Thorn Opalite
The shade attaches to the pendant by means of a three-legged brass 'spider' - its limbs protrude through the plastic and are threaded. Three rubber-tipped thumbscrews ensure that the construction remains rigid. When initially acquired, the shade was absolutely caked in dust - it had been discarded on top of a filing cabinet in a corridor and remained there for several years until being liberated by me. Following a thorough cleaning, the shade was installed in its new home.
For old time's sake, a 13W Philips SL lamp was fitted - these shades were designed for filament lamps of up to 200W! Notice how the shade support limbs are positioned above the lighting centre - this prevents their shadows from appearing on the plastic. The inverse conical design allows a portion of the luminous flux to be reflected up to the ceiling - an excellent way of providing indirect lighting.
The narrower end of the shade is open, allowing access to the lamp. Although the plastic appears slightly misshapen here, it is simply due to the angle of the photograph.