Witness sun's defiance to human powers, Washington, D.C., September 8. Senor Adolfo Niebuhr, of Argentine, Dr. Richard Plobet, of Germany, and Dr. Eugen Melchinger, of Germany, witness the failure of Dr. Charles G. Abbott's sun ray machine. The device which is said to be capable of operating half-horsepower steam engine by the sun's heat failed when the concentrated heat proved too much for the soldier connections The men are representatives of their respective countries to the Third World Power Conference which is now being held in this city