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
Thoracic diaphragm abdomen. The dome curves upwards. The superior surface of the dome forms the floor of the thoracic cavity, and the inferior surface the roof of the abdominal cavity. As a dome, the diaphragm has peripheral attachments to structures that make up the abdominal and chest walls. The muscle fibres from these attachments converge in a "central tendon", which forms the crest of the dome. Its peripheral part consists of muscular fibers that take origin from the circumference of the inferior thoracic aperture and converge to be inserted into a central tendon. The muscle fibres of the diaphragm emerge from many