Abstract: A mechanical computer for a compensated meter counter assembly for a gas meter includes a one-way clutch with an input hub drivingly releasable and connectable to an output shaft for driving a register. A computer arm carried by the input hub oscillates along a specified arc about the axis of the hub between an initial position and a travel limiting cam surface positioned in response to temperature changes. An adjustably settable connection is provided between the arm and the hub for selectively pivoting said arm about said hub to position the outer end of the arm in a selectively set angular position relative to said hub and along the arc. In this position the outer end of the arm is held so as to precisely register with the initial position of the arc at the start of each oscillation.