The Foot as the Unit of Measurement
Having determined that the unit of measurement at Castel del Monte has the dimension of 0.302 m, one question on interest is to find if there is a unit of linear measurement from ancient times that matches this dimension. Table 3 lists some of the known measures of linear measurement from Egyptian to modern times, compared to the unit of measurement at Castel del Monte.
Table 3. Comparison to Various Historical Units of Measurement
|Ancient Unit of Measurement||Measure (m)||Variance (%)|
|Naples palm - others||0.2180||-27.81%|
|Palermo palm - Palaiseau 1816||0.2420||-19.87%|
|Naples palm - Rose 1900||0.2640||-12.58%|
|Castel del Monte unit||0.3020|
The ancient units of measurement closest to the one used at Castel del Monte is the Egiptian and the Roman foot. Curiously, the modern standard foot comes even closer than the Roma foot, with a deviation of less than 1%, Fig. 17.
Figure 17. Comparison of Castel del Monte unit of measurement to other known foot dimensions.
The measure for ancient unit of measurements varied significantly based on historical times and among various regions and cities of Europe. It is likely that the unit of measurement at Castel del Monte was another variation of the Roman foot.
Yet there is the intriguing possibility that the unit of measurement at Castel del Monte is a variation of the modern standard foot. This is not a surprising result given the Germanic origins of the English foot that the modern standard foot is based on (Stecchini). The emperor, Frederick II Hohenstaufen, was also king of Germany and the castle does bear strong northern-European influence, such as the Gothic cross vaults.
There is no knowledge about how the foot was subdivided at Castel del Monte; decimal fractions are used in this study. Historically the foot was divided for common usage either in 12 or 16 units, measures that relate to fingers.
It is ideally possible to discover the subdivision unit of the foot at Castel del Monte, because it is thought that the builder might have rounded up some measures to even quantities of this subdivision.
This may have been the case, for example, for stone blocks in the façade whose specific dimensions were not critical to the structure, other than maintaining the same height in separate courses. Stone cutters may have been inclined to rounding off the height of these stone blocks to the nearest whole-fraction of the foot. A statistical-like study of the thousands of stone blocks in the wall of the castle may indeed yield evidence of this subdivision.
Stecchini, L. The Origin of the English Measures. http://www.metrum.org/measures/metrics.htm