William Penrose Hallowell, Jr., '15, of Minneapolis, Minn., died suddenly in his room in Hampden Hall yesterday afternoon. He had been troubled with insomnia and it is believed that he took an overdose of sleeping powders. He was found dead at 5 o'clock by M. M. Mitchell '15, of Winchester, who was a great friend of Hallowell's and had arranged to dine with the latter last evening. Hallowell was a graduate of Middlesex School. He was interested in track athletics, and last year was a member of the Freshman track squad.