You might like this book then: https://www.amazon.com/c-Numbers-q-Numbers-Classical-Analogy...
Generally speaking, I find that the more expensive a rare academic tome is, the more likely there are legal/etc. versions online (PDFs, HTML, DjVu, etc.), indexed by Google. That seems to be much more true for STEM texts than those of the humanities, though.
I'd love to see that the case for this book https://www.amazon.com/Molecular-Vision-Life-Rockefeller-Fou...