Anker (Anchor) stones began life in the late 19th century with the Lilienthal brothers—yes, the glider-flying Lilienthals—who experimented with stone building blocks to teach structure and form. Businessman Friedrich A. Richter saw the potential, refined the material into a durable, precisely molded composite, and launched the Anker Steinbaukasten system from Rudolstadt, Germany. The magic was (and still is) the module: pieces follow an exact grid so arches, lintels...
