By Alfonso Bermejo, Architect
Geometrical relationships of the Masjid al‐Uwayna mosque`s mihrab from Wadi Bani Khalid, Sultanate of Oman. By Alfonso Bermejo Oroz, Architect bermoz1@gmail.com 0034 654823739 0034 958571648 0034 615257053
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By Alfonso Bermejo, Architect
When we see certain complex shape, made of many different shapes interlaced, we usually get the feeling of harmonious proportions between all the parts. There are several ways to research the relatioships in between the parts involved in a geometrical composition of the building, fachade or decoration. In the Masjid al‐Uwayna mosque`s mihrab we easily get this feeling due its composition has been thoughtfully design by the craftsman Talib bin Mushmel Al Manahi in the 16th century. The composition of the panel is designed from a main framing band decorated with interlace roundels surrounding an arch ant the mihrab itself niche. The niche is carved within the width of the Qibla’s mosque wall. The rest of the whole surface is heavily decorated with geometrical, floral and vegetal decorative patterns.
This is an easy way to define the style used in the parts in the decoration. However there are many relationships in between the parts of the composition and the whole of the mihrab, that provide us the sense of beauty and harmony in their proportions.
Geometrical relationships between the size and the diagonal of the square.
The golden section
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By Alfonso Bermejo, Architect
One way to draw a golden section
Another relationship of the sizes of a rectagule but taken from parts of the pentagon, from Pitagoras (Ancient Greek)
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By Alfonso Bermejo, Architect
To research on these complex relationships we must consider the relation of the main dimensions, width of the base and the height. In the al Uwaynah’s mihrab the main relationships are that the heigth is the diagonal of the square with the sizes of the width, and the heidth of the niche is a half of the total height. This proportions set the main relation of the part of the whole decoration.
The dimensions os the niche are set also in the relationship of the size of a square and its diagonal. The framed niche is three times the size of the base (blue squares). The internal part of the kufic writing with the triangular fronton is also a square (the green one) related to the main square. The relationship is based in the rotation of the square (the green one) made from the middle of the size of the main blue square. Doing this again we find out that the fronton is related to the green square. The yellow square, rotated again, remarks the fronton with the three bowls.
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By Alfonso Bermejo, Architect
This shows out a precise and harmonious sense of the proportions of the parts and the whole.
The main part of what is considered to be the most important pattern in Oman, is set in a frame based in the proportions of the golden section. Euclid provides the first written definition for the the golden ratio: "A straight line is said to have been cut in extreme and mean ratio when, as the whole line is to the greater segment, so is the greater to the lesser."
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By Alfonso Bermejo, Architect
The pattern. Most of the mihrabs in Oman, share partly the same geometrical composition based on circufenrences of which devided into an 45º inclined square patterns.
The framing part, dimensional relationships. 6
By Alfonso Bermejo, Architect
There are also some interesting relationships between the dimension used in the framing parts. Taken as a basic unit of dimension, the yelow circle from the smallest framing, we can easily find out the the interlaced roundels frame has four times this unit of dimension. There is another small frame of a unit dimension and then another foru times roundel frame. The width of the niche is seven times the basic dimensional unit. The most used measurement system of history is the one that relates measures with human elbow. Probably an elbow, in terms of dimension in this composition, is four times the yellow circle. Then the small frame is 1/4th of this hypotetical elbow and the width of the niche can be easily measure as one elbow and 3/4th parts.
The mihrab finally installed at The National Museum of Oman. May 2015.
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