Brihat Samhita
हस्तविशालं कुण्डकं अधिकृत्याम्बुप्रमाणनिर्देशः । पञ्चाशत्पलं आढकं अनेन मिनुयाज्जलं पतितम् ॥ २३-०२ ॥
Falling rain should be collected in a vessel with a circular mouth, a cubit in diameter and the collected rain should be measured with a vessel whose capacity is an Āḍhaka, which is equal to 50 phalās.
english translation
hastavizAlaM kuNDakaM adhikRtyAmbupramANanirdezaH । paJcAzatpalaM ADhakaM anena minuyAjjalaM patitam ॥ 23-02 ॥
hk transliteration by Sanscript