CHAPTER II 



MORE ABOUT THE CLAY 



Apparatus required. 



Clayj about 6 lbs, ; a little dried^ powdered clay ; 

 sand, about 6 lbs. Six glass jars or cylinders [2]. 

 Six beakers [1]. Six egg-cups [1]. Six funnels and 

 stands [2]. Six per/orated glass or tin disks [2]. Six 

 glass tubes [2]. Two tubulated bottles Jitted with corks. 

 Soine seeds. Six smaU jars about 2 in. x 1 in>. [2]. 

 Bricks. The apparatus in Fig. 9. Pestle and mortar. 



We have seen in the last chapter that clay will float 

 in water and only slowly settles down. Is this because 

 clay is lighter than water? Probably not, because a 

 lump of clay seems very heavy. Further, if we put 

 a small ball of clay into water it at once sinks to the 

 bottom. Only when we rub the clay between our 

 fingers or work it with a stick — in other words, when 

 we break the ball into very tiny pieces — can we get it 

 to float again. We therefore conclude that the clay 

 floated in our jars (p. 6) for so long not because it was 

 lighter than water, but because the pieces were so 

 small. 



Clay is exceedingly useful because of its stickiness. 

 Dig up some clay, if there is any in your garden, or 

 procure some from a brick works. You can mould 

 it into any shape you like, and the purer the clay the 



