It is a very interesting story about how the stethoscope was invented. It all started on a cool morning in September of 1816. Laennec was 35 years old at the time anad while on a walk he saw two children playing with a long piece of solid wood and a pin. One child put their ear to one end of the pole and the other child scratched the opposite end of the pole with a pin. The child who put their ear to the pole had the sound of the pin amplified.
http://www.youtube.com/watch?v=xjHanUVFYPc
