A load mechanism applies a compressive force along the axis of a slender bar; a dial gauge records the lateral deflection, while a force gauge reads the compressive load. By exchanging the end fittings (pinned or clamped at each end) the student reproduces all four classical Euler cases and verifies
Fcr=π2EI/Le2 from a force–deflection plot. A set of bars in two materials and four cross-sections isolates the individual roles of
E,
I and
L in the critical load.