Three historians, a philosopher, and a linguist will become assistant professors in the University, effective July 1.

Daniel H. Calhoun, Fritz K. Ringer, and Mack Walker, all instructors in History, Charles D. Parsons '54, and Joseph A. Van Campen, research fellow in Slavic Languages and Literatures, will gain the posts.

Calhoun is the author of "The American Civil Engineer: Origins and Conflicts." Since 1959 he has assisted Frank B. Freidel, professor of History, in the basic course in American history for Harvard students, and has done research in the Center for the Study of the History of Liberty in America. In 1962-63, he will teach the history of American education.

Ringer and Walker, who this year joined in teaching the history of Germany from 1648 to 1848, next year will combine to teach the history of Continental Europe, 1815 to 1870. They also teach in Harvard's General Education Program.

Parsons, a native of Cambridge, has been teaching at Cornell University for the past year. He received the A.B. summa cum laude in 1954, the A.M. in 1956, and the Ph.D. in 1961 from Harvard.

Van Campen has taught at Harvard for the past two years. A native of Truckville, Pa., he received the A.B. in 1953 and the A.M. in 1955 from the University of Chicago.