LAST Wednesday night, the Cambridge School Committee took the first step toward insuring that education of the pupils of the Houghton School will not suffer during the two years between the demolition of their old building and the opening of the new one. The Committee approved the construction of temporary classrooms for the children and asked Acting City Manager Ralph J. Dunphy to find a suitable location for them.

By this vote, the Committee rejected two other proposals--having double sessions for the Houghton pupils at another school, or scattering them in classes throughout the city. Parents and teachers at the Houghton School had opposed these alternatives which, they said, would hamper the education of their children by over-burdening the facilities of Cambridge's other schools.

Dunphy has told the School Committee that the $300,000 needed to build the classrooms is available; now all that is needed is a place to put the buildings.

The Houghton PTA has suggested that the city build the classrooms on Lindstrom Field, where the children could take advantage of the gymnasium, library, and hot lunch program of the nearby Morse School. But so far the Recreation Department has refused to let the School Committee use Lindstrom Field on the grounds that it might interfere with the recreation program there.

The Recreation Department view is dubious. Houghton parents have suggested that the city might erect the classrooms around the perimeter of the field, leaving the inside for ballplayers. Even if this could not be done, one ball field could easily be relocated on another playground.

Mr. Dunphy should persuade the Recreation Department to reverse this short-sighted stand. If he cannot do this, he should have an acceptable site to offer the School Committee by their next meeting, so that the portable classrooms can be constructed to give Houghton children, long the worst housed in the city, an adequate education for the next two years.