motion, at Selfridges's department store in London. Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill", whose painted face had higher contrast, talking and moving. By 26 January 1926, he had demonstrated the transmission of an image of a face in motion by radio. This is widely regarded as the world's first public television demonstration. Baird's system used the Nipkow disk for both scanning the image and displaying it. A brightly illuminated subject was placed in front of a spinning Nipkow disk set with lenses which swept images across a static photocell. The thallium sulphide (Thalofide) cell, developed by Theodore Case in the U.S., detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronized with the first. The brightness of the neon lamp was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one scan line of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognize a human face. In 1927, Baird transmitted a signal over of telephone line between London and Glasgow. In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. In 1929, he became involved in the first experimental mechanical television service in Germany. In November of the same year, Baird and Bernard Natan of Pathé established France's first television company, Télévision-Baird-Natan. In 1931, he made the first outdoor remote broadcast, of The Derby. In 1932, he demonstrated ultra-short wave television. Baird's mechanical system reached a peak of 240-lines of resolution on BBC telecasts in 1936, though the mechanical system did not scan the televised scene directly. Instead a 17.5 mm film was shot, rapidly developed and then scanned while the film was still wet. A U.S. inventor, Charles Francis Jenkins, also pioneered the television. He published an article on "Motion Pictures by Wireless" in 1913; transmitted moving silhouette images for witnesses in December 1923; and on 13 June 1925 publicly demonstrated synchronized transmission of silhouette pictures. In 1925 Jenkins used the Nipkow disk