Read it through once

Most of the Parthenon's imposing columns are still standing, but the roof is gone. It was a perfect building two hundred and fifty years ago, when a shell dropped into the Venetian magazine stored here, and the explosion which followed wrecked and unroofed it. I remember but little about the Parthenon, and I have put in one or two facts and figures for the use of other people with short memories. Got them from the guide-book.