No 5 Blast Furnace Casting

A modern view of  a no. 5 casting; Bob Proctor tells us: ”If you ever wanted to view the inside of the furnace then you would use the eye piece, this is at the bottom of the silver goose-necks and looks like a protrusion. You would firstly make sure there was no leaking hot blast (500C) by moving your hand over the toughened glass eye-piece and then you could see through the blow pipe and tuyere into the heart of the furnace where the droplets of slag/iron cascaded down through the incandescent coke.” All working  furnace-side wore blue glasses, otherwise their eyes would feel the pain! If possible using a sweat-rag, not their hand – 500C is not good for the skin! – but  well-worth taking the precautions, it is a beautiful sight.  The glass eye-piece (mica initially, then toughened quartz glass is called a pee-pee.

Thanks to Bob Proctor for the comment.