CHAPTER IX 



THE greatest of the dangers we have to fear from House 

 Flies is the infecting of our foodstuffs with the germs of 

 diseases. The fact that flies breed in the most loathsome 

 of filth, wallow in it, eat it, vomit and excrete it on our 

 food, should of itself be sufficient inducement to make us 

 use every endeavour to exclude it from our houses. This 

 can be done by screening. Any intelligent carpenter can 

 fit up wire door and window screens. There are many 

 advantages in screening doors and windows in warm 

 climates such as that of South Africa. Mosquitoes and 

 various troublesome insects would be excluded ; the dwell- 

 ing may, by screening the windows and doors with fly- 

 proof wire gauze, be thoroughly ventilated both day and 

 night. This would prove a great boon to those who fear 

 to keep their windows and doors open after retiring to 

 rest, for fear of burglars and snakes. Air passing through 

 a fine wire gauze is broken up so effectually, that even 

 should a strong wind blow direct against it, the current 

 of air will have its force broken, and there will consequently 

 be no draught in the room. In this way a constant move- 

 ment of the air in the room will be assured. 



Health is largely dependent on a supply of pure air 

 night and day, therefore for this reason alone, all those 

 who can afford it should have their dwellings screened. 



The screened frames for the windows should not be 

 screwed on. It is preferable to hinge them, or to fix them 



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