"What shall we try in our furnace to start with?"
"The ore you found yesterday. The first thing to do is to crush it up as fine as possible. When that is done we can put it in the round furnace."
"You mean in the firebrick furnace?"
"Yes; although we do not need such a high heat. Almost any furnace would do, as the roasting of the ore does not require a high heat."
"What is the best way to roast it?"
"It will be necessary to put it on one of the iron plates, and great care must be taken to keep it a uniform heat, but not too intense."
The process of roasting is a very particular one and requires quite a time to get the best results. When this was done the next step was to take the roasted ore, and mix it with half its weight of powdered coke. They had a good quantity of the coke on hand, which was also crushed.
"You remember, George, we had a crucible made with a hole at the bottom. Get that and also some fire clay dust, and moisten the dust so we can make a stiff mortar from it. We must make a tubular connection with the hole in the bottom of the crucible."
When this was done the crucible was put into the furnace, after it had been charged with the coke dust and crushed zinc ore.
"Why is it necessary first to crush the ore and roast it, and then afterwards put it in the crucible with the crushed coke?"