CHAPTER XXI. YET ANOTHER FURNACE. SUCH A ONE AS I MADE IN THE CASTLE OF ST. ANGELO AT THE TIME OF THE SACK OF ROME.
These kinds of furnaces are the best of all. It was dire necessity that taught me how to make them, because I had absolutely no means at hand for doing my work. Being in a confined place, where I had to set about using my wits, I made a virtue of necessity. I broke the bricks out of a room, & with these bricks I set to work to construct a furnace in the form of a bake-oven.[125] The bricks were arranged alternately, so that between every brick was an opening of about two fingers wide, & as I went on I narrowed them in upwards.[126] When I had raised it about a cubit’s height from the ground, I constructed[127] a grating of shovel handles and spears which I broke. And from this point I continued building the furnace up and round to about one-and-a-quarter cubit’s height, narrowing it in towards the top. Then I found an iron ladle which they were by chance using in the kitchen, & as it was pretty big I caked it round with a paste of ash & pounded clay,[128] and filled it with as much gold as it would contain, and gave it the full fire straight off as there was no danger of the crucible cracking. When the first lot was cast I filled it up again, and so on, till I had melted up about 100 lbs. of gold. The whole thing went very easily, and ’tis about the best and simplest method you can employ. Perhaps you think that I ought to go and give you a diagram of it all here in my book, but I fancy that anyone who knows anything at all about the craft of founding will perfectly well understand by description. So that’s enough for furnaces.