<p>CHARLOTTESVILLE - It might not be the mystery of the century, but historical researchers at Monticello are puzzling over just how Thomas Jefferson's elaborate but primitive system of privies operated both inside the great house and out.</p>
<p>Was the waste meant to be flushed away by water or hauled out by a wheeled device called an "earth car?" Were the privies locked for use only by the select? Were they used according to gender or station? What was used for toilet paper? Did they wash their hands after? What was the purpose of the long tunnels connected to the privies that Jefferson referred to as "sinks"? Why did he call the privies "air closets?"</p>