Subject: What would allow to solid lead balls to hit the ground at differnet time?

An early Italian scientist dropped two solid lead balls of different sizes off 
the Leaning Tower of Pizza.  The balls were dropped simultaneously and hit the 
ground simultaneously.  Without changing the amount of lead in the two balls, 
what ways could I modify one or both of the balls so that they hit the ground 
at different times when dropped simultaneously.  Which ball would hit the 
ground first and why?

Re: What would allow to solid lead balls to hit the ground at differnet time?