YES! This is beautiful. The wheels turning wheels explaining the
   formulas; gear ratios and such - beautifully illustrated.* . . .
   . * Of course the trouble with mathematical perfection; it only
   LOOSELY _can_ have a basis in reality... but not without a whole
   lot of trouble. Someone forgets to oil one of the wheels...
   forklift backs into it and well, all those formulas go to
   heck.[1]tumblr_nhr191UoYM1tlppcdo1_400

References

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   1. http://icopiedyou.com/wp-content/uploads/2015/09/tumblr_nhr191UoYM1tlppcdo1_400.gif