Then they raise the Walls to the _Furnance_ on this Foundation; But do not lay the ends of their Bricks close together. But lay the ends of each Brick about three Inches off each other, to serve for _Wind-holes_ till they _Trim_ round about: Then they lay another _Lay_ of Bricks leaving other such _Wind-holes_ over the middle of the last _Lay_ of Bricks, and so _Trim_ as they work round either with half Bricks or Bats that the _Wind-holes_ of the last _Lay_ may be covered: And in this manner and order they lay so many _Lays_ till the Walls of the _Furnance_ be raised about three Bricks higher than the _Mouths_ of the _Melting-Pots_, still observing to leave such _Wind-holes_ over the middle of every Brick that lies under each _Lay_. Then they fill the sides of the _Furnance_ round about the _Melting-Pots_, and over them with _Charcoal_, and _Fire_ it at several _Wind-holes_ in the bottom till it burn up and all over the _Furnance_, which a moderate Wind in about an Hours time will do: And about half an Hours time after they lay their Ears near the Ground and listen to hear a _Bubling_ in the _Pots_; and this they do so often till they do hear it. When they hear this _Bubling_, they conclude the _Iron_ is melted: But yet they will let it stand, perhaps half an hour longer or more, according as they guess the Fire to be Hotter or Cooler, that they may be the more assured it is all throughly Melted. And when it is Melted the Melting _Pot_ will not be a quarter full. And in or against that time they make another small _Furnance_ close to the first, (to set an _Iron-Pot_ in, in which they Melt _Lead_) on that side from whence the Wind blows; Because the Person that Lades the _Lead_ out of the _Iron-Pot_ (as shall be shewed by and by) may be the less annoyed with the Fumes of the _Mettal_, in both _Furnances_. This _Furnance_ is made of three or four _Course_ of Bricks open to the windward, and wide enough to contain the designed _Iron-Pot_, with room between it and the sides to hold a convenient quantity of _Charcoal_ under it, and about it. Into this _Iron-Pot_ they put for every three Pound of _Iron_, about five and twenty pounds of _Lead_. And setting Fire to the _Coals_ in this little _Furnance_ they Melt and Heat this _Lead_ Red-hot.