Per fact, summer sultriness is particularly high during August sopra South Italy
As referred in the retroterra section, the carefully per situ observation of the Altar Machine allowed detect several damages on the wood elements like cracks, deformations, surface detachments and scratches, dust layers, colour modifications, and many holes caused by the insects. Wood deterioration was due onesto the manufacturing process, puro the Altar Machine usage, and puro the microclimate con the apsidal settore of the church. The numerous galleries produced by the xylophagous insects weakened the wood, making the substitution of elements or the introduction of plugs necessary.
The identification Ricerca match of the wood species was undertaken because the diagnosis of the botanical species represents a great importance durante the technological and historical artistic study of a wooden artefact coppia puro possible implications relating to the conservation. Per fact, every species exhibits peculiar characteristics that delineate the physical, mechanical and durability properties of the material as features of the xylem of the tree botanical species.
The species identification allowed esatto find six different kinds of wood that were used con relation to the technological characteristics of the altar elements. The results are summarized con Table 3.
The wood species used for the Machine elements could be easily found on the territory of Gangi. The availability and the cost of timber influenced the choice of the wood by local artisans . The presence of Picea abies Karst per the tabernacle can be probably traced back preciso per restoration intervention. In fact, this alpine species, due to its excellent technological characteristics, has been widely marketed and often has been found con restored wooden structures con Sicily .
Chestnut wood was used per the back structural elements of the altar due puro its excellent physical and mechanical properties per relation puro the density. Moreover, the chestnut wood has a natural durability and it exhibits per moderate shrinking [21, 22]. Chestnut wood has been used sopra Italy especially for roof beams and also for the outer surface of the doors coppia preciso the properties of its heartwood. The chestnut heartwood has a natural pleasant colour that darkens during time [23, 24].
The walnut wood was found con the winch drum (cylindrical element on which the ropes are wrapped durante order onesto raise the statue). The use of this species is related mainly to the low coefficient of shrinkage that ensures dimensional stability during the thermo hygrometric variations .
The different species within the Pinus, Quercus, and Populus genera cannot be distinguished exclusively on the basis of anatomical features [21, 25–27]. Therefore the identification of botanical species was not obtained.
Pine wood has been used for the realization of some plugging elements on the back side of the Machine. These elements probably were movable, but today we are not able puro understand their function.
The decoration elements are made of poplar, per wood species widely used mediante Italy for the creation of painted panels and other decorated works of art [21, 28]. Con fact, it is characterized by low density, easy seasoning and processing, and colour homogeneity that make it particularly suited puro apply the painted layers, sopra spite of this wood could be easily attacked by xylophages.
Microclimatic analysis
The microclimate campaign was carried out during the summer that can be considered the most critical period for the artefact. Moreover, mediante August the Machine is moved on the occasion of religious celebrations and many people crowd the church influencing the microclimate.
It must be stressed that the monitoring campaign was short but, we think, significant and useful for the purpose of this rete informatica that is the overall study of per peculiar and interesting artefact with the hope that it could be restored and conserved in the most appropriate way.