In the press, and shortly will be published, price five shillings, dedicated, by permission, to the Most Noble the Marquis of Lansdowne, president of the Council, an entirely new work, illustrative of the great utility of fractions; showing how they may be applied to the formation of rules, by means of which all numerical questions in common arithmetic, of any amount, may be solved mentally: or, A quadrantal system of Calculation | lit.salon