Natural magick by John Baptista Porta, a Neapolitane ; in twenty books ... wherein are set forth all the riches and delights of the natural sciences.
Porta, Giambattista della, 1535?-1615.

How an Habergeon or Coat of Arms is to be tempered.

Take soft Iron Armour of small price, and put it into a pot, strewing upon it the Powders abovesaid; cover it, and lute it over, that it have no vent, and make a good Fire about it: then at the time fit, take the Pot with iron pinchers; and striking the Pot with a Hammer, quench the whole Herness, red hot, in the foresaid water: for so it becomes most hard, that it will easily resist the strokes of Poniards. The quantity of the Powder is, that if the Harness be ten or twelve pounds weight, lay on two pounds and a half of Powder, that the Powder may stick all over: wet the Armour in water, and rowl it in the Powder, and lay it in the pot by courses. But, because it is most hard, lest the rings of a Coat of Male should be broken, and flie in pieces, there must be strength added to the hardness. Workmen call it a Return. Taking it out of the Water, shake it up and down in Vinegar, that it may be po∣lished, and the colour be made perspicuous: then make red hot a plate of Iron, and lay part of the Coat of Male, or all of it upon the same: when it shews an Ash-colour, workmen call it Berotinum: cast it again into the water, and that hardness abated; and will it yield to the stroke more easily: so of a base Coat of Male, you shall have one that will resist all blows. By the mixture of Sharp things, iron is made hard and brittle; but unless strengh be added, it will flie in pieces with every blow: therefore it is needful to learn perfectly how to add strength to it.