Voyage of the H.M.S Challenger, on a Scientific Marine Expedition, published in 1885:
"reproduced from original documents in the library holdings of
Dartmouth College, Hanover, New Hampshire, USA Copyright © 2003 by Dr. David C. Bossard"
I haven't had time to read this, but some aspects were mentioned in this Ars post,
Researchers match modern ocean temperature records to those of the 1870s.