On 7 Sep 2003 06:46:15 -0700, a particular chimpanzee named
(David) randomly hit the keyboard and
produced:

Somewhere recently I saw an ad for a method of providing natural light
to an otherwise dark internal room - the concept was a light collector
of some sort mounted on the roof, with a duct or pipe to convey light
down into the body of the house, to a light panel or something in the
ceiling.

I've seen it used a couple of times. It gives about the light of a
low wattage bulb, which is probably plenty in a WC or corridor. No
idea about durability. As for weather-tightness; I would have thought
no worse than a rooflight. Try www.monodraught.co.uk.
--
Hugo Nebula
"You know, I'd rather see this on TV,
Tones it down" - Laurie Anderson