The readiest reckoner ever invented, : for assisting the tradesman, the merchant, the gentleman, &c. in finding the amount, at any given price, of any number from one to ten thousand. ... The whole constructed, and separately calculated, / by Stephen Simpson and Edward Wise, accountants.

Licence: Public Domain Mark

Credit: The readiest reckoner ever invented, : for assisting the tradesman, the merchant, the gentleman, &c. in finding the amount, at any given price, of any number from one to ten thousand. ... The whole constructed, and separately calculated, / by Stephen Simpson and Edward Wise, accountants. Source: Wellcome Collection.