Construction system

A construction system comprising an elongate substantially rectangular prismatic member having two pairs of grooves parallel to the longitudinal axis thereof, the grooves of each pair being in opposite faces of said member, the first pair having a cross-sectional shape which is a segment of a circle, opening to the respective face at a slot which defines the chord of said segment, the centre of said circle lying inwardly of said slot, the second pair having a rectangular cross section and opening to the respective face by a slot the width of which is less than the width of said rectangle, the slots of the first pair of grooves being of substantially the same width as those of the second pair of grooves, the diameter of the first pair of grooves being substantially equal to the width of the second pair of grooves, the width of the faces of the construction member being in the ratio of 2:1, and connecting elements each comprising a connecting portion adapted to enter said slots, a locking portion adapted to enter any of said grooves, a body portion adapted to engage against a face of said member, said body portion being dimensioned to fit co-axially within a groove of said first pair of grooves of a further such member, said body portion comprising locking means adapted to engage the said groove to lock said body portion therein.