A prominent New York City attorney and his wife have bequeathed a major private collection of 20th century sculpture to the Chazen Museum of Art at UW-Madison, a gift valued at $30 million, museum officials announced Monday. The collection from the estate of the late Terese and Alvin S. Lane includes more than 70 sculptures and 250 preparatory drawings from artists such as Pablo Picasso, Alexander Calder, David Smith and Christo. “I wouldn?t hesitate to say that, as far as 20th century modernism, this makes us a major study center,” said Russell Panczenko, museum director.