Colonial porringers have one handle
Later ones were made of brass or aluminum as well. Peculiarity of these bowls are their flat handles. And unlike regular cups or bowls, their handles face upwards :)
Original porringers are very rare and uncommon today. This is because, porringers made in USA prior to the American Revolution (c. 1776) were looted from kitchens and turned in, to make bullets for soldiers. The most famous colonial porringers are probably those made by Paul Revere. Nowadays, Porringers are given as a gift for the Christening of a child. Porringers resemble smaller quaich, a Scottish drinking vessel.