Height gage

In a height gage, a generally horizontally disposed base and a generally vertically disposed column extending upwardly therefrom, said column having a plurality of vertically disposed surfaces, a slide embracing said column and presenting slide surfaces to the surfaces of said column, characterized by said slide being expandible and formed by a plurality of plates, resilient means connecting said plates, said means of a character to flex and cause expansion of the embracing slide upon the existence of fluid pressure between the surfaces of said slide and column to form a frictionless fluid bearing and subsequent contraction in the absence of such fluid pressure to grip the column, said slide surfaces having a plurality of fluid openings and means to supply fluid to said fluid openings to expand said slide.