For kitchen utensils, tiles, and other objects subject to heat or breakage, the same Fremington clay received an admixture of fine pebbles, or gravel, secured at a special place in the bed of the River Torridge in Bideford. The use of gravel was described by 18th-century writers as well as by later historians. As found in America, the gravel-tempered ware apparently is unique among the products of either English or colonial American potters. A specialty of the North Devon potteries was the manufacture of ovens made of the same gravel-tempered clay as the kitchen utensils. The appearance of these ovens and the method of making them remained virtually the same from the 17th through the 19th centuries. At Jamestown, a wholly reconstructed oven reveals typical North Devon traits throughout, while a fragment of an oven from the John Howland House site near Plymouth displays, under a microscope, the same qualities of paste and temper as in a fragment of an oven obtained in Bideford by the Smithsonian Institution. Sherds of gravel-tempered utensils from several American sites also match the oven fragments. Paste characteristics, exclusive of the temper, are the same in the sgraffito ware, the gravel-tempered ware, and the ovens. Furthermore, the gravel-tempered ware occasionally is found with a plain coating of slip, which, under the glaze, has the same yellow color as the sgraffito ware, while an undecorated variant of the sgraffito ware also occurs with a similar plain slip. [Illustration: FIGURE 35.--Baker's portable oven in a woodcut from Ulrich von Richenthal's _Concilium zu Constancz_, printed at Augsburg, Germany, in 1483. Lessing J. Rosenwald Collection, Library of Congress.] [Illustration: FIGURE 36.--Detail from De Bry's engraving of Le Moyne's painting of Fort Caroline, depicting an oven on a raised platform under a crude shed. Fort Caroline was a French Hugenot settlement established in Florida in 1564. Rare Book Room, Library of Congress.] All these wares, including the ovens, are interrelated--the specimens found in America having been shipped in a busy North Devon-North American trade. The North Devon towns, moreover, were an important pottery-making center for export markets in the West of England, Ireland, and North America. Thousands of parcels of earthenware were shipped to the American colonies from Bideford and Barnstaple during the 17th century. Any doubts that ovens were among these overseas shipments are dispelled by the knowledge that they continually were being shipped in the English coastwise trade, and also by intrinsic and comparative evidence that oven sherds found on American sites are of North Devon origin.