(i) Orientation of Buildings (Diṇnirṇaya or Prācī-sādhana)

Diṅnirṇaya or Prācī-sādhana is done through a technical device called Śaṅkusthāpana. Śaṅku is the gnomon by means of which the cardinal points are ascertained for the orientation of building. Hindu treatises on the science of architecture deal with the rules as laid down on the principles of dialling under this title of Śaṅkusthāpana. Astronomical treatises like Sūrya-siddhānta, Siddhānta-śiromaṇi, Līlāvatī, Brahma-siddhānta-sphoṭa of Brahmagupta and Pañcasiddhānta of Varāhamihira and architectural treatises like Mānasāra (Ch.VI), Mayamata (VI), Śilparatna (XI), Kāśyapa-śilpa (l), Vāstu-vidyā (III), Manuṣyālaya-Candrikā (II) and Tantrasammuccaya, Īśānaśivagurudevapaddhati etc. etc. have all dealt with this cardinal principle of architecture.

It has two principal aspects the technical device and the scientific-cum-philosophical import. Let us take up the first.

The Mānasāra’s technique (vide V. L.) consists of the device as laid down hereunder:

“The gnomon is made of the wood of certain trees. It may be 24, 18 or 12 aṅgulas in length, and the width at the base should be respectively 6, 5 and 4 aṅgulas. It tapers from the bottom towards the top.

For the purpose of ascertaining the cardinal points, a gnomon of 12, 18 or 24 aṅgulas is erected from the centre of a watered place (salila-sthala) and a circle is described with the bottom of the gnomon as its centre and with a radius twice its length. Two points are marked where the shadow (of the gnomon) after and before noon meets the circumference of the circle. The line joining these two points is the east-west-line. From each of these east and west points a circle is drawn with their distance as radius. The two interesting points, which are called the head and tail of the fish (timi), are the north and the south points. The intermediate regions are found in the same way, through the fish formed between the points of the determined quarters.

As regards the principles of dialling, each of the twelve months is divided into three parts of ten days each and the increase and decrease of shadow (avacchāyā) (cf. Vitruvius, Book IX, Chap. VIII, ‘...the principles of dialling and the increase and decrease of the days in the different months’—translated by Gwilt), are calculated for these several parts of the different months”.

The Tantrasamuccaya (vide Mallaya) on the other hand prescribes the technique with some difference:

“The direction contained in the text is simple. It is with reference to the land which is situated either to the north or south of the equator (Akṣa). Level the ground (in a Sākṣadeśa) and plant a gnomon at the centre, the gnomon being of 12 aṅgulas of length. Describe a circle round it with a radius more than its length (say double the length). During the course of the sun from morning till evening three points will be secured, two touching the circumference and one in the centre, the interval in the course of their marking being equal. The three points are obtained by marking the end of the shadow projected during three different times, the interval between them being equal. With these three points as the centre, draw three circles of the same radius. Two figures in the form of two fish will be produced where the circles cut. The head and tail of each fish will lie in the North-South direction. Strike two nails at the points (i.e. head and tail) of each fish and then extend two threads cutting through the central cord of the two fishes. At a certain point in the North (when the sun is in the South of the Equator) these two threads extended will meet. From this meeting point in the north extend another thread southwards till it joins the central point at the base of the gnomon. This thread which joins the northern point with the point at the base of the gnomon will give the North-South line. Having found the due North and South as described above, with the two points (i.e. meeting-points northern as well as southern) as centres two circles should be described. A figure in the form of a fish lying in the direction East-West will be obtained. Hold a thread joining the head and tail of this fish, and die due East and West will be known”.

The method that is described in other texts like the Mānasāra is a little different. According to the Mānasāra only two circles are to be drawn and consequently one fish will be secured while determining The author of T. S. describes in the wake of Gurudeva, who after having laid down the usual procedure (cf. Īśānaśivagurudevapaddhati Vol. III, T. Samarāṅgaṇasūtradhāra Edition, Paṭala XXIV, stanzas 1 to 13) remarks that it is good so far as the land lying on the equator is concerned. As regards land lying to the North or South of the Equator, the method is different, and in this context he prescribes the method that we have observed just now. Gurudeva (vide V. L.) his prescribed two alternatives in respect of the land lying whether on the Equator or to the North or South of the Equator and the author of Tantrasamuccaya has followed the latter alternative. Both these devices may be illustrated in the diagrams appended in the appendices.

It may be interesting to note that this device of dialling and ascertaining the cardinal points of heaven was also popular in other ancient countries like Greece and Rome. Vitruvius, the celebrated Greek writer-architect has similar prescriptions and the following quotation from Gwilt’s translation would bring home to the readers the universal importance of the technique adopted in ancient time: “Let a marble slab be fixed level in the centre of the space enclosed by the walls, or let the ground be smoothed or levelled, so that the slab may not be necessary. In the centre of this plane, lor purpose of marking the shadow correctly, a brazen gnomon must be erected.

The Greeks call this gnomon skiatheras.

The shadow cast by the gnomon is to be marked about the fifth anti-meridional hour and the extreme point of the space whereon the gnomon stands, as a centre, with a distance equal to the length of the meridian, watch the shadow which the gnomon continues to cast till the moment when its extremity again toadies the circle which has been described. From the two points, thus obtained in the circumference of the circle, describe two arcs intersecting each other and through their intersection and the centre of the. circle first described draw a line to its extremity; this line will indicate the north and south points.”

Needless to quote further as Vitruvius has much more elaborations to complete the whole technique full of diagrams.

With this brief outline of the device, let us come to its significance in the context of an architectural planning from a stand-point of scientific implication.

“With the Hindus, orientation played a very important part in the scheme of their daily life, as to them the Sun was the giver of all life. Even, a witness had to face the East during the process of examination. (Vide Institutes of Manu). This love of orientation had permeated their ideas of design The full significance of this aspect of the Hindu mind would be appreciated as the underlying theory is grasped.

The theory of the orientation of buildings, secular as well as ecclesiastical, as laid down by Indian designers of structures consists in setting them in plan in such a way that they may secure the maximum of benefit from the solar radiation automatically and irrespective of the fact whether occupants will it or not. Temples, living places, assembly halls, audience rooms and a host of structures to meet the needs of men of all grades, are, thus, so adjusted in plan as to secure an eastern frontage. The minutest rules are prescribed for the most advantageous setting of structures with this end in view. When once the site of premises is selected, the next step consists in the determination of true East, for which elaborate rules are laid down and eVen as the Construction progresses from the base upwards to that top, several independent checks are imposed with a view that no deviation could be made by workers, during different stages of construction so that the finished structure would have a truly eastern frontage.

Fixation or cardinal points, thus, occupied a prominent place in the preliminary operations of building construction, just after the selection of site and before the actual construction starts.

Khāta and Śilānyāsa, it may be pointed out, have an ulterior significance constructively as well as ritualistically. This later aspect regarding ritualistic process will be dealt with in detail later on.

The eastern facet of structures, both in plan and elevation, when truly set in direction, according to the rules laid down as shown above, gets a full and direct exposure to the field of action of solar radiation. As soon as the early dawn breaks, the eastern varandah is flooded, so to say, by the early invisible ultra-violet radiation which is the first in order to be felt; as the dawn advance into Uṣa, Aruṇa and actual sunrise, the different luminous visible rays go on impinging that facet. They can thus be utilized as the exigencies of life demand, as towards sunrise all the radiations from ultra-violet on the extreme northern end of the eastern facet to the whole range of visible radiation; ending in Infra-red on the extreme Southern end of the same have their full pay. It has been observed that ultra-violet radiation has recieved more attention than the visible and Infra-red radiation, owing to the fact that it produces fluorescence, photographic action and many known biological effects.

It is very significant in this phase of Indian thought that both the extremes of this eastern belt are denoted by Īśa (N. E. portion) and Agni (S. E. portion) the counterparts of, so to say, ultra-violet or violet and Red or Infra-red radiation of the Solar spectrum of the Western science. The very names Īśa and Agni and their individual lakṣaṇas, which are given to these quarters from earliest times in the Indian History go to suggest that the phenomenon of refraction and diffraction.dispersion) were well known to Indian Aryans.

Indian architects were not slow in availing themselves of the cooperation of the priestly class wherever necessary. In order that structures may not be marred by the slightest deviation so for as their true East and West were concerned, the Sthapatis had devised means where, with the principles of orientation was rigidly maintained throughout the actual construction starting from the Khāta (laying a foundation) right upto the extreme top.

It was for this security that they had requisitioned the aid of ritualism.

At every distinctive stage of a structure where the possibillity of disturbance was foreseen, there were enjoined ritualistic ceremonials in order that they may serve as checks to the work of construction”

(Mankad.)

Lastly as regards the philosophical import, this technique of the orientation of buildings is very intimately related with another equally significant and important canon, the Vāstu-puruṣa-maṇḍala, the metaphysical plan of a Hindu building, a temple-diagram or a site-plan of a residential house.

‘The surface of earth, in traditional Indian Cosmology, is regarded as demarcated by sunrise and sunset, by the points where the sun apparently emerges above and sinks below the horizon; by the East and West and also by the North and South points. It is therefore represented by the ideogram or maṇḍala of a square. (The square does not refer to the outline of the earth. It connects the 4 points established by the primary pairs of opposites, the apparent sunrise and sunset points, East and West; and South and North. The earth is therefore called ‘caturbhṛṣṭi’, four-cornered (R.V. X 58.3) and is symbolically shown as Pṛthivī-maṇḍala, whereas considered in itself, the shape of the earth is circular, (RV. X. 89.1; S.B. VII. I. L 37). The identification of the square with the Vedi is in shape only and not in size and belongs to the symbolism of the Hindu temple.

The Vedi represents and is the levelled earth, a place of sacrifice or worship:

“No part of the ground should rise above it; for it was from there that the gods ascended to heaven” (S B. III. 1. 1. 1—2).

The site, the earth, should be even and firm, for it is the starting place of the ascent (S. B VIII 5. 2. 16). The link between the earth and the end of ascent stretches upward into space, the intermediate region (anta-rikṣa). From it also it leads downward and rests on earth. In it the temple has its elevation. The Vastupuruṣamaṇḍala, the temple-diagram and metaphysical plan is laid out on the firm and level ground, it is the intellectual foundation of the building, a forecast of its ascent, and its projection on earth’—H.T. (pp. 17.)