use the "Approved by A.S.C." tag in their advertising. In the early 1930s, Arnold developed an attachment for the Mitchell Camera, which reduced the noise created during filming. It was a 48 cycle synchronous motor used to drive the camera, and it greatly reduced the vibration, and completely eradicated the noise of the motor. Along with a new version of the camera which was introduced in 1933, it was hailed as "...the greatest forward step in recent years." The combination of the new camera with the Arnold motor allowed the camera, without a hood (or blimp), to be used as close as a yard from the microphone. Another invention of Arnold's in the early 30s was a rolling tripod, which would be further refined by Mole-Richardson company, which gave it the name, the "Mole-Richardson rolling tripod". Arnold also invented the MGM camera crane, which was a substantial improvement over prior versions. it was about half the size of earlier versions, and 1/17 as heavy, as well as cutting costs by 90%. It elevated to 26 feet, weighed 3300 pounds, and cost $3,500. The crane could swing through a complete horizontal circle, while the arm could rotate 90 degrees. During this same period Arnold also designed the "rotambulator", a radically new design of camera dolly, which allowed a stable platform to move from about 18 inches off the floor to a height of eight feet. The operator could also rotate the entire assembly through a complete 360 degree circle. Arnold was also an avid 16mm camera fan, and would share his expertise with anyone who showed an interest. One of those he taught was Clark Gable. With the passage of the National Industrial Recovery Act of 1933, the National Recovery Administration was created, and part of its responsibilities included the creation of a motion picture code. At the hearing held in Washington D.C., Arnold was included as one of a long list of speakers who had requested to be heard. His attendance at the hearings in Washington caused him to miss the wedding of his good friend, Lee Garmes, for whom he was supposed to be the best man. By the end of 1933, Arnold's rotambulator was in use at several studios, replacing the tripods, dollies, and light cranes. In 1935 Arnold invented a new type of camera blimp, decreasing the weight of the old model from 240 to 100 pounds,