30 THE BOOK OF NATURE STUDY 



country. The above are given merely as examples which the 

 teacher may find useful in giving lessons on heavy rainfall ; many 

 other similar cases will be found detailed in the books of reference 

 given at the end of this article. 



While speaking of the effects of excessive rainfall the teacher 

 will of course again draw attention to its effects on human life. 

 Floods destroy life and property ; they interfere with traffic, and 

 so check the free exchange of commodities, thus leading to indirect 

 losses ; their effect on agriculture is always injurious seeds or 

 young plants may be washed out of the ground ; large amounts of 

 fertile, well-manured soil are swept into the rivers and thus totally 

 lost ; ripe or ripening crops may be rendered useless, as was the 

 case during the continuous wet of the autumn of 1907, when the 

 cut corn was actually washed from the fields into the rivers. 

 Again, as a summer thunderstorm will show well, a torrential rain 

 of short duration produces a smaller beneficial effect on growing 

 crops than a gentle long-continued fall. This should be em- 

 phasised by drawing attention to the rapid drying of the roads 

 after a thunder-shower, and the almost immediate swelling of the 

 streams, showing that much of the water is running off the land at 

 once. Explain that Great Britain is remarkable for the high 

 average yield of the land, and show that one factor in this pro- 

 ductiveness is the uniform distribution of the rainfall through the 

 year, and the rarity of heavy falls ; but again, this deduction 

 should come after, and not before, actual observations have been 

 made. 



