28 



SCIENCE OF HOME AND COMMUNITY 



direction of air currents as shown by the smoke. Make a 

 drawing of the room and show the direction of currents by 

 means of arrows. Open some windows and test again for air 

 currents. Find out which combination of open windows gives 

 the best circulation of air. 



2. Is a change of air provided? When you first come in 

 from outdoors do you detect odors in the room? Are there 

 any openings through which air enters the room? Does this 

 air come from outdoors, from the cellar, or is it return air taken 

 from the room? Are there any openings where the impure air 

 can escape ? 



3. Is the room kept at the proper temperature (from, 68 to 

 70) ? Read the thermometer several times during the day. 

 Place it in different parts of the room and at different heights 

 from the floor and take the readings. Make a record of all the 

 readings in a table like the following. 



4. Is the proper degree of humidity maintained (from 50 to 60 

 per cent) ? Determine the per cent of humidity, using the method 

 explained in demonstration 8. Find also the humidity outdoors. 



5. Which of the four essentials of ventilation are provided 

 in your home? Which ones are not provided? What can be 

 done to provide those essentials that are lacking ? 



Ventilation by windows. Unfortunately in many of our 

 homes no special provision was made for ventilation when 

 the house was built, so we must plan our ventilation as best 



