Obviously, the answer here is. 
You're marrying the wrong wives!

And maybe they never had the rhyme nor reason to do so prior to your engagement, but should have the capacity to learn with a patient teacher. Gender is not a handicap in either mathematics, navigation or heavy lifting.
But entrust resourcefulness when one must (calculator, GPS, pulleys & levers) 

My partner is always just that, a partner and if they can't take part in the XYZ... 
Then there is a break in partnership.

Her job isn't to just sit there and look pretty, though at times she does that as well. 
It's an unanticipated multi tasking, I don't discourage.  ;-) 

Dan in NY

On Oct 9, 2009, at 3:46 PM, Rocket J Squirrel wrote:

>  can
>  women within one standard deviation of the median read a map? None
> of my
> three wives has ever known how to read a map.