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
The Eye in the Door The Eye in the Door The Eye in the Door is a novel by Pat Barker, first published in 1993, and forming the second part of the "Regeneration" trilogy. "The Eye in the Door" is set in London, beginning in mid-April, 1918, and continues the interwoven stories of Dr William Rivers, Billy Prior, and Siegfried Sassoon begun in "Regeneration". It ends some time before the conclusion of the First World War later the same year. The third part of the trilogy, "The Ghost Road", continues the story. Whereas "Regeneration" is an anomalous, but not unique, mixture of fact and fiction,