A declaration concerning the newly invented art of double writing : wherein are expressed the reasons of the authors proceedings in procuring a priviledge for the same : as also of the time, manner, and price, of the discovery of the said art, and of the instruments belonging thereunto ... : whereunto is annexed a copie of an ordinance of both houses of Parliament, approving the feasibility and great use of the said invention, and allowing a priviledge to the inventor, for the sole benefit thereof for 14 years, upon the penalty of one hundred pounds.