The Thomas Heatherwick Studio won a competition in 2002 to create a major sculpture for the new building.  The Trust had a desire for a sculpture that would,  " ... complement the cool but dramatically deep space allocated for it", on the Gower Street end of the atrium.  Since none of the entrances were wide enough to bring in a sculpture that would fill the allocated space, in true Heatherwick style, they decided to create one that could enter through the letterbox.  Heatherwick Studios say that, "The vertical void seemed almost like a gravity chamber, and the pool of water at the base was a catalyst to thinking that led Thomas Heatherwick and his colleagues to experiment with liquid.  He says, 'The aim was to produce a sinuous, curvaceous form, and one that had variety, so it would look different from each of the building's nine floors."

The development process involved dropping hot metal into water and creating twisting tumbling forms as the metal cooled.  Once they had selected their favourite metal shape they scanned it in three dimensions.  The name Bleigiessen comes from the tradition in Germany of dropping hot lead into water at New Years to create forms which can be read like tea leaves to forecast your fortune in the coming year.

Heatherwick's mother was the founder of the Bead Society of Great Britain and this gave him the idea of replicating the form using glass beads strung on wires.  "Working closely with British company, Flux Glass Design Ltd, Thomas Heatherwick Studio designed a glass bead, a transparent sphere that would subtly change colour and vary in brightness as you move in relation to it, and that would throw patterns of light on to surrounding walls.  To create the sculpture almost 27,000 very fine stainless steel wires (0.5 mm in diameter and 30 m long) were threaded with glass beads (over 140,00 of them weighing almost 40 tonnes)."  The end result can be seen below.