Books like Up the Walls of the World
James Tiptree, Jr.
Up the Walls of the World is 319 pages, about 5 hours 51 minutes at 250 words a minute.
12 books to read next
How long each takes
Dreamcatcher 13.5 h 
The Uplift War 11.7 h 
To Sleep in a Sea of Stars 16.1 h 
Everybody's Guide to Natural ESP 4.0 h 
Adulthood Rites 5.4 h 
Contact 7.9 h 
Cachalot 5.1 h 
Voyage to the City of the Dead 4.5 h 
Phenomena 10.0 h 
Children of Time 11.3 h 
Mind of My Mind 4.0 h 
Clay's Ark 3.9 h Bar height shows length. Estimated at 250 words a minute.