A quick tour of the Square last night squelched any hopes that the five--cent beer might to Cambridge.

The lot of the bartender and tavern keeper is a hard one. Local foam pumpers, already harried by a slew of new restrictions, explain that there just isn't any percentage in a five cent brew as far as they are concerned.

And when you probe the facts, it turns out that there really isn't any percentage for the drinker either.

It's all a matter of (1) size of the glass, (2) amount of foam, and (3) percent of Scotch blood in the bartender. Right now a keg of beer yields between 190 and 220 ten cent glasses. Cronin's uses a nine-ounce glass, one of the largest around here, and settle for 190 per barrel. The Wursthaus, on the other hand, employs an eight-ounce glass, and works every barrel for well over 200 servings.

The gimmick in the five cent beer is the small glass that surrounds it. The publicity conscious barkeep in New York now in the national spotlight is supposed to use a six-ounce stein for his nickel brew. Local pourers suspect his heads foam unusually high. Another tavern on 96th Street sells ten cent beer in nine-ounce glasses, and five cent helpings in four-ounce steins. The profit here still goes to the clever samaritan who paid for the television set over your head.

Now if you figure that the average barrel costs a little over $12, it's easy to calculate the profit on a keg. If the elbow bender is to gain on a nickel beer, it has to hold at least five ounces. At that price, it's impossible for any bartender to clear operating costs, much less make an additional profit.

What's more, a Massachusetts law now pending may slap a dollar tax on every barrel. Stick around, you may soon see a fifteen cent helping of hops . . . and still no free lunch.