YOU KNOW where to buy books and records, pin-striped bell-bottoms and Tom Jones shirts, the New York Times and Ramparts. But do you know where to eat in Harvard Square? If you're overwhelmed by the possibilities or ignorant of the choices, pay attention to this guide. For just five dollars a day you can eat well in Harvard Square. In the right places you'll be served not only food but also horoscopes, fights, excitement, adventure, bathos, pathos, and even high tragedy--gratuitously, of course.

Our guide for this tour will be Joe Blitman, an Adams House senior who has not eaten a House meal since his girlfriend was knocked off by a Cabot Hall milk machine three years ago. Now for the tour.

Rising punctually at eleven, Blitman heads out into the Square. Since he always misses his English 10 lectures at ten o'clock, he meets his English 10 section woman for a late breakfast at the University Restaurant.

The UR is actually a restaurant, with two Greek owners, an elaborate menu, and Budweiser in bottles. After morning lectures, professors and students assemble in the wall booths to discuss God, Man, and Law over a cup of coffee. During the rest of the day the UR is occupied by pairs of middle-aged ladies, graduate students with briefcases, and lonely men in raincoats.

The trick of the UR experience is to get one of the three window booths which overlook Mass. Ave. If you're gregarious, you can knock on the window whenever your friends walk by. If you're cool, you can wait for them to knock first. Blitman orders a cup of black coffee and an order of English muffins--for 30 cents. Miss English 10 has an Athenian Salad with Greek cheese. While she is explaining the morning lecture to Blitman, she gives out six knocks and receives 21. She is cool. At noon, Blitman, his head ringing, gets up to go to French 125. He leaves a nickel tip for both of them. The University Restaurant is one of the few Harvard eating places where you should leave a tip. But the service is miserably slow--the nickel is plenty.

The Spa

After class Blitman joins the happy throng headed for Mr. Bartley's Burger Cottage. Known as "the Spa," Bartley's combines the best qualities of a Ricky Nelson malt shop and a large brick oven. Cheery red and white signs tumble across two walls. There are too many to read, so don't try. They are all about hamburgers, anyway; Mr. Bartley's offers twenty different kinds, ranging from Hawaiian to Saute'ed Mushroom.

Don't be alarmed if you can't get in the door at first. The crowd is just hung up on a large coat-pole which blocks the aisle. If you wait, there will be a seat--sometime.

At rush hour Bartley's is strictly for undergraduates and Widener types. Students arrive in groups of four and five, or at least in pairs. They laugh and joke a lot; and they don't mind waiting fifteen minutes for a hamburger. If you're in a hurry, try the counter. For amusement there are two highly comical drink machines, one containing grape, the other red punch. Always in motion, they slop and squirt the liquid up, down, all around. On especially good days, they become phallic; the punch machine plays the male to the grape machine's female.

The star of Bartley's is Florence, the heavyset, bespectacled waitress who works from midmorning to mid-afternoon. During the rush hour she takes charge like a floor manager at a Demoratic convention. Try to get to know Florence. She is an amateur astrologer. If she likes you, She is an amateur astrologer. If she likes you, she will cull information for your horoscope by asking for your birthdate and the days on which you have broken bones. Then, weeks later, Florence will predict your future in a handwritten report which may run upwards of nine pages. Afterwards you will sit in Florence's section and leave her tips. Nevertheless, Florence has a certain altruistic concern and helpfulness which you won't find at Coney Island.

Blitman, surrounded by white levis and old tweed jackets, orders a Bartley's Buns 21. The price--$1.10--is steep, but, after all, this is lunch. The Buns 21 boasts two Bartley burgers, two buns, and some scattered potato chips. Accessories include a little paper cup of cole slaw--about one blue plastic forkful--and a pickle. Two pickles if you know Florence. He also orders a large coke for twenty-five cents. Five minutes later, he's done. A ten cent tip for Florence. And don't forget to get a twelve cent box of crackerjacks at the cashier's counter.

NOW COMES ONE of those grueling stretches when Blitman has to amuse himself. We'll leave him to his fun until four when he makes his way along Mt. Auburn Street to Hazen's. There is something unsettling entrance about Hazen's. The impersonal turnstile entrance with its clanging bell. The antiseptic toy counters. The lippiputian nursery school stools. The place oozes sterility. Creeping Brighamism is permeating the Square.

Blitman asks for an extra thick shake and a creme-filled chocolate Ring Ding. He is punched for forty cents. Although he doesn't like Hazen's much, Blitman does get a big kick out of the way his plastic sanitary straw stands straight up in his shake. And he likes to observe the teen-bopper subculture in action. At night, Hazen's absorbs the Bartley crowd. During the weekdays, it becomes a Cambridge streetcorner moved indoors, a refuge for the lustful, sallow, acne-splattered teen set. Precocous little girls with rampaging breasts bump and grind to the Seeds and the Stones. Cheeseburger boys in thick maroon coats and plaid pants leer through clouds of smoke. Everyone is doing all right.

Now that Theresa is gone, Hazen's waitresses are an undistinguished lot, a makeshift collection of young girls, middle-aged women, and grandmothers. Only wiry Chas, the efficient cook, has any class. Joe Blitman leaves Hazen's in the midst of a Mamas and Papas sing-along.

As dinner-time approaches, Blitman is in good shape. He has spent only $2.32. There is a lot of time and a lot of food yet to come.