Shore durometer "durometer" (ISV "duro-" and "-meter"; attested since the 19th century), but today that name usually refers to Shore hardness; other devices use other measures, which return corresponding results, such as for Rockwell hardness. There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the ASTM D2240 type A and type D scales. The A scale is for softer ones, while the D scale is for harder ones. However, the ASTM D2240-00 testing standard calls for a total of 12 scales, depending on the intended use: types A,
North Shore (Lake Superior) efforts, many of the forests along the North Shore are now protected from deforestation, but there is still a strong paper industry that relies on pulpwood. In 1855 when a lock system first allowed steamboats onto the lake, eastern tourists began to travel onto Lake Superior for recreational purposes. They would then canoe or be ferried from Duluth up the North Shore and would stay in hunting and fishing camps. In the 1920s, the North Shore highway was built, which helped make the North Shore accessible by land. At the same time commercial fishermen began to go out of business