The Great Hamburg Blight--a disease as crippling in its way as the Dutch one that knocks off elms--has long since withered the sickly local strain. Harvard Square burgers are invariably thin and grease-sodden, often gray and crumbling, and occasionally even square in shape; encased in that permanent invalid of the American baking industry, the bun, they are, even so, mechanically consumed in sickening quantities every day. They cost anywhere from 15 cents to 40 cents. And every single one of them is accompanied, like a whale with its pilot fish, by a small, awkward slice of cucumber pickle. All very depressing.

Up untill about four months ago, only Long Island had managed to escape this national disaster. Garden City, N.Y., bastion of decent food, boasted a chain of three hamburg stands (all of which, to boost the appeal of their product, were forced to serve their standard 1/4-pound burgers by means of model electric trains).

Last May, however, the Islanders gained a local disciple, named Joel Bartley, who was intrigued, thankfully, not by the desperate gimmick of Lionel side-cars, but by the size and quality of their cargo. Mr. Bartley owns the Square's Harvard Spa Luncheonette (in the past little more than a collection of odds and ends: a good part of a stationery shop, half of a grocery more, and just a truncated bit of a soda fountain). Reportedly, Bartley had been dissatisfied with this assortment of leftovers for some time; and a hamburg revival became his means for a change.

"His heart lies in the food business, not in the grocery store," Spa chef Homer Schwartz says of his boss; but in Bartley's final reorganization scheme, it was the stationery shop, not the drygoods-and-deli that made way for his new hamburger grill. Since June, Bartley and Schwartz have been offering local customers Long Island style full 1/4-pound, ground-chuck hamburgers for a novel 48 cents.

Unquestionably, Bartley's burgers are the best buy this side of Montauk Point. The meat is firm and red; comes in a full-sized pat ("When you take a thin piece of meat at high temperatures, you lose all the juice," Schwartz explains); and in a variety of new-fashioned forms, including a Gourmet Garlic Burger, at 50 cents ("The students at Harvard sort of helped create the demand for that," says Schwartz laconically). And, then, each burger-be it a Harvard Double Burger, at 80 cents, or a Bacon Cheese Burger, at 65 cents--comes with fresh cole slaw in addition to the inevitable pickle. "Everybody gives pickles and we have to be a little different, so he comes up with cole slaw." Thus, once again, Schwartz.

Since the grill's gala inaugural in June, Spa business has tripled. Starting Monday, Bartley will also offer breakfast on his redoubtable grill; for the grease-weary this may be close to an embarras de richesse.