Please explain to me Lothar Meyer's volume curve

Please explain to me Lothar Meyer’s volume curve

Lothar-Meyers-Graph-1-300x252

Lothar Meyer used atomic mass and atomic volume in x and y axis respectively and found the periodicity of elements.Elements of same group is found in the same position of the curve.

Lothar Meyer was the first scientist to notice the periodic trends in periodic properties. He observed that the element with the same physical and chemical properties occupy the same positions on the curve. This idea helps to arrange the elements with similar properties as the same group in the table.