Rockwell scale for specialized applications. There are special scales for measuring case-hardened specimens. Rockwell scale The Rockwell scale is a hardness scale based on indentation hardness of a material. The Rockwell test determines the hardness by measuring the depth of penetration of an indenter under a large load compared to the penetration made by a preload. There are different scales, denoted by a single letter, that use different loads or indenters. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale (see below). When testing metals, indentation hardness correlates linearly with
On the Rocks (play) there is nothing new in this, since the "extermination of what the exterminators call inferior races is as old as history." What is new is that modern politicians since the French revolution have created a social principle of extermination, whether it be of aristocrats as in the case of France, or Jews as in Germany. This is an outgrowth of class conflict, but in the future such decisions can be made scientifically. On the Rocks (play) On the Rocks: A political Comedy (1932) is a play by George Bernard Shaw which deals with the social crisis of the Great Depression.