 While in the bathroom , Bart notices that the water in the sink always drains <unk> . Lisa explains ( not entirely correctly ) that the water never drains the other way except in the southern hemisphere , due to the Coriolis effect , but Bart does not believe her . To confirm this , Bart makes phone calls to various countries in the southern hemisphere . Lisa points out how expensive international calls are , so Bart decides to make a collect call instead . He calls Australia , where a little boy answers the phone . <unk> to represent the " International Drainage Commission " , Bart is informed that the toilet and sink are both draining clockwise . Frustrated , Bart asks him to go and check the toilets of the neighbors . The call takes six hours to complete , since the boy lives in the outback , and Bart <unk> to hang up the phone . Later , the boy 's father is billed A $ 900 ( referred to as " <unk> " ) . The father calls Bart and demands that he pay , but Bart only taunts him . Unfortunately for Bart , the father 's neighbour is a federal Member of Parliament , who reports Bart 's offense to the Prime Minister — who is relaxing naked in a nearby pond . 
