Exploration 5 Resources

 

http://www.bcae1.com/speaker.htm

Speaker……

 

http://www.sciencetoymaker.org/SpeakPhone/assembl.html

How to make a speaker phone……

 

http://en.wikipedia.org/wiki/Telephone

Telephones……

 

http://inventors.about.com/library/inventors/bltelephone.htm

Telephones……