This 1903 book, which became a standard work, made recent German research on invariant theory available to British mathematicians.

Preface; 1. Introduction; 2. The fundamental theorem; 3. Transvectants; 4. Transvectants (continued); 5. Elementary complete systems; 6. Gordan's theorem; 7. The quintic; 8. Simultaneous systems; 9. Hilbert's theorem; 10. Geometry; 11. Apolarity and rational curves; 12. Ternary forms; 13. Ternary forms (continued); 14. Apolarity (continued); 15. Types of covariants; 16. General theorems on quantics; Appendices; Index.