work of tie beams and cross beams,
Yingzao Fashi Some of Li's book used material from preexisting architectural writings, but most of it is documentation of the inherited traditions of craftsmen and architects passed down by word of mouth. Li's book provides a glossary of technical terms that includes mathematical formulae. He incorporated
topography in his estimations for buildings on various types of sites. He also estimated the monetary costs of hiring laborers of different skill levels and types of expertise in crafts. His estimates take a day's work as their basis and include the materials needed, taking into account the season in which the work was done. Li's work incorporates building rules and regulations, accounting information, standards for materials used in construction, and the classification of various crafts. The 34 chapters in the book specify in detail the units of measurement, the construction of moats and fortifications, and standards for
stonework as well as for greater and lesser woodwork. It includes the specifications (and illustrations) for constructing bracketing units with inclined arms and joints for columns and beams, as well as directions for
wood carving, turning and drilling, sawing, bamboo work, tiling,
wall building,
painting and decoration, and the formulas for decorative paints, glazes and various coatings. Included are the mixing proportions for
mortars in
masonry, brickwork and
glazed tile. The book provides hand-drawn illustrations of all the practices and standards. He outlined structural
carpentry in great detail, providing standard dimensional measurements for all the components. For instance, Li developed a standard 8-rank grading system for different sizes of timber elements. The system was known as the
cai-fen system of units and could be applied to buildings. Although others were written and compiled beforehand, Li's technical manual on
Chinese architecture has survived intact and in its entirety. ==Gallery==