▁with ▁West ▁El st ree , ▁Cal dec ote ▁Hill , ▁South ▁Ald en ham , ▁Ald en ham , ▁Bus he y ▁He ath ▁and ▁Ald en ham ▁and ▁Bus he y ▁and ▁Ald en ham ▁being ▁proposed . ▁The ▁previous ▁station ▁on ▁the ▁route ▁would ▁have ▁been ▁El st ree ▁South ▁to ▁the ▁east . ▁ ▁The ▁extension ▁was ▁part ▁of ▁the ▁Northern ▁He ights ▁project ▁which ▁was ▁intended ▁to ▁elect r ify ▁a ▁number ▁of ▁steam - oper ated ▁London ▁and ▁North ▁Eastern ▁Railway ▁( L NER ) ▁branch ▁lines ▁and ▁to ▁incorpor ate ▁them ▁into ▁the ▁Northern ▁line . ▁Much ▁of ▁the ▁land ▁for ▁the ▁extension ▁came ▁from ▁the ▁purchase ▁in ▁ 1 9 2 2 ▁by ▁the ▁L PT B ' s ▁prec ursor ▁the ▁Under ground ▁Electric ▁Rail ways ▁Company ▁of ▁London ▁of ▁the ▁un built ▁Wat ford ▁and ▁Ed g ware ▁Railway ▁( W & ER ). ▁The ▁W & ER ▁had ▁planned ▁an ▁extension ▁of ▁the ▁Ed g ware , ▁High gate ▁and ▁London ▁Railway ▁to ▁Wat ford ▁J unction ▁via ▁Bus he y , ▁but ▁it ▁had ▁never ▁raised ▁the ▁capital ▁required ▁and ▁its ▁powers ▁to ▁construct ▁a ▁line ▁had ▁exp ired ▁in ▁ 1 9 1 1 . ▁The ▁specific ▁route ▁to ▁Bus he y ▁He ath ▁was ▁approved ▁by ▁parliament ▁in ▁October ▁ 1 9 3 7 . ▁The ▁L PT B ' s ▁principal ▁purpose ▁for ▁the ▁extension ▁was ▁to ▁stim ulate ▁the ▁development ▁of ▁new ▁resident ial ▁areas ▁to ▁increase