PAPERS OX HIGH SCHOOL SCIENCE 415 



Electric Light Company were present to conduct the 

 exercise. The production and transmission of the cur- 

 rent over high voltage wires was first considered by the 

 Superintendent. After stating the reason for high volt- 

 age transmission it was explained how it was again 

 stepped down and distributed to the various places for 

 consumption. The limits of the lamp socket and use of 

 fuses were next considered. Several different appliances 

 were used and explained. The merits of each were con- 

 sidered. The amount of current consumed was deter- 

 mined by use of the voltmeter and ammeter. The cost per 

 hour for each devise was found. The electrical driven 

 brush and the straight type vacuum cleaner were com- 

 pared. The advantages and disadvantages of each were 

 pointed out to the class. The same was done with the 

 vacuum and rotary washing machine. 



One laboratory exercise has also been devoted to the 

 study of ways in which alternating current can be 

 changed to direct current. This exercise was taken up 

 because a large number of storage batteries are used on 

 radio outfits. Eight different types of rectifiers were 

 secured and examined. The motor generator was studied 

 and it was pointed out that it could be made by using 

 an ordinary motor and an old generator from some dis- 

 carded automobile. One boy later reported a good out- 

 fit with no cost except the time in a machine shop re- 

 quired to make a pully for the generator. Others made 

 transformers and bought a tungar bulb at a consider- 

 able saving. Some made the more simple and less costly 

 nodon valve rectifier. We devoted about a week to the 

 subject of radio. Seven boys built neutrodyne sets and 

 several built simpler sets. 



Color and light in home decorating offers another in- 

 teresting project for both the boys and girls. It is just 

 as important as to study pitch quality and harmony in 

 sound. How many of us know how to use compliment- 

 ary colors \ Where to use intensity of color and how 

 much ! How sunlight and artificial light cause the color 

 to change, and why ! What is meant by warm and cool 

 colors and where to use them? How color and the size 



