▁only ▁to ▁his ▁desire ▁to ▁have ▁access ▁to ▁historical ▁sources ▁through ▁the ▁expedition , ▁but ▁to ▁spend ▁some ▁time ▁away ▁from ▁St . ▁Petersburg . ▁It ▁was ▁while ▁engaged ▁in ▁this ▁trip ▁that ▁he ▁developed ▁his ▁concept ▁of ▁Eth n ography . ▁ ▁On ▁the ▁suggestion ▁of ▁the ▁astronom er ▁Joseph ▁Nicolas ▁Del is le ▁( 1 6 8 8 – 1 7 6 8 ), ▁who ▁had ▁been ▁h ired ▁by ▁Peter ▁the ▁Great ▁to ▁work ▁in ▁St . ▁Petersburg , ▁the ▁Academy ▁of ▁Science ▁entr usted ▁the ▁job ▁of ▁astronom ical ▁and ▁ge ographic ▁met ro log y ▁to ▁Del is le ' s ▁younger ▁brother , ▁Louis ▁De ▁l ' Is le ▁de ▁la ▁C roy ère ▁( 1 6 9 0 – 1 7 4 1 ). ▁Louis ▁had ▁been ▁working ▁at ▁the ▁Academy ▁as ▁an ▁adj unct ▁for ▁astronom y . ▁In ▁ 1 7 2 7 ▁he ▁was ▁promoted ▁to ▁professor ▁and ▁was ▁sent ▁on ▁a ▁three - year ▁expl oration ▁survey ▁of ▁Ar kh angel sk ▁and ▁the ▁K ola ▁pen ins ula , ▁giving ▁him ▁some ▁experience ▁in ▁expl oration ▁exped itions . ▁C roy ère ' s ▁participation ▁in ▁the ▁academic ▁portion ▁of ▁the ▁expedition ▁later ▁became ▁controvers ial ▁when ▁his ▁compet ence ▁was ▁question ed ▁by ▁G mel in ▁and ▁Müller . ▁ ▁The ▁participants ▁in ▁the ▁academic ▁portion ▁of ▁the ▁expedition ▁were ▁answer able ▁not ▁to ▁its ▁leader ▁Ber ing , ▁but ▁to ▁the ▁St . ▁Petersburg ▁a cademy . ▁Each ▁of