When I read online, I try to make the window narrow enough to keep the text column at about 5 or 6 inches, then just scan down. If the window width doesn't get small enough, I have been known to copy entire books into a word processing software to get the format and font size I want.
I also have my glasses made with executive bifocals and trifocals (the lines go all the way across the lenses) so I don't have to move my head side to side to see a wider area.
I tried reading the Moby Dick sample, and by the end of it I was just confused.