- An instrument for the accurate measurement of small
differences of height; esp. of the differences in the height of the
upper surfaces of two columns of mercury or other fluid, or of the same
column at different times. It consists of a telescopic leveling
apparatus (d), which slides up or down a perpendicular metallic
standard very finely graduated (bb). The telescope is raised or
depressed in order to sight the objects or surfaces, and the
differences in vertical height are thus shown on the graduated
standard.
Definition
[ n.]