TABLE OF CONTENTS. 



ART. SECT. 



I. NATURE AND SCIENCE. 



I'AGE 



1. ,, Sensations and Things . . .5 



2. ,, Causes and Effects 5 



3. ,, The reason Why. Explanation 6 



4. ,, Propert.es arid Powers 7 



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



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



brought together or separate.! by Men .... 8 



7. ,, Many Objects and Chains of Caii-.es 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 . . . . . ia 



y. ,, 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 i} 



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 ; ic 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 cjnditions. Mass. D-insi:y . . ;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 occupi-S 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 \\ords, it d.splaces its own Weight of Water 36 



27. ,, Water Presses in all Directions 37 



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



tum o-f Moving Water 40 



29. ., The Energy of Moving Water 43 



30. ,, The Properties of Water are Constant 47 



31. ,, Increase of Heatat first causes Water to Increase in Volume 48 



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



33. ,, The taking away cf 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 .... i . 52 



36. ,, 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 begin with, but 



after a time Expands . . . . ' . . . .57 



