TABLE OF CONTENTS. 



ART. SECT. 



I. NATURE AND SCIENCE. 



PACK 



T. ,, Sensations and Things ........ 5 



2. ,, Causes and Effects 5 



3. ,, The reason Why. Explanation . . . . . .6 



4. ,, Propert.es and Powers . 7 



5. Artificial and Natural Objects. Nature .... 8 



6. ,, Artificial Things are only Natural Things shaped and 



brought together or separated by Men . . 8 



7. ,, Many Objects and Chains of Causes and Effects in Nature 



are out of our reach . . ... 10 



,, The Order of Nature : nothing happens by Accident, and 



there is no such thing as Chance . 10 



9. ,, Laws of Nature ; Laws, are not Causes 12 



10. ,, Knowledge of Nature is the Guide of Practical Conduct 14 



11. ,, Science: the Knowledge of the Laws of Nature obtained by 



Observation, Experiment, and Reasoning . . .16 



II. MATERIAL OBJECTS. (A.) MINERAL BODIES. 



12. ,, The Natural Object Water 19 



ij. ,, A Tumbler of Water ..... . . 20 



14. ,, Water occupies Space ; it offers Resistance . it has Weight ; 



and is able to transfer Motion which it has acquired ; it is 

 therefore a form of Matter 20 



15. ,, Water is a liquid 21 



16. ,, Water is almost incompressible ...... 22 



17. ,, The Meaning of Weight 24 



18. ,, Gravity and Gravitation 25 



19. ,, The cause of Weight : Attraction: Force . . . .27 



20. , , The Weight of Water is Proportioned to its Bulk . . .28 



21. ., The Measuring of Weights. The Balance . ... 29 



22. ., The Weight of the same Bulk or Volume of Water is Con- 



stant under the same conditions. Mass. Density . . ;o 



23. ,, Equal Volumes of Different Things under the same circum- 



stances, have Different Weights : the Density of Different 

 Bodies is Different . ...... 32 



24. ,, The Meaning of Heavy and Light Specific Gravity . . 33 



25. ,, Things of greater Specific Gravity than Water sink in 



Water ; Things of less Specific Gravity float . . 34 



26. ,, A Body which Floats in Water always occupies as much 



Space beneath the level of the Surface of the Water as is 

 equal to the Volume of Water which weighs as much as that 

 Body ; in other words, it displaces its own Weight of Water 36 



27. ,, Water Presses in all Directions 37 



23. ,, The Transference of Motion by Moving Water : the Momen- 



tum af Moving Water ....... 40 



29. ., The Energy of Moving Water 43 



30. ,, The Properties of Water are Constant 47 



3 1 - Increase of Heatat first causes Water to Increase in Volume 48 



32. ,, Increase of Heat at length causes Water to becc me Steam . 50 



33. The taking away of Heat from Steam causes the Steam to 



change into Hot Water ....... 51 



34. When Water is changed into Steam, its Volume becomes 



about 1,700 times greater than it was at first . . 51 



35- Gases or Elastic Fluids. Air ; . 52 



S'j. ,, Steam is an Elastic Fluid or Gas 54 



37. ,, Gases and Vapours 55 



38. The Evaporation of Water at ordinary Temperatures . . 56 

 39- When Hot Water is cooled, it Contracts to beg n with, but 



after a time Expands .57 



