Johannes "Hanns" Evangelist Hörbiger (29 November 1860, in Atzgersdorf – 11 October 1931, in Mauer), better known as Hanns Hörbiger, was an Austrian engineer from Vienna with roots in Tyrol. He took part in the construction of the Budapest subway and in 1894 invented a new type of valve essential for compressors still in widespread use today. He is also remembered today for his pseudoscientific Welteislehre ("World Ice doctrine").