The practical counting house, or, Calculation and accountantship illustrated : in all the cases that can occur in trade, domestic or foreign, proper or company, in buying, selling, drawing, remitting, exporting, importing, factorage, brokerage, insurance, exchange, &c. : to which is added an appendix, containing precedents of writing, English and Scots, proper for every regular counting house : and a book of rates, exhibiting, at one view, the duty and drawback upon every commodity the British merchant exports or imports, with a summary of the laws respecting the same /