Close to the hamlet of Woolsthorpe (the birth place of Sir Isaac Newton), in the parish of Colsterworth, Lincolnshire, on Thursday, 21st January 1932, the miners quarrying ore for the Frodingham Iron & Steel Co. unearthed a remarkably perfect furnace or bloomery of the Roman period. In shape it was box-like, roughly but carefully hand-moulded of grey indurated clay of the local Upper Lias formation; a fragment of an ammonite fossil was found in a crack. The length was nearly 3 ft., the upper or north-west end was about 22 in., and the lower or south-east end about 24 in. in width. The top was practically level and flat, but the bottom dipped, slightly from the northwest end for about 21 in., then very sharply, so that the depth increased from 15 in. at the north-west end to 21 in. at the other. The sides were irregular, about 6 in. thick at most, and in the middle of each was a tuyere hole, some 6 in. in diameter, sharply splayed externally. The ends were open; the north-west one was evidently the charging, and the other the tipping end. The actual bottom was only about half an inch thick of the same clay, but below this were 3 or 4 in. of a different bluish clay and under it some apparently partly burned oolitic limestone brought from near by. The natural soil is the ironstone whose quarrying led to the discovery of the furnace (pl. XLIV, fig. 1).