The way of making the Covers of the Tests, which are called Muffles

First, a Type or Mold is to be made of Wood, answering to the bigness of the Test, but not with one Handle, as those are made for the purifying of silver, but with two oblong Necks, and without Chaps or Chinks, which otherwise are wont to happen, that so the Cover may remain entire. Then to this wooden Mould the Earth is to be applied, and the Cover to be wrought in the usual manner.