▁assist ▁in ▁the ▁construction ▁and ▁transport ation ▁of ▁a ▁boat ▁needed ▁for ▁his ▁film . ▁This ▁boat ▁was ▁the ▁African ▁Queen , ▁which ▁was ▁used ▁for ▁the ▁feature ▁film ▁The ▁African ▁Queen ▁( st arring ▁Hum ph rey ▁Bog art ▁and ▁Kath ar ine ▁He p burn ; ▁ 1 9 5 1 ). ▁After ▁his ▁first ▁trip ▁to ▁Africa , ▁Turn b ull ▁tra ve led ▁to ▁Y ellow kn ife ▁in ▁the ▁North west ▁Territ ories , ▁where ▁he ▁worked ▁as ▁a ▁ge ologist ▁and ▁gold ▁min er ▁for ▁a ▁year , ▁before ▁he ▁went ▁back ▁to ▁school ▁to ▁obtain ▁another ▁degree . ▁ ▁Upon ▁returning ▁to ▁Oxford ▁in ▁ 1 9 5 4 , ▁ ▁Turn b ull ▁began ▁special izing ▁in ▁the ▁anth rop ology ▁of ▁Africa . ▁He ▁remained ▁in ▁Oxford ▁for ▁two ▁years ▁before ▁another ▁field ▁trip ▁to ▁Africa , ▁finally ▁foc using ▁on ▁the ▁Belg ian ▁Congo ▁( 1 9 5 7 – 5 8 ) ▁and ▁U g anda . ▁After ▁years ▁of ▁field work , ▁he ▁finally ▁achieved ▁his ▁anth rop ology ▁doctor ate ▁from ▁Oxford ▁in ▁ 1 9 6 4 . ▁ ▁Turn b ull ▁became ▁a ▁natural ized ▁citiz en ▁of ▁the ▁United ▁States ▁in ▁ 1 9 6 5 , ▁after ▁he ▁moved ▁to ▁New ▁York ▁City ▁to ▁become ▁cur ator ▁in ▁charge ▁of ▁African ▁Eth n ology ▁at ▁the ▁American ▁Museum ▁of ▁Natural ▁History ▁in ▁ 1 9 5 9 . ▁He ▁later ▁res ided ▁in ▁Lanc aster ▁County