Roentgen (unit) Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. In 1928 it was the first international measurement quantity for ionising radiation to be defined for radiation protection, and was an easily replicated method of measuring air ionization directly by using an ion chamber. It is named after the German physicist Wilhelm Röntgen, who discovered X-rays. Although relatively easy to measure, it had
1890s in Western fashion 1890s in Western fashion Fashion in the 1890s in European and European-influenced countries is characterized by long elegant lines, tall collars, and the rise of sportswear. It was an era of great dress reforms led by the invention of the drop-frame safety bicycle, which allowed women the opportunity to ride bicycles more comfortably, and therefore, created the need for appropriate clothing. Fashionable women's clothing styles shed some of the extravagances of previous decades (so that skirts were neither crinolined as in the 1850s, nor protrudingly bustled in back as in the late 1860s and mid-1880s, nor tight as in the