Collections : [University of Michigan William L. Clements Library]

Adam R. Barr of Conestoga Township, Pennsylvania, created this mathematics exercise book or cipher book of mathematical operations, rules and theorems, and example problems. Sections labeled with calligraphic lettering include the Single Rule of 3, Double Rule of 3, Simple Interest, Insurance, Commission, Barter, Fellowship, Exchange, Vulgar Fractions, Decimal Fractions, and others.

Adam R. Barr of Conestoga Township, Pennsylvania, created this mathematics exercise book or cipher book of mathematical operations, rules and theorems, and example problems. Sections labeled with calligraphic lettering include the Single Rule of 3, Double Rule of 3, Simple Interest, Insurance, Commission, Barter, Fellowship, Exchange, Vulgar Fractions, Decimal Fractions, and others.

This arithmetic copybook was compiled by an anonymous student in the nineteenth century. It includes rules and examples for addition, subtraction, multiplication, and division, as well as practical examples relating to money and weights and measures.

This currently unidentified student's cypher book contains mathematical rules and examples largely in the service of commerce. Entries relate to the addition of money, addition of Troy weight, addition of dry measure, subtraction, a numeration table, a multiplication table, the Golden Rule (i.e. the rule of three), and similar concepts. Currency in this volume is almost exclusively British coinage, but at least one problem references conversion of British pounds into the (newly created) U.S. dollar. The covers of the volume are (apparently re-used) canvas, possibly sailcloth. The cypher book was owned by the Higgins family of Cape Cod, Massachusetts, and it contains names of Higgins family members, but the author is yet undetermined.