 Complete the following phrase:  In May 1938, he took his first trip to the United States, and in December, held a radio program about the Romanian pavilion at the New York Worlds Fair. He returned to the United States in the summer of 1939, in order to attend the Worlds Fair, and again took to the airwaves on the subject. That autumn marked the first appearance of Simetria, an annual magazine of art and criticism that appeared in eight editions, through 1947. Cantacuzino was one of four editors, and his office and studio, at the corner of Calea Griviței with Calea Victoriei, served as headquarters. Over the course of the magazines run, he published numerous studies, articles, reviews and notes. During the 