The object of the Buen Retiro Factory was almost wholly to supply the Crown with costly ware, and would-be visitors were jealously excluded. Townsend wrote in 1786: "I tried to obtain admission to the china manufacture, which is likewise administered on the king's account, but his Majesty's injunctions are so severe, that I could neither get introduced to see it, nor meet with anyone who had ever been able to procure that favour for himself. I was the less mortified upon this occasion, because from the specimens which I have seen, both in the palace at Madrid and in the provinces, it resembles the manufacture of Sèvres, which I had formerly visited in a tour through France." Laborde also complained that the factory was "wholly inaccessible: all entrance to it is interdicted, and its existence is only ascertained by the exhibition which is made of its productions in the royal palace." The same writer refers to another class of work which was produced here, namely, stone mosaic. "The process by which stone is wrought into pictures is as delicate as it is curious: a selection is made from marble fragments of various shades and dimensions, which are found, by judicious assimilation, to produce no bad resemblance to painting." Jean François de Bourgoing, French Minister at Madrid, was lucky enough, in 1782, to penetrate into the factory and view the process. "Le Monarque actuel," he wrote, "a établi dans leur intérieur une fabrique de porcelaine, dont l'entrée est jusqu'à présent interdite à tout le monde. On veut sans doute que ses essais se perfectionnent dans le silence, avant de les exposer aux regards des curieux. Ses productions ne peuvent encore se voir que dans les Palais du Souverain, ou dans quelques Cours d'Italie, auxquelles il les envoie en présens. On travaille dans le même édifice à certains ouvrages de marqueterie, qui sont encore peu connus en Europe. J'y pénétrai un jour, sous les auspices d'un étranger distingué en faveur duquel le Roi avoit levé la prohibition rigoureuse, qui en exclut tout le monde. Je suis témoin de la patience and de l'adresse avec lesquelles on taille and on rapproche divers petits morceaux de marbre coloré, pour en former des tableaux assez compliqués, qui en faisant à-peu-près le même effet que la peinture, ont sur elle l'avantage de braver par leur couleur immortelles les ravages du temps, qui n'épargnent pas les plus belles productions de cet art."[102] [102] _Nouveau Voyage en Espagne_; Vol. I., pp. 232, 233.