Crucibles are porcelain-like containers used in chemistry to heat substances to very high temperatures. Crucible tongs are large pincers made of welded steel that are used to grasp and take a hot...
This is allegorical imagery from blacksmithing. Ordinarily, a blacksmith would hold work on his anvil with his tongs and strike it with his hammer.
The imagery implies he would work with such...
(n.) A vessel or melting pot, composed of some very refractory substance, as clay, graphite, platinum, and used for melting and calcining substances which require a strong degree of heat, as metals,...