Origins and Architecture of The Taj Mahal - Dimensional Organisation

Dimensional Organisation

The Taj complex is ordered by grids. The complex was originally surveyed by J.A. Hodgson in 1825, however the first detailed scholastic examination of how the various elements of the Taj might fit into a coordinating grid was not carried out until 1989 by Begley and Desai. Numerous 17th century accounts detail the precise measurements of the complex in terms of the gaz or zira, the Mughal linear yard, equivalent to approximately 80–92 cm. Begley and Desai concluded a 400-gaz grid was used and then subdivided and that the various discrepancies they discovered were due to errors in the contemporary descriptions.

Research and measurement by Koch and Richard André Barraud in 2006 suggested a more complex method of ordering that relates better to the 17th century records. Whereas Begley and Desai had used a simple fixed grid on which the buildings are superimposed, Koch and Barraud found the layout's proportions were better explained by the use of a generated grid system in which specific lengths may be divided in a number of ways such as halving, dividing by three or using decimal systems. They suggest the 374-gaz width of the complex given by the contemporary historians was correct and the Taj is planned as a tripartite rectangle of three 374-gaz squares. Different modular divisions are then used to proportion the rest of the complex. A 17-gaz module is used in the jilaukhana, bazaar and caravanserais areas whereas a more detailed 23-gaz module is used in the garden and terrace areas (since their width is 368 gaz, a multiple of 23). The buildings were in turn proportioned using yet smaller grids superimposed on the larger organisational ones. The smaller grids were also used to establish elevational proportion throughout the complex.

Koch and Barraud explain such apparently peculiar numbers as making more sense when seen as part of Mughal geometric understanding. Octagons and triangles, which feature extensively in the Taj, have particular properties in terms of the relationships of their sides. A right-handed triangle with two sides of 12 will have a hypotenuse of 17; similarly if it has two sides of 17 its hypotenuse will be 24. An octagon with a width of 17 will have sides of exactly 7, which is the basic grid upon which the mausoleum, mosque and Mihman Khana are planned.

Discrepancies remain in Koch and Barraud's work which they attribute to numbers being rounded fractions, inaccuracies of reporting from third persons and errors in workmanship (most notable in the caravanserais areas further from the tomb itself).

A 2009 paper by Prof R. Balasubramaniam of the Indian Institute of Technology found Barraud's explanation of the dimensional errors and the transition between the 23 and 17 gaz grid at the great gate unconvincing. Balasubramaniam conducted dimensional analysis of the complex based on Barraud's surveys. He concluded that the Taj was constructed using the ancient Aṅgula as the basic unit rather than the Mughal 'gaz', noted in the contemporary accounts. The Aṅgula, which equates to 1.763 cm and the Vistasti (12 Angulams) were first mentioned in the Arthasastra in c. 300 BC and may have been derived from the earlier Indus Valley Civilisation. In this analysis the forecourt and caravanserai areas were set out with a 60 Vistasti grid, and the riverfront and garden sections with a 90-vistari grid. The transition between the grids is more easily accommodated, 90 being easily divisible by 60. The research suggests that older, pre-Mughal methods of proportion were employed as ordering principles in the Taj.