In 1930, the Rotolactor, invented by Henry W. Jeffries, was housed in the lactorium of the Walker Gordon Laboratory Company, Inc., at Plainsboro, N.J. This was a 50-stall revolving platform that enabled the milking of 1,680 cows in seven hours by rotating them into position with the milking machines. A Rotolactor was displayed at the 1939 New York World's Fair as part of the "Dairy World of Tomorrow," exhibit in the Borden building. The glass-enclosed revolving Rotolactor platform carried 150 pedigreed cows were washed, dried, and mechanically milked twice daily. A favorite attraction of the Food Zone, the Rotolactor epitomized how technology advanced the production of such a widely-used product as milk.