1. An apparatus for balancing a non-linear torque produced by an offset mass rotating with respect to a support, comprising: a four bar linkage wherein each bar is pivotally connected to two other bars of the linkage to form a quadrangle, means for securing a first bar to said rotating mass, means for securing said support to a second bar, and resilient means coupled to said second bar, and a third bar for producing a linear torque on the third bar as that third bar rotates, said bars each having a predetermined length, the length of each bar being a function of the angular displacement of the third bar with respect to the angular displacement of the rotating mass, the length of the bars being such that the linear torque at the third bar balances said non-linear torque.

4. In combination: a body rotatably mounted at a first pivot spaced from the body center of gravity, support means for rotatably mounting said body at said first pivot, a first member rotatably mounted to said body at a second pivot spaced from said first pivot a first predetermined distance, a second member rotatably mounted to said first member at a third pivot spaced from said second pivot a second predetermined distance, said second member being rotatably mounted to said support means at a fourth pivot spaced from said third pivot a third predetermined distance, said fourth and first pivots being spaced a fourth predetermined distance, the torque produced by said body when said body is rotated about said first pivot being non-linear, said first, second, third and fourth distances being a function of the angular displacement of said body, and means for providing a linear torque on one of said members, body and support means to counterbalance said non-linear torque.

10. In combination: a four bar linkage, said bars each having a length which is a function of the angular displacement of a first bar with respect to a second bar, means for securing a mass to said first bar, resilient means coupled to said second bar for applying a linear torque to said second bar as said second bar rotates, said linear torque having a value which counterbalances the torque produced by said mass when rotating.