Augustus De Morgan (1806-1871) was a British mathematician, perhaps best remembered today for his work in logic. De Morgan’s *Differential and Integral Calculus* was published in 1842. It was sponsored by the Society for the Diffusion of Useful Knowledge, an organization devoted to bringing knowledge to the “common man,” i.e. the British working class. De Morgan also wrote 712 articles for the Society’s *Penny Cyclopedia, *a cheap periodical intended for the same purpose. In his mathematical writing, he took great care to tailor the material to the learning needs of his audience.

The “Advertisement” found in the front of De Morgan’s *Calculus* serves as a preface to the work, clarifying the author’s intentions in writing the work.

Instruction in differentiation begins on page 117. Note De Morgan’s use of a table to promote recognition of an operational pattern.

Often included with his *Calculus* was De Morgan's *Elementary Illustrations for the Differential and Integral Calculus* (1832), a sort of study-guide that clarified important points and supplied further advice on learning calculus. In 1899, Open Court published a revised and updated edition of this work.

A bibliography provided in this book indicates the popular English language calculus texts available at the close of the 19^{th} century.

*The images above are presented courtesy of the University of Pennsylvania Libraries.*

Index to Mathematical Treasures