Work on Mellon's gift to National Capitol progressing rapidly. Washington, D.C., Nov. 3. Construction of the new National Gallery of Art, a gift of the late Andrew Mellon to the United Stated Government, is progressing rapidly. The building, which is expected to be the most beautiful and one of the largest galleries in the world, is slated to be completed in 1940. It is situated on the mall within a stone's throw of the U.S. Capitol, 11/3/38