CONTENTS. xv 



BOOK III. 



METHODS OF MEASUREMENT. 



CHAPTER XIII. 



THE EXACT MEASUREMENT OF PHENOMENA. 



SECTION PAGE 



1. The Exact Measurement of Phenomena . . .313 



2. Division of the Subject . . . . .318 



3. Continuous Quantity . . . . .318 



4. The Fallacious Indications of the Senses . . .320 



5. Complexity of Quantitative Questions . . .323 



6. The Methods of Accurate Measurement . . , 328 



7. Conditions of Accurate Measurement . . . 328 



8. Measuring Instruments . . . . .330 



9. The Method of Repetition . ... 336 



10. Measurements by Natural Coincidence . . .341 



11. Modes of Indirect Measurement .... 345 



12. Comparative Use of Measuring Instruments . . .349 



13. Systematic Performance of Measurements . . .351 



14. The Pendulum . . . . . .352 



15. Attainable Accuracy of Measurement . . .354 



CHAPTER XIV. 



UNITS AND STANDARDS OP MEASUREMENT. 



1. Units and Standards of Measurement . . .357 



2. Standard Unit of Time . . . . .359 



3. The Unit of Space and the Bar Standard . . .365 



4. The Terrestrial Standard . . . . .367 



5. The Pendulum Standard ..... 369 



6. Unit of Density . . . . . .371 



7. Unit of Mass . . . . . .372 



8. Subsidiary Units ...... 374 



9. Derived Units . . . . . .375 



10. Provisionally Independent Units . . . .377 



11. Natural Constants and Numbers .... 380 



12. Mathematical Constants . . . . .381 



13. Physical Constants . . . . . .383 



14. Astronomical Constants . . . . .384 



15. Terrestrial Numbers . . . . .385 



16. Organic Numbers . . . . . 385 



17. Social Numbers . . . . . .386 



CHAPTER XV. 



ANALYSIS OF QUANTITATIVE PHENOMENA. 



1. Analysis of Quantitative Phenomena . . . .387 



2. Illustrations of the Complication of Effects . . .388 



3. Methods of Eliminating Error . . . .391 



