- Oct 4 Dutch mathematician Christiaan Huygens patents the pocket watch

### Event of **Interest**

Oct 29 Gottfried Wilhelm Leibniz makes the first use of the long s, ∫, for integral, helping discover integral and differential calculus

- Oct 4 Dutch mathematician Christiaan Huygens patents the pocket watch

Oct 29 Gottfried Wilhelm Leibniz makes the first use of the long s, ∫, for integral, helping discover integral and differential calculus