BARKER, SIR HERBERT ATKINSON ), British manipulative surgeon, was born in Southport, Lanes., April 21, 1869. At an early age he showed an aptitude for manipulative surgery and in 1889 was placed under the tutorship of J. Atkin son. On the latter's death in 1904, Barker took over the practice, specializing in the correction of abnormalities of the joints by manipulation, and the cure of derangements of knee cartilages and flat-foot. Although he performed a large number of success ful operations the medical profession refused to admit him offi cially to their ranks; Dr. Axham was struck off the English Med ical Register for acting as his anaesthetist ; and during the World War Barker's offer to give free treatment for joint and bone affec tions to officers and soldiers was rejected, owing to the opposition of the British army medical authorities. He was knighted, how ever, in 1922, as the result of a memorial to the prime minister signed by many distinguished surgeons. In 1925 he retired from his practice and went to live in Italy. His works consist prin cipally of articles in various periodicals. In 1927 he published his memoirs, Leaves from My Life. (See MANIPULATIVE SURGERY.) BARKER'S MILL, a mechanical contrivance invented by a Dr. Barker about the end of the i 7th century. It consisted of a hollow vertical cylinder, provided with a number of horizontal arms fitted with lateral apertures; the contrivance was mounted so as to rotate about the vertical axis. By allowing water to enter the vertical tube, a rotation, due to the discharge through the lateral orifices, was set up.