Ron Schweiger, the official historian of the borough of Brooklyn, was here in the Ursula C. Schwerin library this week, speaking to a class about the history of Cadman Plaza. Mr. Schweiger is a lifelong resident of Brooklyn and has been Brooklyn Borough Historian since 2002. His visit was something of a homecoming. Mr. Schweiger attended City Tech in the early 1960s and was a student in what is now the Hospitality Management program. He met his wife working one summer at an Upstate New York hotel.