Con fact, summer sultriness is particularly high during August in South Italy
As referred sopra the preparazione section, the carefully mediante 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 coppia onesto the manufacturing process, to the Altar Machine usage, and to the microclimate in the apsidal reparto 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 of the wood species was undertaken because the diagnosis of the botanical species represents verso great importance sopra the technological and historical artistic study of verso wooden artefact due puro possible implications relating sicuro the conservation. Durante 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 preciso find six different kinds of wood that were used con relation sicuro 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 sopra the tabernacle can be probably traced back onesto a restoration intervention. Durante fact, this alpine species, paio onesto its excellent technological characteristics, has been widely marketed and often has been found per restored wooden structures con Sicily .
Chestnut wood was used durante the back structural elements of the altar due puro its excellent physical and mechanical properties sopra relation puro the density. Moreover, the chestnut wood has a natural durability and it exhibits a moderate shrinking [21, 22]. Chestnut wood has been used durante Italy especially for roof beams and also for the outer surface of the doors coppia sicuro the properties of its heartwood. The chestnut heartwood has per natural pleasant colour that darkens during time [23, 24].
The walnut wood was found mediante the winch drum (cylindrical element on which the ropes are wrapped per order onesto raise the statue). The use of this species is related mainly onesto 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 esatto understand their function.
The decoration elements are made of poplar, a wood species widely used mediante Italy for the creation of painted panels and other decorated works of art [21, 28]. In fact, it is characterized by low density, easy seasoning and processing, and colour homogeneity that make it particularly suited sicuro apply the painted layers, durante spite of this wood could be easily attacked by xylophages.
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 tavolo mousemingle 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 a peculiar and interesting artefact with the hope that it could be restored and conserved mediante the most appropriate way.