An essay on gold coin. [electronic resource] : In which is shewn the general use of currency, and the present state of our gold coin; with Arguments to prove the Necessity of a New Coinage; pointing out the distinct Value and Weight that each Piece of Gold ought to be of. Also the principles of hydrostatics, Shewing how to discover any Adulteration in Gold Coin, either by the Pen, or Tables ready calculated to shew the Par of Weight of each Piece, either in Air or Water. With a description and use of the most improved weighing instruments; shewing their Properties when really accurate. Intended For the Service of Bankers, Public Offices, and Trade in General. To this Edition is subjoined the Substance of the late Gold Act; with Answers to the very severe Strictures upon it, &c. in a Tract intitled A Critical Enquiry, &c. By Thomas Hatton, Author of a Treatise upon Clock and Watch Work.