A concrete lesson in democracy is on view this week in Harvard Square, just a few yards from University Theater. With the courage and indignation of a Carric Chapman Catt, Cambridge's street crew has defended itself against a vicious, foulmouthed, wild-eyed smear campaign that really doesn't exist, but might.

Last fall the workmen dumped a few tons of concrete into the Square's car-jammed read bed to alleviate traffic conditions. They patty-caked it into a rotund island around the kiosk, and Harvard Square became a circle. Results were immediate and beneficial. Harrassed drivers took one look at the obstacle course, and thenceforth drove to work via Fresh Pond Parkway or Wellesley Hills. The traffic problem was solved.

Then the Boston road scandal broke last month. Boston's Financial Commission drilled into year-old street jobs and dug up dishonesty and corruption. Where contracts called for excavations, back fill, crushed till, asphalt, oil, gravel, and hot-top asphalt, they found nothing but hot-top asphalt. The repair was only skin deep; beneath the hot-top asphalt lay the old street and fraud.

At Harvard, suspicious eyes turned to the Square, Hushed voices asked: is the concrete real? is the cement truly 1:4? and, most awful of all, just what lies beneath?

Cambridge's workmen didn't snub the rumors or try to stifle them. Forthrightly and honestly, they blasted open their kiosk island and laid it before the public gaze. Thundering pneumatic drills proved the strength of their concrete. Sledge hammers exposed cross-section after cross-section, showing it pure and well-mixed to the last pebble. Today, disinterested students can stand before a saw-horse guard rail and examine the dismembered rubble: mute testimony to the honesty and conviction of a few simple workmen.

Congratulations are due to these men and their hard-hitting action. At the cost of only a few thousand dollars, they have saved their good name, and the name of the City of Cambridge.