152 SCIENCE OF HOME AND COMMUNITY 



power for turning the dishes is furnished by a motor. The 

 water may be heated either by electricity or by a fire. 



Electricity for heating. One means of heating is the 

 luminous radiator. This consists of a frame in which vary- 

 ing numbers of lamps may be screwed. These are usually 

 inclosed in a bulb of frosted glass. The filaments in the 

 lamp give off their heat by radiation to objects near. Such 

 a radiator may be moved from one room to another and 

 may be used like a fireplace to take the chill off a room in 

 the late fall and early spring. 



Another form of heater is the convector. The principle 

 involved here is the same as in appliances for cooking. 

 Various forms of heating elements are used. These heat the 

 air and cause a circulation, the warm air rising and the cooler 

 air coming near to be heated. The amount of heat may be 

 controlled by means of switches. In another type of con- 

 vector the elements become red hot and give off a glow like 

 the luminous radiator. 



Electric fan. The electric fan is operated by a motor. 

 Its use in summer for cooling purposes is well known, but 

 it has other uses. It may be used in the winter to help heat 

 the house. For this purpose it may be placed in the cold-air 

 inlet of a hot-air furnace, it may be placed over a register, 

 or it may be placed in front of a steam or hot-water radiator 

 and a current of air directed against it. In each case the 

 room is heated more quickly. Fans may also be used in 

 drying fruits and vegetables. 



Other uses of the motor. Other uses of the motor besides 

 those which have already been mentioned are to run a sew- 

 ing machine, turn an ice cream freezer or coffee grinder, and 

 work a pump. 



Sewing machine motor. Small motors may now be at- 

 tached to the table of a sewing machine which will run the 

 machine by means of a belt. The stopping and starting 

 of the motor and the control of the speed may be regulated 



