Prékopa Ágnes (szerk.): Ars Decorativa 30. (Budapest, 2016)
Kornélia HAJTÓ: Zsolnay Pyrogranite: Tradition and Fact
gary, he started research into silicates. He settled in Hungary in 1867, when he was appointed Head of the Department of Minerals and Geology in the Technical University. He became head of the Department of Chemical Engineering in 1870. In 1873, he gave lectures on the ceramics industry at a series of “popular science evenings”.11 Wartha and Zsolnay shared a passionate interest in technology of ceramics. The flourishing of eosine glaze ware is seen as one outcome of their friendship and cooperation. Here we investigate Wartha’s views on architectural ceramics in an attempt to determine the nature of Pyrogran- ite ware. The Archives of the Museum of Applied Arts hold the following handwritten letter, which unfortunately bears no addressee or date. “Sunday evening, 7 pm My dear friend, Unfortunately, I do not have sufficient experience on the applicability of “Pyrogranite”. True “Pyrogranite” was exhibited in the Russian department of the 1889 Paris World Fair. It resembled Hungarian keramit and was fired almost up to incipient melting. Of the test pieces supplied, one (bullseye) absorbed 8% water and the other (ornament plaque), 5.5%, so they were slightly porous. But I think it could compete with the finest facing stone, which is also porous and in many cases is less durable than ordinary terracotta. If the decision rested with me, I would confidently use this material, as long as it does not come into contact with any kind of lead glaze. I will look at the stove tiles soon. In friendship, Dr V. Wartha”'2 The subject and tone of the letter suggests that it was addressed to Vilmos. The brief description reveals much about how a chemical engineer and ceramics expert viewed Pyrogranite. His ideal reference as architectural ceramic was the Russian “Pyrogranite” he had seen at the Paris World Fair, a material he compared with keramit. In his book Az agyagipar [The Ceramics Industry], he defines keramit as unglazed coloured ceramic fired to melting point, with hardness comparable to that of granite.13 The term keramit is still used for a dense fired conchoidal-fracture ceramic, mostly in tiles. It is very hard and durable and in the past was frequently used for paving tiles.14 Zsolnay’s own tiles and paving bricks were much denser and harder than its architectural ceramics. Wartha found the two samples of Pyrogranite he tested to absorb 5.5% and 8% water respectively, and he considered them slightly porous. The table below shows comparative figures for Zsolnay’s architectural ceramics. The company produced façade elements and parapet ornaments for the internal courtyard of Parliament and ornamental items for the Museum of Applied Arts building and for St Ladislaus’ Church, Kőbánya. They vary widely in density and water absorption and are visibly of uneven quality. For comparison, the table also gives figures for the Museum’s original non-Pyrogranite roof tiles and for French Bigot ceramics. Table 1. Water absorption of samples of various architectural ceramic items15 Photos by Kornélia Hajtó > 122
