Hardness test is Mohs scale, which is used in mineralogy. One tool to make this measurement is the sclerometer. Another tool used to make these tests is the pocket hardness tester. This tool consists of a scale arm with graduated markings attached to a four-wheeled carriage. A scratch tool with a sharp rim is mounted at a predetermined angle to the testing surface. In order to use it a weight of known mass is added to the scale arm at one of the graduated markings, the tool is then drawn across the test surface. The use of the weight and markings
71 Harrington Street, The Rocks Iron. As at 27 April 2001, Archaeology Assessment Condition: Partly disturbed. Assessment Basis: Area under building only. Terraced into hill slope. As at 30 March 2011, this house and site are of State heritage significance for their historical and scientific cultural values. The site and building are also of State heritage significance for their contribution to The Rocks area which is of State Heritage significance in its own right. The site has historical significance as part of the Colony's hospital site in 1807, and the building as part of the 19th century housing stock in The Rocks. It has aesthetic