Series of shots inside Atla Vista Postal Terminal; CU of blinking lights on control panel of letter sorting machine (0:39). Various shots of mail flow (7:30). CSs of worker (man) feeding letters into machine (1:30). DOLLY MSs along letter sorting machine (1:09). MS back view of worker (man) feeding letters into machine (0:09). CU of sorted letters falling into slots (0:42).