In the field of accounting Van Deventer contributed to the theory of discounted cash flow.
In 1905 he became superintendent of production, and cost manager, at the pump factory Goulds Manufacturing Company in Seneca Falls.
In 1907 he moved to the Buffalo Forge company, where he became general superintendent and factory manager.
In 1927 he moved to the McGraw Hill Publishing company, where he started as consulting editor.
[3] Furthermore Van Deventer was a member of the American Society of Mechanical Engineers, and of the New York Business Publishing association, where he was chairman in 1923/24 and president in 1924/25.