. manually either

hope someone will find the minutes to tell this newb what hes doing wrong!

here's my setup,
dualbooting windowsxp and gentoo
windows is the first partition
gentoo is the next three (wich i figure would be hda2,3,4)
hda4 is reiserfs, honestly i forgot the version, but was back in the late 2.4 days

knoppix has created /mnt/sda, so i try to
mount -t reiserfs /dev/hda4 /mnt/sda
but get
not a valid blockdevice

i've tried a variety of /dev/h* with no result so far with little result!

basicly i want to rescue some data from the gentoo install before i wipe it, hoped that i could access it with knoppix, ive done stunts like this before, and the drives were autodetected with no probs.

any ideas to what i may be doing wrong ?