quantity of light into the interior, and also highlighted the chosen subjects, which otherwise were lost among hundreds of other images. This style of window, introduced at Tours in about 1265, was soon followed at Troyes Cathedral, and then spread quickly to other cathedrals in France and then England. This revolution in the format of display was accompanied by an even more important revolution in technique, with the use of silver stain, a method for painting onto glass with enamel paints, which were then heated and fused onto the glass. This allowed the more expressive figures, shading and three-dimensions, closer to paintings than to mosaics. The sizes of the pieces of glass became larger, and the amount of lead bars in the window smaller. The figures in stained glass windows began to resemble those in medieval miniature paintings in realism. Rose windows The cathedral has three rose windows in the west front and the two ends of the transept. The most original is that of the north transept, installed in the beginning of the 14th century. The rose was installed in a square section of window already filled with glass. where the rose was installed, problems of stability appeared, and it had to be reinforced by a vertical stone bar behind the window, dividing it in two, and by additional buttresses on the exterior. Pipe Organ The pipe organ is located in the south transept. The case and decoration date to the 16th century. The instrument now in place was made in the 18th century by the family firm founded by Robert Clicquot. Bells The cathedral has four major bells located in the south tower. The bourdon, the largest and deepest-sounding, is Christus, made in 1749 and weighing 1900 kilos. It originally hung in the nearby Abbey of St. Paul in Cormery. In 1793, during the Revolution, most church bells were seized and melted down to make cannon and other armament. Towns were allowed to have only a single bell to warn of a fire. The inhabitants of Coermery resisted and rolled the bell to another town to preserve i. Finally, in 1807, it was taken to Tours and installed in the tower. The other three bells are: Maurice (1350 kilos, 1864); Gatien (980 kilos, 1884), Martin (310 kilos, 14th century The Cloister of La Psalette and the Archbishop's Palace To the north of the cathedral is a small cloister,