‘From the time that man's age increases from ten years to
an Asankhya and again decreases from an Asankhya to
ten years, is an Antaḥkalpa. Were the surface of the earth
to increase in elevation at the rate of one inch in a 1000
years and the process to continue in the same proportion,
the elevation would extend to 28 miles before the Antaḥ-
kalpa would be concluded. Twenty Antaḥkalpas make an
Asankhyakalpa. Four Asankhyakalpas make a Mahākalpa.’
(Hardy, Manual of Buddhism.) E. antar and kalpa.