Bird Study 



35 



6. If you carry an umbrella on a windy morning, which catches 

 more wind, the under or the top side? Why is this? Does the curved 

 surface of the wing act in the same way? 



7. Take a wing feather. Are the barbs as long on one side of the 

 quill as on the other? Do they lie at the same angle from the quill on 

 both sides ? If not why ? 



8. Which side of the quill lies on the outer side and which on the 

 inner side of the wing? 



9. Is the quill of the feather curved? 



10. Which side is uppermost in the wing, the convex or the concave 

 side? Take a quill in one hand and press the tip against the other. 

 Which way does it bend easiest, toward the convex or the concave side? 

 What had this to do with the flight of the bird? 



11. If the bird flies by pressing the wings against the air on 

 the down stroke, why does it not push itself downward with its 

 wings on the up stroke"' 



12. What is the shape and arrangement of the feathers so as to 

 avoid pushing the bird back to earth when it lifts its wings? 



13. Why do you have a rudder to a boat? 



14. Do you think a bird could sail through the air without some- 

 thing to steer with? What is the bird's rudder? 



15. Have you ever seen a young bird whose tail is not yet grown, 

 try to fly? If so, how did it act? 



1 6. Does the hen when she flies keep the tail closed or open like 

 a fan? 



17. Compare a tail feather with a wing feather and describe the 

 difference. 



