dave@dave-laptop:~$ ls /media
cdrom  cdrom0
dave@dave-laptop:~$ 
dave@dave-laptop:~$ sudo mkdir /media/external-ntfs; sudo mount /dev/sdb /media/external-ntfs; ls /media
[sudo] password for dave:
mount: you must specify the filesystem type
cdrom  cdrom0  external-ntfs
dave@dave-laptop:~$