User:Diabl0658
From DwarfFortressWiki
I just had the greatest idea ever. Its called...
[edit] Magma Construction Tower
You need a magma pipe (magma pools dont replenish their magma supply), a river, iron/nickel/steel screw pumps, and bauxite mechanisms to build it.
Basically a large tower that pumps magma and water up into two seperate tubes at the top and pours them into a mold somewhere below the end of the tube. One layer at a time is poured, first magma and then water to cool it. The finished product will be a natural looking block of solid obsidian that can be mined into whatever. It can even be modified to work as goblin defense, pouring magma and water ontop of invading armies and doing all sorts of wonderful things to them!

