“Rainbow” bridges, such as the one that occupies the dramatic
center of the Beijing qingming scroll, are so called because of the way
in which the bridge arches, resembling a rainbow. The bridge pictured
is an elaborate wooden bridge that spans the river and offers room for
peddlers to show their wares to the pedestrians crossing from one side
of the river to the other.
The technology of the bridge is impressive. In Song times one observer remarked that the bridge had no piers, but rather spanned the river using giant timbers curved like a rainbow. What keeps the bridge up is a series of interlocking horizontal and cantilevered beams.
• Secrets of Lost Empires: China Bridge [NOVA, PBS]
Companion website to a 2000 PBS program documenting the “effort
by a NOVA-assembled crew of scholars and timber framers to design and
build a Chinese bridge known only from an ancient painting [the Beijing
qingming scroll].” Includes an essay, China’s
Age of Invention, that highlights many Song-dynasty inventions.