"Let me try some of it, and don't say anything about it to Harry. And now, while I think about it, why couldn't we make some crocks out of our clay, so we can use them for our milk. We can't put them in the copper vessels and the iron is just as bad."
"That is a splendid idea; and you might as well vitrify them."
"What do you mean by vitrifying them?"
"Putting the glaze on them, just like the common crocks have."
"That would be simply fine."
The Professor explained the process, which consisted in making the crocks out of the best clay available, and then burning them. Afterwards an intense heat must be made in the furnace, and after soaking the crocks in a strong solution of salt brine, they must be put in and burned again; the greater the heat, the better.
The boys started at this with a will, and when they had arranged to make the crocks they found it most difficult to put them into a round and uniform shape.
"I would suggest that you make a potter's wheel for that purpose."
"A potter's wheel? What is it like?"
"It is the simplest thing imaginable. Do you think, Harry, you could turn out a wooden vessel just the size of the outside of an ordinary milk crock, and turn it with a central stem below, and also have a little pulley on that stem?"