At this time Adorno was in intense correspondence with Walter Benjamin about the latter's "Arcades Project". After receiving an invitation from Horkheimer to visit the Institute in New York, Adorno sailed for New York on June 9, 1937, and stayed for two weeks. While he was in New York, Horkheimer's essays "The Latest Attack on Metaphysics" and "Traditional and Critical Theory," which would soon become instructive for the Institute's self-understanding, were the subject of intense discussion. Soon after his return to Europe, Gretel moved to Britain, where she and Adorno were married on September 8, 1937; a little over a month later, Horkheimer telegrammed from New York with news of a position Adorno could take with the Princeton Radio Project, then under the directorship of the Austrian sociologist Paul Lazarsfeld. Yet Adorno's work continued with studies of Beethoven and Richard Wagner (published in 1939 as "Fragments on Wagner"), drafts of which he read to Benjamin during their final meeting, in December on the Italian Riviera. According to Benjamin, these drafts were astonishing for "the precision of their materialist deciphering" as well as the way in which "musical facts ... had been made socially transparent in a way that was completely new to me." In his Wagner study, the thesis later to characterize "Dialectic of Enlightenment"—man's domination of nature—first emerges. Adorno sailed for New York on February 16, 1938. Soon after settling into his new home on Riverside Drive, Adorno met with Lazarsfeld in Newark, New Jersey, to discuss the Project's plans for investigating the impact of broadcast music.