A method has been developed for analyzing the X-ray diffraction patterns of amorphous solids, and the atomic arrangement in two simple glasses has been completely worked out. In SO2, for example, each silicon is tetra-hedrally surrounded by 4 oxygens at a distance 1.60 AIR, and each oxygen is shared between two such tetrahedral groups. The mutual orientation of the two groups about their common direction of bonding is random, and hence it is a random three-dimensional network which is built up. The configuration does not repeat at regular intervals and hence is noncrystalline; it is this feature which distinguishes the glassy state from the crystalline.