as a tangent to each of the circle's sides. This type of construction is used generously in Gothic buildings. For instance, rounded quatrefoils were used in tiled pavements like the ones in the Gloucester Cathedral or in Great Malvern, Worcestershire, England. It was also common in the work of the Chinese and Japanese. Rounded multifoils Rounded multifoils are found in different parts of Gothic buildings such as circular windows and pointed windows containing circular lights. These designs can have rings ranging from seven to eleven small circles. They are often seen in England but have become quite popular in French Gothic architecture. This design has been used since medieval times in tiles used in Gothic buildings. The tile pavement used in Jervaulx Abbey in Yorkshire, England, had rings of six and twelve circles inside another circle. Tracing floors and épures As the complexity of tracery increased, so did the need for masons to draw out their designs in advance, either as a way of experimenting with patterns or as a way of communicating their designs to other craftsmen or to their patrons. Because of the cost and size limitations of parchment sheets, such designs would normally be drawn by incising onto a whitewashed board or a conveniently placed section of flat wall. In the latter case, the wall would be prepared with a thin layer of plaster, which would show the design more clearly. A number of churches and cathedrals still show the faint remains of these tracings (or épures as they are known in France), from where the mason's compass points scratched through the plaster and into the masonry below. (Examples include some experimental 14th-century window tracery patterns at the eastern end of the south wall inside the Galillee porch of Ely Cathedral, or the extensive series of tracings on the flat aisle roofs of Clermont-Ferrand Cathedral.) A number of major building sites (including Westminster Abbey, Wells Cathedral and York Minster) originally had dedicated tracery chambers, where the architects could prepare their designs in relative comfort. The availability of a large flat floor surface meant that designs could be drawn life-size and the individual elements of bar tracery laid out on the plan to test their goodness of fit, before hoisting them up the scaffolding for installation in the actual window openings. This also meant that masons could carry on working through the winter season, when building work would