Roentgen (unit) One roentgen deposits of absorbed dose in dry air, or in soft tissue. One roentgen of X-rays may deposit anywhere from in bone depending on the beam energy. This tissue-dependent conversion from kerma to absorbed dose is called the F-factor in radiotherapy contexts. The conversion depends on the ionizing energy of a reference medium, which is ambiguous in the latest NIST definition. The roentgen has its roots in the Villard unit defined in 1908 by the American Roentgen Ray Society as "the quantity of radiation which liberates by ionisation one esu of electricity per cm of air under normal conditions
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