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NATURE TEACHING 



the open edges together, as if closing the book, and notice 

 that the water rises between the glasses, being highest 

 where the space between the glasses is narrowest, and 

 lowest where the space is widest. This is another ex- 

 ample of capillary attraction, and shows that the effect 

 is greater in small spaces and cavities than in large ones. 

 Make diagrams showing the position of the water when 



FlG. 17. Experiment to show that 

 water rises, by capillary attraction, 

 higher in narrow than in wide cavities. 



FIG. 1 8. Experiment to 

 demonstrate the rise of 

 water in soils by capil- 

 lary attraction. 



the glasses are somewhat widely separated and when 

 close together. 



Take a tube, such as a narrow lamp-chimney, tie a 

 muslin or linen cap over the bottom end and fill with 

 soil. Flace the tube, thus filled, upright in a saucer of 

 water, and note the manner in which the water slowly 

 rises through the soil (see Fig 18). This experiment may 

 be made quantitative if the tube is weighed, before and 

 after filling with soil, to give the weight of soil used ; and 

 again after standing for some time, say for twenty-four 



