<p>A multi-scale mechanism comprising a rotatable driving shaft; a first scale mounted along the axis of said rotatable driving shaft, said scale including first and second sets of coarse scale divisions for indicating a coarse range of magnitude in two different systems of units as a function of the position of said first scale with respect to said rotatable driving shaft; a second scale for indicating a fine scale range of magnitude in one of said systems of units; a third scale for indicating a fine scale range of magnitude in the other of said systems of units; said third scale operatively connected to said rotatable driving shaft; and a gear assembly connected between said second scale and said third scale having a predetermined gear ratio such that said second scale is caused to move at a different rate than said third scale.</p>