This rotary trivet (sometimes referred to as a grill) is made of iron. Its legs would be set up and the trivet by the fire for cooking. It measures around 2.5″ thick x 10″ wide x 24″ long. For source and more details, click here.
Image from: http://www.cr.nps.gov/museum/exhibits/revwar/guco/gucofood.html
