I recall from liner notes that Lobachevsky's name was chosen purely to fit the meter (and match someone's song about Stanislavsky). I had read about Lobachevsky (in E.T. Bell's Men of Mathematics, and possibly a little elsewhere before that) before I heard the Tom Leher song. Some time afterward, I commented to a college acquaintance that it wasn't really fair of Lehrer, since Lobachevsky had been not only a great mathematician, but apparently a very good man. He was surprised to learn that there really had been a Lobachevsky. I was surprised at him for that. We're all parochial in some way . . .