Many postscript files from Europe or other countries will be formatted for A4 size paper. That's great, but A4-sized postscript jobs are frequently either truncated when printed or will send the printers into a manual-feed mode where they wait for someone to load them with A4 paper.
You can avoid these problems if you process the A4-size postscript file with mpage before printing it.
mpage -1 -o -U europe.ps | lpr -P ps4
...should do the trick. The -1 option prints a single page on each side of a sheet of paper. The -o option turns off the outlines that mpage puts around a document by default, and the -U option formats each page for US Letter size paper.
As always, see the man page for mpage for more details.