The curriculum remained largely unchanged until the end of Dr. Colston's 20-year term as principal in 1942. Upon his retirement, Tech was led briefly by acting principal Ralph Breiling, who was succeeded by Principal Harold Taylor in 1944. Tech's modernization would come under Principal William Pabst, who assumed stewardship in 1946 after serving as chair of the Electrical Department. Pabst created new majors and refined older ones, allowing students to select science and engineering preparatory majors including Aeronautical, Architecture, Chemical, Civil, Electrical (later including Electronics and Broadcast), Industrial Design, Mechanical, Structural, and Arts and Sciences. A general College Preparatory curriculum was added later.