E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Sittings in Banco. Sittings of the Superior Court of Common Law in its own bench or court, and not in circuit, as a judge of Nisi Prius (q.v.). (Banc is Italian for bench or seat of justice.)
So much bancoi.e. so much bank money, as distinguished from current coin. At Hamburg, etc., currency is inferior to bank money. (Not money in the bank, but the fictitious value set on cash by bankers.)