Flooding is progressing nicely. While it continues, I thought I'd post the results of an experiment I conducted during the first flooding, after the dome was first excavated, concerning the magma-safety of nether-cap.
3rd Moonstone, 149 Early Winter - Showing 69,500 stones. The magma has begun to reach the entry hall to the Murdershot Citadel, which contains an array of crafts and buildings made of nether-cap, in an attempt to test nether-cap's magma-resistance.
21st Moonstone - All of the nether-cap buildings and items remained unharmed! Buildings which contained items, such as the coffin containing the remains of Id Zonlerom, remained unharmed, but the items inside spontaneously combusted from heat. The same for loose items: syrup boils in barrels, copper weapons melt in bins, and the gem bin currently contains 8 'magmas' and 2 !!rough light yellow diamonds!!. A hen in a nether-cap cage bled to death, ostensibly from the heat.
14th Hematite, 153, Early Summer - A cyclops has arrived. Three megabeast attacks in three consecutive years? He was easily slain by the same dwarf that slew the previous two. Also, the nether-cap bins, after cooling back off, reveal interesting results: the bin which contained a copper shield, which melted into a glob of molten copper during the flood, now contains a single unit of 'copper.' This stone can apparently be designated to be melted. Also, a gem bin, which contained 2 rough yellow diamonds and 8 other gemstones originally (which melted into 8 units of 'magma,' and the diamonds spontaneously combusted) now contains, again, the original 8 gemstones. The gems are cut - I don't recall if they were originally or not. Further tests must be conducted.