354 HOW ELECTRICITY IS USED IN THE HOME 



into the bag. The dirt is held here by the tight, close mesh 

 of the cloth, but the air passes out into the room again 

 after being filtered through the cloth. 



For thorough cleaning a vacuum of T V to -f of an at- 

 mosphere is desirable, but such a high vacuum makes the 



tool stick to the 

 carpet and causes 

 rapid wearing. For 

 ordinary sweeping 

 where it is desired 

 to remove only the 

 surface litter, a vac- 

 uum of T V of an 

 atmosphere is suffi- 

 cient. The low vac- 

 uum machines are 

 termed "vacuum 

 sweepers " by some, 

 and the high pres- 

 sure machines "vac- 

 uum cleaners." 

 There are numerous 

 hand-driven vac- 



uum sweepers on 

 the market. These 

 give a lower vacuum, 

 as a rule, than the 

 electrically driven ones, and yet they are satisfactory 

 for superficial sweeping. Carpets and rugs cleaned by 

 " sweepers " need removal and beating occasionally. 



Electric heating devices. Many modern homes now are 

 equipped with electric toasters, grills, coffee percolators, 



Vacuum cleaning system. 



