Rotunde


The Rotunde in Vienna's Leopoldstadt district was a building erected for the 1873 Vienna World's Fair. The building was a partially covered circular wrought iron construction, tall, with a diameter of. While the Rotunde stood, its dome was the largest in the world, larger than the Pantheon in Rome..
The Rotunde burned down in 1937. Its former site is now occupied by buildings associated with the Vienna University of Economics and Business, and with Messe Wien.

Construction

The Rotunde was designed by the Austrian architect Baron Karl von Hasenauer, and was built by the German entrepreneur and bridge builder and his company based in Duisburg. The Scottish civil engineer John Scott Russell was responsible for the dome, which was built with wrought iron.
The German engineer and journalist Wilhelm Heinrich Uhland reported, that the Rotunde weighed approximately "80,000 hundredweight, or about 4000 tons", that is,.
Conversions of the Rotunde's weight

A centner is a unit of mass equal to 100 of some base unit of mass. The German equivalent of the centner is the Zentner, and its base unit was traditionally the pound, the definition of which varied in Germany. In 1854 the Zollpfund was defined by the German Customs Union as being equal to 500 grams. The "Zollzentner" or "Zollcentner" is a Zentner/centner with the Zollpfund as its base unit: the Zollzentner is equal to 100 Zollpfund.
Accordingly, the weight of the Rotunde reported by Uhland can be converted into metric units:
So, by "4000 tons", Uhland presumably meant 4,000 tonnes/metric tons, not short or long tons.

The central building of the World's Fair was accepted enthusiastically by the public. After the World's Fair, the Rotunde was used for shows and fairs.

Fiakerlied

performed in the Rotunde on 24–25 May 1885, singing Gustav Pick's new composition, the Fiakerlied, for the first time.

Jubilee Exhibition 1898

In 1898, Emperor Franz Joseph's Jubilee Exhibition was held in the Rotunde. The "Collective Exhibition of Austrian Automobile Builders", organized by the , was held as part of the Jubilee Exhibition. Four automobiles from manufacturers in Austria-Hungary were shown: the automobile built by Siegfried Marcus in 1888–1889, an Egger-Lohner electric automobile, an Egger-Lohner petrol automobile, and the Nesselsdorfer Wagenbau-Fabriks-Gesellschaft Präsident.