Metal Spinning, originally a traditional craft to produce a 'bowl' or that shape which evolved into pots, pans, pitchers etc.

Before the era of hydraulics and pressing, a boiler maker would have  spun two halves (typically in brass) and joined them - resulting in a sphere or float. 
ND Spinning - boasting a beautifully authentic hand spun aluminium light pendant/shade. 

Priced on order.