Dahl's heatsinkshttp://www.fractalforums.com/index.php?action=gallery;sa=view;id=4024Dahl—One of the poorer sections of Trantor. The main job of the lower class is heatsinking, where workers supervise the conversion of heat from the planet's core directly into electric power; 'heatsinkers' were generally looked down upon by other Dahlites. Naturally, most Dahlites hated the Empire, and the soldiers of the Empire ('sunbadgers'). Dahlites were dark skinned, black-haired, and fairly short. Dahlite males wore a large, thick mustache, and all carried knives (then very backward). Rather than using 'Mr.', 'Mrs.', or 'Dr.', as forms of address, Dahlites always used 'Master' and 'Mistress' (never 'Doctor'). The name Dahl may be reference to the Indian dalit or untouchable caste. Known Dahlites: Yugo Amaryl, Mother Rittah, Raych Seldon.
http://en.wikipedia.org/wiki/Trantor