With reference to the civilization of the Mound-builders, however much writers may differ, we think the following conclusions may be safely accepted: That they came into the country in comparatively small numbers at first (if they were not Autochthones, and there is no substantial proof that the Mound-builders were such), and during their residence in the territory occupied by the United States they became extremely populous. Their settlements were widespread, as the extent of their remains indicate. The magnitude of their works, some of which approximate the proportions of Egyptian pyramids, testify to the architectural talent of the people and the fact that they had developed a system of government which controlled the labor of multitudes, whether of subjects or slaves. They were an agricultural people, as the extensive ancient garden-beds found in Wisconsin and Missouri indicate. Their manufactures afford proof that they had attained a respectable degree of advancement, and show that they understood the advantages of the division of labor.[81] Their domestic utensils, the cloth of which they made their clothing, and the artistic vessels met with everywhere in the mounds, point to the development of home culture and domestic industry. There is no reason for believing that the people who wrought stone and clay into perfect effigies of animals have not left us sculptures of their own faces in the images exhumed from the mounds. [Illustration: Large Clay Vessel from Milledgeville, Georgia. Size 14 Inches High and 13 Inches across Aperture. (Nat. Mus.)] They mined copper, which they wrought into implements of war, into ornaments and articles for domestic use. They quarried mica for mirrors and other purposes.[82] They furthermore worked flint and salt mines. They probably possessed some astronomical knowledge, though to what extent is unknown.