# Wood Utilization in Windmill Mechanisms on Sikinos Island (Greece)
## 4 Wood Species Used in Windmills (Sikinos)
Of course, the choice of wood species was also determined by the availability and possibility of their supply, since finding oaks was impossible on most of the Cyclades islands, with a potential exception of the low-height kermes oak species. Thus, the large shaft, which is made of oak wood, probably red, i.e., from the species of turkey oak (_Quercus cerris_) or Macedonian oak (_Quercus trojana_), may come either from Northern Greece or Asia Minor, where the main distribution areas of the above species are located. Corresponding information is available from the study of [PERSON] and [PERSON] [3], who reported timber imports from Mount Athos or Asia Minor mainly for the windshaft, \"katoplakes\" and \"anemi\", respectively. A heavy \begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Mechanism** & **Wood Species in the** **Silinos Mechanism** & \multicolumn{3}{c}{**Reference Wood Species (Empirically Identified)**} \\ \cline{3-5}
\begin{tabular}{c} Kermes oak, wild olive, \\ mulberry \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Sikinos windmill mechanism wood species scientifically recognized: comparison with those reported in the literature (empirically recognized [2,3,15]). weight (0.82-1.02 g/cm\({}^{3}\)) and high hardness are also evident in olive wood [22], which was used for the construction of individual components of small dimensions and could have come from the Sikinos island due to the high availability. In fact, the choice of olive wood species for the \"violas\" construction, i.e., at the pivot points of the shaft, facilitated its rotational movement, preventing damage, attributed to the natural oiliness of the specific wood. Furthermore, the ash wood used for the construction of \"anemi\" is a species of moderate-to-heavy weight (0.52-0.87 g/cm\({}^{3}\)) [22] and hard, though of a high modulus of elasticity, with great mechanical strength and particular resistance to the impact of bending forces [24], properties that are both of great significance because of its continuous rotation, as well as in cases where, because of an inappropriate adjustment of the wheel position, its cogs may collide with the body of the \"anemi\". On the contrary, for the construction of the wheel, with the exception of the cogs, the wood of plane, elm and chestnut were used [22], with the plane and elm being mainly of medium weight (0.60-0.72 g/cm\({}^{3}\) and 0.46-0.70 g/cm\({}^{3}\), respectively) and hardness, while the chestnut shows a low-to-medium weight (0.37-0.70 g/cm\({}^{3}\)) and low-to-medium hardness [22]. The use of these wood species is probably related to the desire to decrease the weight of the structure for an easier rotation due to the large size of the wheel, which produced a higher pressure on the cogs. That is the reason why they were made of a hard and very heavy wood species (evergreen oak). Also, the use of chestnut in the \"stavros\" construction is justified by the high dimensional stability of this species. In this way, the risk of developing defects in the connection of the individual parts of the wheel is eliminated. Additionally, for the construction of the wheel rim, some species with an already curved trunk or characterized by the ease of the curvature had to be used, since the rim of the wheel was composed of four curved pieces. Plane and elm species are, among others, some of the species that bend comparatively easier [24]. The use of elm in constructions with curved parts, such as the wheels of carriages, has been established since ancient times [25]. The curved wooden part, in some cases, seems to be achieved by applying a combination of curvature and a suitable cutting. On the contrary, in the rotation and orientation system of the \"fteroti\" (\"panarika\", \"katoplakes\"), many individual pieces were used that created an almost polygonal structure in places, thus limiting the necessity of using already curved elements.