Figure 14 is a photograph of someone standing on platform weighing scales. Only the feet of the person are shown in the picture. The scales have a flat surface on which to stand and a large round instrument face with a pointer that rotates when the person stands on the platform. The face has two scales. The inner scale is graduated in kilograms and the outer scale is graduated in stones. The position on the scales where the pointer stops indicates the mass in either kilograms or stones.

 1.2.4 Ammonia synthesis by bulk production