▁follows ▁the ▁assumption ▁of ▁the ▁author ▁that ▁the ▁world ▁was ▁divided ▁into ▁two ▁contin ents , ▁Asia ▁and ▁Europe . ▁He ▁dep ict s ▁the ▁line ▁between ▁the ▁P ill ars ▁of ▁Her cules ▁through ▁the ▁Bos por us , ▁and ▁the ▁Don ▁River ▁as ▁a ▁boundary ▁between ▁the ▁two . ▁H ec at æ us ▁is ▁the ▁first ▁known ▁writer ▁who ▁thought ▁that ▁the ▁C asp ian ▁flows ▁into ▁the ▁circum ference ▁ocean — an ▁idea ▁that ▁pers isted ▁long ▁into ▁the ▁H ellen ic ▁period . ▁He ▁was ▁particularly ▁inform ative ▁on ▁the ▁Black ▁Sea , ▁adding ▁many ▁ge ographic ▁places ▁that ▁already ▁were ▁known ▁to ▁Gree ks ▁through ▁the ▁colon ization ▁process . ▁To ▁the ▁north ▁of ▁the ▁Dan ube , ▁according ▁to ▁H ec at æ us , ▁were ▁the ▁R hip æ an ▁( g ust y ) ▁Mountains , ▁beyond ▁which ▁lived ▁the ▁Hyper b ore ans — pe op les ▁of ▁the ▁far ▁north . ▁H ec at æ us ▁dep icted ▁the ▁origin ▁of ▁the ▁N ile ▁River ▁at ▁the ▁southern ▁circum ference ▁ocean . ▁His ▁view ▁of ▁the ▁N ile ▁seems ▁to ▁have ▁been ▁that ▁it ▁came ▁from ▁the ▁southern ▁circum ference ▁ocean . ▁This ▁assumption ▁helped ▁H ec at æ us ▁solve ▁the ▁mystery ▁of ▁the ▁annual ▁flo oding ▁of ▁the ▁N ile . ▁He ▁believed ▁that ▁the ▁waves ▁of ▁the ▁ocean ▁were ▁a ▁primary ▁cause ▁of ▁this ▁occurrence . ▁It ▁is ▁worth ▁mention ing ▁that ▁a ▁similar ▁map ▁based ▁upon ▁one ▁designed