Diaphragm (optics) 1889 "Dictionary of Photography" (see figure), but disappeared after Ernst Abbe's theory of stops unified these concepts. According to Rudolf Kingslake, the inventor of the iris diaphragm is unknown. Others credit Joseph Nicéphore Niépce for this device, around 1820. Mr. J. H. Brown, a member of the Royal Microscopical Society, appears to have invented a popular improved iris diaphragm by 1867. Kingslake has more definite histories for some other diaphragm types, such as M. Noton's adjustable "cat eye" diaphragm of two sliding squares in 1856, and the Waterhouse stops of John Waterhouse in 1858. Diaphragm (optics) In optics, a diaphragm
Sigurd Snake-in-the-Eye Snake-in-the-eye features prominently in History Channel's historical drama television series "Vikings" played by David Lindström. Sigurd Snake-in-the-Eye Sigurd Snake-in-the-eye (Old Norse: Sigurðr ormr í auga) was a Viking warrior in the middle of the 9th Century. He was supposedly one of the sons of the legendary Viking Ragnar Lothbrok. "Snake-in-the-eye" as part of Sigurd's name denoted a physical characteristic. He was born with a mark in his eye, described as the image of the Ouroboros (a snake biting its own tail). The snake mark had been prophesied by his mother Aslaug, the daughter of the Valkyrie Brynhildr. As a boy,