Vibrating Machine : This apparatus is suitable for making cubes of 70.7 mm., for mortar strength evaluation. The mould is mounted on a vibrating platform with a frequency of 12,000±400 vibrations per minute. To the platform are attached four matched springs. The whole assembly is operated by a revolving shaft with an eccentric mechanism. The machine is supplied with a timer, a switch mounted on a steel panel and a 70.7 mm.