I had a pdf file that was too large to email, but I needed to email.  So I quickly broke it up into two smaller files.  I used this command:

$ gs -dNOPAUSE -dBATCH -dFirstPage=1 -dLastPage=34 -sDEVICE=pdfwrite -sOutputFile=physics1.pdf -f Physics\ Faculty.pdf 
$ gs -dNOPAUSE -dBATCH -dFirstPage=35 -dLastPage=68 -sDEVICE=pdfwrite -sOutputFile=physics2.pdf -f Physics\ Faculty.pdf