Glass Chain
The Glass Chain or Crystal Chain sometimes known as the "Utopian Correspondence" was a chain letter that took place between November 1919 and December 1920. It was a correspondence of architects that formed a basis of expressionist architecture in Germany. It was initiated by Bruno Taut.| Name | pen-name | location |
| Wilhelm Brückman | Brexbach | Emden |
| Hermann Finsterlin | Prometh | Stuttgart |
| Paul Gösch | Tancred | Berlin |
| Jakobus Göttel | Stellarius | Cologne |
| Walter Gropius | Maß | Weimar |
| Wenzel Hablik | W.H. | Itzehoe |
| Hans Hansen | Antischmitz | Cologne |
| Carl Krayl | Anfang | Tuttlingen |
| Wassili Luckhardt | Zacken | Berlin |
| Hans Luckhardt | Angkor | Berlin |
| Hans Scharoun | Hannes | Insterburg |
| Bruno Taut | Glas | Berlin |
| Max Taut | No Name | Berlin |
