You've got one day to figure out if Harvard's academic world squares with what you thought. With only 30 of Harvard' s thousands of courses open to visiting pre-frosh, your choices have already been narrowed. But you can get a sense of the way classes work.

Here's the lowdown on the classes to hit on a typical Harvard Monday.

If you have the energy to wake up for a 9 a.m. class after an eventful weekend, "Chemistry 7" is your best bet. See a real, introductory Harvard chemistry class, brimming with premeds. Don't be worried by the many students sleeping beside you. The real work gets done in midnight cram sessions the night before problem sets and unit tests.

For a taste of the Moral Reasoning Core, Michael Blake packs the room with his course: Moral Reasoning 62: "Reasoning In and About the Law" at 10 a.m. At noon, another intriguing Moral Reasoning core class, Moral Reasoning 54: "If There Is No God, All Is Permitted," offers a reading list ranging from St. Augustine to Frederic Neitzchze.

A mid-morning stop at 11 a.m. with the class known popularly as "Nazi" is not quite as horrible as it sounds. Foreign Cultures 76: "Mass Culture in Nazi Germany: The Power of Images and Illusions" is one of the most well-liked classes in the notoriously slim pickings of the Foreign Cultures Core requirement.

For those not interested in moral reasoning, noon at Harvard offers a taste of history at its most entertaining with the deftly taught History 1635: "The History of Baseball." Professor of History William Gienapp is demanding, but his lecture style has earned him a cult following.

Computer Science 124: "Data Structures and Algorithms" at 1 p.m. offers a glimpse into the envious life of a computer science concentrator at Harvard.

At 2 p.m., stop off at Bert Vaux's Linguistics 80: "Dialectics of English," for a brush with a topic most high schools rarely mention. Though the class is notoriously simple and often taken as an elective, Vaux is a widely-known lecturer who manages to pulls in hundreds for his fall core class, Social Analysis 34: "The Knowledge of Language."