Natyashastra
वैश्यस्तम्भस्य मूले तु रजतं सम्प्रदापयेत् । शूद्रस्तम्भस्य मूले तु दद्यादायसमेव च ॥ ५२॥
At the base of the Vaishya pillar, silver should be offered, and at the base of the Shudra pillar, copper should be given.
english translation
vaizyastambhasya mUle tu rajataM sampradApayet । zUdrastambhasya mUle tu dadyAdAyasameva ca ॥ 52॥
hk transliteration by Sanscript