Model: M901

Special Features:

Vertical guide bar hollow, close grained cast iron; telescope achromatic objective, 90 degrees cross hairs

Properties:

An instrument of accurate measurement of distances or of the small difference of distance or height such as the upper surfaces of two columns of mercury or other fluids or of the same column at different times. It consists essentially of a telescope, horizontally mounted on a carriage, which travels on an accurate vertical and/or horizontal guide and with an accurately graduated scale.