The negociator's magazine [electronic resource] : or the most authentic account yet published, of the monies, weights, and measures, of the principal places of trade in the known world. Also an account of the European exchanges in general; ... To which are added, curious calculations of great use in the West-Indian and American trades, .. / By Richard Hayes. The tenth edition, revised, methodized, and improved with the addition of several new and useful tables, by Benjamin Webb