He also described a demonstration of a sword's quality: at one stroke it cut clean through 10 large nails hammered into a wooden upright of a building, yet its edge was quite undulled. With an effort the blade could be bent almost double, but when released it snapped back as straight as a bowstring.
他還記述了當時的一把寶劍：有人將十支大釘釘入柱中，揮此寶劍一削，釘子全部截斷，劍鋒卻纖毫無損；用力彎曲，劍身如勾，放開來鏗然有聲，又如箭弦一般平直。