CHAPTER XIV.

UNITS AND STANDARDS OF MEASUREMENT.

1. Units and Standards of Measurement 305

2. Standard Unit of Time 307

3. The Unit of Space and the Bar Standard 312

4. The Terrestrial Standard 314

5. The Pendulum Standard 315

6. Unit of Density 316

7. Unit of Mass 317

8. Natural System of Standards 319

9. Subsidiary Units 320

10. Derived Units 321

11. Provisional Units 323

12. Theory of Dimensions 325

13. Natural Constants 328

14. Mathematical Constants 330

15. Physical Constants 331

16. Astronomical Constants 332

17. Terrestrial Numbers 333

18. Organic Numbers 333

19. Social Numbers 334