The aim of this paper is to clarify the metrological structure and the proportion of the elevations of the arcades consisting the cloister of the Cistercian abbey of Sénanque through the analysis of measures of this cloister built between 1185-1220, whose design is largely different from that of Le Thoronet or of Silvacane belonging to the same school of architecture. The previous literatures insist that the cloister of Sénanque is modelled rather on that of the Vaison-la-Romaine Cathedral belonging to the Romanesque architecture in Provence.
The plan of the cloister of Sénanque is not exact square, but a rectangle whose northern and southern galleries are relatively longer than west and east galleries. The elevations of arcades on the garth side of cloister are also different from those on the side of the galleries. The garth side elevations contain four arcades in each gallery and rectangular pillars on both sides of each arcade. While the shape of the arches of the arcades in the eastern and western galleries is semi-circular, that in the southern and northern galleries is slightly flattened. Because the arcade width of the northern and southern galleries is about 346mm longer than that of the eastern and western galleries. Therefore, the total length of the arcade of the northern or southern gallery is about 1,262mm longer than that of the eastern or western gallery.
When we apply the foot whose unit of measurement is 230-249mm derived from the foot A which we have already attested in our previous paper on the chapter house of the same abbey, the measures of the principal elements of the arcade elevation in the galleries show the round numbers as their measures. This foot can be considered as a “pes manualis” attested in the divers historical medieval texts.
Concerning the proportion of the arcades, that in the eastern and western galleries can be interpreted as a composition based on a square (1:1). But that in southern and northern galleries is based on an equilateral triangle (12:14=6:7). This proportional relationship (6:7) is used as an approximate ratio of an equilateral triangle in the medieval time as the historical documents.
These proportions could be verified through above mentioned “pes manualis” derived from the foot used for the principal constructive parts which we call the foot A in our previous paper.
In conclusion, we insist that the architectural parts, of the abbey of Sénanque, whose metrological compositions are understood with this “pes manualis” derived from the foot used for the principal building element of this abbey can be interpreted as the parts built in the second phase of the total construction process.