Yes, this is an old calculus textbook. Yes, it was written sometime in the early 1900s. When Oliver E. Glenn from the University of Pennsylvania wrote this text, modern computers and even electronic calculators had not been invented yet.

I have included this textbook because in my small library of calculus textbooks, it was often the oldest book (I think from the 1940s) that proved the most helpful. The language was just different enough that it lead to understanding the concepts much better than my more modern, assigned textbook did.

## Table of Contents for *A Treatise on the Theory of Invariants*

- The Principles of Invariant Theory
- Properties of Invariants
- The Processes of Invariant Theory
- Reduction
- Gordan’s Theorem
- Fundamental Systems
- Combinants and Rational Curves
- Seminvariants. Modular Invariants
- Invariants of Ternary Forms

View this Free Online Material at the source:

A Treatise on the Theory of Invariants