LIBRARY 



X 



39- 



TABU 



NATURE AND SCIENCE. 



PAGK 



Sensations and Things ........ 5 



Causes and Effects 5 



The reason Why. Explanation 6 



Properties and Powers 7 



Artificial and Natural Objects. Nature _ . . . .8 

 Artificial Things are only Natural Things shaped and 



brought together or separated by Men . . . .8 

 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 . . . . .to 

 Laws of Nature ; Laws are not Causes . ';. . . .12 

 Knowledge of Nature is the Guide of Practical C -ndr.ct . 14 

 Science : the Knowledge of the Laws of Nature obtained by 



Observation, Experiment, and Reasoning . . . .16 



MATERIAL OBJECTS. (A.) MINERAL BODIES. 



The Natural Object Water 19 



A Tumbler of Water 20 



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 



Water is a liquid 21 



Water is almost incompressible . . . . . .22 



The Meaning of Weight 24 



Gravity and Gravitation 25 



The cause of Weight: Attraction: Force . . . -27 

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



The Measuring of Weights. The Bah 

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

 stant under the same conditions. Mass. Density . 

 Equal Volumes of Different Things under the same circum- 

 stances, have Different Weights : the Density of Different 



Bodies is Different 



The Meaning of Heavy and Light Specific Gravity _. 

 Things of greater Specific Gravity than Water sink in 



Water ; Things of less Specific Gravity float . 

 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 d splaces its own Weight of Water 



Water Presses in all Directions 



The Transference of Motion by Moving Water : the Momen- 

 tum of Moving Water ....... 



The Energy of Moving Water 



The Properties of Water are Constant 



Increase of Heatat first causes Water to Increase in Volume 

 Increase of Heat at length causes Water to become Steam . 

 The taking away of Heat from Steam causes the Steam to 



change into Hot Water . . . . 



When Water is changed into Steam, its Volume becomes 



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



, Gases or Elastic Fluids. Air . . . .- v \t 



, Steam is an Elastic Fluid or Gas . . . . \ . <{ . 



, Gases and Vapours ;- . 



, The Evaporation of Water at ordinary Temperatures . 

 , When Hot Water is cooled, it Contracts to begin with, but 

 after a time Expands 



