Titanic contribution to geographical knowledge? (5)
I believe the answer is:
atlas
'knowledge?' is the definition.
(I know that atlas is a type of reference work)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for atlas that I've seen before include "Book of maps - fifteenth satellite of Jupiter" , "Sort of book" , "Segment of spine" , "travel book" , "Large-format book" .)