Moreover, several wood defects like knots and ring shake were identified

Moreover, several wood defects like knots and ring shake were identified

Mediante fact, summer sultriness is particularly high during August sopra South Italy

As referred sopra 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 coppia esatto the manufacturing process, to the Altar Machine usage, and onesto the microclimate per 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 per wooden artefact coppia sicuro possible implications relating onesto the conservation. Durante fact log in misstravel, 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 puro find six different kinds of wood that were used per relation preciso the technological characteristics of the altar elements. The results are summarized sopra 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 in the tabernacle can be probably traced back onesto per restoration intervention. Con fact, this alpine species, due to its excellent technological characteristics, has been widely marketed and often has been found per restored wooden structures per Sicily .

Chestnut wood was used durante the back structural elements of the altar paio puro its excellent physical and mechanical properties sopra relation preciso the density. Moreover, the chestnut wood has per natural durability and it exhibits a moderate shrinking [21, 22]. Chestnut wood has been used mediante Italy especially for roof beams and also for the outer surface of the doors due esatto the properties of its heartwood. The chestnut heartwood has verso 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 in order esatto 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 preciso understand their function.

The decoration elements are made of poplar, a wood species widely used per Italy for the creation of painted panels and other decorated works of art [21, 28]. Mediante fact, it is characterized by low density, easy seasoning and processing, and colour homogeneity that make it particularly suited onesto apply the painted layers, in 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, sopra 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 sistema that is the overall study of verso peculiar and interesting artefact with the hope that it could be restored and conserved sopra the most appropriate way.