The Use of Arches in Muslim Architecture

Muslim architecture is architecture of the Near, Middle East, India and the Iberian Peninsula, the principles of which were formed after the 7^th century, under the influence of Islam as the dominant religion in the region (Grabar 15). Out of all the arts related to Muslim culture, architecture is the most notable, original, and impressive one. Originally, the construction of mosques and Muslim houses of worship was based on the regional tradition. Nevertheless, over time, a new style has been developed, which has preserved the specifics of the local religious buildings and has been subordinated to the needs of the new cult. Traditionally, there are five schools of Muslim architecture: the Syrian-Egyptian, Persian, Indian, and the Ottoman Maghreb (smaller ones, for example, Iraq and Central Asian are derived).

At the beginning of its development, the Muslim architecture of pre-Islamic tradition perceived local architecture. In Iran, the basis of early Muslim Sassanid architecture was based on tradition, in Syria and Asia Minor – on the elements of Byzantine architecture, in Egypt – Coptic culture (Critchlow 25). Muslim art, which originated in the 8^th century, appears at a time when schools of Byzantine architecture were developed fully; however, under their influence it fell. However, in countries in which it arose, Byzantine art had not taken deep roots yet (Critchlow 26). Rather than accept the Byzantine methods, Muslim art refers to the source from which it originated and was inspired by the principles that prevailed in Constantinople architecture coming to combinations and forms, completely alien to the Greek empire (Grabar 16).

During the 7^th and 8^th centuries, the centers of Islamic architecture were Damascus and Cairo (Critchlow 29). Until the 9^th century, this center was moved to Baghdad and then Cordoba.

The first steps of Islamic art can be traced back to Syria. At the time of the conquest of the territory, there was a dominant type of building terrace (a flat roof) to the arcades. They has remained until now in Damascus and is different from the ancient system of Hauran (the area to the East from the river Jordan), except that the stone roof was replaced with wooden decking. In origin, the Iranian monuments of the early centuries of Islam relate to this system; the mosque arch appeared later and was marked in the history of Muslim architecture in the second period of Iranian influence.

The first mosque was built in Medina after the Hijra of the Prophet. At that time, it was a large courtyard surrounded by a wall. On the north side (facing Jerusalem), the trunks of the palm-roof were strengthened to protect the faithful from the sun. However, this building was not a sanctuary for there were the doors of the home of Muhammad and his wives in the same yard. At first, war councils were held at this place, and after the battle – the wounded were demolished here; therefore, it was more of the future headquarters of the Muslim community. However, even in this primitive building, one can notice the contours of the future Muslim temples. Indeed, the very first mosques, which were built in major cities of the conquered territories, had a roof, which rested on the columns. Sometimes, these were trunks of trees; sometimes columns from the ruined buildings of Greco-Roman-Byzantine period were taken for this purpose. After Mecca had been conquered by Islam, the mosque was put in each niche – the mihrab, which indicated qibla – direction to Mecca.

The other aspect of Muslim architecture is an arch. Arches of various kinds – horseshoe, “broken,” with columns and “stalactites” as the capitals – are a favorite method of decorating the houses of worship of Islam. Arches are used to design sets of columns between the prayer halls, as well as, for decorating windows (including false ones). Stalactite small caps are usually collected from different elements (starting from 7), creating a ledge of a column. These are the stalactite cornices in the courtyard of the palace Lion Al Gambra (Granada) (Critchlow 32). There, in the Hall of Two Sisters, one can see the stalactite ornament at the top of the wall of the mihrab and windows placed above it. Sometimes, stalactites adorn the arch above the main entrance to the mosque, as it is done in the mosque of Sultan Hassan in Cairo (1536) (Hoag 8).

Decorative elements used in Muslim architecture, are derived from the same source as the construction techniques are; they are either Iranian or Byzantine.

Columns and Arches

Columns were borrowed from ancient buildings, as in Byzantine architecture, set on a capital abacus, on which the heel of arches rested. Only in the 13^th century, columns could be found as an original character. Columns as the Alhambra and the Alcazar in Seville have the form of contemporary fine Gothic columns, resembling cubic Byzantine capitol with only minor changes in style (Elbouri, Critchlow 105).

Talking about classification of the main types of schools in Muslim arcades, as a decoration in the masonry arches alternating white and colored wedge-shaped stones are often found; sometimes, the front surface is covered with radial fluted arches. Hence, its massiveness, as in Byzantine architecture, often emphasizes the archivolt as a band of the outline of its external line.

Arches are widely used in windows and doors constructions. This ornamental band of the same frequency is applied in both arches of the window and door openings. Therefore, just as in Christian architecture of Syria, this tape will never form a complete frame windows. Instead of meeting at the bottom of the doorway, window border makes a bend and passes to a nearby window, describing the buildings around the undulating continuous line (Elbouri, Critchlow 108). The example A, in Fig. 75, is taken from the Sicilian monument, built purely in Arab receptions (Cuba in Palermo) (Hoag 88). In Iranian Mosque (B), pointed arch doors bordered with the same ornaments and inscribed in a rectangular tambourine (Critchlow 56). This simple and accurate technique is used on a colossal scale, such as at the entrances to the great mosques of Isfahan, making a majestic impression.

Profiling and Proportions of the Arches

Conventional methods of forming arches are shown in Fig. 82 and 83. In Fig. 82, a Syrian technique embodied in Maussa is reproduced. Here, the pointed arch has two centers, the distance between the axes is equal to exactly one-eighth of the arch span. This arch with the same curvature was popular in those countries where the main building material was stone. The Iranians, who used to build of brick, allowed a more complex shape, marked in Delafua (Fig. 83) (Hoag 57). Here, each half of the arch consists of two parts, AL and LS with different radii.

To get the bottom of the arches AL, a half of a flight of OA is divided into four equal parts (points I, II, III, IV); the center is the point I and perpendicular from the point III will determine the point L edge of the bottom of the arch (Elbouri, Critchlow 22).

The top of an arch is defined by the following: build a square OABS and a half flight on a divide into six equal parts (points 1, 2, 3, 4, 5, 6), and then draw a line 51, which is being extended to the distance equal to its length, determining the center P of the second part of the arch. Thus, obtained pointed arch roughly fits into a semicircle, and it has no greater height than a round roof. In addition, its advantage is that it gives a small thrust. With regard to the foundations, usually they are at the height of the impost, defined by an equilateral triangle.

The Geometric Regularity of the Building Plan

Acceptance of graphic styles, the use of which one can see in the details of arabesques, applies to most building plans. Maus stated that the plan of the mosque Sahra is very common in Iranian star ornament, which ends with mark corners of exterior walls and the position of the internal support pillars (Critchlow 98). In Sultanie, Delafua set that the size of the building was determined by the diameter of the circle inscribed in a polygon base. When drawing a vertical, equal to the diameter of this – one can get the height of the inner ledge, doubling it – one can get the position of the top of the dome. These are some methods of geometric patterns construction. This architecture is so bizarre in appearance; however, in fact, it has a geometrized design. Just a simple law could bring order to the complexity of its plans.

The Building Techniques

One can imagine the arcade set in parallel rows, and the arcades – a terrace or a roof with a slight bias: these were the first mosques in Egypt, Syria, and Spain. The Iranians, who built almost only of brick, never entered into the practice of the arcade on pillars – they had arcade resting on square stone pillars; on the contrary, the Arab arcade is usually based on columns.

Forms of Arches

Regardless of the semicircular arch, the Muslims often use the horseshoe arch (Fig. 60, B) which is extremely rarely encountered in Byzantine architecture, as well as the lancet arch (A), completely foreign to the Byzantine Empire (Hoag 45).

Pointed arch is an arch, which can be found in Sasanian Iran; it is the usual form of the Arabic arches (Critchlow 45). With respect to spreading out the use of this form, a real progress could be marked if the Arabs did not diminish the benefits of its unfortunate location of masonry joints, the lines that all converge in one center (A) (Hoag 45). Note, however, that this error never occurs in the vaults of hewn stone where it would entail complications. On the contrary, it facilitates the laying of brick arches, allowing a person to adjust the slope of the rows of masonry with a simple cord, shown at A (Hoag 45).

Horseshoe arch. The design of horseshoe arches has a similar feature: the lines converge in the masonry joints in the center, which does not coincide with the center of curvature.

Horseshoe arch can be met in the Sassanian designs of Ktezifona, where its roots can be also found. In order to set the centering, the supports of the arch (Fig. 61, A) have a ledge R, at its foot (Hoag 65). Upon completion of the work of masons, inner surface of the arch was covered with plaster. It was natural to take the plaster for the treatment of a ledge in the form of a slope, which constitutes the continuation of the inner surface of the arch. This form of transition has created the outline of the arch in the shape of a horseshoe. In addition, in the Arab buildings, this outline has survived through the most experienced construction method.

The origin of a trilobate arch (Fig. 61, B) is explained by considerations of the same order (Hoag 65). In a country where forests are rare, wood has been used only for centering the top of the arch, where it has been installed on the consoles S, acting on the inner surface of the arch. At the end of the works, console was not destroyed but was preserved and handled with a plaster. A similar treatment in itself makes the inner surface with three arches form so characteristic for the Arabic art.

Carinate arch is a late version, undoubtedly borrowed from India. A completely unexplained building of brick in the Arab, a carinate arch, was appropriate in such an architecture, as Indian, which enjoyed the series of overlap masonry. The usage of it in the last period of Arab art was no longer justified, and the imitation of one of the structural errors was typical in the era of decline.

The System of Arcades

With stacked and interlocking arches, people come to a strange, at first glance, location of the arches, which are rising in tiers and intertwining, as shown in Fig. 62. Such an arrangement is based on the need to achieve significant height of the arcade in the columns of a small size.

In Cordoba, the second tier of columns was simply put on the first tier of columns (drawing A) (Hoag 66). However, this add-on could be built only by reducing the resistance; in order to avoid in the design of possible distortion, people needed to have recourse for the intermediate arches. The origin of the double series of arches, indicated in the figure A, is explained by this fact.

Then, when the principle has already been established, the idea to combine pairwise composite struts by means of interlacing arches naturally arose; hence, a variant B appeared (interlacing arches are indicated in the figure with a dotted line). This new method had an advantage that it ensured greater rigidity, and it was rational in all respects. If to cut scalloped interlocking arches, startling in its effect arcades of Cordoba mosque are obtained with all their details. Festoons (Fig. 63, C) can be obtained by means of projections masonry treated with plaster (Hoag 66).

Arch with delicate tambourines, a kind of arch without tympanum, indeed, are at risk of deformation. To make it more stable in its upper part, at the Alhambra (Fig. 63, M) tympana of the bricks in a grid, whose cells were filled with decorative panels, were erected over them (Hoag 66). 

In conclusion, the Muslim art uses many different techniques, which are clearly classified by schools. Hence, the Muslims created a rich basis of different arcades with unique designs, each of which was explained by historical and purposeful functions.