288 GENERAL SCIENCE 



to remove some of the dungeon-like gloom and throw 

 a ray of hope into the hearts of the occupants, as well as 

 to remove some of the disease germs that may be lurking 

 there waiting for a victim. Modern factory builders have 

 come to recognize the valuable effects of light on the work- 

 men, and such buildings are filled with numerous large 

 windows. The buildings of the National Cash Register 

 Company of Dayton, Ohio, have so many large windows 

 that they look almost like glass structures. 



QUESTIONS AND EXERCISES 



1. Name the parts of the eye. Give the use of each part. 



2. Can you see objects that are black? Explain. 



3. Explain why the persons in a moving picture show seem 

 to be moving. 



4. What are some defects of the eye? What is the remedy 

 for such defects? 



5. How can improper use of the eyes produce headache? 

 Give the remedy for such a headache. 



6. Make some general statements for the care of the eyes. 



7. What is the relation between light and health? 



