20 Frith Street been presented to the museum of Görlitz by Baron de Gersdorf. (Baron von Gersdorff from Saxony, possibly?). Gersdorf authenticated the first ascent of Mont Blanc by Jacques Balmat and physician Michel-Gabriel Paccard in 1786. Exchaquet was also the director of mines and foundries at Servoz in Haut-Faucigny, where attempts were made to emulate the success of the English steel-makers who, however, were using the very best imported Swedish Oregrounds iron. In 1816 Troye co-authored with one S. Glover "A Description of the Inundation of the Valley of Bagnes in Swisserland". Troye published an account of Mont Blanc and his models
Jacques Gabriel of de Cotte's retirement in December 1734 and held the post until he was succeeded by his "vastly more gifted" son, Ange-Jacques Gabriel in 1742. Gabriel's work in Paris has been much remodelled. Mariette's "Architecture françoise" offers plates illustrating several "hôtels particuliers" by Gabriel. He completed the Palais Bourbon (begun by Giardini, continued by Pierre Cailleteau Lassurance). He completed the Hôtel de Lassay nearby. He was responsible for the Hôtel Peyrenc de Moras (de Biron), 1728-31. "Il étoit expert dans la conduite du bâtiment, mais il n'auroit pas pu dessiner le moindre bout d'ornement"; ). Jacques Gabriel Jacques Gabriel (1667–1742)