The Diary of George Templeton Strong, Edited by Allan Nevins and Milton Halsey Thomas
Frederic Edwin Church Wikipedia page. I dont know exactly which landscape Strong saw. Maybe this one.
Here is an 1857 painting by Louis Remy Mignon .
Pretty pictures by Mr. Church, but neither the Andes of Ecuador nor the Valley of Mexico (if that’s what the other painting is, with the horseman) is particularly “sultry.”