Keeps eye on allied purchases of arms. Washington, D.C., Nov. 27. Holding one of the most responsible posts in Washington these days is Lieut. Col. Charles Hines, Secretary of the Army-Navy Munitions Board. His principal duty is to see that allied purchases of arms do not interfere with arms production for U.S. defense. He knows how Britain and France have shifted their buying from normal imports to war goods. Also he knows how carefully they are rationing every dollar of foreign exchange