| 摘要 |
Several conical frustums are stacked upon each other, each combrising curved structural sheets (44). Along the tops and bottoms of the frustums are plates which have curved outer edges to which the sheets are secured. Successively higher frustums have lower angles of inclination. The plates are inclined to bisect the angles between adjacent frustums. The tops of lower frustums conform to the bases of the next higher frustums, so as to carry the weight of the higher frustums. |
