Activities in the American kitchen are vastly different from what they were half a century ago, partly because of the use of refrigerators. Between 1930 and 1940 the refrigerator saturation index rose from 12 percent to 63 percent (Merchandising Week).Electric refrigerators helped make kitchen planning possible because the ice box did not have to be placed by the back door so that the ice man could reach it and water pans could be emptied. Work place design principles moved from industry into the home, and home economists, who had long been concerned about the relationship between the worker and work place in the home, studied various kitchen-appliance-cabinet arrangements to arrive at optimum work triangles that are now familiar in kitchen planning.