wrought iron strings (before the invention of Bessemer steel) – are very finely graduated and fiery. In the second half of the 19th century, simplification and impoverishment of the piano's sound variety occurred with two-layer, industrially produced Dolge hammers. To Herz's work as a piano maker can also be attributed the implementation of a simplified version of Sebastian Erard's double repetition. Through the "Herz spring" (Repetierfeder) the mechanics of the instrument found their modern form. In 1849, the Academy of San Juan de Letrán launched a convocation, with the object of acquiring a suitable letter for a hymn that represented Mexicans, especially abroad. In this call, three compositions were received, of which two were chosen: that of the American composer Andrew Davis Bradburn, and that of the Mexican poet Félix María Escalante, which was set to music by the Austrian Henry Herz; however, this hymn was not to the taste of the people. Herz's anthem appears in the 1934 film, Juárez y Maximiliano as Maximilian and Carlota's musical theme. It also appears in Carlota: The Mad Empress. Among the most important performance venues in Paris were halls built by the instrument manufacturers. In 1838, Herz and his brother Jacques Simon Herz followed this model and built the 668-seat Salle des Concerts Herz on the rue de la Victoire, used for performances by Berlioz and Offenbach. The Ecole Spéciale de Piano de Paris, which the brothers founded, was housed in the same building. The building was still in use for concerts as late as 1874 but was demolished in that year. Herz was possibly married to Pauline Thérèse Lachmann (or Esther Lachmann), a French courtesan known as La Païva. It is generally believed that they married in London, but it is not clear that this actually occurred. In any case, such a marriage would have been bigamous, as she was already married. By him she had a daughter. Her extravagant spending nearly ruined Herz's finances, and he traveled to America in 1848 to pursue business opportunities. While he was away, Herz's family turned Thérèse out of the house. Career as a pianist A celebrated pianist, Herz traveled worldwide, including tours in Europe, Russia, Mexico, South America, and in the United States of America between 1846 and 1850, where he concertized all the way to San Francisco. His performances were compared to the more extravagant manner of Leopold de Meyer, concertizing in