Mathematical Treasure: John Bart Geijsbeek’s Ancient Double-Entry Bookkeeping

John Bart Geijsbeek (1872–1949; he also went by John Bart Molenaar as his father’s name was hyphenated) was an emigrant from the Netherlands who earned a law degree from the University of Denver in 1907 and served in university administration for much of his career. He also did accounting work for the Colorado state government and utilities. In addition to preparing an accounting textbook and book-length reports on his professional duties, he self-published Ancient Double-Entry Bookkeeping in Denver in 1914. The book examines the mathematical business practices that he gleaned from Lucas Pacioli’s 1494 Summa and other sources. He also provided facsimiles and translations of relevant pages.

The “Table of Contents” provides an outline of the book’s coverage:

An example of the juxtaposition of facsimile and translation:

A full digitization of the copy owned by the University of California is available from the Internet Archive.

Index to Mathematical Treasures