In early 1896, Zeppelin's lecture on steerable airship designs given to the Association of German Engineers (VDI) so impressed them that the VDI launched a public appeal for financial support for him. This led to a first contact with Carl Berg who supplied aluminium alloys which Zeppelin had tested, and by May 1898 they, together with Philipp Holzmann, Daimler, Max von Eyth, Carl von Linde, and Friedrich Voith, had formed the joint stock company "Gesellschaft zur Förderung der Luftschiffart". Zeppelin invested 441,000 Marks, over half the total capital. Actual construction then started of what was to be the first successful rigid airship, the Zeppelin LZ1.