FOR another week the audiences at the Columbia, where the rollicking comedy "The New Boy" is being presented will have every night three hours of shaking laughter over this jolly play. Ever since the opening night the theatre has been crowded and the constant re-echo of vociferous mirth and the general verdict of Boston coincides with that of New York that there is more amusing material in "The New Boy" than in any comedy presented here for years. The action is lively and the comical situations follow each other as fast as professional foot racers. There is ginger and go and snap in every scene. It is questionable if that always funny comedian, James T. Powers, has ever had a character more suited to his inimitable fun making faculties, nor has he ever portrayed one in Boston in which he has scored a more pronounced success. Others in the cast include Frederic Robinson, R. F. Cotton, Helen Kinniard, Charles Greene, Helen Gardiner, W. R. Shirley and William Cody.