phrase query

[fowler784]

Can you please give me the origin of the phrase

DAFT AS A BRUSH ?

[Quizmonster]

There is a vague suggestion - though personally I would treat it with a hefty dose of salt! - that it may be related to the days of Victorian child chimney-sweeps. The claim is that they were sometimes lowered head-first down chimneys in order to clean them, as well as having to climb up them. They often banged their heads whilst doing the former and so perhaps became a bit daft whilst being used as a brush.
I can't help feeling a known practice was just dragooned into offering an explanation of the phrase, however!

[gary baldy]

Found an interesting (and completely different) suggestion here:

http://www.iol.ie/~tadhgs/nametadhg.htm

(4 paragraphs down)

[jno]

a collection of suggestion, none of them definitive, here