Machine performs half a day's manual labor in 5 minutes. Washington, D.C., Dec. 22. H.J. Keegan of the U.S. Bureau of Standards, using the spectrophotometer to determine the different colors in a piece of cloth. It formerly took a man a half a day to make this spectrum analysis but now the machine does it in five minutes. The machine measures the % of light transmitted or reflected at various wave lengths in the visible spectrum