This article is from the Amiga FAQ, by Ignaz Kellerer with numerous contributions by others.
There are some archives which are too large to fit on one disk. To transfer them on disks you need to split them into smaller pieces and transfer each part on a separate disk. I recommend Martin Schlodder's `Splitter'. (Aminet, `util/misc/splitter_121.lha'. The archive contains binaries for MS-DOS and should be compilable without problems on any Unix system.