FOR THE USE OF TEACHERS. 



No. 18. 



Leaflet 



On Nature Study. 



Especially Adapted to the Use of Children in Schools 

 IN Rural Districts. 



PREPARED BY THE 



FACULTY OF PURDUE UNIVERSITY. 



THE WORK OF WATER. 



By Prof. A. W. Duff. 



One of the busiest of all busy things is water. It is always work- 

 ing, usually doing useful work, but sometimes causing great damage. 

 It carries more freight than all the railways; it breaks up more soil 

 than al] the ploughs; it cuts more rock than all the quarrymen; it soars 

 higher than the highest mountain, and digs deeper than the deepest 

 mine. It is the most active thing in the world. 



The Jiext time it is raining see what becomes of the raindrops that 

 fall on a sloping load. First, they make small imprints in the dust; 

 then they join to form pools; these pools overflow and streams start 

 down the road; these streams unite to form larger streams, and near 

 the foot of the slope you have a small brook, which has dug out a 

 regular channel for itself. If you follow it far enough you will prob- 

 ably find that it joins other brooks and becomes a large stream and 

 flows into a river which finally reaches the sea. 



Note.— The material of this paper will suggest subjects for several 

 lessons. Although the primary purpose is to teach children to observe for 

 themselves, the explanation of some of the phenomena referred to would 

 be difficult if attention were not called to operations of Nature beyond the 

 ordinary range of observation. Hence, this leaflet departs somewhat from 

 the principle laid down in the Introduction to Nature Study as found in 

 Leaflet No. 1. 



