Preface; 1. Capillary action; 2. Electrical units of measurement; 3. The sorting demon of Maxwell; 4. Elasticity viewed as possibly a mode of motion; 5. The size of atoms; 6. Steps towards a kinetic theory of matter; 7. The six gateways of knowledge; 8. The wave theory of light; 9. On the age of the sun's heat; 10. On the sun's heat; 11. Electrical measurement; Index.