古人铸鉴

gu古ren人zhu铸jian鉴，jian鉴da大ze则ping平，jian鉴shi师ze则tu凸。mian面jian鉴ao凹ze则zhao照ren人mian面da大，tu凸ze则zhao照ren人mian面shi师。shi师jian鉴bu不neng能quan全shi视ren人mian面，gu故ling令neng能tu凸，shou收ren人mian面ling令shi师，ze则jian鉴sui虽shi师er而neng能quan全na纳ren人mian面。reng仍fu复liang量jian鉴zhi之shi师da大，zeng增sun损gao高xia下，chang常ling令ren人mian面yu与jian鉴da大shi师xiang相ruo若。ci此gong工zhi之qiao巧zhi智，hou后ren人bu不neng能zao造。bi比de得gu古jian鉴，jie皆gua刮mo磨ling令ping平，ci此shi师kuang旷suo所yi以shang伤zhi知yin音ye也。

shi世you有tou透guang光jian鉴，jian鉴bei背you有ming铭wen文，mian面er二shi十zi字，zi字ji极gu古，mo莫neng能du读。yi以jian鉴cheng承ri日guang光，ze则bei背wen文ji及er二 shi十zi字jie皆tou透，zai在wu屋bi壁shang上le了le了fen分ming明。ren人you有yuan原qi其li理，yi以wei谓zhu铸shi时bo薄chu处xian先leng冷，wei唯bei背wen文shang上cha差hou厚hou后leng冷，er而tong铜suo缩duo多。wen文sui虽zai在bei背，er而jian鉴mian面yin隐ran然you有ji迹，suo所yi以yu于guang光zhong中xian现。yu予guan观zhi之，li理cheng诚ru如shi是。ran然yu余jia家you有san三jian鉴，you又jian见ta他jia家suo所cang藏，jie皆shi是yi一yang样，wen文hua画ming铭zi字wu无xian纤yi异zhe者，xing形zhi制shen甚gu古。wei唯ci此jian鉴guang光tou透，qi其ta他jian鉴sui虽zhi至bo薄zhe者，jie皆mo莫neng能tou透。yi意gu古ren人bie别zi自you有shu术 。