Letter from the Assistant Secretary of Labor, transmitting detailed statement of expenditures from appropriations, "contingent expenses, Department of Labor, 1916," for the period from November 18, 1917, to November 7, 1918; "contingent expenses, Department of Labor, 1917," for the period from November 18, 1917, to November 7, 1918; and "contingent expenses, Department of Labor, 1918," for the period from July 1, 1917, to November 7, 1918.