Indentation hardness test, performed with either 3 gf or 9 gf loads, preceded the development of microhardness testers using traditional indenters. In 1925, Smith and Sandland of the UK developed an indentation test that employed a square-based pyramidal indenter made from diamond. They chose the pyramidal shape with an angle of 136° between opposite faces in order to obtain hardness numbers that would be as close as possible to Brinell hardness numbers for the specimen. The Vickers test has a great advantage of using one hardness scale to test all materials.The first reference to the Vickers indenter with low loads was made
107-109 George Street, The Rocks Regency Style. The buildings have been continuously occupied for commercial retail purposes since construction in 1861. The building's scale, detailing and alignment to the street is typical of that found along the west side of George Street and lining the harbourside as part of the Business Precinct of The Rocks. The buildings are part of the rich fabric of The Rocks which is highly regarded by residents, Sydney people and visitors and acknowledged by the Australian Heritage Commission and the National Trust as part of The Rocks Urban Conservation Area. The potential archaeological resource on the site is representative of