中国古代机械与器物的图像表达

表达方法是知识的创造和发展的一个重要方面,对知识的承传也有重要影响。技术知识的图像表达与绘画艺术密切相关。中国画家在以再现视觉效果为追求的对位置向背方面的揣摸及绘画实践中总结出了一些与现在的透视理论一致的绘画方法,并将这些方法用于机械、器物的绘画之中。晋代,数学家已经运用文字和图来阐释数学知识,地图专家总结了绘图的法则。唐代画家在描绘台阁、车舆、器物等时追求“形似”,敦煌壁画多具有纵向的移动透视或散点透视画法的特征,间有相当于一点透视的画法。五代画家的三维空间描绘物体的方法可以按照正确的比例表达物体的尺寸和形状。此后,画家对机械、器物、建筑的描绘达到了细致入微的程度。北宋时期,图与说的结合成为科技书籍的表达模式,它突破了“不收图”的编书传统。作者运用等同于移动透视、正投影、近似轴测投影和近似平行投影的画法和文字解说表达出机械、器物等的详细构造。有些著作以装配图、零件图等两张或两张以上的组合视图表达复杂的器物或机械结构。图、说结合的表达模式一直延续到19世纪近代工程图学传入中国时期,并融入现代工程、机械表达方法之中。

The Visual Representation of Ancient Chinese Machines and Devices

A major aspect of the creation and development of knowledge is the mode of its representation, and this has had a major influence on the transmission of knowledge. There is an intimate connection between the visual expression and representation in painting of technological knowledge. In their representation of visual effects and their search for contrastive backgrounds and in their practice of painting, Chinese artists developed a number of painting techniques that conformed in overall fashion to modern perspective theory and they used these methods to depict machinery and artefacts within their paintings. In the Jin Dynasty mathematicians used both text and image to explicate mathematical knowledge, and cartographers synthesised the principles of painting and drawing. When painting buildings, carriages and vessels, Tang Dynasty artists sought out Verisimilitude' (xiangsi), and many Dunhuang murals hit on some aspects of artistic perspective through a form of vertical recession or by means of a 'scattered dot' perspective painting technique. In the Five Dynasties period, the methods of painting three-dimensional objects could take advantage of mathematically determined proportions and forms. Painters later attained higher levels of precision in depicting machines, objects and buildings. In the Northern Song period, the integrated use of illustration and text became the major mode in the presentation in science and technology texts, and there was a break with the tradition of 'non-illustrated' books. Authors made use of shifted perspective, orthographic projection, approximations of axial or lateral projection, and approximations of parallel projection in illustrations depicting the detailed structures of machines and devices. Some works made use of bound accompanying illustrations and any number of loose-leaf separate single illustrations or sets of illustrations to demonstrate the complex workings and structures of implements or machines. These forms of illustration combining image and text continued to be used down to the 19th century, when modern technical drawing was introduced to China, and elements of the traditional techniques were blended with modern illustrative techniques.