The Heart and Its Mechanical Counterpart--A plastic actual-size model of the human heart is displayed alongside a "mechanical heart," a specially designed pump used to duplicate the human heart's functions in the artificial heart and lung machine described in Cleveland today by Dr. Charles B. Bailey, renowned heart surgeon of Hahnemann Medical College. The pump, no larger than the human heart it is intended to replace, is designed to push blood refreshed in an artificial lung cylinder back into the patient's blood system with a gentle, pulsing action that does not damage blood cells. by Associated Press