▁and ▁Jan ▁May en ▁Island . ▁During ▁the ▁seven - month ▁trip ▁he ▁collected ▁marine ▁spec im ens ▁and ▁recorded ▁ocean ▁curr ents , ▁ice ▁movements ▁and ▁the ▁weather . ▁ ▁On ▁his ▁return ▁to ▁Edinburgh ▁he ▁re - enter ed ▁the ▁University ▁to ▁complete ▁his ▁studies ▁( 1 8 6 8 – 7 2 ) ▁in ▁ge ology ▁under ▁Sir ▁Arch ib ald ▁Ge ik ie . ▁ ▁Ch allen ger ▁Ex ped ition ▁In ▁ 1 8 7 2 ▁Murray ▁assist ed ▁in ▁prepar ing ▁scientific ▁appar atus ▁for ▁the ▁Ch allen ger ▁Ex ped ition ▁under ▁the ▁direction ▁of ▁the ▁expedition ' s ▁chief ▁scient ist , ▁Charles ▁Wy ville ▁Thom son . ▁When ▁a ▁position ▁on ▁the ▁expedition ▁became ▁available ▁Murray ▁joined ▁the ▁crew ▁as ▁a ▁natural ist . ▁During ▁the ▁four - year ▁voyage ▁he ▁assist ed ▁in ▁the ▁research ▁of ▁the ▁o ce ans ▁including ▁collect ing ▁marine ▁samples , ▁making ▁and ▁not ing ▁observations , ▁and ▁making ▁improvements ▁to ▁marine ▁instrument ation . ▁After ▁the ▁expedition ▁Murray ▁was ▁appointed ▁Chief ▁Ass istant ▁at ▁the ▁Ch allen ger ▁offices ▁in ▁Edinburgh ▁where ▁he ▁managed ▁and ▁organ ised ▁the ▁collection . ▁After ▁Thom son ' s ▁death ▁in ▁ 1 8 8 2 ▁Murray ▁became ▁Director ▁of ▁the ▁office ▁and ▁in ▁ 1 8 9 6 ▁published ▁The ▁Report ▁on ▁the ▁Scient ific ▁Results ▁of ▁the ▁Vo y age ▁of ▁HMS ▁Ch allen ger , ▁a ▁work ▁of ▁more ▁than ▁ 5 0 ▁volumes ▁of ▁reports . ▁