Kautilya's Arthashastra 2.19.34

2.19.34

śuṣkasāradārumayaṃ samaṃ caturbhāgaśikhaṃ mānaṃ kārayet, antaḥśikhaṃ vā //

Cubic measures shall be so made of dry and strong wood that when filled with grains, the conically heaped-up portion of the grains standing on the mouth of the measure is equal to ¼th of the quantity of the grains (so measured); or the measures may also be so made that a quantity equal to the heaped-up portion can be contained within (the measure).