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

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