تناسبات پنهان در برج مقبره‌های قرن هشت و نه ه.ق. مازندران

Mazandaran is one of the Iranian culture domains possessing tombs with unique structural properties. Eighth and ninth centuries AH are the periods of the formation and persistence of tower tombs in Mazandaran. They often have similar structures and include Colonial dome, body, and drum. Although many of them have sustained damages during the long years, the main issue is the shortage of coherent and scientific studies about the structure of these tombs for the preservation and repair them. The present study’s main goal is the identification and discovery of the proportion’s existent in the primary elements of the Timurid era’s tombs in Mazandaran (body, drum, and Colonial dome). Based thereon, about thirty historical tombs were investigated through a positivism approach and via field studies and document research, and their common and distinct points were recognized. In between, seven tombs were selected for more precise investigation due to the contextual and structural similarity. The effort has been made in this study to find answers to questions like the following: what is the intention of the existence of hidden proportions in the tombs from the eighth and ninth centuries AH in Mazandaran? Are the studied tombs related in terms of shape and structure and do they follow similar proportional order? The present study will show that the studied tombs have 1:1, 1:2, and 1:3 proportions in the body, drum, and Colonial dome. The identification of the hidden proportions can be promising in the reading and reconstruction of the primary lines in the damaged tombs. Moreover, a continuation of the research in this regard can lead to the discovery of a particular “proportion system” in this area. Although the studied tombs have a diverse formation system, there is a special and nearly identical proportion governing their structure.
Keywords: Proportions, Mazandaran, Tower Tombs, The Eighth and Ninth Centuries A.H.
 
Introduction
Tabarestan is the resort and burial place of Imamzadehs and their tombs in the historical periods of Timurid, Safavid, and Qajar with various construction patterns. This paper studied thirty tombs in different parts of Mazandaran province. They belong to different regions of Mazandaran and have a three-part structure; The body, drum, and dome present in all tombs (Table 1). Comparative studies and field studies on them led to a relative knowledge of the tombs and strengthened the possibility of special proportions in the three-part structure of the tombs. The height of the body, drum, and dome represented a kind of geometric connection, and by further analysis, some physical similarities were found between them. The similarities were examined, and the following seven tombs built in one period were selected for further study:

Darvish Fakhr Al-din in Babol
Darvish Alam Bazigar Kola in Bobol
Imamzadeh Ghasem Hashtel in Babol
Darvish Golema, Sari
Imamzadeh Ali Akbar, Owsa
Imamzadeh Saleh, Marz Roud
Dome Shater, Sari

The main problem is the increasing growth of inappropriate conservative measures and distortion of dynamic proportions in the three-part structure of tombs. Heterogeneous physical interventions in recent years in the tombs of Mazandaran have caused damage to the body and the destruction of geometry, patterns, and proportions in the structure of tombs. Accordingly, two questions and hypotheses are raised in the paper. 1- What is the purpose of the existence of dynamic proportions in the tombs of the 8th and 9th centuries AH of Mazandaran? The tombs of the 8th and 9th centuries AH in Mazandaran have systematic proportions of 1:1, 1:2, and 1:3 in the body, drum, and colonial dome. These elements are structurally and formally related to each other, and by changing the scale of each, the other element will also be readable and will change in harmony with the overall shape of the building. The mentioned proportions are especially present in these tombs and can be identified. 2- Do the tombs under study have a formal and structural relationship with each other and follow a similar proportional order? Although the tombs under study have a diverse formation system, special and almost the same proportions govern their structure. Identifying dynamic proportions can be helpful in re-reading and reconstructing the main lines of similarly damaged tombs. Continuation of this process may lead to the discovery of another “proportional system” in this area. This research tried to investigate the dimensions of the drum, dome, and body in the seven mentioned tombs and, through this, to achieve dynamic proportions in the three-part structure of the tombs.
 
The Proportions Between the Body, Colonial Dome, and Drum in the Toms of the Eighth and Ninths Century A.H.
The tombs studied are often related to the Timurid period. These buildings were located outside the city and near the cemetery and were built for pilgrimage. Octagonal tombs with multi-faceted roofs and three-part facades are the criteria of some tombs of Mazandaran in this period. They are often seen with quadrangular, octagonal (Blair, 1983, 69), dodecagon, and cruciform plans, and sometimes other spaces were created as a prayer hall next to the main courtyard.
A case study was started to examine the mentioned proportions among thirty tombs located in Mazandaran. In the study of plain tombs, a number of them that were very similar in terms of scale, structure, and type of materials were selected for the study. The facade of the remaining 7 tombs was surveyed, and proportions revealed formed the research findings. Based on the surveyed dimensions, the dimensions that are close to each other in terms of the composition of the body, drum, and dome are divided into three categories (A is the height of the dome house body):

Tombs with the height of A<6m
Tombs with the height of 6<A<8m
Tombs with the height of A=8m

According to the correlation research approach, the proportion between the components of the tombs will change based on their height. The higher the body as the first variable, the lower the height of the drum and the colonial dome as the second variable to maintain static balance against stresses. These two variables are correlated with each other and introduce the following system:

The proportion of buildings with body height less than six meters: [1:1 proportion] Includes: Body (3) drum (1) Colonial dome (3)
The proportion of buildings with a body height of six to eight meters: [1:2 proportion] includes: body (2) drum (0.5) colonial dome (1)
The proportion of buildings with a body height of eight meters: [2:3 proportion] includes: body (3) drum (1.25) colonial dome (2).

 
 
Conclusion
The study of the three-part structure of the tombs of the 8th and 9th centuries AH has led to the results that this research has called “dynamic proportions”. These proportions have motion and can make a change in the quality of the main elements such as the body, drum, and colonial dome depending on the type of proportion (1/1, 1/2, and 1/3). The studied seven tombs have a correlation, formal and structural relationship with each other, and follow an almost similar system of formation and proportions. They are located linearly in the geographical area of Sari, Babol, and Amol. Their structure is mass and brick, and they were built in the 8th and 9th centuries AH. These similar qualities can be used in the comparative study and comparison of the tombs of Mazandaran. Besides, understanding dynamic proportions can help designers and architects in the design of buildings, monuments, and tombs to establish and inspire the architecture of tombs of this period. Recognizing this quality is like a guide and recommendation that introduces standards related to the structure of tombs. This paper is only an entry in connection with the discovery of the proportional system of tombs of the 8th and 9th centuries, AH, and the continuation of the process of recognizing the proportions of tombs may lead to the discovery of another “proportional system” in this area.