5.47   121   based on 8 members 
3EP281AV   0.50   6.23   121   Estonia Est002 (EXTRATERR) (1516-1998) 
BratPIr    0.43   4.91   107   Mälardalen (Bråthen), questionable segments removed (1153-1904) 
se_005Go   0.35   4.10   121   Gotland, Lunds univ. (EXTRATERR) (1125-1987) 
East Sve   0.34   3.90   121   East Svealand Aneby+Askersu+Bettna+Sissham+Saltsjöba (1662-2005) 
swed304S   0.33   3.88   121   Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910 (1661-1910) 
SödraDal   0.32   3.63   121   SDalar 1 Södra Dalarna      PISY (1362-2005) 
DALARNA    0.30   3.49   121   Dalarna, Lunds universitet (EXTRATERR) (932-1888) 
NMVKMEAS   0.30   3.44   120   Kaptensudden, unknown origin in Stockholm area (1672-1870) 
I.e. the best T-value is 6.2 towards the reference from Estonia at year 1792. That is a quite certain dating of the outermost ring of the stock.
The "Aimo" was built in Åbo and launched in 1866. If this stock is a part from "Aimo" - which we have good reasons to presume - some 70 rings of sapwood have been cut away as the outermost ring in this "slice" grew in 1792.

Firewood from the Old Town

The Old Town of Stockholm
Baggensgatan. Photo: Per Danielson
8.5*8.5 inches (20*21 centimetres)
A friend of mine came recently with a slice from their firewood cellar, at Baggensgatan in the Old Town of Stockholm, and asked if I could date it. Anyhow the thin ring widths indicated that the wood was not too young.

Later, I found that the 60 innermost rings had a mean width of 2 mm, the outermost 152 rings had a mean width of 0.7 mm! Where can I buy that quality of wood today?

I've measured three radii from the "slice", available here as a .rwl file.

When Tested Towards References like for the Aimo stock, the best matching result looks like:

 
                  T-    Over 
           Corr   Test   lap  Year 
all...     0.31   4.79   212  1619   based on 37 members 
BratPIr    0.56   6.79   101  1619   Mälardalen (Bråthen), questionable segments removed 
SödraDal   0.38   5.99   212  1619   SDalar 1 Södra Dalarna    PISY 
Gagnef-s   0.36   5.66   212  1619   Gagnef-Djura 
DALARNA    0.33   5.09   212  1619   Dalarna, Lunds universitet (EXTRATERR) 
9M45678    0.31   4.65   212  1353   Denmark (WestDK) Old version 
swed304S   0.34   4.53   164  1958   Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910 
Saltsjob   0.29   4.37   212  1958   Saltsjöbaden 
..... 
Year numbers occurring more than once: 
 1619    7 
 1958    5 
 1755    2 
_ 
With the reference dated to 1958, there was no better match than corr-coeff = 0.34 
So 1619 might be a good candidate! With the reference dated to 1619, the best matches were: 
                    T-  Over 
           Corr   Test   lap 
all...     0.42   6.63   212   based on 5 members 
BratPIr    0.56   6.79   101   Mälardalen (Bråthen), questionable segments removed (1153-1904) 
SödraDal   0.38   5.99   212   SDalar 1 Södra Dalarna    PISY (1362-2005) 
Gagnef-s   0.36   5.66   212   Gagnef-Djura (1362-1831) 
DALARNA    0.33   5.09   212   Dalarna, Lunds universitet (EXTRATERR) (932-1888) 
SWED305B   0.31   4.14   169   Björbo, Dalarna (1451-2002) 
I.e. that tree actually grew between 1407 and 1619 (we can be very certain about that number!), though there may be some sapwood cut away, so the tree was cut some years after 1619. I.e. it is of the same time as the old Wasa ship!
We do not know from which house the wood originates, as old wood is often placed in containers when houses are repaired - and from there that wood is sometimes saved by people with a need of firewood.

Was grandma's cottage built before the Russian fire in 1719?

In 1719 Russian troops burnt down towns, houses and forests along the Swedish Baltic coast. Few houses were left.
Today, old houses of this region are almost never from the time before 1719.

At Dalarö was a fortification - Dalarö Skans, today a museum - which the Russians did not approach.
So question was, might it be that grandma's old cottage at Jutholmen near Dalarö Skans survived the Russian fire?

I got the slice above from Jesper Steen. It was cut when the house at Jutholmen was rebuilt and the slice had been laying for some years.
I measured seven radii of various length from the slice. The measurements are available here as JH001.rwl
The size of the slice is 5 * 11 inches.
The cottage at Jutholmen. The stem was removed from the place of the window in the middle of the photo.
A Test Towards Reference run as with the samples above gives these best matches:
 
                  T-    Over 
           Corr   Test   lap  Year 
all...     0.30   3.82   150  1725   based on 37 members 
se_005Go   0.39   5.14   150  1725   Gotland, Lunds univ. (EXTRATERR) 
SWED302N   0.39   4.97   143  1725   Nämdö, Stockholm archipelago 
3EP281AV   0.33   4.28   150  1725   Estonia Est002 (EXTRATERR) 
_ 
Bettna_M   0.31   3.98   150  1984   Bettna, Eastern middle-Sweden, west of Stockholm 
SE006-La   0.30   3.84   150   643   Lappland, Lund (EXTRATERR) 
EXFin002   0.30   3.82   150  1787   Fin002 N.Finland (EXTRATERR) 
..... 
Year numbers occurring more than once: 
 1725    4 
 1611    3 
 1984    3 
 1946    2 
With the reference dated to 1725: 
                    T-  Over 
           Corr   Test   lap 
all...     0.30   3.82   150   based on 37 members 
se_005Go   0.39   5.14   150   Gotland, Lunds univ. (EXTRATERR) (1125-1987) 
SWED302N   0.39   4.97   143   Nämdö, Stockholm archipelago (1583-1995) 
3EP281AV   0.33   4.28   150   Estonia Est002 (EXTRATERR) (1516-1998) 
gud14      0.28   1.77    38   Gudbrandsdalen, Norway (1687-1950) 
NKarelia   0.24   3.04   150   North Karelia, Finland (1472-2001) 
Bettna_M   0.24   1.58    42   Bettna, Eastern middle-Sweden, west of Stockholm (1683-1997) 
Gagnef-s   0.23   2.93   150   Gagnef-Djura (1362-1831) 
FINL2_4_   0.23   2.82   150   SouthEast Finland (536-2002) 
East Sve   0.22   1.80    64   East Svealand Aneby+Askersu+Bettna+Sissham+Saltsjöba (1662-2005) 
DALARNA    0.21   2.61   150   Dalarna, Lunds universitet (EXTRATERR) (932-1888) 
BratPIr    0.19   1.51    62   Mälardalen (Bråthen), questionable segments removed (1153-1904) 
SödraDal   0.19   2.36   150   SDalar 1 Södra Dalarna 
_ 
With only the three best matching members: 
                    T-  Over 
           Corr   Test   lap 
all...     0.43   5.74   150   based on 3 members 
se_005Go   0.39   5.14   150   Gotland, Lunds univ. (EXTRATERR) (1125-1987) 
SWED302N   0.39   4.97   143   Nämdö, Stockholm archipelago (1583-1995) 
3EP281AV   0.33   4.28   150   Estonia Est002 (EXTRATERR) (1516-1998) 
I.e. the sample matches best (and with quite sufficient probability) to the year 1725 towards references from the nearby island of Nämdö and from Gotland - quite distant.
Probably the tree has grown neither on Nämdö nor on Gotland. Currently we do not have more references that might reveal from where the tree came.

There are probably a few outermost year rings which were cut away when the house was built. It is reasonable to state that the tree was cut sometime in the interval 1725-1750.
I.e. that log out of grandma's cottage was certainly cut quite a long time after the Russian fire of 1719!


"Flotsam and jetsam": Did grandpa use flotsam to build his barn?

95 * 290 millimetres (4*11.5 inches)
At Långholmen close to Runmarö is an old "fisherman's croft" with an old barn. A thick plank in the barn wall draw the owner's attention: Where did it come from? It was heavily infested by the house longhorn beetle, so only chance to measure it was to cut off a slice from the plank. With a sufficiently large ground surface there could be a chance to find a measurement path between the windling grub tunnels.

I have measured three radii from that plank. The .rwl file is available as WBERG.rwl.

A Test Towards Reference run as with the samples above gives these best matches:
 
                  T-    Over 
           Corr   Test   lap  Year 
all...     0.36   5.35   193  1736   based on 37 members 
swed023_   0.54   8.96   193  1736   940    1 Jamtland, historisch proj EXTRAT. - no PCAB 
NFinland   0.46   7.21   193  1736   Northern Finland 
EXFin002   0.46   7.19   193  1736   Fin002 N.Finland (EXTRATERR) 
SE006-La   0.42   6.48   193  1736   Lappland, Lund (EXTRATERR) 
NKarelia   0.42   6.44   193  1736   North Karelia, Finland 
_ 
FINL2_4_   0.34   4.96   193  1866   SouthEast Finland 
SödraDal   0.33   4.85   193  1736   Södra Dalarna,  Axelson, Israels. PISY 
DALARNA    0.31   4.45   193  1736   Dalarna, Lunds universitet (EXTRATERR) 
... 
Year numbers occurring more than once: 
 1736    9 
 1896    3 
 1860    2 
With the reference (the plank) then dated to 1736 and with only the five best matches of the collection: 
                    T-  Over 
           Corr   Test   lap 
all...     0.57   9.47   193   based on 5 members 
swed023_   0.54   8.96   193   Jamtland, historisch proj EXTRAT. - no PCAB (1107-1827) 
NFinland   0.46   7.21   193   Northern Finland (1410-2001) 
EXFin002   0.46   7.19   193   Fin002 N.Finland (EXTRATERR) (6-1993) 
SE006-La   0.42   6.48   193   Lappland, Lund (EXTRATERR) (-309-1993) 
NKarelia   0.42   6.44   193   North Karelia, Finland (1472-2001) 
With that high T-values the dating to 1736 can be considered correct and the origin of the tree is somewhere along the coasts of the  the Gulf of Bothnia (North of the real Baltic).

With at least 14 unmeasured outer rings, the felling year of the tree shifts from 1736 to 1750, though we do not know how much sapwood that has been cut away! Anyhow it seems that grandpa actually used some flotsam timber that "blessed the coast" to build the barn! Perhaps that type of planks which were used to cover the openings to the hold (the cargo space) of a ship.

Note: "Flotsam and jetsam"?, see Wikipedia on "flotsam"


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