Dendrochronological dating
From Fritz Schweingruber et al., Atlas of Woody Plant Stems: Evolution, Structure and Environmental Modifications (Springer, 2006)
The annual growth of a tree - the growth ring - becomes visible because different cells are formed at the beginning and end of each growth period. In winter, trees do not grow in our climate (darker part of the growth ring) and in spring the cells are large-holed (lighter part of the growth ring). The growth rings of a tree register the climate: in a mild year they are wider, in a cold year narrower. The irregular sequence of narrow and wide growth rings is typical of a tree species, the period and the region in which the tree grew. This characteristic has been used to date a woody sample whose age is unknown. In the dendrochronology laboratory, the widths of the growth rings over time are converted into a curve (= growth curve) and compared with a standard curve. If a growth curve corresponds to an interval of the standard curve, it can be traced back to the year in which the plant was cut. Standard curves for a tree species and a region were created by superimposing the growth curves of woody samples of different ages with a sufficient margin of overlap (see image above).
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This dating method was used to date the two Rustici a Campiroi.
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Stone cottage
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Based on the dendrochronological dating of the central load-bearing larch beam, the barn was probably built in the early 1800s*.
*Mark Bertogliati, EcoEng SA, www.ecoeng.ch
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2 cores were drilled into the central load-bearing larch beam of the floor of block A
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According to the dendrochronological analysis carried out on the two samples, the felling of the trunk was carried out after 1792.
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Assuming a total of 20 rings for the partially missing sapling, it can be assumed that the barn was built between 1800-1815.
Rustico Campiroi
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The dendrochronological dating of Rustico Campiroi gave a presumed construction period of around 1814*, thus in the same period as the stone Rustico.
*Mark Bertogliati, EcoEng SA, www.ecoeng.ch
Additional dendrochronological dating was carried out on the larch supporting post on the ground floor. The dating indicates 1870-1875 as the period of the erection of the supporting post (most likely a replacement of the previous one as the barn is older, see above).
6 cores were drilled to obtain the dendrochronological dating of the barn, 2 of which are in relief in the photo.
Dendrochronological dating in the geographical and historical context
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What were the major events in Ticino in the early 1800s, when the two cottages were built?
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The beginning of the 1800s was characterised by the formation of the canton and the expansion of the transport network.
On 12.4.1798, with the birth of the Helvetic Republic, the emancipation of the beyliks led to the creation of the cantons of Lugano and Bellinzona. It was the Act of Mediation (1803) that sanctioned the birth of the canton of Ticino, which Napoleon Bonaparte decided should have a constitution similar to that of the other newly formed cantons. The canton was subdivided into eight districts, corresponding to the beyliks, into 38 circles, which served as electoral districts, and into about 250 municipalities, heirs of the neighbourhoods. The exercise of sovereignty was delegated to the Grand Council (110 members), which, however, limited itself to voting on laws proposed by the executive.
Continuing a policy which had begun under the Mediation (in 1810, for example, the Monte Ceneri road was completed and between 1810 and 1830 the road between Biasca and Airolo was built), the canton invested in the construction of the road network to unite the different parts of Ticino and stimulate trade, the main source of state revenue (duties and tolls).
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As one can see in the two illustrations below, the population of the villages on the left-hand slopes of the valley increased in the early 1800s (Calonico had 166 inhabitants in 1836). This situation probably prompted the development of new areas and therefore the construction of new stables on the Campiroi mountains. The construction of the horizontal wheel mill at Calonico also dates back to the same period (1813) (see "nearby attractions" below).
