Palyopama

Palya means a pit or granary and upamā means a comparison, so the name says plainly what it is: a measure by likeness. The pit is one yojana wide and one yojana deep, filled with the hair-tips of a child under seven days old, cut fine and packed so tightly that fire, water and wind cannot get through.

There are three kinds, and they are used for different jobs. Addhā palyopama removes one piece every hundred years and measures the lifespans of beings, which is the one meant whenever a lifespan on this atlas is given in palyopama. Uddhāra palyopama removes one piece every Samaya and is used to count the continents and oceans of Madhya Loka. Kṣetra palyopama counts instead the space-points the hairs touch, and is larger again than the other two.

Each of the three has a gross and a subtle form, the subtle one dividing every hair-tip into innumerable further parts. The subtle addhā palyopama is the working unit.

The point of the analogy is not to make the number tractable. It is to make clear that the number is not the sort of thing that can be reached by multiplying, and that the honest way to convey it is to describe a task and let the listener feel its length.