Abstract: A container (1), such as a yogurt or cream pot, is of tube-like form with a side wall of circular cross-section tapering towards the base (2) from an open mouth (3). The base and mouth comprise opposite ends of the container. A flange plate (4) surrounds the open mouth (3) and is provided with sockets in the form of through holes (5) punched through each of the four corners. The base (2) of the container has a central cruciform projection (6) and in the angles between each pair of arms of the cruciform a projecting plug or stud (7) is formed. The holes (5) and studs (7) comprise mutually interchangeable connection parts. A plurality of like containers (1) can, when empty, be assembled in a desired spatial relationship by interengaging a stud (7) in a hole (5). The building system so formed thus forms a knock-down constructional toy.

Abstract: A container (1), such as a yoghurt or cream pot, is of tube-like form with a side wall of circular cross-section tapering towards the base (2) from an open mouth (3). The base and mouth comprise opposite ends of the container. A flange plate (4) surrounds the open mouth (3) and is provided with sockets in the form through holes (5) punched through each of the four corners. The base (2) of the container has a central cruciform projection (6) and in the angles between each pair of arms of the cruciform a projecting plug or stud (7) is formed. The holes (5) and studs (7) comprise mutually interchangeable connection parts. A plurality of like containers (1) can, when empty, be assembled in a desired spatial relationship by interengaging a stud (7) in a hole (5). The building system so formed thus forms a knock-down constructional toy.