The Science of Architecture

Two fitting spansA 'span' (சாண் - saan) is a traditional unit of measurement roughly equal to the distance between the tip of the thumb and the tip of the little finger when the hand is fully extended. make one cubitA 'cubit' (முழம் - muzham) is the distance from the elbow to the tip of the middle finger.. Understand this measurement system clearly and without confusion.
(Meaning: 8 grains of barley make one finger-widthவிரல் - viral; approximately 3/4 of an inch.; 12 finger-widths make one span; 2 spans make one cubit. Divide and understand the measurements in this manner.)

The measuring rod is used for temples, towers, halls, and houses. We have explained the measurements for towers, halls, pavilions, and mansions. For all permanent structures and summits, use the finger-measure of the kidaguA specific long-form measuring rod used in ancient Tamil architecture.. For towers and halls, use the six-finger cubit.
(Meaning: Permanent structures, summits, houses, pavilions, and mansions are to be measured with the finger-units of the kidagu. Towers and halls are measured with the six-finger cubit. In this system, twelve fingers are called a visadhi. Twice that—24 fingers—is known as a kidagu.)

Measuring rods made of bamboo are for the Vedic priests.
Rods made of flawless AachaHardwickia binata; a strong, durable timber. are for the kings who receive tribute.
Rods made of VengaiPterocarpus marsupium; East Indian Kino tree, prized for its strength. belong to the farmers.
The fine Teak rod is declared for the merchant class.
(Meaning: Bamboo rods are for Brahmins; Aacha rods are for Kings; Teak rods are for Merchants; Vengai rods are for Farmers.)

For the fitting leveling rodமட்டக்கோல் - mattakkol; a tool used to ensure surfaces are flat or horizontal., use Tamarind-Vengai, Teak, or Aacha. For the various types of houses, Tamarind-Vengai, Naga, and Aacha are suitable. For the esteemed merchants, Teak; for the farmers, Vengai. For the Gods, fashion the rod out of iron with proper form.
(Meaning: There are four types of wood suitable for the leveling rod: Tamarind-Vengai, Teak, and Aacha. Among these, the Tamarind-wood rod is for priests; the Aacha rod is for kings; the Teak rod is for merchants; the Vengai rod is for farmers. A rod made of solid iron is for the deities.)

To explain the proportions of the leveling rod to you clearly: let one end be ten finger-widths wide...