When we consider that the writers of the time had in view different elements of the population, it is less difficult to harmonize their conflicting statements. While there are contrary statements made as to the agriculture of the Romans, it seems to be a satisfactory reconciliation of these statements to regard the less progressive northern tribes as purely pastoral and the inhabitants of the other parts of the island as agriculturalists as well as herdsmen. After the Romans became established, wheat came to be one of the chief articles of export. The producers harvested this grain by cutting off the heads and storing them in pits under the ground. These pits were protected against frost. Each day the farmers took out the wheat longest stored, and ground it into meal. The process of removing the grain from the cob was, according to what we know of it, similar to the method still in use down to the seventeenth century in some parts of Britain. This consisted of twirling in the fire several heads of wheat, which the woman performing the operation held in her left hand, while with a stick held in her right hand she beat off the loosened grain at the very instant that the chaff was consumed. The grain was then usually ground in a hand mill, although there is reason to believe that water mills also were used to some extent. The meal was then mixed, and baked over the fire in little loaves, or flat cakes. The whole process occupied but a couple of hours. The houses of the people, to which the women were confined the greater part of the winter, were mean little structures. They were circular in shape, and were made of wattles or wood, and sometimes of stone. These wigwam-like structures were roofed with straw, and had as their sole external decoration the trophies of the chase and the battlefield. A chief's house was triumphantly adorned with the skulls of his enemies, nailed up against the eaves of the porch, among the horns and bones of beasts. Sometimes the heads of foes slain in battle were embalmed, and furnished gruesome ornamentation for the interior of the house. But notwithstanding these testimonials of a savage nature, there were evidences of comfort that had in them the indication of an approach to civilization. The houses were connected by narrow, tortuous paths, and were usually surrounded by a stockade as a protection against assault.