> Go for a real challenge - a non-polluting steam mouse!
Steam is tricky for a first attempt but it would be easy enough to
convert my current (nearly working) electric "mechanical" mouse to solar
power as the motor used is designed for very low power operation. I may have
a go at steam when I retire as I always fancied making a steam engine.
BTW, Heinz Wolf used to lecture on the subject of "A steam engine in
every school, rather than a computer". There is something very satisfying
about technology that you can explain to a 10 year old without "magic" words
such as algorithm, microprocessor etc. You can explain how a steam engine
works in a few minutes using language that everyone understands; you cannot
do that with a maze-solving mouse.