This week's continuous cold, inconvenient downpour depressed everyone in town except Cambridge's overjoyed umbrella salesman.

Sales during the past three weeks smashed all previous records. "We have sold more than 2,000 umbrellas since the opening of school," said a smiling Harvard Coop salesman, "far more than we sold during last September's hurricane."

The Coop offers its drenched customers two models: the $3.98 version is a push-it-up-yourself model, and is recommended especially for those with athletic pretensions. The more popular $5.00 model requires only that the carrier exert enough energy to push a "release button." whereupon the umbrella flies open with astonishing rapidity, somewhat endangering the owner, umbrella, and by-standers.