The East Indian calculator, or, Tables for assisting computation of batta, interest, commission, rent, wages, &c. in Indian money : with copious tables of the exchanges between London, Calcutta, Madras, and Bombay, and of the relative value of coins current in Hindostan : tables of the weights of India and China, with their respective proportions, &c. : to which is subjoined an account of the monies, weights, and measures of India, China, Persia, Arabia, &c. / collected from the best sources and latest authorities, by Thomas Thornton ..