Labor and laboring classes. Rate of wages for laborers and mechanics employed on public buildings, veto message, message returning without approval bill ([S.] 3847), to amend act approved Mar. 3, 1931, relating to rate of wages for laborers and mechanics employed by contractors and subcontractors on public buildings [so as to provide that prevailing rate of wages shall be paid to laborers and mechanics employed on certain public works of United States and District of Columbia].