A poster for a Dada artist found in a New Jersey flea market hangs in the kitchen of Michael Gross, author of three works about the houses of the rich and powerful, in his two-bedroom home near Central Park in New York, Feb. 19, 2014. Gross, a former rock music reporter, now lives within the halo effect of 15 Central Park West, described as "the world's most powerful address" in his most recent book. (Bruce Buck/The New York Times)