Thanks for all the responses by the way -- very good of you.

So from this, we are saying that it won't have been the dimmer switch
that went bang, but the actual transformer in the lamp, meaning the
lamp is now knackered?

So whats my plan of action? There are ten bulbs, each labelled 12V10W,
so what transformer should I replace it with in order to

(a) allow the lights to work
(b) ensure we dont get any more load bangs
(c) be able to fit a dimmer switch

?

Cheers
Colin