How to make the printing type: mold some small clay pieces, stamp letters on them, bake until hard, and then arrange them in an iron case.

• 用泥活字印刷的方法是:先做出许多小泥块,象刻印章一样在每个泥块上刻一个字,用火烧后,成为坚硬的泥活字。把这些字排在铁框子里压平,就可以印书了。