'First the pulley. With these window-washers haul br themselves up to the tip-top or drop'. br 'Yes', she said, with minimal interest. 'Next'. br br 'Then there's the lever. Useful for prising treasure'. br 'Very well, she said, 'but I can't tell you how I try br never to pry'. br br 'Well, there's the wheel. Often invented, excellent for gliding br singly, in tandem, in trio or more'. br 'Of course', said she, 'and number four'? br br 'Um', I said, starting to perspire, br and giving my brains a wrench-'the plane, if you desire'. br 'I've never been inclined. Continue please'. br br 'The wedge', I said, recalling that br a wedge could not be beaten for br dividing night from day and dog from cat. br br 'Then there's the screw', I muttered, turning blue. br 'Let's come back to that. br 'Continue'.