During World War II, he worked at the MIT Radiation Lab developing radar techniques.
In 1946 he returned to Pittsburgh as an assistant professor and spent the rest of his career there.
In 1955, he published Introductory Nuclear Physics, which became a classic text and was translated into four languages.
Now in its tenth edition in a two-volume set revised by Jearl Walker, and under the title Fundamentals of Physics, it is still highly regarded.
It is noted for its clear standardized diagrams, very thorough but highly readable pedagogy, outlook into modern physics, and challenging, thought provoking problems.