http://www.invento-hq.com/rb_clas_e.htm
Terry, you may be interested in this toy - the roller ball. I bought one
from a local shop. It is a gyroscope in a transparent enclosure. Spinning it
up with a string to start it, then holding it and doing a sort of twisty
wrist motion, allows the thing to accelerate up to 10,000 rpm when it is
very difficult to hold. I did not realise that forced precession of a gyro
could "drive" it to go faster - it seems counter intuitive.
