THE CRAFT OF FIRE

It worked! We melted brass in our little primitive clay furnace :   To make sure we  were working with the right material , I bought a thin rod of guaranteed brass and sliced it up into five pieces, and put it in the crucible. We forgot to take photos at first, excited and busy, but here are the rods sticking up out of the crucible, surrounded by charcoal (thermocouple poking in from the right). We started the fire around 2pm and the temperature increased very steadily and easily.  Unfortunately, we didn't take notes (what was I thinking?) but we guess that in about an hour the pyrometer was reading over 1000º C.  I was sure it couldn't really be that hot (a reading with only one thermocouple is not so accurate) so we let it go a little while longer, but then finally pulled out the crucible to have a look. The brass rods were no longer poking out of the crucible, meaning they had melted!  But we could see they weren't fully melted, so we put the crucible back in, added more

My friend Magor suggested I could determine the identity of the mystery metal from our previous furnace melt by calculating its density. Great idea! The formula for calculating density is: d = M/V. That is, density is equal to the mass of the object divided by its volume. So I weighed the door plates: 115 g. Then I tried to measure their volume with the water displacement method. It was a bit tricky since the cup I had wasn't very exact in the measurements it showed, but I figured I could at least get  close  to a possible density, and then I could compare and see if it was at least in the range of   brass (density of 8.5 g/cm 3 ) or aluminum (2.7 g/cm 3 ). I started with 150 ml in the cup and ended with 174, so that's 24 ml (or 24 cm 3 ). So, door plate density : d = 115/24 d = 4.79 g/cm 3 Hmmm. A not very helpful result. Looks like these door plates are actually  Yttrium ! (haha.) Whatever this metal is, it seems to be sitting right between brass and aluminum on the density