Mohs scale of mineral hardness finding the hardest material that the given material can scratch, or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on the Mohs scale would fall between 4 and 5. "Scratching" a material for the purposes of the Mohs scale means creating non-elastic dislocations visible to the naked eye. Frequently, materials that are lower on the Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. While these microscopic dislocations are permanent and sometimes detrimental to the harder material's structural
Worshipful Company of Scientific Instrument Makers or using scientific instruments. This could be any kind of scientific instrument: a measuring instrument, like a feeler gauge or an atomic clock, or an imaging instrument like a PET scanner. It might even be a piece of control engineering incorporating many instruments. What makes the Company a community is partly a shared interest in scientific instruments and, more generally, in science and engineering. It is also partly a shared love of good company, of meeting for discussion over food and wine, and of bringing partners or guests to a grand banquet in distinguished surroundings. But what makes the Company