The stress concentration factors for rectangular slots with semicircular ends with their major axes inclined to the direction of a uniaxial tension field were investigated by photoelastic methods. A major portion of this thesis deals with the problem of loading a circular disk such as to create an approximately uniform tension field. This circular disk was used to investigate the stress concentration factors of the slots which were compared to the known results of a slot perpendicular to a tension field in a rectangular plate. The maximum value for the stress concentration factor occured when the slot was perpendicular to the direction of the tension field. A method of determining the stress concentration was developed which required only the recording of the load at which each fringe appeared on the edge of the slot. This method gave results with 6% of accepted values. / Master of Science