More than two hundred men patrolled the Harvard Forest mopping up the remnants of the fire that roared through 125 acres of experimental tree plantations Tuesday.

George W. Yonkers, chief of the Petersham, Massachusetts, fire department said that the fire fighters were hampered by forty-five-mile-an-hour winds and the dryest possible forest conditions.

Yonkers said that the fire was still dangerous to the town of Petersham until it should rain. He added that there had been no precipitation for two weeks and that "Everybody is praying for rain." Yonkers called Tuesday's holocaust "the biggest fire in the history of Petersham and the Harvard Forest." Petersham has a population of 850 and is surrounded by woods.

The cause of the fire could not be determined, although it was believed to have started near Route 32, burning eastward into the Harvard Forest. The fire began at 1:30 p.m. and was quenched by 7:30 p.m., before destroying Forest buildings and even more valuable timber.

In the late afternoon, the fire began to "crown" spectacularly, spontaneously igniting from one tree-top to the next.

Mrs. Mariam Hambelton, Secretary to the Harvard Forest, reported that the six forest employees had been continuously occupied in fighting the fire since its beginning.

The Harvard Forest, as well as the Harvard Black Rock Forest in Southern New York, is run for research, not commercial purposes. Students working for the degree of Master in Forestry from Harvard receive their training at the forest.