▁broad ▁appeal ▁of ▁his ▁work ▁was ▁the ▁sense ▁that ▁the ▁reader ▁could ▁really ▁learn ▁knowledge ▁of ▁ge ology , ▁bi ology , ▁astronom y , ▁pale ont ology , ▁ocean ography ▁and ▁the ▁ex otic ▁locations ▁and ▁cult ures ▁of ▁the ▁world ▁through ▁the ▁advent ures ▁of ▁Ver ne ' s ▁protagon ists . ▁This ▁great ▁wealth ▁of ▁information ▁distinguished ▁his ▁works ▁as ▁" ency c lop edic ▁nov els ". ▁▁▁ ▁The ▁first ▁of ▁Ver ne ' s ▁nov els ▁to ▁carry ▁the ▁title ▁Vo y ages ▁Ext ra ord ina ires ▁was ▁The ▁Advent ures ▁of ▁Captain ▁H atter as , ▁which ▁was ▁the ▁third ▁of ▁all ▁his ▁nov els . ▁▁ ▁The ▁works ▁in ▁this ▁series ▁included ▁both ▁fiction ▁and ▁non - f iction , ▁some ▁with ▁over t ▁science ▁fiction ▁elements ▁( e . g ., ▁J our ney ▁to ▁the ▁Center ▁of ▁the ▁Earth ) ▁or ▁elements ▁of ▁scientific ▁rom ance ▁( e . g ., ▁Tw enty ▁Th ous and ▁Le agues ▁Under ▁the ▁Sea ). ▁ ▁Th eme ▁In ▁a ▁late ▁interview , ▁Ver ne ▁aff ir med ▁that ▁Het zel ' s ▁am bit ious ▁commission ▁had ▁become ▁the ▁running ▁literary ▁theme ▁of ▁his ▁novel ▁sequence : ▁ ▁However , ▁Ver ne ▁made ▁clear ▁that ▁his ▁own ▁object ▁was ▁more ▁literary ▁than ▁scientific , ▁saying ▁" I ▁do ▁not ▁in ▁any ▁way ▁pose ▁as ▁a ▁scient ist " ▁and ▁explaining ▁in ▁another ▁interview : ▁ ▁Public ation ▁In ▁the ▁system ▁developed ▁by ▁Het zel ▁for