In article .com,
"Martin Pentreath" writes:

Rather than running two cables can I (for the sake of neatness and
economy of cable) use four-core cable, with two separately-switched
lives? The fountain and the lighting would then both share the neutral
and the earth. Just need to know so that I can order some cable and put
it in now.

As others have said, that's fine.

However, what I would probably do in such a scenario would be to
send a single permanently live feed down the garden. Tap off this
through FCU and remote control switches for the fountain and lights.
I would use X10 switches which carry the control signalling over the
mains. This would enable you to easily add other things in the
future, and you could install a regular waterpoofed 13A socket in
the garden too, which I find extremely useful.

--
Andrew Gabriel