Skutudden
In 1914 my mother lived here at Skutudden in a house which is now demolished. The crofter family was an old couple living with their two cows and a pig. They grew what was needed for their animals and themselves and certainly, fishing was of great importance. At that time the landscape was open and light - nowadays it is quite dark because of all trees. Though still in 1948 when my mother used to take me here, this was still a beautiful and light farming landscape.
Dating two samples from the cottage
When the croft cottage was renovated almost all replaced old wood was thrown away and burnt. Only two pieces were left, which I later got for a dendrochronological investigation. The result of this investigation shows that the oldest sample - which looks as reused timber - was cut in the winter of 1732/1733, the other sample was cut in the winter of 1796/1797.
It is puzzling that the sample from 1732 matches better towards a reference from the distant Dalarna than towards a reference from the nearby Nämdö (corrcoeff=0.45) or Tyresö (Sisshammar, corrcoeff=0.38 - not shown here). Accordingly we have reasons to guess that the house is partly built out of reused wood bought from elsewhere. More samples from the cottage might reveal more of the story of this building.
This side of the timber block (dated to 1732) was certainly cut long time ago. In the middle of the cut we can see half a hole for a dowel (a thick stick) possibly used as support for a plank to walk on along the wall during house building. The diameter of the hole is 35 millimetres (1.4 inches). The length of the hole is 80 millimetres (3.2 inches). The fact that the block is cut across the whole might indicate that the block with its hole has been reused for a second house. This is how it looks when old timber has been reused when a house was built. We find holes, grooves and notches which were created for the first building.
SNSU01 - The piece from 1796 has red paint on what has been the outside. The inner side has been tapped with small pins which certainly have been used to support clay plaster on the wall.
How was this dating done? - The sample from 1732 (SNSU02)
Two radii were measured with CooRecorder.
The data was then imported into CDendro and a mean value curve was created out of the two radii. (Lower curves are ring widths, upper curves are normalized values.)
The mean value curve of the two radii was then compared to a mean value curve from the nearby island of Nämdö some 17 miles East of Saltsjöbaden. (Our curve from Saltsjöbaden does not reach longer back than to the year 1765 with at least three trees behind each ring width value. So it is not very useful in this case.)
SNSU02_2.d12 Transformation: Proportion of last two years growth (2,0,T)
compared to the reference Namdo_1.d12 Dated to 1995
Minimum overlap used when finding best match: 35
Table sorted by TTest
--Rel Over Corr TTest BaPi GLK (year)
-year lap coeff corr
13 53 0.46 3.7 0.52 0.68 (1982)
263 53 0.45 3.6 0.37 0.55 (1732)
119 53 0.40 3.1 0.45 0.64 (1876)
134 53 0.34 2.6 0.30 0.58 (1861)
65 53 0.34 2.6 0.29 0.58 (1930)
346 53 0.32 2.4 0.34 0.66 (1649)
2 53 0.30 2.2 0.23 0.60 (1993)
214 53 0.26 1.9 0.30 0.62 (1781)
The very big problem with this sample is that we have too few rings! At least we need some 60-80 rings to make a reliable dating, here we have only 53. Also, the TTest-value (T-value) should be well above 5 to make a dating reliable. Here the highest is only 3.7!
Next step is to run the Test Towards UNDATED Reference command from a collection of 37 members, each representing a mean value curve from an area in Sweden, Norway, Denmark, Estonia or Finland. With that command and "With condensed report" checked, we will get a list with the best matching years - one from each of these 37 members. (For this test, our undated sample should be the reference in CDendro!)
T- Over Corr Test lap Year all... 0.57 4.94 53 1732 based on 37 members Norw014B 0.55 4.71 53 1910 SödraDal 0.55 4.67 53 1732 Södra Dalarna, Axelson, Israels. PISY SWED305B 0.53 4.50 53 1732 Björbo, Dalarna DALARNA 0.53 4.45 53 1732 Dalarna, Lunds universitet (EXTRATERR) SE006-La 0.51 4.24 53 775 Lappland, Lund (EXTRATERR) 9M45678 0.51 4.23 53 399 Denmark (WestDK) Old version EXFin002 0.50 4.16 53 923 Fin002 N.Finland (EXTRATERR) Gagnef-s 0.50 4.11 53 1732 Gagnef-Djura .... Year numbers occurring more than once: 1732 7 1906 4 1843 2 1887 2 1934 2
The year 1732 is apparently some sort of favourite! If we now provisionally date our sample to 1732, we can use the Test Towards (DATED) Reference command to get a list showing how well all our 37 samples match at that year. By then using only the nine best matching members, we get this result ("With condensed report" still checked!):
T- Over
Corr Test lap
all... 0.66 6.31 53 based on 9 members
SödraDal 0.55 4.67 53 Södra Dalarna, Axelson, Israels. PISY 1362-2005
SWED305B 0.53 4.50 53 Björbo, Dalarna 1451-2002
DALARNA 0.53 4.45 53 Dalarna, Lunds universitet (EXTRATERR) 932-1888
Gagnef-s 0.50 4.11 53 Gagnef-Djura 1362-1831
NMVKMEAS 0.47 3.80 53 Kaptensudden, unknown origin in Stockholm area 1672-1870
BratPIr 0.47 3.78 53 Mälardalen (Bråthen), questionable segments removed 1153-1904
FINL2_4_ 0.46 3.71 53 SouthEast Finland 536-2002
SWED302N 0.45 3.64 53 Nämdö, Stockholm archipelago 1583-1995
3EP281AV 0.45 3.60 53 Estonia Est002 (EXTRATERR) 1516-1998
I.e. a mean value curve (see all... above) created out of these nine members gives us a correlation coefficient of 0.66 and a TTest-value of 6.3 for the match at the year 1732. Such high values usually indicate a reliable dating!
How was this dating done? - The sample from 1796 (SNSU01)
Matching the other sample from the cottage towards the Nämdö (ITRDB:Swed302) curve shows:
--Rel Over Corr TTest BaPi GLK (year) -year lap coeff corr 199 63 0.48 4.2 0.49 0.71 (1796) 181 63 0.38 3.3 0.41 0.63 (1814) 124 63 0.35 3.0 0.32 0.70 (1871) 74 63 0.34 2.8 0.36 0.70 (1921) 36 63 0.32 2.7 0.39 0.57 (1959)
The crossdating above towards the Nämdö mean value curve failed with the highest T-value well below 5!
Doing an analysis (as for the other sample) with a collection of 37 mean value curves from the surrounding areas, we get the following best matches:
T- Over
Corr Test lap Year
all... 0.49 4.38 63 1796 based on 37 members
swed304S 0.59 5.67 63 1796 Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910
East SvealandNOSU 0.58 5.59 63 1796 East Svealand (Aneby+Bettna+Sisshammar+Askersudn+SBaden exkl Skutudden
swed328T 0.53 4.80 62 1796 Tyresta (SE Stockholm 5911 01816) Linderholm PISY 1734-2000 (cropped)
ANEBYALL 0.55 4.69 52 1796 Aneby in Småland
3EP281AV 0.50 4.45 63 1796 Estonia Est002 (EXTRATERR)
DALARNA 0.49 4.41 63 1796 Dalarna, Lunds universitet (EXTRATERR)
Karesuan 0.50 4.26 56 1828 Karesuando, Sweden
SWED302N 0.48 4.24 63 1796 Nämdö, Stockholm archipelago
se_005Go 0.47 4.19 63 1796 Gotland, Lunds univ. (EXTRATERR)
As seen above, the year 1796 is a strong contender! With the sample dated to 1796 and with only the nine best matching mean value curves selected:
T- Over
Corr Test lap
all... 0.66 6.91 63 based on 9 members
swed304S 0.59 5.67 63 Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910
East SvealandNOSU 0.58 5.59 63 East Svealand (Aneby+Bettna+Sisshammar+Askersudn+SBaden exkl Skutudden
ANEBYALL 0.55 4.69 52 Aneby in Småland
swed328T 0.53 4.80 62 Tyresta (SE Stockholm 5911 01816) Linderholm PISY 1734-2000 (cropped)
BratPIr 0.51 3.89 45 Mälardalen (Bråthen), questionable segments removed
3EP281AV 0.50 4.45 63 Estonia Est002 (EXTRATERR)
DALARNA 0.49 4.41 63 Dalarna, Lunds universitet (EXTRATERR)
SWED302N 0.48 4.24 63 Nämdö, Stockholm archipelago
se_005Go 0.47 4.19 63 Gotland, Lunds univ. (EXTRATERR)
With a TTest value near 7, this means that the dating to 1796 is reliable!
The measurement series are available within this .rwl file: SNSU.rwl
The croft cottage at Igelboda, Saltsjöbaden
When the old croft cottage was demolished in 2006, I got two samples, one from a wall near the entrance and the other from a stock laying on the ground partly in the clay under the chimney shaft.
Crossdating the sample from 1849 (SNIT01)
We first run the Test Towards UNDATED Reference command from a collection of members, where each member represents a mean value curve from an area in Sweden, Norway, Denmark, Estonia or Finland. That command will find the best matching year for each member. Having "With condensed report" checked we get a sorted list with the best matches at the top:
2009-01-26 21:51:48 Cybis CDendro, Algorithm: Proportion of last two years growth (2,0,T)
Correlations between available references in D:\ake\tree\All\all.fil and
D:\ake\tree\sn\Igelboda\SNIT01.d12
based on best matches giving dating to years according to the year-column below and with overlap >= 47
Results sorted according to decreasing T-Test values.
T- Over
Corr Test lap Year
all... 0.44 4.41 81 1107 based on 37 members
swed304S 0.61 6.86 81 1849 Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910
swed328T 0.56 6.09 81 1849 Tyresta (SE Stockholm 5911 01816) Linderholm PISY 1734-2000 (cropped)
se_005Go 0.56 6.02 81 1849 Gotland, Lunds univ. (EXTRATERR)
BratPIr 0.56 5.16 60 1849 Mälardalen (Bråthen), questionable segments removed
SWED302N 0.49 5.06 81 1849 Nämdö, Stockholm archipelago
FINL2_4_ 0.48 4.82 81 648 SouthEast Finland
swed016_ 0.48 4.66 74 1849 Glaskogen, swed016
....
Year numbers occurring more than once:
1849 11
1770 2
1792 2
With only the best 5 matching curves and the sample provisionally dated to 1849:
2009-01-26 21:58:35 Cybis CDendro, Algorithm: Proportion of last two years growth (2,0,T)
Correlations between available references in D:\ake\tree\All\all.fil and
D:\ake\tree\sn\Igelboda\SNIT01.d12
dated to 1849 with corr >= 0.49 and with overlap >= 60
Results sorted according to decreasing correlation coefficient values.
T- Over
Corr Test lap
all... 0.64 7.45 81 based on 5 members
swed304S 0.61 6.86 81 Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910 1661-1910
swed328T 0.56 6.09 81 Tyresta (SE Stockholm 5911 01816) Linderholm PISY 1734-2000 (cropped) 1734-2000
se_005Go 0.56 6.02 81 Gotland, Lunds univ. (EXTRATERR) 1125-1987
BratPIr 0.56 5.16 60 Mälardalen (Bråthen), questionable segments removed 1153-1904
SWED302N 0.49 5.06 81 Nämdö, Stockholm archipelago 1583-1995
The tables above clearly show that 1849 is a correct dating of the sample taken from the wall.
Crossdating the sample from 1787 (SNIT02)
2009-01-26 22:04:28 Cybis CDendro, Algorithm: Proportion of last two years growth (2,0,T) Correlations between available references in D:\ake\tree\All\all.fil and D:\ake\tree\sn\Igelboda\SNIT02.d12 based on best matches giving dating to years according to the year-column below and with overlap >= 53 Results sorted according to decreasing T-Test values. T- Over Corr Test lap Year all... 0.53 5.87 91 1787 based on 37 members swed304S 0.65 8.06 91 1787 Tyresö, Sisshammar (SE Stockholm 5913 1821) Andreason PISY 1661-1910 East SvealandNOSU 0.60 7.15 91 1787 East Svealand (Aneby+Bettna+Sisshammar+Askersudn+SBaden exkl Skutudden SWED302N 0.53 5.90 91 1787 Nämdö, Stockholm archipelago swed328T 0.59 5.22 53 1787 Tyresta (SE Stockholm 5911 01816) Linderholm PISY 1734-2000 (cropped) BratPIr 0.49 5.02 82 1787 Mälardalen (Bråthen), questionable segments removed .....
The table above clearly shows that 1787 is a correct dating of the sample that was picked up from the ground in the clay under the chimney shaft. A few rings may be missing in the outermost part of the stock - meaning that the tree was cut some years after 1787 - though I do not think so!
The measurement series are available within this .rwl file: SNIT.rwl
This is the new house which replaced the old one (which was in a very bad condition).