How much farther away is it than the other?

I have read the article in question. What do you mean by "the other"?

From the text:

On the title page of one of them, I found the traced outline of his hand; on the title page of the other was an outline of an erection so huge that it ran off the page, annotated with a little arrow and the remark “scale 100%.”

David is attemoting to relive or experience the world of Robinson Crusoe.