Glass ovens existed from a very early period in the central provinces of Spain, which probably imitated from the 16th century the productions of Cadalso. We know from papers at the Archives of the Convent, of two of these which paid a yearly rent to the monastery of San Jeronimo de Guisando, from 1478 to 1480. One of these glass works was situated at the Venta del Cojo on the borders of Escalona, and the other at the Venta de los Toros de Guisando. It is evident that a glass manufactory existed at Toledo, from some accounts which I have found in the Archives of the Cathedral, in which Bartolomé Lopez, vidriero, is mentioned in 1546--Pedro Fernandez in 1590, and Tomas Nuñez in 1660; as furnishing glass vessels, principally lamps for the cathedral. Tomas Nuñez is also paid for "three crosses of crystalline glass." In a letter written in 1690 to Count Gondomar, the celebrated ambassador to James I., (Archives of the Palace at Madrid), I find a glass manufactory mentioned which existed at Cebreros in the province of Segovia. The writer says, "Your lordship knows we have a glass oven here; this week we have made the glass called crystalline, of which I send in a basket sixteen specimens for my lady Dna. Costanza." Larruga tells us in his "Memorias," [Madrid, 1792, Vol. XVI., p. 222,] "That in 1680 a glass manufactory was established at San Martin de Valdeiglesias, where glass in the Venetian style was made--the glass was excellent. This manufactory was under the direction of Diodonet Lambot a native of Namur. He was succeeded by Santiago Bandoleto, who was by no means as skilful. Glass ovens were also established at the Torre de Estevan, Hambroz, under the direction of Guillermo Torcada." At Recuenco, in the province of Cuenca, glass works existed at the beginning of the 16th century; but in 1722 Don Fernando Lopez de Aragon established a manufactory on a large scale. The glass made there was used by the king and the greater part of the rich people at Madrid. In 1739 two other glass works existed there, which continued their operations during the rest of the century. In the same province several glass ovens existed towards the middle of the last century. The principal ones were established in the villages of Arbetota, Vindel and Armallones; only coarse specimens were made there, but at an earlier period their productions had been, Larruga tells us in the nineteenth volume of his "Memorias," very important. The glass works which we find mentioned in the "Atlante Español," [Madrid, 1795,] were also of a very inferior quality; they were established at the end of the last century at Busot, in the province of Alicante, Hinojares and Carolina, province of Jaen. The "Correo de España," [Vol. I. Madrid, 1771,] mentions an important glass manufactory which existed at Andorra near Alcañiz, and one where glass of an inferior quality was made at Cabra, in the province of Cordova. Cabanilles, "Historia y descripcion del reino de