For that matter, I'd be surprised if drilling couldn't be taken care of by a cantrip.

I'm not aware of any official cantrip that would do it, but it wouldn't involve more power than that demonstrated by http://www.d20srd.org/srd/spells/mending.htm or http://www.d20srd.org/srd/spells/prestidigitation.htm , and so, even if there are no arcane spellcasters actually working for the circus, it wouldn't cost very much, relatively speaking, if they hired a wizard.