In 1544, sixty-two windows in the nave of Segovia cathedral were filled with painted glass prepared chiefly at Valladolid and Medina del Campo, though some was brought from Flanders. The remaining windows were left unfilled till 1676, in which year a canon of the cathedral, named Tomás de la Plaza Aguirre, succeeded in rediscovering a formula for the practise of this craft, and the panes yet needed were made and coloured at Valdequemada by Juan Danis, under Plaza Aguirre's supervision. Thirty-three additional windows were completed from this factory. According to Lecea y García, the chapter of Segovia cathedral possess, or possessed for many years, two curious manuscripts relating severally to _The painting of glass windows_, by Francisco Herranz, and _Glass-making_, by Juan Danis--the same who owned and worked the factory at Valdequemada. These interesting treatises were examined by Bosarte, who has described them. He says that the one on glass-making consisted of twenty-three sheets of clear writing, and the one on glass-painting of eight sheets; both manuscripts being in quarto size. The latter contained, distributed beside the text, sketches of the various instruments required for this craft. The other and longer monograph consisted of the following chapters:--(1) How to draw upon glass. (2) How to cut glass. (3) How to paint and shade glass. (4) Of the substances and ingredients for painting glass. (5) How to give a flesh-colour to glass. (6) How to give a yellow or golden colour to white or pale blue glass, but no other. (7) How to fire glass. (8) How to make the glass-oven. Windows were painted in the cathedral of Palma de Mallorca by Sebastián Danglés in 1566 and by Juan Jordá in 1599, in that of Málaga by Octavio Valerio in 1579, and in those of Tarragona and Avila respectively, by Juan Guasch in 1571, and by Pierre de Chiberri in 1549. This craftsman was undoubtedly a foreigner. The following entry which concerns him is quoted by Rosell de Torres from the _Libro de Fábrica_ of Segovia cathedral: "By order of the Canon Juan Rodriguez, on the twelfth day of August, I paid to Pierre de Chiberri, master-maker of window-glass, the sum of 56,560 _maravedis_, 34,960 for the casings of seven large windows with their side-windows--in all twenty-one casings--besides ten casings for the windows of the lower chapels, containing altogether MMMCCCCXCVI palms, amounting at ten _maravedis_ the palm to the aforesaid 34,960 maravedis: also 19,125 _maravedis_ for CCCLXXII palms of glass for the said chapels at a _real_ and a half each palm, plus 2476 _maravedis_ for certain glass which had yet to be measured because it was in the skylights. The total sum amounts to the aforesaid 56,560 _maravedis_."[116] [116] Isidoro Rosell de Torres, _Las Vidrieras pintadas en España_ (published in the _Museo Español de Antigüedades_).